From a9d2fae89fa8eb638203d8a4da435c647c12dfa3 Mon Sep 17 00:00:00 2001 From: Alan Maguire Date: Tue, 12 Jul 2022 13:31:45 +0100 Subject: selftests/bpf: add a ksym iter subtest add subtest verifying BPF ksym iter behaviour. The BPF ksym iter program shows an example of dumping a format different to /proc/kallsyms. It adds KIND and MAX_SIZE fields which represent the kind of symbol (core kernel, module, ftrace, bpf, or kprobe) and the maximum size the symbol can be. The latter is calculated from the difference between current symbol value and the next symbol value. The key benefit for this iterator will likely be supporting in-kernel data-gathering rather than dumping symbol details to userspace and parsing the results. Signed-off-by: Alan Maguire Acked-by: Yonghong Song Link: https://lore.kernel.org/r/1657629105-7812-3-git-send-email-alan.maguire@oracle.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 16 +++++ tools/testing/selftests/bpf/progs/bpf_iter.h | 7 +++ tools/testing/selftests/bpf/progs/bpf_iter_ksym.c | 74 +++++++++++++++++++++++ 3 files changed, 97 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_ksym.c (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index 7ff5fa93d056..a33874b081b6 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -27,6 +27,7 @@ #include "bpf_iter_test_kern5.skel.h" #include "bpf_iter_test_kern6.skel.h" #include "bpf_iter_bpf_link.skel.h" +#include "bpf_iter_ksym.skel.h" static int duration; @@ -1120,6 +1121,19 @@ static void test_link_iter(void) bpf_iter_bpf_link__destroy(skel); } +static void test_ksym_iter(void) +{ + struct bpf_iter_ksym *skel; + + skel = bpf_iter_ksym__open_and_load(); + if (!ASSERT_OK_PTR(skel, "bpf_iter_ksym__open_and_load")) + return; + + do_dummy_read(skel->progs.dump_ksym); + + bpf_iter_ksym__destroy(skel); +} + #define CMP_BUFFER_SIZE 1024 static char task_vma_output[CMP_BUFFER_SIZE]; static char proc_maps_output[CMP_BUFFER_SIZE]; @@ -1267,4 +1281,6 @@ void test_bpf_iter(void) test_buf_neg_offset(); if (test__start_subtest("link-iter")) test_link_iter(); + if (test__start_subtest("ksym")) + test_ksym_iter(); } diff --git a/tools/testing/selftests/bpf/progs/bpf_iter.h b/tools/testing/selftests/bpf/progs/bpf_iter.h index 97ec8bc76ae6..e9846606690d 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter.h +++ b/tools/testing/selftests/bpf/progs/bpf_iter.h @@ -22,6 +22,7 @@ #define BTF_F_NONAME BTF_F_NONAME___not_used #define BTF_F_PTR_RAW BTF_F_PTR_RAW___not_used #define BTF_F_ZERO BTF_F_ZERO___not_used +#define bpf_iter__ksym bpf_iter__ksym___not_used #include "vmlinux.h" #undef bpf_iter_meta #undef bpf_iter__bpf_map @@ -44,6 +45,7 @@ #undef BTF_F_NONAME #undef BTF_F_PTR_RAW #undef BTF_F_ZERO +#undef bpf_iter__ksym struct bpf_iter_meta { struct seq_file *seq; @@ -151,3 +153,8 @@ enum { BTF_F_PTR_RAW = (1ULL << 2), BTF_F_ZERO = (1ULL << 3), }; + +struct bpf_iter__ksym { + struct bpf_iter_meta *meta; + struct kallsym_iter *ksym; +}; diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_ksym.c b/tools/testing/selftests/bpf/progs/bpf_iter_ksym.c new file mode 100644 index 000000000000..285c008cbf9c --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_ksym.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022, Oracle and/or its affiliates. */ +#include "bpf_iter.h" +#include + +char _license[] SEC("license") = "GPL"; + +unsigned long last_sym_value = 0; + +static inline char tolower(char c) +{ + if (c >= 'A' && c <= 'Z') + c += ('a' - 'A'); + return c; +} + +static inline char toupper(char c) +{ + if (c >= 'a' && c <= 'z') + c -= ('a' - 'A'); + return c; +} + +/* Dump symbols with max size; the latter is calculated by caching symbol N value + * and when iterating on symbol N+1, we can print max size of symbol N via + * address of N+1 - address of N. + */ +SEC("iter/ksym") +int dump_ksym(struct bpf_iter__ksym *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct kallsym_iter *iter = ctx->ksym; + __u32 seq_num = ctx->meta->seq_num; + unsigned long value; + char type; + int ret; + + if (!iter) + return 0; + + if (seq_num == 0) { + BPF_SEQ_PRINTF(seq, "ADDR TYPE NAME MODULE_NAME KIND MAX_SIZE\n"); + return 0; + } + if (last_sym_value) + BPF_SEQ_PRINTF(seq, "0x%x\n", iter->value - last_sym_value); + else + BPF_SEQ_PRINTF(seq, "\n"); + + value = iter->show_value ? iter->value : 0; + + last_sym_value = value; + + type = iter->type; + + if (iter->module_name[0]) { + type = iter->exported ? toupper(type) : tolower(type); + BPF_SEQ_PRINTF(seq, "0x%llx %c %s [ %s ] ", + value, type, iter->name, iter->module_name); + } else { + BPF_SEQ_PRINTF(seq, "0x%llx %c %s ", value, type, iter->name); + } + if (!iter->pos_arch_end || iter->pos_arch_end > iter->pos) + BPF_SEQ_PRINTF(seq, "CORE "); + else if (!iter->pos_mod_end || iter->pos_mod_end > iter->pos) + BPF_SEQ_PRINTF(seq, "MOD "); + else if (!iter->pos_ftrace_mod_end || iter->pos_ftrace_mod_end > iter->pos) + BPF_SEQ_PRINTF(seq, "FTRACE_MOD "); + else if (!iter->pos_bpf_end || iter->pos_bpf_end > iter->pos) + BPF_SEQ_PRINTF(seq, "BPF "); + else + BPF_SEQ_PRINTF(seq, "KPROBE "); + return 0; +} -- cgit v1.3-18-gd494 From 8ed2f5a6f385b5fff313208b90ea83f7121bd909 Mon Sep 17 00:00:00 2001 From: Hengqi Chen Date: Tue, 12 Jul 2022 10:57:45 +0800 Subject: libbpf: Error out when binary_path is NULL for uprobe and USDT binary_path is a required non-null parameter for bpf_program__attach_usdt and bpf_program__attach_uprobe_opts. Check it against NULL to prevent coredump on strchr. Signed-off-by: Hengqi Chen Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220712025745.2703995-1-hengqi.chen@gmail.com --- tools/lib/bpf/libbpf.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index cb49408eb298..72548798126b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10545,7 +10545,10 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); - if (binary_path && !strchr(binary_path, '/')) { + if (!binary_path) + return libbpf_err_ptr(-EINVAL); + + if (!strchr(binary_path, '/')) { err = resolve_full_path(binary_path, full_binary_path, sizeof(full_binary_path)); if (err) { @@ -10559,11 +10562,6 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, if (func_name) { long sym_off; - if (!binary_path) { - pr_warn("prog '%s': name-based attach requires binary_path\n", - prog->name); - return libbpf_err_ptr(-EINVAL); - } sym_off = elf_find_func_offset(binary_path, func_name); if (sym_off < 0) return libbpf_err_ptr(sym_off); @@ -10711,6 +10709,9 @@ struct bpf_link *bpf_program__attach_usdt(const struct bpf_program *prog, return libbpf_err_ptr(-EINVAL); } + if (!binary_path) + return libbpf_err_ptr(-EINVAL); + if (!strchr(binary_path, '/')) { err = resolve_full_path(binary_path, resolved_path, sizeof(resolved_path)); if (err) { -- cgit v1.3-18-gd494 From bf3f00378524adae16628cbadbd11ba7211863bb Mon Sep 17 00:00:00 2001 From: Anquan Wu Date: Tue, 12 Jul 2022 11:15:40 +0800 Subject: libbpf: Fix the name of a reused map MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit BPF map name is limited to BPF_OBJ_NAME_LEN. A map name is defined as being longer than BPF_OBJ_NAME_LEN, it will be truncated to BPF_OBJ_NAME_LEN when a userspace program calls libbpf to create the map. A pinned map also generates a path in the /sys. If the previous program wanted to reuse the map， it can not get bpf_map by name, because the name of the map is only partially the same as the name which get from pinned path. The syscall information below show that map name "process_pinned_map" is truncated to "process_pinned_". bpf(BPF_OBJ_GET, {pathname="/sys/fs/bpf/process_pinned_map", bpf_fd=0, file_flags=0}, 144) = -1 ENOENT (No such file or directory) bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=4, value_size=4,max_entries=1024, map_flags=0, inner_map_fd=0, map_name="process_pinned_",map_ifindex=0, btf_fd=3, btf_key_type_id=6, btf_value_type_id=10,btf_vmlinux_value_type_id=0}, 72) = 4 This patch check that if the name of pinned map are the same as the actual name for the first (BPF_OBJ_NAME_LEN - 1), bpf map still uses the name which is included in bpf object. Fixes: 26736eb9a483 ("tools: libbpf: allow map reuse") Signed-off-by: Anquan Wu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/OSZP286MB1725CEA1C95C5CB8E7CCC53FB8869@OSZP286MB1725.JPNP286.PROD.OUTLOOK.COM --- tools/lib/bpf/libbpf.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 72548798126b..68da1aca406c 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4232,7 +4232,7 @@ int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate) int bpf_map__reuse_fd(struct bpf_map *map, int fd) { struct bpf_map_info info = {}; - __u32 len = sizeof(info); + __u32 len = sizeof(info), name_len; int new_fd, err; char *new_name; @@ -4242,7 +4242,12 @@ int bpf_map__reuse_fd(struct bpf_map *map, int fd) if (err) return libbpf_err(err); - new_name = strdup(info.name); + name_len = strlen(info.name); + if (name_len == BPF_OBJ_NAME_LEN - 1 && strncmp(map->name, info.name, name_len) == 0) + new_name = strdup(map->name); + else + new_name = strdup(info.name); + if (!new_name) return libbpf_err(-errno); -- cgit v1.3-18-gd494 From 94bf6aad5dbed1c93618035ec31b37927538c276 Mon Sep 17 00:00:00 2001 From: Linkui Xiao Date: Thu, 14 Jul 2022 09:56:47 +0800 Subject: selftests/bpf: Return true/false (not 1/0) from bool functions Return boolean values ("true" or "false") instead of 1 or 0 from bool functions. This fixes the following warnings from coccicheck: tools/testing/selftests/bpf/progs/test_xdp_noinline.c:407:9-10: WARNING: return of 0/1 in function 'decap_v4' with return type bool tools/testing/selftests/bpf/progs/test_xdp_noinline.c:389:9-10: WARNING: return of 0/1 in function 'decap_v6' with return type bool tools/testing/selftests/bpf/progs/test_xdp_noinline.c:290:9-10: WARNING: return of 0/1 in function 'encap_v6' with return type bool tools/testing/selftests/bpf/progs/test_xdp_noinline.c:264:9-10: WARNING: return of 0/1 in function 'parse_tcp' with return type bool tools/testing/selftests/bpf/progs/test_xdp_noinline.c:242:9-10: WARNING: return of 0/1 in function 'parse_udp' with return type bool Generated by: scripts/coccinelle/misc/boolreturn.cocci Suggested-by: Stanislav Fomichev Signed-off-by: Linkui Xiao Signed-off-by: Andrii Nakryiko Reviewed-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20220714015647.25074-1-xiaolinkui@kylinos.cn --- .../selftests/bpf/progs/test_xdp_noinline.c | 30 +++++++++++----------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c index 125d872d7981..ba48fcb98ab2 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c @@ -239,7 +239,7 @@ bool parse_udp(void *data, void *data_end, udp = data + off; if (udp + 1 > data_end) - return 0; + return false; if (!is_icmp) { pckt->flow.port16[0] = udp->source; pckt->flow.port16[1] = udp->dest; @@ -247,7 +247,7 @@ bool parse_udp(void *data, void *data_end, pckt->flow.port16[0] = udp->dest; pckt->flow.port16[1] = udp->source; } - return 1; + return true; } static __attribute__ ((noinline)) @@ -261,7 +261,7 @@ bool parse_tcp(void *data, void *data_end, tcp = data + off; if (tcp + 1 > data_end) - return 0; + return false; if (tcp->syn) pckt->flags |= (1 << 1); if (!is_icmp) { @@ -271,7 +271,7 @@ bool parse_tcp(void *data, void *data_end, pckt->flow.port16[0] = tcp->dest; pckt->flow.port16[1] = tcp->source; } - return 1; + return true; } static __attribute__ ((noinline)) @@ -287,7 +287,7 @@ bool encap_v6(struct xdp_md *xdp, struct ctl_value *cval, void *data; if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct ipv6hdr))) - return 0; + return false; data = (void *)(long)xdp->data; data_end = (void *)(long)xdp->data_end; new_eth = data; @@ -295,7 +295,7 @@ bool encap_v6(struct xdp_md *xdp, struct ctl_value *cval, old_eth = data + sizeof(struct ipv6hdr); if (new_eth + 1 > data_end || old_eth + 1 > data_end || ip6h + 1 > data_end) - return 0; + return false; memcpy(new_eth->eth_dest, cval->mac, 6); memcpy(new_eth->eth_source, old_eth->eth_dest, 6); new_eth->eth_proto = 56710; @@ -314,7 +314,7 @@ bool encap_v6(struct xdp_md *xdp, struct ctl_value *cval, ip6h->saddr.in6_u.u6_addr32[2] = 3; ip6h->saddr.in6_u.u6_addr32[3] = ip_suffix; memcpy(ip6h->daddr.in6_u.u6_addr32, dst->dstv6, 16); - return 1; + return true; } static __attribute__ ((noinline)) @@ -335,7 +335,7 @@ bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval, ip_suffix <<= 15; ip_suffix ^= pckt->flow.src; if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct iphdr))) - return 0; + return false; data = (void *)(long)xdp->data; data_end = (void *)(long)xdp->data_end; new_eth = data; @@ -343,7 +343,7 @@ bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval, old_eth = data + sizeof(struct iphdr); if (new_eth + 1 > data_end || old_eth + 1 > data_end || iph + 1 > data_end) - return 0; + return false; memcpy(new_eth->eth_dest, cval->mac, 6); memcpy(new_eth->eth_source, old_eth->eth_dest, 6); new_eth->eth_proto = 8; @@ -367,8 +367,8 @@ bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval, csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr))) - return 0; - return 1; + return false; + return true; } static __attribute__ ((noinline)) @@ -386,10 +386,10 @@ bool decap_v6(struct xdp_md *xdp, void **data, void **data_end, bool inner_v4) else new_eth->eth_proto = 56710; if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct ipv6hdr))) - return 0; + return false; *data = (void *)(long)xdp->data; *data_end = (void *)(long)xdp->data_end; - return 1; + return true; } static __attribute__ ((noinline)) @@ -404,10 +404,10 @@ bool decap_v4(struct xdp_md *xdp, void **data, void **data_end) memcpy(new_eth->eth_dest, old_eth->eth_dest, 6); new_eth->eth_proto = 8; if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr))) - return 0; + return false; *data = (void *)(long)xdp->data; *data_end = (void *)(long)xdp->data_end; - return 1; + return true; } static __attribute__ ((noinline)) -- cgit v1.3-18-gd494 From 7fb27a56b9ebd8a77d9dd188e8a42bff99bc3443 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Thu, 14 Jul 2022 10:23:16 +0200 Subject: selftests/bpf: Do not attach kprobe_multi bench to bpf_dispatcher_xdp_func Alexei reported crash by running test_progs -j on system with 32 cpus. It turned out the kprobe_multi bench test that attaches all ftrace-able functions will race with bpf_dispatcher_update, that calls bpf_arch_text_poke on bpf_dispatcher_xdp_func, which is ftrace-able function. Ftrace is not aware of this update so this will cause ftrace_bug with: WARNING: CPU: 6 PID: 1985 at arch/x86/kernel/ftrace.c:94 ftrace_verify_code+0x27/0x50 ... ftrace_replace_code+0xa3/0x170 ftrace_modify_all_code+0xbd/0x150 ftrace_startup_enable+0x3f/0x50 ftrace_startup+0x98/0xf0 register_ftrace_function+0x20/0x60 register_fprobe_ips+0xbb/0xd0 bpf_kprobe_multi_link_attach+0x179/0x430 __sys_bpf+0x18a1/0x2440 ... ------------[ ftrace bug ]------------ ftrace failed to modify [] bpf_dispatcher_xdp_func+0x0/0x10 actual: ffffffe9:7b:ffffff9c:77:1e Setting ftrace call site to call ftrace function It looks like we need some way to hide some functions from ftrace, but meanwhile we workaround this by skipping bpf_dispatcher_xdp_func from kprobe_multi bench test. Reported-by: Alexei Starovoitov Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20220714082316.479181-1-jolsa@kernel.org --- tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c index 335917df0614..d457a55ff408 100644 --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -364,6 +364,8 @@ static int get_syms(char ***symsp, size_t *cntp) continue; if (!strncmp(name, "rcu_", 4)) continue; + if (!strcmp(name, "bpf_dispatcher_xdp_func")) + continue; if (!strncmp(name, "__ftrace_invalid_address__", sizeof("__ftrace_invalid_address__") - 1)) continue; -- cgit v1.3-18-gd494 From 3a2a58c4479a6acd4421db41e1e1ffd804763a5a Mon Sep 17 00:00:00 2001 From: Pu Lehui Date: Thu, 14 Jul 2022 10:46:11 +0800 Subject: tools: runqslower: Build and use lightweight bootstrap version of bpftool tools/runqslower use bpftool for vmlinux.h, skeleton, and static linking only. So we can use lightweight bootstrap version of bpftool to handle these, and it will be faster. Suggested-by: Andrii Nakryiko Signed-off-by: Pu Lehui Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220714024612.944071-3-pulehui@huawei.com --- tools/bpf/runqslower/Makefile | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'tools') diff --git a/tools/bpf/runqslower/Makefile b/tools/bpf/runqslower/Makefile index da6de16a3dfb..8b3d87b82b7a 100644 --- a/tools/bpf/runqslower/Makefile +++ b/tools/bpf/runqslower/Makefile @@ -4,7 +4,7 @@ include ../../scripts/Makefile.include OUTPUT ?= $(abspath .output)/ BPFTOOL_OUTPUT := $(OUTPUT)bpftool/ -DEFAULT_BPFTOOL := $(BPFTOOL_OUTPUT)bpftool +DEFAULT_BPFTOOL := $(BPFTOOL_OUTPUT)bootstrap/bpftool BPFTOOL ?= $(DEFAULT_BPFTOOL) LIBBPF_SRC := $(abspath ../../lib/bpf) BPFOBJ_OUTPUT := $(OUTPUT)libbpf/ @@ -86,6 +86,5 @@ $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(BPFOBJ_OU $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(BPFOBJ_OUTPUT) \ DESTDIR=$(BPFOBJ_OUTPUT) prefix= $(abspath $@) install_headers -$(DEFAULT_BPFTOOL): $(BPFOBJ) | $(BPFTOOL_OUTPUT) - $(Q)$(MAKE) $(submake_extras) -C ../bpftool OUTPUT=$(BPFTOOL_OUTPUT) \ - ARCH= CROSS_COMPILE= CC=$(HOSTCC) LD=$(HOSTLD) +$(DEFAULT_BPFTOOL): | $(BPFTOOL_OUTPUT) + $(Q)$(MAKE) $(submake_extras) -C ../bpftool OUTPUT=$(BPFTOOL_OUTPUT) bootstrap -- cgit v1.3-18-gd494 From 9ff5efdeb0897547cffc275e88d2a55462d9b08e Mon Sep 17 00:00:00 2001 From: Jon Doron Date: Fri, 15 Jul 2022 21:11:22 +0300 Subject: libbpf: perfbuf: Add API to get the ring buffer Add support for writing a custom event reader, by exposing the ring buffer. With the new API perf_buffer__buffer() you will get access to the raw mmaped()'ed per-cpu underlying memory of the ring buffer. This region contains both the perf buffer data and header (struct perf_event_mmap_page), which manages the ring buffer state (head/tail positions, when accessing the head/tail position it's important to take into consideration SMP). With this type of low level access one can implement different types of consumers here are few simple examples where this API helps with: 1. perf_event_read_simple is allocating using malloc, perhaps you want to handle the wrap-around in some other way. 2. Since perf buf is per-cpu then the order of the events is not guarnteed, for example: Given 3 events where each event has a timestamp t0 < t1 < t2, and the events are spread on more than 1 CPU, then we can end up with the following state in the ring buf: CPU[0] => [t0, t2] CPU[1] => [t1] When you consume the events from CPU[0], you could know there is a t1 missing, (assuming there are no drops, and your event data contains a sequential index). So now one can simply do the following, for CPU[0], you can store the address of t0 and t2 in an array (without moving the tail, so there data is not perished) then move on the CPU[1] and set the address of t1 in the same array. So you end up with something like: void **arr[] = [&t0, &t1, &t2], now you can consume it orderely and move the tails as you process in order. 3. Assuming there are multiple CPUs and we want to start draining the messages from them, then we can "pick" with which one to start with according to the remaining free space in the ring buffer. Signed-off-by: Jon Doron Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220715181122.149224-1-arilou@gmail.com --- tools/lib/bpf/libbpf.c | 16 ++++++++++++++++ tools/lib/bpf/libbpf.h | 16 ++++++++++++++++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 33 insertions(+) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 68da1aca406c..77ae83308199 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -11734,6 +11734,22 @@ int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx) return cpu_buf->fd; } +int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, size_t *buf_size) +{ + struct perf_cpu_buf *cpu_buf; + + if (buf_idx >= pb->cpu_cnt) + return libbpf_err(-EINVAL); + + cpu_buf = pb->cpu_bufs[buf_idx]; + if (!cpu_buf) + return libbpf_err(-ENOENT); + + *buf = cpu_buf->base; + *buf_size = pb->mmap_size; + return 0; +} + /* * Consume data from perf ring buffer corresponding to slot *buf_idx* in * PERF_EVENT_ARRAY BPF map without waiting/polling. If there is no data to diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index e4d5353f757b..c51d6e6b3066 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -1053,6 +1053,22 @@ LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); +/** + * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying + * memory region of the ring buffer. + * This ring buffer can be used to implement a custom events consumer. + * The ring buffer starts with the *struct perf_event_mmap_page*, which + * holds the ring buffer managment fields, when accessing the header + * structure it's important to be SMP aware. + * You can refer to *perf_event_read_simple* for a simple example. + * @param pb the perf buffer structure + * @param buf_idx the buffer index to retreive + * @param buf (out) gets the base pointer of the mmap()'ed memory + * @param buf_size (out) gets the size of the mmap()'ed region + * @return 0 on success, negative error code for failure + */ +LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, + size_t *buf_size); struct bpf_prog_linfo; struct bpf_prog_info; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 94b589ecfeaa..4c4c40b8f935 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -362,4 +362,5 @@ LIBBPF_1.0.0 { libbpf_bpf_link_type_str; libbpf_bpf_map_type_str; libbpf_bpf_prog_type_str; + perf_buffer__buffer; }; -- cgit v1.3-18-gd494 From 55d00c37ebc396539b10ab73203bfd5e189c3660 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 14 Jul 2022 00:07:51 -0700 Subject: libbpf: generalize virtual __kconfig externs and use it for USDT Libbpf supports single virtual __kconfig extern currently: LINUX_KERNEL_VERSION. LINUX_KERNEL_VERSION isn't coming from /proc/kconfig.gz and is intead customly filled out by libbpf. This patch generalizes this approach to support more such virtual __kconfig externs. One such extern added in this patch is LINUX_HAS_BPF_COOKIE which is used for BPF-side USDT supporting code in usdt.bpf.h instead of using CO-RE-based enum detection approach for detecting bpf_get_attach_cookie() BPF helper. This allows to remove otherwise not needed CO-RE dependency and keeps user-space and BPF-side parts of libbpf's USDT support strictly in sync in terms of their feature detection. We'll use similar approach for syscall wrapper detection for BPF_KSYSCALL() BPF-side macro in follow up patch. Generally, currently libbpf reserves CONFIG_ prefix for Kconfig values and LINUX_ for virtual libbpf-backed externs. In the future we might extend the set of prefixes that are supported. This can be done without any breaking changes, as currently any __kconfig extern with unrecognized name is rejected. For LINUX_xxx externs we support the normal "weak rule": if libbpf doesn't recognize given LINUX_xxx extern but such extern is marked as __weak, it is not rejected and defaults to zero. This follows CONFIG_xxx handling logic and will allow BPF applications to opportunistically use newer libbpf virtual externs without breaking on older libbpf versions unnecessarily. Tested-by: Alan Maguire Reviewed-by: Alan Maguire Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220714070755.3235561-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 95 ++++++++++++++++++++++++++++++++---------------- tools/lib/bpf/usdt.bpf.h | 16 +------- 2 files changed, 66 insertions(+), 45 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 77ae83308199..2df8b98d97bd 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1694,7 +1694,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val, switch (ext->kcfg.type) { case KCFG_BOOL: if (value == 'm') { - pr_warn("extern (kcfg) %s=%c should be tristate or char\n", + pr_warn("extern (kcfg) '%s': value '%c' implies tristate or char type\n", ext->name, value); return -EINVAL; } @@ -1715,7 +1715,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val, case KCFG_INT: case KCFG_CHAR_ARR: default: - pr_warn("extern (kcfg) %s=%c should be bool, tristate, or char\n", + pr_warn("extern (kcfg) '%s': value '%c' implies bool, tristate, or char type\n", ext->name, value); return -EINVAL; } @@ -1729,7 +1729,8 @@ static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val, size_t len; if (ext->kcfg.type != KCFG_CHAR_ARR) { - pr_warn("extern (kcfg) %s=%s should be char array\n", ext->name, value); + pr_warn("extern (kcfg) '%s': value '%s' implies char array type\n", + ext->name, value); return -EINVAL; } @@ -1743,7 +1744,7 @@ static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val, /* strip quotes */ len -= 2; if (len >= ext->kcfg.sz) { - pr_warn("extern (kcfg) '%s': long string config %s of (%zu bytes) truncated to %d bytes\n", + pr_warn("extern (kcfg) '%s': long string '%s' of (%zu bytes) truncated to %d bytes\n", ext->name, value, len, ext->kcfg.sz - 1); len = ext->kcfg.sz - 1; } @@ -1800,13 +1801,20 @@ static bool is_kcfg_value_in_range(const struct extern_desc *ext, __u64 v) static int set_kcfg_value_num(struct extern_desc *ext, void *ext_val, __u64 value) { - if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) { - pr_warn("extern (kcfg) %s=%llu should be integer\n", + if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR && + ext->kcfg.type != KCFG_BOOL) { + pr_warn("extern (kcfg) '%s': value '%llu' implies integer, char, or boolean type\n", ext->name, (unsigned long long)value); return -EINVAL; } + if (ext->kcfg.type == KCFG_BOOL && value > 1) { + pr_warn("extern (kcfg) '%s': value '%llu' isn't boolean compatible\n", + ext->name, (unsigned long long)value); + return -EINVAL; + + } if (!is_kcfg_value_in_range(ext, value)) { - pr_warn("extern (kcfg) %s=%llu value doesn't fit in %d bytes\n", + pr_warn("extern (kcfg) '%s': value '%llu' doesn't fit in %d bytes\n", ext->name, (unsigned long long)value, ext->kcfg.sz); return -ERANGE; } @@ -1870,16 +1878,19 @@ static int bpf_object__process_kconfig_line(struct bpf_object *obj, /* assume integer */ err = parse_u64(value, &num); if (err) { - pr_warn("extern (kcfg) %s=%s should be integer\n", - ext->name, value); + pr_warn("extern (kcfg) '%s': value '%s' isn't a valid integer\n", ext->name, value); return err; } + if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) { + pr_warn("extern (kcfg) '%s': value '%s' implies integer type\n", ext->name, value); + return -EINVAL; + } err = set_kcfg_value_num(ext, ext_val, num); break; } if (err) return err; - pr_debug("extern (kcfg) %s=%s\n", ext->name, value); + pr_debug("extern (kcfg) '%s': set to %s\n", ext->name, value); return 0; } @@ -3687,7 +3698,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj) ext->kcfg.type = find_kcfg_type(obj->btf, t->type, &ext->kcfg.is_signed); if (ext->kcfg.type == KCFG_UNKNOWN) { - pr_warn("extern (kcfg) '%s' type is unsupported\n", ext_name); + pr_warn("extern (kcfg) '%s': type is unsupported\n", ext_name); return -ENOTSUP; } } else if (strcmp(sec_name, KSYMS_SEC) == 0) { @@ -7287,14 +7298,14 @@ static int kallsyms_cb(unsigned long long sym_addr, char sym_type, return 0; if (ext->is_set && ext->ksym.addr != sym_addr) { - pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n", + pr_warn("extern (ksym) '%s': resolution is ambiguous: 0x%llx or 0x%llx\n", sym_name, ext->ksym.addr, sym_addr); return -EINVAL; } if (!ext->is_set) { ext->is_set = true; ext->ksym.addr = sym_addr; - pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr); + pr_debug("extern (ksym) '%s': set to 0x%llx\n", sym_name, sym_addr); } return 0; } @@ -7498,28 +7509,50 @@ static int bpf_object__resolve_externs(struct bpf_object *obj, for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; - if (ext->type == EXT_KCFG && - strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { - void *ext_val = kcfg_data + ext->kcfg.data_off; - __u32 kver = get_kernel_version(); + if (ext->type == EXT_KSYM) { + if (ext->ksym.type_id) + need_vmlinux_btf = true; + else + need_kallsyms = true; + continue; + } else if (ext->type == EXT_KCFG) { + void *ext_ptr = kcfg_data + ext->kcfg.data_off; + __u64 value = 0; - if (!kver) { - pr_warn("failed to get kernel version\n"); + /* Kconfig externs need actual /proc/config.gz */ + if (str_has_pfx(ext->name, "CONFIG_")) { + need_config = true; + continue; + } + + /* Virtual kcfg externs are customly handled by libbpf */ + if (strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { + value = get_kernel_version(); + if (!value) { + pr_warn("extern (kcfg) '%s': failed to get kernel version\n", ext->name); + return -EINVAL; + } + } else if (strcmp(ext->name, "LINUX_HAS_BPF_COOKIE") == 0) { + value = kernel_supports(obj, FEAT_BPF_COOKIE); + } else if (!str_has_pfx(ext->name, "LINUX_") || !ext->is_weak) { + /* Currently libbpf supports only CONFIG_ and LINUX_ prefixed + * __kconfig externs, where LINUX_ ones are virtual and filled out + * customly by libbpf (their values don't come from Kconfig). + * If LINUX_xxx variable is not recognized by libbpf, but is marked + * __weak, it defaults to zero value, just like for CONFIG_xxx + * externs. + */ + pr_warn("extern (kcfg) '%s': unrecognized virtual extern\n", ext->name); return -EINVAL; } - err = set_kcfg_value_num(ext, ext_val, kver); + + err = set_kcfg_value_num(ext, ext_ptr, value); if (err) return err; - pr_debug("extern (kcfg) %s=0x%x\n", ext->name, kver); - } else if (ext->type == EXT_KCFG && str_has_pfx(ext->name, "CONFIG_")) { - need_config = true; - } else if (ext->type == EXT_KSYM) { - if (ext->ksym.type_id) - need_vmlinux_btf = true; - else - need_kallsyms = true; + pr_debug("extern (kcfg) '%s': set to 0x%llx\n", + ext->name, (long long)value); } else { - pr_warn("unrecognized extern '%s'\n", ext->name); + pr_warn("extern '%s': unrecognized extern kind\n", ext->name); return -EINVAL; } } @@ -7555,10 +7588,10 @@ static int bpf_object__resolve_externs(struct bpf_object *obj, ext = &obj->externs[i]; if (!ext->is_set && !ext->is_weak) { - pr_warn("extern %s (strong) not resolved\n", ext->name); + pr_warn("extern '%s' (strong): not resolved\n", ext->name); return -ESRCH; } else if (!ext->is_set) { - pr_debug("extern %s (weak) not resolved, defaulting to zero\n", + pr_debug("extern '%s' (weak): not resolved, defaulting to zero\n", ext->name); } } diff --git a/tools/lib/bpf/usdt.bpf.h b/tools/lib/bpf/usdt.bpf.h index 4181fddb3687..4f2adc0bd6ca 100644 --- a/tools/lib/bpf/usdt.bpf.h +++ b/tools/lib/bpf/usdt.bpf.h @@ -6,7 +6,6 @@ #include #include #include -#include /* Below types and maps are internal implementation details of libbpf's USDT * support and are subjects to change. Also, bpf_usdt_xxx() API helpers should @@ -30,14 +29,6 @@ #ifndef BPF_USDT_MAX_IP_CNT #define BPF_USDT_MAX_IP_CNT (4 * BPF_USDT_MAX_SPEC_CNT) #endif -/* We use BPF CO-RE to detect support for BPF cookie from BPF side. This is - * the only dependency on CO-RE, so if it's undesirable, user can override - * BPF_USDT_HAS_BPF_COOKIE to specify whether to BPF cookie is supported or not. - */ -#ifndef BPF_USDT_HAS_BPF_COOKIE -#define BPF_USDT_HAS_BPF_COOKIE \ - bpf_core_enum_value_exists(enum bpf_func_id___usdt, BPF_FUNC_get_attach_cookie___usdt) -#endif enum __bpf_usdt_arg_type { BPF_USDT_ARG_CONST, @@ -83,15 +74,12 @@ struct { __type(value, __u32); } __bpf_usdt_ip_to_spec_id SEC(".maps") __weak; -/* don't rely on user's BPF code to have latest definition of bpf_func_id */ -enum bpf_func_id___usdt { - BPF_FUNC_get_attach_cookie___usdt = 0xBAD, /* value doesn't matter */ -}; +extern const _Bool LINUX_HAS_BPF_COOKIE __kconfig; static __always_inline int __bpf_usdt_spec_id(struct pt_regs *ctx) { - if (!BPF_USDT_HAS_BPF_COOKIE) { + if (!LINUX_HAS_BPF_COOKIE) { long ip = PT_REGS_IP(ctx); int *spec_id_ptr; -- cgit v1.3-18-gd494 From ce6dc74a0a4a22047fdaf893047483b303b64898 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 14 Jul 2022 00:07:52 -0700 Subject: selftests/bpf: add test of __weak unknown virtual __kconfig extern Exercise libbpf's logic for unknown __weak virtual __kconfig externs. USDT selftests are already excercising non-weak known virtual extern already (LINUX_HAS_BPF_COOKIE), so no need to add explicit tests for it. Tested-by: Alan Maguire Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220714070755.3235561-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/core_extern.c | 17 +++++++---------- tools/testing/selftests/bpf/progs/test_core_extern.c | 3 +++ 2 files changed, 10 insertions(+), 10 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/core_extern.c b/tools/testing/selftests/bpf/prog_tests/core_extern.c index 1931a158510e..63a51e9f3630 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_extern.c +++ b/tools/testing/selftests/bpf/prog_tests/core_extern.c @@ -39,6 +39,7 @@ static struct test_case { "CONFIG_STR=\"abracad\"\n" "CONFIG_MISSING=0", .data = { + .unkn_virt_val = 0, .bpf_syscall = false, .tristate_val = TRI_MODULE, .bool_val = true, @@ -121,7 +122,7 @@ static struct test_case { void test_core_extern(void) { const uint32_t kern_ver = get_kernel_version(); - int err, duration = 0, i, j; + int err, i, j; struct test_core_extern *skel = NULL; uint64_t *got, *exp; int n = sizeof(*skel->data) / sizeof(uint64_t); @@ -136,19 +137,17 @@ void test_core_extern(void) continue; skel = test_core_extern__open_opts(&opts); - if (CHECK(!skel, "skel_open", "skeleton open failed\n")) + if (!ASSERT_OK_PTR(skel, "skel_open")) goto cleanup; err = test_core_extern__load(skel); if (t->fails) { - CHECK(!err, "skel_load", - "shouldn't succeed open/load of skeleton\n"); + ASSERT_ERR(err, "skel_load_should_fail"); goto cleanup; - } else if (CHECK(err, "skel_load", - "failed to open/load skeleton\n")) { + } else if (!ASSERT_OK(err, "skel_load")) { goto cleanup; } err = test_core_extern__attach(skel); - if (CHECK(err, "attach_raw_tp", "failed attach: %d\n", err)) + if (!ASSERT_OK(err, "attach_raw_tp")) goto cleanup; usleep(1); @@ -158,9 +157,7 @@ void test_core_extern(void) got = (uint64_t *)skel->data; exp = (uint64_t *)&t->data; for (j = 0; j < n; j++) { - CHECK(got[j] != exp[j], "check_res", - "result #%d: expected %llx, but got %llx\n", - j, (__u64)exp[j], (__u64)got[j]); + ASSERT_EQ(got[j], exp[j], "result"); } cleanup: test_core_extern__destroy(skel); diff --git a/tools/testing/selftests/bpf/progs/test_core_extern.c b/tools/testing/selftests/bpf/progs/test_core_extern.c index 3ac3603ad53d..a3c7c1042f35 100644 --- a/tools/testing/selftests/bpf/progs/test_core_extern.c +++ b/tools/testing/selftests/bpf/progs/test_core_extern.c @@ -11,6 +11,7 @@ static int (*bpf_missing_helper)(const void *arg1, int arg2) = (void *) 999; extern int LINUX_KERNEL_VERSION __kconfig; +extern int LINUX_UNKNOWN_VIRTUAL_EXTERN __kconfig __weak; extern bool CONFIG_BPF_SYSCALL __kconfig; /* strong */ extern enum libbpf_tristate CONFIG_TRISTATE __kconfig __weak; extern bool CONFIG_BOOL __kconfig __weak; @@ -22,6 +23,7 @@ extern const char CONFIG_STR[8] __kconfig __weak; extern uint64_t CONFIG_MISSING __kconfig __weak; uint64_t kern_ver = -1; +uint64_t unkn_virt_val = -1; uint64_t bpf_syscall = -1; uint64_t tristate_val = -1; uint64_t bool_val = -1; @@ -38,6 +40,7 @@ int handle_sys_enter(struct pt_regs *ctx) int i; kern_ver = LINUX_KERNEL_VERSION; + unkn_virt_val = LINUX_UNKNOWN_VIRTUAL_EXTERN; bpf_syscall = CONFIG_BPF_SYSCALL; tristate_val = CONFIG_TRISTATE; bool_val = CONFIG_BOOL; -- cgit v1.3-18-gd494 From 6f5d467d55f0d8fc2143179dd4869d408ae3bd25 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 14 Jul 2022 00:07:53 -0700 Subject: libbpf: improve BPF_KPROBE_SYSCALL macro and rename it to BPF_KSYSCALL Improve BPF_KPROBE_SYSCALL (and rename it to shorter BPF_KSYSCALL to match libbpf's SEC("ksyscall") section name, added in next patch) to use __kconfig variable to determine how to properly fetch syscall arguments. Instead of relying on hard-coded knowledge of whether kernel's architecture uses syscall wrapper or not (which only reflects the latest kernel versions, but is not necessarily true for older kernels and won't necessarily hold for later kernel versions on some particular host architecture), determine this at runtime by attempting to create perf_event (with fallback to kprobe event creation through tracefs on legacy kernels, just like kprobe attachment code is doing) for kernel function that would correspond to bpf() syscall on a system that has CONFIG_ARCH_HAS_SYSCALL_WRAPPER set (e.g., for x86-64 it would try '__x64_sys_bpf'). If host kernel uses syscall wrapper, syscall kernel function's first argument is a pointer to struct pt_regs that then contains syscall arguments. In such case we need to use bpf_probe_read_kernel() to fetch actual arguments (which we do through BPF_CORE_READ() macro) from inner pt_regs. But if the kernel doesn't use syscall wrapper approach, input arguments can be read from struct pt_regs directly with no probe reading. All this feature detection is done without requiring /proc/config.gz existence and parsing, and BPF-side helper code uses newly added LINUX_HAS_SYSCALL_WRAPPER virtual __kconfig extern to keep in sync with user-side feature detection of libbpf. BPF_KSYSCALL() macro can be used both with SEC("kprobe") programs that define syscall function explicitly (e.g., SEC("kprobe/__x64_sys_bpf")) and SEC("ksyscall") program added in the next patch (which are the same kprobe program with added benefit of libbpf determining correct kernel function name automatically). Kretprobe and kretsyscall (added in next patch) programs don't need BPF_KSYSCALL as they don't provide access to input arguments. Normal BPF_KRETPROBE is completely sufficient and is recommended. Tested-by: Alan Maguire Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220714070755.3235561-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf_tracing.h | 51 +++++++++++++++++++++++++++++++++------------ tools/lib/bpf/libbpf.c | 2 ++ 2 files changed, 40 insertions(+), 13 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h index 11f9096407fc..f4d3e1e2abe2 100644 --- a/tools/lib/bpf/bpf_tracing.h +++ b/tools/lib/bpf/bpf_tracing.h @@ -2,6 +2,8 @@ #ifndef __BPF_TRACING_H__ #define __BPF_TRACING_H__ +#include + /* Scan the ARCH passed in from ARCH env variable (see Makefile) */ #if defined(__TARGET_ARCH_x86) #define bpf_target_x86 @@ -140,7 +142,7 @@ struct pt_regs___s390 { #define __PT_RC_REG gprs[2] #define __PT_SP_REG gprs[15] #define __PT_IP_REG psw.addr -#define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma("GCC error \"use PT_REGS_PARM1_CORE_SYSCALL() instead\""); 0l; }) +#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1_CORE_SYSCALL(x) #define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ((const struct pt_regs___s390 *)(x), orig_gpr2) #elif defined(bpf_target_arm) @@ -174,7 +176,7 @@ struct pt_regs___arm64 { #define __PT_RC_REG regs[0] #define __PT_SP_REG sp #define __PT_IP_REG pc -#define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma("GCC error \"use PT_REGS_PARM1_CORE_SYSCALL() instead\""); 0l; }) +#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1_CORE_SYSCALL(x) #define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ((const struct pt_regs___arm64 *)(x), orig_x0) #elif defined(bpf_target_mips) @@ -493,39 +495,62 @@ typeof(name(0)) name(struct pt_regs *ctx) \ } \ static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args) +/* If kernel has CONFIG_ARCH_HAS_SYSCALL_WRAPPER, read pt_regs directly */ #define ___bpf_syscall_args0() ctx -#define ___bpf_syscall_args1(x) ___bpf_syscall_args0(), (void *)PT_REGS_PARM1_CORE_SYSCALL(regs) -#define ___bpf_syscall_args2(x, args...) ___bpf_syscall_args1(args), (void *)PT_REGS_PARM2_CORE_SYSCALL(regs) -#define ___bpf_syscall_args3(x, args...) ___bpf_syscall_args2(args), (void *)PT_REGS_PARM3_CORE_SYSCALL(regs) -#define ___bpf_syscall_args4(x, args...) ___bpf_syscall_args3(args), (void *)PT_REGS_PARM4_CORE_SYSCALL(regs) -#define ___bpf_syscall_args5(x, args...) ___bpf_syscall_args4(args), (void *)PT_REGS_PARM5_CORE_SYSCALL(regs) +#define ___bpf_syscall_args1(x) ___bpf_syscall_args0(), (void *)PT_REGS_PARM1_SYSCALL(regs) +#define ___bpf_syscall_args2(x, args...) ___bpf_syscall_args1(args), (void *)PT_REGS_PARM2_SYSCALL(regs) +#define ___bpf_syscall_args3(x, args...) ___bpf_syscall_args2(args), (void *)PT_REGS_PARM3_SYSCALL(regs) +#define ___bpf_syscall_args4(x, args...) ___bpf_syscall_args3(args), (void *)PT_REGS_PARM4_SYSCALL(regs) +#define ___bpf_syscall_args5(x, args...) ___bpf_syscall_args4(args), (void *)PT_REGS_PARM5_SYSCALL(regs) #define ___bpf_syscall_args(args...) ___bpf_apply(___bpf_syscall_args, ___bpf_narg(args))(args) +/* If kernel doesn't have CONFIG_ARCH_HAS_SYSCALL_WRAPPER, we have to BPF_CORE_READ from pt_regs */ +#define ___bpf_syswrap_args0() ctx +#define ___bpf_syswrap_args1(x) ___bpf_syswrap_args0(), (void *)PT_REGS_PARM1_CORE_SYSCALL(regs) +#define ___bpf_syswrap_args2(x, args...) ___bpf_syswrap_args1(args), (void *)PT_REGS_PARM2_CORE_SYSCALL(regs) +#define ___bpf_syswrap_args3(x, args...) ___bpf_syswrap_args2(args), (void *)PT_REGS_PARM3_CORE_SYSCALL(regs) +#define ___bpf_syswrap_args4(x, args...) ___bpf_syswrap_args3(args), (void *)PT_REGS_PARM4_CORE_SYSCALL(regs) +#define ___bpf_syswrap_args5(x, args...) ___bpf_syswrap_args4(args), (void *)PT_REGS_PARM5_CORE_SYSCALL(regs) +#define ___bpf_syswrap_args(args...) ___bpf_apply(___bpf_syswrap_args, ___bpf_narg(args))(args) + /* - * BPF_KPROBE_SYSCALL is a variant of BPF_KPROBE, which is intended for + * BPF_KSYSCALL is a variant of BPF_KPROBE, which is intended for * tracing syscall functions, like __x64_sys_close. It hides the underlying * platform-specific low-level way of getting syscall input arguments from * struct pt_regs, and provides a familiar typed and named function arguments * syntax and semantics of accessing syscall input parameters. * - * Original struct pt_regs* context is preserved as 'ctx' argument. This might + * Original struct pt_regs * context is preserved as 'ctx' argument. This might * be necessary when using BPF helpers like bpf_perf_event_output(). * - * This macro relies on BPF CO-RE support. + * At the moment BPF_KSYSCALL does not handle all the calling convention + * quirks for mmap(), clone() and compat syscalls transparrently. This may or + * may not change in the future. User needs to take extra measures to handle + * such quirks explicitly, if necessary. + * + * This macro relies on BPF CO-RE support and virtual __kconfig externs. */ -#define BPF_KPROBE_SYSCALL(name, args...) \ +#define BPF_KSYSCALL(name, args...) \ name(struct pt_regs *ctx); \ +extern _Bool LINUX_HAS_SYSCALL_WRAPPER __kconfig; \ static __attribute__((always_inline)) typeof(name(0)) \ ____##name(struct pt_regs *ctx, ##args); \ typeof(name(0)) name(struct pt_regs *ctx) \ { \ - struct pt_regs *regs = PT_REGS_SYSCALL_REGS(ctx); \ + struct pt_regs *regs = LINUX_HAS_SYSCALL_WRAPPER \ + ? (struct pt_regs *)PT_REGS_PARM1(ctx) \ + : ctx; \ _Pragma("GCC diagnostic push") \ _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \ - return ____##name(___bpf_syscall_args(args)); \ + if (LINUX_HAS_SYSCALL_WRAPPER) \ + return ____##name(___bpf_syswrap_args(args)); \ + else \ + return ____##name(___bpf_syscall_args(args)); \ _Pragma("GCC diagnostic pop") \ } \ static __attribute__((always_inline)) typeof(name(0)) \ ____##name(struct pt_regs *ctx, ##args) +#define BPF_KPROBE_SYSCALL BPF_KSYSCALL + #endif diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2df8b98d97bd..b868f9d9679b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -7534,6 +7534,8 @@ static int bpf_object__resolve_externs(struct bpf_object *obj, } } else if (strcmp(ext->name, "LINUX_HAS_BPF_COOKIE") == 0) { value = kernel_supports(obj, FEAT_BPF_COOKIE); + } else if (strcmp(ext->name, "LINUX_HAS_SYSCALL_WRAPPER") == 0) { + value = kernel_supports(obj, FEAT_SYSCALL_WRAPPER); } else if (!str_has_pfx(ext->name, "LINUX_") || !ext->is_weak) { /* Currently libbpf supports only CONFIG_ and LINUX_ prefixed * __kconfig externs, where LINUX_ ones are virtual and filled out -- cgit v1.3-18-gd494 From 708ac5bea0ce51fa1d70a44a1f817c8b02787c1e Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 14 Jul 2022 00:07:54 -0700 Subject: libbpf: add ksyscall/kretsyscall sections support for syscall kprobes Add SEC("ksyscall")/SEC("ksyscall/") and corresponding kretsyscall variants (for return kprobes) to allow users to kprobe syscall functions in kernel. These special sections allow to ignore complexities and differences between kernel versions and host architectures when it comes to syscall wrapper and corresponding ___sys_ vs __se_sys_ differences, depending on whether host kernel has CONFIG_ARCH_HAS_SYSCALL_WRAPPER (though libbpf itself doesn't rely on /proc/config.gz for detecting this, see BPF_KSYSCALL patch for how it's done internally). Combined with the use of BPF_KSYSCALL() macro, this allows to just specify intended syscall name and expected input arguments and leave dealing with all the variations to libbpf. In addition to SEC("ksyscall+") and SEC("kretsyscall+") add bpf_program__attach_ksyscall() API which allows to specify syscall name at runtime and provide associated BPF cookie value. At the moment SEC("ksyscall") and bpf_program__attach_ksyscall() do not handle all the calling convention quirks for mmap(), clone() and compat syscalls. It also only attaches to "native" syscall interfaces. If host system supports compat syscalls or defines 32-bit syscalls in 64-bit kernel, such syscall interfaces won't be attached to by libbpf. These limitations may or may not change in the future. Therefore it is recommended to use SEC("kprobe") for these syscalls or if working with compat and 32-bit interfaces is required. Tested-by: Alan Maguire Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220714070755.3235561-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 117 ++++++++++++++++++++++++++++++++++++---- tools/lib/bpf/libbpf.h | 46 ++++++++++++++++ tools/lib/bpf/libbpf.map | 1 + tools/lib/bpf/libbpf_internal.h | 2 + 4 files changed, 157 insertions(+), 9 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b868f9d9679b..431409a2336b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4670,6 +4670,8 @@ static int probe_kern_btf_enum64(void) strs, sizeof(strs))); } +static int probe_kern_syscall_wrapper(void); + enum kern_feature_result { FEAT_UNKNOWN = 0, FEAT_SUPPORTED = 1, @@ -4738,6 +4740,9 @@ static struct kern_feature_desc { [FEAT_BTF_ENUM64] = { "BTF_KIND_ENUM64 support", probe_kern_btf_enum64, }, + [FEAT_SYSCALL_WRAPPER] = { + "Kernel using syscall wrapper", probe_kern_syscall_wrapper, + }, }; bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) @@ -8421,6 +8426,7 @@ int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_ksyscall(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); @@ -8441,6 +8447,8 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("uretprobe.s+", KPROBE, 0, SEC_SLEEPABLE, attach_uprobe), SEC_DEF("kprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), SEC_DEF("kretprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), + SEC_DEF("ksyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall), + SEC_DEF("kretsyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall), SEC_DEF("usdt+", KPROBE, 0, SEC_NONE, attach_usdt), SEC_DEF("tc", SCHED_CLS, 0, SEC_NONE), SEC_DEF("classifier", SCHED_CLS, 0, SEC_NONE), @@ -9797,7 +9805,7 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, { struct perf_event_attr attr = {}; char errmsg[STRERR_BUFSIZE]; - int type, pfd, err; + int type, pfd; if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS)) return -EINVAL; @@ -9833,14 +9841,7 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, pid < 0 ? -1 : pid /* pid */, pid == -1 ? 0 : -1 /* cpu */, -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); - if (pfd < 0) { - err = -errno; - pr_warn("%s perf_event_open() failed: %s\n", - uprobe ? "uprobe" : "kprobe", - libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - return err; - } - return pfd; + return pfd >= 0 ? pfd : -errno; } static int append_to_file(const char *file, const char *fmt, ...) @@ -9945,6 +9946,60 @@ err_clean_legacy: return err; } +static const char *arch_specific_syscall_pfx(void) +{ +#if defined(__x86_64__) + return "x64"; +#elif defined(__i386__) + return "ia32"; +#elif defined(__s390x__) + return "s390x"; +#elif defined(__s390__) + return "s390"; +#elif defined(__arm__) + return "arm"; +#elif defined(__aarch64__) + return "arm64"; +#elif defined(__mips__) + return "mips"; +#elif defined(__riscv) + return "riscv"; +#else + return NULL; +#endif +} + +static int probe_kern_syscall_wrapper(void) +{ + char syscall_name[64]; + const char *ksys_pfx; + + ksys_pfx = arch_specific_syscall_pfx(); + if (!ksys_pfx) + return 0; + + snprintf(syscall_name, sizeof(syscall_name), "__%s_sys_bpf", ksys_pfx); + + if (determine_kprobe_perf_type() >= 0) { + int pfd; + + pfd = perf_event_open_probe(false, false, syscall_name, 0, getpid(), 0); + if (pfd >= 0) + close(pfd); + + return pfd >= 0 ? 1 : 0; + } else { /* legacy mode */ + char probe_name[128]; + + gen_kprobe_legacy_event_name(probe_name, sizeof(probe_name), syscall_name, 0); + if (add_kprobe_event_legacy(probe_name, false, syscall_name, 0) < 0) + return 0; + + (void)remove_kprobe_event_legacy(probe_name, false); + return 1; + } +} + struct bpf_link * bpf_program__attach_kprobe_opts(const struct bpf_program *prog, const char *func_name, @@ -10030,6 +10085,29 @@ struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog, return bpf_program__attach_kprobe_opts(prog, func_name, &opts); } +struct bpf_link *bpf_program__attach_ksyscall(const struct bpf_program *prog, + const char *syscall_name, + const struct bpf_ksyscall_opts *opts) +{ + LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts); + char func_name[128]; + + if (!OPTS_VALID(opts, bpf_ksyscall_opts)) + return libbpf_err_ptr(-EINVAL); + + if (kernel_supports(prog->obj, FEAT_SYSCALL_WRAPPER)) { + snprintf(func_name, sizeof(func_name), "__%s_sys_%s", + arch_specific_syscall_pfx(), syscall_name); + } else { + snprintf(func_name, sizeof(func_name), "__se_sys_%s", syscall_name); + } + + kprobe_opts.retprobe = OPTS_GET(opts, retprobe, false); + kprobe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); + + return bpf_program__attach_kprobe_opts(prog, func_name, &kprobe_opts); +} + /* Adapted from perf/util/string.c */ static bool glob_match(const char *str, const char *pat) { @@ -10200,6 +10278,27 @@ static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf return libbpf_get_error(*link); } +static int attach_ksyscall(const struct bpf_program *prog, long cookie, struct bpf_link **link) +{ + LIBBPF_OPTS(bpf_ksyscall_opts, opts); + const char *syscall_name; + + *link = NULL; + + /* no auto-attach for SEC("ksyscall") and SEC("kretsyscall") */ + if (strcmp(prog->sec_name, "ksyscall") == 0 || strcmp(prog->sec_name, "kretsyscall") == 0) + return 0; + + opts.retprobe = str_has_pfx(prog->sec_name, "kretsyscall/"); + if (opts.retprobe) + syscall_name = prog->sec_name + sizeof("kretsyscall/") - 1; + else + syscall_name = prog->sec_name + sizeof("ksyscall/") - 1; + + *link = bpf_program__attach_ksyscall(prog, syscall_name, &opts); + return *link ? 0 : -errno; +} + static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link) { LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index c51d6e6b3066..61493c4cddac 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -457,6 +457,52 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, const char *pattern, const struct bpf_kprobe_multi_opts *opts); +struct bpf_ksyscall_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; + /* attach as return probe? */ + bool retprobe; + size_t :0; +}; +#define bpf_ksyscall_opts__last_field retprobe + +/** + * @brief **bpf_program__attach_ksyscall()** attaches a BPF program + * to kernel syscall handler of a specified syscall. Optionally it's possible + * to request to install retprobe that will be triggered at syscall exit. It's + * also possible to associate BPF cookie (though options). + * + * Libbpf automatically will determine correct full kernel function name, + * which depending on system architecture and kernel version/configuration + * could be of the form ___sys_ or __se_sys_, and will + * attach specified program using kprobe/kretprobe mechanism. + * + * **bpf_program__attach_ksyscall()** is an API counterpart of declarative + * **SEC("ksyscall/")** annotation of BPF programs. + * + * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do + * not handle all the calling convention quirks for mmap(), clone() and compat + * syscalls. It also only attaches to "native" syscall interfaces. If host + * system supports compat syscalls or defines 32-bit syscalls in 64-bit + * kernel, such syscall interfaces won't be attached to by libbpf. + * + * These limitations may or may not change in the future. Therefore it is + * recommended to use SEC("kprobe") for these syscalls or if working with + * compat and 32-bit interfaces is required. + * + * @param prog BPF program to attach + * @param syscall_name Symbolic name of the syscall (e.g., "bpf") + * @param opts Additional options (see **struct bpf_ksyscall_opts**) + * @return Reference to the newly created BPF link; or NULL is returned on + * error, error code is stored in errno + */ +LIBBPF_API struct bpf_link * +bpf_program__attach_ksyscall(const struct bpf_program *prog, + const char *syscall_name, + const struct bpf_ksyscall_opts *opts); + struct bpf_uprobe_opts { /* size of this struct, for forward/backward compatiblity */ size_t sz; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 4c4c40b8f935..0625adb9e888 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -356,6 +356,7 @@ LIBBPF_0.8.0 { LIBBPF_1.0.0 { global: bpf_prog_query_opts; + bpf_program__attach_ksyscall; btf__add_enum64; btf__add_enum64_value; libbpf_bpf_attach_type_str; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 9cd7829cbe41..f01dbab49da9 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -352,6 +352,8 @@ enum kern_feature_id { FEAT_BPF_COOKIE, /* BTF_KIND_ENUM64 support and BTF_KIND_ENUM kflag support */ FEAT_BTF_ENUM64, + /* Kernel uses syscall wrapper (CONFIG_ARCH_HAS_SYSCALL_WRAPPER) */ + FEAT_SYSCALL_WRAPPER, __FEAT_CNT, }; -- cgit v1.3-18-gd494 From d814ed62d3d24eb5c5f904b897e0414c1ccb5740 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 14 Jul 2022 00:07:55 -0700 Subject: selftests/bpf: use BPF_KSYSCALL and SEC("ksyscall") in selftests Convert few selftest that used plain SEC("kprobe") with arch-specific syscall wrapper prefix to ksyscall/kretsyscall and corresponding BPF_KSYSCALL macro. test_probe_user.c is especially benefiting from this simplification. Tested-by: Alan Maguire Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220714070755.3235561-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/progs/bpf_syscall_macro.c | 6 ++--- .../selftests/bpf/progs/test_attach_probe.c | 15 ++++++------ .../testing/selftests/bpf/progs/test_probe_user.c | 27 +++++----------------- 3 files changed, 16 insertions(+), 32 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c b/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c index 05838ed9b89c..e1e11897e99b 100644 --- a/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c +++ b/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c @@ -64,9 +64,9 @@ int BPF_KPROBE(handle_sys_prctl) return 0; } -SEC("kprobe/" SYS_PREFIX "sys_prctl") -int BPF_KPROBE_SYSCALL(prctl_enter, int option, unsigned long arg2, - unsigned long arg3, unsigned long arg4, unsigned long arg5) +SEC("ksyscall/prctl") +int BPF_KSYSCALL(prctl_enter, int option, unsigned long arg2, + unsigned long arg3, unsigned long arg4, unsigned long arg5) { pid_t pid = bpf_get_current_pid_tgid() >> 32; diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c index f1c88ad368ef..a1e45fec8938 100644 --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -1,11 +1,10 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2017 Facebook -#include -#include +#include "vmlinux.h" #include #include -#include +#include #include "bpf_misc.h" int kprobe_res = 0; @@ -31,8 +30,8 @@ int handle_kprobe(struct pt_regs *ctx) return 0; } -SEC("kprobe/" SYS_PREFIX "sys_nanosleep") -int BPF_KPROBE(handle_kprobe_auto) +SEC("ksyscall/nanosleep") +int BPF_KSYSCALL(handle_kprobe_auto, struct __kernel_timespec *req, struct __kernel_timespec *rem) { kprobe2_res = 11; return 0; @@ -56,11 +55,11 @@ int handle_kretprobe(struct pt_regs *ctx) return 0; } -SEC("kretprobe/" SYS_PREFIX "sys_nanosleep") -int BPF_KRETPROBE(handle_kretprobe_auto) +SEC("kretsyscall/nanosleep") +int BPF_KRETPROBE(handle_kretprobe_auto, int ret) { kretprobe2_res = 22; - return 0; + return ret; } SEC("uprobe") diff --git a/tools/testing/selftests/bpf/progs/test_probe_user.c b/tools/testing/selftests/bpf/progs/test_probe_user.c index 702578a5e496..8e1495008e4d 100644 --- a/tools/testing/selftests/bpf/progs/test_probe_user.c +++ b/tools/testing/selftests/bpf/progs/test_probe_user.c @@ -1,35 +1,20 @@ // SPDX-License-Identifier: GPL-2.0 - -#include -#include - -#include - +#include "vmlinux.h" #include #include +#include #include "bpf_misc.h" static struct sockaddr_in old; -SEC("kprobe/" SYS_PREFIX "sys_connect") -int BPF_KPROBE(handle_sys_connect) +SEC("ksyscall/connect") +int BPF_KSYSCALL(handle_sys_connect, int fd, struct sockaddr_in *uservaddr, int addrlen) { -#if SYSCALL_WRAPPER == 1 - struct pt_regs *real_regs; -#endif struct sockaddr_in new; - void *ptr; - -#if SYSCALL_WRAPPER == 0 - ptr = (void *)PT_REGS_PARM2(ctx); -#else - real_regs = (struct pt_regs *)PT_REGS_PARM1(ctx); - bpf_probe_read_kernel(&ptr, sizeof(ptr), &PT_REGS_PARM2(real_regs)); -#endif - bpf_probe_read_user(&old, sizeof(old), ptr); + bpf_probe_read_user(&old, sizeof(old), uservaddr); __builtin_memset(&new, 0xab, sizeof(new)); - bpf_probe_write_user(ptr, &new, sizeof(new)); + bpf_probe_write_user(uservaddr, &new, sizeof(new)); return 0; } -- cgit v1.3-18-gd494 From 24316461200502aa5feddaa72dcbb8059503a528 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 14 Jul 2022 22:31:46 -0700 Subject: selftests/bpf: validate .bss section bigger than 8MB is possible now Add a simple big 16MB array and validate access to the very last byte of it to make sure that kernel supports > KMALLOC_MAX_SIZE value_size for BPF array maps (which are backing .bss in this case). Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220715053146.1291891-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/skeleton.c | 2 ++ tools/testing/selftests/bpf/progs/test_skeleton.c | 4 ++++ 2 files changed, 6 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/skeleton.c b/tools/testing/selftests/bpf/prog_tests/skeleton.c index 180afd632f4c..99dac5292b41 100644 --- a/tools/testing/selftests/bpf/prog_tests/skeleton.c +++ b/tools/testing/selftests/bpf/prog_tests/skeleton.c @@ -122,6 +122,8 @@ void test_skeleton(void) ASSERT_EQ(skel->bss->out_mostly_var, 123, "out_mostly_var"); + ASSERT_EQ(bss->huge_arr[ARRAY_SIZE(bss->huge_arr) - 1], 123, "huge_arr"); + elf_bytes = test_skeleton__elf_bytes(&elf_bytes_sz); ASSERT_OK_PTR(elf_bytes, "elf_bytes"); ASSERT_GE(elf_bytes_sz, 0, "elf_bytes_sz"); diff --git a/tools/testing/selftests/bpf/progs/test_skeleton.c b/tools/testing/selftests/bpf/progs/test_skeleton.c index 1b1187d2967b..1a4e93f6d9df 100644 --- a/tools/testing/selftests/bpf/progs/test_skeleton.c +++ b/tools/testing/selftests/bpf/progs/test_skeleton.c @@ -51,6 +51,8 @@ int out_dynarr[4] SEC(".data.dyn") = { 1, 2, 3, 4 }; int read_mostly_var __read_mostly; int out_mostly_var; +char huge_arr[16 * 1024 * 1024]; + SEC("raw_tp/sys_enter") int handler(const void *ctx) { @@ -71,6 +73,8 @@ int handler(const void *ctx) out_mostly_var = read_mostly_var; + huge_arr[sizeof(huge_arr) - 1] = 123; + return 0; } -- cgit v1.3-18-gd494 From a1ac9fd6c6504aa1838930bbfae6217ab6b95945 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 15 Jul 2022 11:57:36 -0700 Subject: libbpf: fallback to tracefs mount point if debugfs is not mounted Teach libbpf to fallback to tracefs mount point (/sys/kernel/tracing) if debugfs (/sys/kernel/debug/tracing) isn't mounted. Acked-by: Yonghong Song Suggested-by: Connor O'Brien Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220715185736.898848-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 61 +++++++++++++++++++++++++++++++++----------------- 1 file changed, 40 insertions(+), 21 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 431409a2336b..9b55006593c0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9864,6 +9864,34 @@ static int append_to_file(const char *file, const char *fmt, ...) return err; } +#define DEBUGFS "/sys/kernel/debug/tracing" +#define TRACEFS "/sys/kernel/tracing" + +static bool use_debugfs(void) +{ + static int has_debugfs = -1; + + if (has_debugfs < 0) + has_debugfs = access(DEBUGFS, F_OK) == 0; + + return has_debugfs == 1; +} + +static const char *tracefs_path(void) +{ + return use_debugfs() ? DEBUGFS : TRACEFS; +} + +static const char *tracefs_kprobe_events(void) +{ + return use_debugfs() ? DEBUGFS"/kprobe_events" : TRACEFS"/kprobe_events"; +} + +static const char *tracefs_uprobe_events(void) +{ + return use_debugfs() ? DEBUGFS"/uprobe_events" : TRACEFS"/uprobe_events"; +} + static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz, const char *kfunc_name, size_t offset) { @@ -9876,9 +9904,7 @@ static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz, static int add_kprobe_event_legacy(const char *probe_name, bool retprobe, const char *kfunc_name, size_t offset) { - const char *file = "/sys/kernel/debug/tracing/kprobe_events"; - - return append_to_file(file, "%c:%s/%s %s+0x%zx", + return append_to_file(tracefs_kprobe_events(), "%c:%s/%s %s+0x%zx", retprobe ? 'r' : 'p', retprobe ? "kretprobes" : "kprobes", probe_name, kfunc_name, offset); @@ -9886,18 +9912,16 @@ static int add_kprobe_event_legacy(const char *probe_name, bool retprobe, static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe) { - const char *file = "/sys/kernel/debug/tracing/kprobe_events"; - - return append_to_file(file, "-:%s/%s", retprobe ? "kretprobes" : "kprobes", probe_name); + return append_to_file(tracefs_kprobe_events(), "-:%s/%s", + retprobe ? "kretprobes" : "kprobes", probe_name); } static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retprobe) { char file[256]; - snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", - retprobe ? "kretprobes" : "kprobes", probe_name); + snprintf(file, sizeof(file), "%s/events/%s/%s/id", + tracefs_path(), retprobe ? "kretprobes" : "kprobes", probe_name); return parse_uint_from_file(file, "%d\n"); } @@ -10347,9 +10371,7 @@ static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz, static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe, const char *binary_path, size_t offset) { - const char *file = "/sys/kernel/debug/tracing/uprobe_events"; - - return append_to_file(file, "%c:%s/%s %s:0x%zx", + return append_to_file(tracefs_uprobe_events(), "%c:%s/%s %s:0x%zx", retprobe ? 'r' : 'p', retprobe ? "uretprobes" : "uprobes", probe_name, binary_path, offset); @@ -10357,18 +10379,16 @@ static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe, static inline int remove_uprobe_event_legacy(const char *probe_name, bool retprobe) { - const char *file = "/sys/kernel/debug/tracing/uprobe_events"; - - return append_to_file(file, "-:%s/%s", retprobe ? "uretprobes" : "uprobes", probe_name); + return append_to_file(tracefs_uprobe_events(), "-:%s/%s", + retprobe ? "uretprobes" : "uprobes", probe_name); } static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retprobe) { char file[512]; - snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", - retprobe ? "uretprobes" : "uprobes", probe_name); + snprintf(file, sizeof(file), "%s/events/%s/%s/id", + tracefs_path(), retprobe ? "uretprobes" : "uprobes", probe_name); return parse_uint_from_file(file, "%d\n"); } @@ -10916,9 +10936,8 @@ static int determine_tracepoint_id(const char *tp_category, char file[PATH_MAX]; int ret; - ret = snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", - tp_category, tp_name); + ret = snprintf(file, sizeof(file), "%s/events/%s/%s/id", + tracefs_path(), tp_category, tp_name); if (ret < 0) return -errno; if (ret >= sizeof(file)) { -- cgit v1.3-18-gd494 From bdb2bc7599298ebb677e40fc92b1fa9e69e05098 Mon Sep 17 00:00:00 2001 From: Joanne Koong Date: Fri, 15 Jul 2022 12:38:00 -0700 Subject: bpf: fix bpf_skb_pull_data documentation Fix documentation for bpf_skb_pull_data() helper for when len == 0. Fixes: fa15601ab31e ("bpf: add documentation for eBPF helpers (33-41)") Signed-off-by: Joanne Koong Acked-by: Quentin Monnet Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/r/20220715193800.3940070-1-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 3 ++- tools/include/uapi/linux/bpf.h | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) (limited to 'tools') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 379e68fb866f..ffcbf79a556b 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2361,7 +2361,8 @@ union bpf_attr { * Pull in non-linear data in case the *skb* is non-linear and not * all of *len* are part of the linear section. Make *len* bytes * from *skb* readable and writable. If a zero value is passed for - * *len*, then the whole length of the *skb* is pulled. + * *len*, then all bytes in the linear part of *skb* will be made + * readable and writable. * * This helper is only needed for reading and writing with direct * packet access. diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 379e68fb866f..ffcbf79a556b 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2361,7 +2361,8 @@ union bpf_attr { * Pull in non-linear data in case the *skb* is non-linear and not * all of *len* are part of the linear section. Make *len* bytes * from *skb* readable and writable. If a zero value is passed for - * *len*, then the whole length of the *skb* is pulled. + * *len*, then all bytes in the linear part of *skb* will be made + * readable and writable. * * This helper is only needed for reading and writing with direct * packet access. -- cgit v1.3-18-gd494 From 597fbc4682969361dd141aaa58b8cc73a80da85d Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 15 Jul 2022 16:09:51 -0700 Subject: libbpf: make RINGBUF map size adjustments more eagerly Make libbpf adjust RINGBUF map size (rounding it up to closest power-of-2 of page_size) more eagerly: during open phase when initializing the map and on explicit calls to bpf_map__set_max_entries(). Such approach allows user to check actual size of BPF ringbuf even before it's created in the kernel, but also it prevents various edge case scenarios where BPF ringbuf size can get out of sync with what it would be in kernel. One of them (reported in [0]) is during an attempt to pin/reuse BPF ringbuf. Move adjust_ringbuf_sz() helper closer to its first actual use. The implementation of the helper is unchanged. Also make detection of whether bpf_object is already loaded more robust by checking obj->loaded explicitly, given that map->fd can be < 0 even if bpf_object is already loaded due to ability to disable map creation with bpf_map__set_autocreate(map, false). [0] Closes: https://github.com/libbpf/libbpf/pull/530 Fixes: 0087a681fa8c ("libbpf: Automatically fix up BPF_MAP_TYPE_RINGBUF size, if necessary") Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20220715230952.2219271-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 77 +++++++++++++++++++++++++++----------------------- 1 file changed, 42 insertions(+), 35 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 9b55006593c0..b01fe01b0761 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2331,6 +2331,37 @@ int parse_btf_map_def(const char *map_name, struct btf *btf, return 0; } +static size_t adjust_ringbuf_sz(size_t sz) +{ + __u32 page_sz = sysconf(_SC_PAGE_SIZE); + __u32 mul; + + /* if user forgot to set any size, make sure they see error */ + if (sz == 0) + return 0; + /* Kernel expects BPF_MAP_TYPE_RINGBUF's max_entries to be + * a power-of-2 multiple of kernel's page size. If user diligently + * satisified these conditions, pass the size through. + */ + if ((sz % page_sz) == 0 && is_pow_of_2(sz / page_sz)) + return sz; + + /* Otherwise find closest (page_sz * power_of_2) product bigger than + * user-set size to satisfy both user size request and kernel + * requirements and substitute correct max_entries for map creation. + */ + for (mul = 1; mul <= UINT_MAX / page_sz; mul <<= 1) { + if (mul * page_sz > sz) + return mul * page_sz; + } + + /* if it's impossible to satisfy the conditions (i.e., user size is + * very close to UINT_MAX but is not a power-of-2 multiple of + * page_size) then just return original size and let kernel reject it + */ + return sz; +} + static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def) { map->def.type = def->map_type; @@ -2344,6 +2375,10 @@ static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def map->btf_key_type_id = def->key_type_id; map->btf_value_type_id = def->value_type_id; + /* auto-adjust BPF ringbuf map max_entries to be a multiple of page size */ + if (map->def.type == BPF_MAP_TYPE_RINGBUF) + map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries); + if (def->parts & MAP_DEF_MAP_TYPE) pr_debug("map '%s': found type = %u.\n", map->name, def->map_type); @@ -4317,9 +4352,15 @@ struct bpf_map *bpf_map__inner_map(struct bpf_map *map) int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries) { - if (map->fd >= 0) + if (map->obj->loaded) return libbpf_err(-EBUSY); + map->def.max_entries = max_entries; + + /* auto-adjust BPF ringbuf map max_entries to be a multiple of page size */ + if (map->def.type == BPF_MAP_TYPE_RINGBUF) + map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries); + return 0; } @@ -4875,37 +4916,6 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map) static void bpf_map__destroy(struct bpf_map *map); -static size_t adjust_ringbuf_sz(size_t sz) -{ - __u32 page_sz = sysconf(_SC_PAGE_SIZE); - __u32 mul; - - /* if user forgot to set any size, make sure they see error */ - if (sz == 0) - return 0; - /* Kernel expects BPF_MAP_TYPE_RINGBUF's max_entries to be - * a power-of-2 multiple of kernel's page size. If user diligently - * satisified these conditions, pass the size through. - */ - if ((sz % page_sz) == 0 && is_pow_of_2(sz / page_sz)) - return sz; - - /* Otherwise find closest (page_sz * power_of_2) product bigger than - * user-set size to satisfy both user size request and kernel - * requirements and substitute correct max_entries for map creation. - */ - for (mul = 1; mul <= UINT_MAX / page_sz; mul <<= 1) { - if (mul * page_sz > sz) - return mul * page_sz; - } - - /* if it's impossible to satisfy the conditions (i.e., user size is - * very close to UINT_MAX but is not a power-of-2 multiple of - * page_size) then just return original size and let kernel reject it - */ - return sz; -} - static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, bool is_inner) { LIBBPF_OPTS(bpf_map_create_opts, create_attr); @@ -4944,9 +4954,6 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b } switch (def->type) { - case BPF_MAP_TYPE_RINGBUF: - map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries); - /* fallthrough */ case BPF_MAP_TYPE_PERF_EVENT_ARRAY: case BPF_MAP_TYPE_CGROUP_ARRAY: case BPF_MAP_TYPE_STACK_TRACE: -- cgit v1.3-18-gd494 From e134601961fef4516df9413b270fb96ef6d034bc Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 15 Jul 2022 16:09:52 -0700 Subject: selftests/bpf: test eager BPF ringbuf size adjustment logic Add test validating that libbpf adjusts (and reflects adjusted) ringbuf size early, before bpf_object is loaded. Also make sure we can't successfully resize ringbuf map after bpf_object is loaded. Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20220715230952.2219271-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c b/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c index eb5f7f5aa81a..1455911d9fcb 100644 --- a/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c @@ -50,6 +50,13 @@ void test_ringbuf_multi(void) if (CHECK(!skel, "skel_open", "skeleton open failed\n")) return; + /* validate ringbuf size adjustment logic */ + ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), page_size, "rb1_size_before"); + ASSERT_OK(bpf_map__set_max_entries(skel->maps.ringbuf1, page_size + 1), "rb1_resize"); + ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), 2 * page_size, "rb1_size_after"); + ASSERT_OK(bpf_map__set_max_entries(skel->maps.ringbuf1, page_size), "rb1_reset"); + ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), page_size, "rb1_size_final"); + proto_fd = bpf_map_create(BPF_MAP_TYPE_RINGBUF, NULL, 0, 0, page_size, NULL); if (CHECK(proto_fd < 0, "bpf_map_create", "bpf_map_create failed\n")) goto cleanup; @@ -65,6 +72,10 @@ void test_ringbuf_multi(void) close(proto_fd); proto_fd = -1; + /* make sure we can't resize ringbuf after object load */ + if (!ASSERT_ERR(bpf_map__set_max_entries(skel->maps.ringbuf1, 3 * page_size), "rb1_resize_after_load")) + goto cleanup; + /* only trigger BPF program for current process */ skel->bss->pid = getpid(); -- cgit v1.3-18-gd494 From c5d22f4cfe8dfb93f1db0a1e7e2e7ebc41395d98 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 19 Jul 2022 12:50:32 +0300 Subject: selftests/bpf: fix a test for snprintf() overflow The snprintf() function returns the number of bytes which *would* have been copied if there were space. In other words, it can be > sizeof(pin_path). Fixes: c0fa1b6c3efc ("bpf: btf: Add BTF tests") Signed-off-by: Dan Carpenter Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/r/YtZ+aD/tZMkgOUw+@kili Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index 941b0100bafa..ef6528b8084c 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -5338,7 +5338,7 @@ static void do_test_pprint(int test_num) ret = snprintf(pin_path, sizeof(pin_path), "%s/%s", "/sys/fs/bpf", test->map_name); - if (CHECK(ret == sizeof(pin_path), "pin_path %s/%s is too long", + if (CHECK(ret >= sizeof(pin_path), "pin_path %s/%s is too long", "/sys/fs/bpf", test->map_name)) { err = -1; goto done; -- cgit v1.3-18-gd494 From b77ffb30cfc5f58e957571d8541c6a7e3da19221 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 19 Jul 2022 12:51:28 +0300 Subject: libbpf: fix an snprintf() overflow check The snprintf() function returns the number of bytes it *would* have copied if there were enough space. So it can return > the sizeof(gen->attach_target). Fixes: 67234743736a ("libbpf: Generate loader program out of BPF ELF file.") Signed-off-by: Dan Carpenter Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/r/YtZ+oAySqIhFl6/J@kili Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/gen_loader.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c index 927745b08014..23f5c46708f8 100644 --- a/tools/lib/bpf/gen_loader.c +++ b/tools/lib/bpf/gen_loader.c @@ -533,7 +533,7 @@ void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *attach_name, gen->attach_kind = kind; ret = snprintf(gen->attach_target, sizeof(gen->attach_target), "%s%s", prefix, attach_name); - if (ret == sizeof(gen->attach_target)) + if (ret >= sizeof(gen->attach_target)) gen->error = -ENOSPC; } -- cgit v1.3-18-gd494 From c6018fc6e7b6fcc4ac5430870c2e8b4ca556621a Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 19 Jul 2022 12:49:34 +0300 Subject: libbpf: Fix sign expansion bug in btf_dump_get_enum_value() The code here is supposed to take a signed int and store it in a signed long long. Unfortunately, the way that the type promotion works with this conditional statement is that it takes a signed int, type promotes it to a __u32, and then stores that as a signed long long. The result is never negative. This is from static analysis, but I made a little test program just to test it before I sent the patch: #include int main(void) { unsigned long long src = -1ULL; signed long long dst1, dst2; int is_signed = 1; dst1 = is_signed ? *(int *)&src : *(unsigned int *)0; dst2 = is_signed ? (signed long long)*(int *)&src : *(unsigned int *)0; printf("%lld\n", dst1); printf("%lld\n", dst2); return 0; } Fixes: d90ec262b35b ("libbpf: Add enum64 support for btf_dump") Signed-off-by: Dan Carpenter Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/YtZ+LpgPADm7BeEd@kili --- tools/lib/bpf/btf_dump.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 400e84fd0578..627edb5bb6de 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -2045,7 +2045,7 @@ static int btf_dump_get_enum_value(struct btf_dump *d, *value = *(__s64 *)data; return 0; case 4: - *value = is_signed ? *(__s32 *)data : *(__u32 *)data; + *value = is_signed ? (__s64)*(__s32 *)data : *(__u32 *)data; return 0; case 2: *value = is_signed ? *(__s16 *)data : *(__u16 *)data; -- cgit v1.3-18-gd494 From 14229b8153a3ca51d97a22a18c68deeae64afce0 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 19 Jul 2022 12:53:01 +0300 Subject: libbpf: Fix str_has_sfx()'s return value The return from strcmp() is inverted so it wrongly returns true instead of false and vice versa. Fixes: a1c9d61b19cb ("libbpf: Improve library identification for uprobe binary path resolution") Signed-off-by: Dan Carpenter Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Cc: Alan Maguire Link: https://lore.kernel.org/bpf/YtZ+/dAA195d99ak@kili --- tools/lib/bpf/libbpf_internal.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'tools') diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index f01dbab49da9..4135ae0a2bc3 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -108,9 +108,9 @@ static inline bool str_has_sfx(const char *str, const char *sfx) size_t str_len = strlen(str); size_t sfx_len = strlen(sfx); - if (sfx_len <= str_len) - return strcmp(str + str_len - sfx_len, sfx); - return false; + if (sfx_len > str_len) + return false; + return strcmp(str + str_len - sfx_len, sfx) == 0; } /* Symbol versioning is different between static and shared library. -- cgit v1.3-18-gd494 From ef2c6f370a637e6f84c813f31fe0ebb4ced2ed69 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 21 Jul 2022 15:42:34 +0200 Subject: tools/resolve_btfids: Add support for 8-byte BTF sets A flag is a 4-byte symbol that may follow a BTF ID in a set8. This is used in the kernel to tag kfuncs in BTF sets with certain flags. Add support to adjust the sorting code so that it passes size as 8 bytes for 8-byte BTF sets. Cc: Jiri Olsa Signed-off-by: Kumar Kartikeya Dwivedi Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20220721134245.2450-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/bpf/resolve_btfids/main.c | 40 ++++++++++++++++++++++++++++++++++------ 1 file changed, 34 insertions(+), 6 deletions(-) (limited to 'tools') diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c index 5d26f3c6f918..80cd7843c677 100644 --- a/tools/bpf/resolve_btfids/main.c +++ b/tools/bpf/resolve_btfids/main.c @@ -45,6 +45,19 @@ * .zero 4 * __BTF_ID__func__vfs_fallocate__4: * .zero 4 + * + * set8 - store symbol size into first 4 bytes and sort following + * ID list + * + * __BTF_ID__set8__list: + * .zero 8 + * list: + * __BTF_ID__func__vfs_getattr__3: + * .zero 4 + * .word (1 << 0) | (1 << 2) + * __BTF_ID__func__vfs_fallocate__5: + * .zero 4 + * .word (1 << 3) | (1 << 1) | (1 << 2) */ #define _GNU_SOURCE @@ -72,6 +85,7 @@ #define BTF_TYPEDEF "typedef" #define BTF_FUNC "func" #define BTF_SET "set" +#define BTF_SET8 "set8" #define ADDR_CNT 100 @@ -84,6 +98,7 @@ struct btf_id { }; int addr_cnt; bool is_set; + bool is_set8; Elf64_Addr addr[ADDR_CNT]; }; @@ -231,14 +246,14 @@ static char *get_id(const char *prefix_end) return id; } -static struct btf_id *add_set(struct object *obj, char *name) +static struct btf_id *add_set(struct object *obj, char *name, bool is_set8) { /* * __BTF_ID__set__name * name = ^ * id = ^ */ - char *id = name + sizeof(BTF_SET "__") - 1; + char *id = name + (is_set8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__")) - 1; int len = strlen(name); if (id >= name + len) { @@ -444,9 +459,21 @@ static int symbols_collect(struct object *obj) } else if (!strncmp(prefix, BTF_FUNC, sizeof(BTF_FUNC) - 1)) { obj->nr_funcs++; id = add_symbol(&obj->funcs, prefix, sizeof(BTF_FUNC) - 1); + /* set8 */ + } else if (!strncmp(prefix, BTF_SET8, sizeof(BTF_SET8) - 1)) { + id = add_set(obj, prefix, true); + /* + * SET8 objects store list's count, which is encoded + * in symbol's size, together with 'cnt' field hence + * that - 1. + */ + if (id) { + id->cnt = sym.st_size / sizeof(uint64_t) - 1; + id->is_set8 = true; + } /* set */ } else if (!strncmp(prefix, BTF_SET, sizeof(BTF_SET) - 1)) { - id = add_set(obj, prefix); + id = add_set(obj, prefix, false); /* * SET objects store list's count, which is encoded * in symbol's size, together with 'cnt' field hence @@ -571,7 +598,8 @@ static int id_patch(struct object *obj, struct btf_id *id) int *ptr = data->d_buf; int i; - if (!id->id && !id->is_set) + /* For set, set8, id->id may be 0 */ + if (!id->id && !id->is_set && !id->is_set8) pr_err("WARN: resolve_btfids: unresolved symbol %s\n", id->name); for (i = 0; i < id->addr_cnt; i++) { @@ -643,13 +671,13 @@ static int sets_patch(struct object *obj) } idx = idx / sizeof(int); - base = &ptr[idx] + 1; + base = &ptr[idx] + (id->is_set8 ? 2 : 1); cnt = ptr[idx]; pr_debug("sorting addr %5lu: cnt %6d [%s]\n", (idx + 1) * sizeof(int), cnt, id->name); - qsort(base, cnt, sizeof(int), cmp_id); + qsort(base, cnt, id->is_set8 ? sizeof(uint64_t) : sizeof(int), cmp_id); next = rb_next(next); } -- cgit v1.3-18-gd494 From a4703e3184320d6e15e2bc81d2ccf1c8c883f9d1 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 21 Jul 2022 15:42:35 +0200 Subject: bpf: Switch to new kfunc flags infrastructure Instead of populating multiple sets to indicate some attribute and then researching the same BTF ID in them, prepare a single unified BTF set which indicates whether a kfunc is allowed to be called, and also its attributes if any at the same time. Now, only one call is needed to perform the lookup for both kfunc availability and its attributes. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20220721134245.2450-4-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 3 +- include/linux/btf.h | 33 ++----- kernel/bpf/btf.c | 106 ++++++++++----------- kernel/bpf/verifier.c | 14 ++- net/bpf/test_run.c | 70 +++++--------- net/ipv4/bpf_tcp_ca.c | 18 ++-- net/ipv4/tcp_bbr.c | 24 ++--- net/ipv4/tcp_cubic.c | 20 ++-- net/ipv4/tcp_dctcp.c | 20 ++-- net/netfilter/nf_conntrack_bpf.c | 49 +++------- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 10 +- 11 files changed, 145 insertions(+), 222 deletions(-) (limited to 'tools') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 11950029284f..a97751d845c9 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1924,7 +1924,8 @@ int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, struct bpf_reg_state *regs); int btf_check_kfunc_arg_match(struct bpf_verifier_env *env, const struct btf *btf, u32 func_id, - struct bpf_reg_state *regs); + struct bpf_reg_state *regs, + u32 kfunc_flags); int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, struct bpf_reg_state *reg); int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, diff --git a/include/linux/btf.h b/include/linux/btf.h index 1bfed7fa0428..6dfc6eaf7f8c 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -12,14 +12,11 @@ #define BTF_TYPE_EMIT(type) ((void)(type *)0) #define BTF_TYPE_EMIT_ENUM(enum_val) ((void)enum_val) -enum btf_kfunc_type { - BTF_KFUNC_TYPE_CHECK, - BTF_KFUNC_TYPE_ACQUIRE, - BTF_KFUNC_TYPE_RELEASE, - BTF_KFUNC_TYPE_RET_NULL, - BTF_KFUNC_TYPE_KPTR_ACQUIRE, - BTF_KFUNC_TYPE_MAX, -}; +/* These need to be macros, as the expressions are used in assembler input */ +#define KF_ACQUIRE (1 << 0) /* kfunc is an acquire function */ +#define KF_RELEASE (1 << 1) /* kfunc is a release function */ +#define KF_RET_NULL (1 << 2) /* kfunc returns a pointer that may be NULL */ +#define KF_KPTR_GET (1 << 3) /* kfunc returns reference to a kptr */ struct btf; struct btf_member; @@ -30,16 +27,7 @@ struct btf_id_set; struct btf_kfunc_id_set { struct module *owner; - union { - struct { - struct btf_id_set *check_set; - struct btf_id_set *acquire_set; - struct btf_id_set *release_set; - struct btf_id_set *ret_null_set; - struct btf_id_set *kptr_acquire_set; - }; - struct btf_id_set *sets[BTF_KFUNC_TYPE_MAX]; - }; + struct btf_id_set8 *set; }; struct btf_id_dtor_kfunc { @@ -378,9 +366,9 @@ const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id); const char *btf_name_by_offset(const struct btf *btf, u32 offset); struct btf *btf_parse_vmlinux(void); struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog); -bool btf_kfunc_id_set_contains(const struct btf *btf, +u32 *btf_kfunc_id_set_contains(const struct btf *btf, enum bpf_prog_type prog_type, - enum btf_kfunc_type type, u32 kfunc_btf_id); + u32 kfunc_btf_id); int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, const struct btf_kfunc_id_set *s); s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id); @@ -397,12 +385,11 @@ static inline const char *btf_name_by_offset(const struct btf *btf, { return NULL; } -static inline bool btf_kfunc_id_set_contains(const struct btf *btf, +static inline u32 *btf_kfunc_id_set_contains(const struct btf *btf, enum bpf_prog_type prog_type, - enum btf_kfunc_type type, u32 kfunc_btf_id) { - return false; + return NULL; } static inline int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, const struct btf_kfunc_id_set *s) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 5869f03bcb6e..4d9c2d88720f 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -213,7 +213,7 @@ enum { }; struct btf_kfunc_set_tab { - struct btf_id_set *sets[BTF_KFUNC_HOOK_MAX][BTF_KFUNC_TYPE_MAX]; + struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX]; }; struct btf_id_dtor_kfunc_tab { @@ -1616,7 +1616,7 @@ static void btf_free_id(struct btf *btf) static void btf_free_kfunc_set_tab(struct btf *btf) { struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; - int hook, type; + int hook; if (!tab) return; @@ -1625,10 +1625,8 @@ static void btf_free_kfunc_set_tab(struct btf *btf) */ if (btf_is_module(btf)) goto free_tab; - for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) { - for (type = 0; type < ARRAY_SIZE(tab->sets[0]); type++) - kfree(tab->sets[hook][type]); - } + for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) + kfree(tab->sets[hook]); free_tab: kfree(tab); btf->kfunc_set_tab = NULL; @@ -6172,7 +6170,8 @@ static bool is_kfunc_arg_mem_size(const struct btf *btf, static int btf_check_func_arg_match(struct bpf_verifier_env *env, const struct btf *btf, u32 func_id, struct bpf_reg_state *regs, - bool ptr_to_mem_ok) + bool ptr_to_mem_ok, + u32 kfunc_flags) { enum bpf_prog_type prog_type = resolve_prog_type(env->prog); struct bpf_verifier_log *log = &env->log; @@ -6210,10 +6209,8 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, if (is_kfunc) { /* Only kfunc can be release func */ - rel = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), - BTF_KFUNC_TYPE_RELEASE, func_id); - kptr_get = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), - BTF_KFUNC_TYPE_KPTR_ACQUIRE, func_id); + rel = kfunc_flags & KF_RELEASE; + kptr_get = kfunc_flags & KF_KPTR_GET; } /* check that BTF function arguments match actual types that the @@ -6442,7 +6439,7 @@ int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, return -EINVAL; is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; - err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global); + err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, 0); /* Compiler optimizations can remove arguments from static functions * or mismatched type can be passed into a global function. @@ -6455,9 +6452,10 @@ int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, int btf_check_kfunc_arg_match(struct bpf_verifier_env *env, const struct btf *btf, u32 func_id, - struct bpf_reg_state *regs) + struct bpf_reg_state *regs, + u32 kfunc_flags) { - return btf_check_func_arg_match(env, btf, func_id, regs, true); + return btf_check_func_arg_match(env, btf, func_id, regs, true, kfunc_flags); } /* Convert BTF of a function into bpf_reg_state if possible @@ -6854,6 +6852,11 @@ bool btf_id_set_contains(const struct btf_id_set *set, u32 id) return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL; } +static void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id) +{ + return bsearch(&id, set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func); +} + enum { BTF_MODULE_F_LIVE = (1 << 0), }; @@ -7102,16 +7105,16 @@ BTF_TRACING_TYPE_xxx /* Kernel Function (kfunc) BTF ID set registration API */ -static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, - enum btf_kfunc_type type, - struct btf_id_set *add_set, bool vmlinux_set) +static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, + struct btf_id_set8 *add_set) { + bool vmlinux_set = !btf_is_module(btf); struct btf_kfunc_set_tab *tab; - struct btf_id_set *set; + struct btf_id_set8 *set; u32 set_cnt; int ret; - if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) { + if (hook >= BTF_KFUNC_HOOK_MAX) { ret = -EINVAL; goto end; } @@ -7127,7 +7130,7 @@ static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, btf->kfunc_set_tab = tab; } - set = tab->sets[hook][type]; + set = tab->sets[hook]; /* Warn when register_btf_kfunc_id_set is called twice for the same hook * for module sets. */ @@ -7141,7 +7144,7 @@ static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, * pointer and return. */ if (!vmlinux_set) { - tab->sets[hook][type] = add_set; + tab->sets[hook] = add_set; return 0; } @@ -7150,7 +7153,7 @@ static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, * and concatenate all individual sets being registered. While each set * is individually sorted, they may become unsorted when concatenated, * hence re-sorting the final set again is required to make binary - * searching the set using btf_id_set_contains function work. + * searching the set using btf_id_set8_contains function work. */ set_cnt = set ? set->cnt : 0; @@ -7165,8 +7168,8 @@ static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, } /* Grow set */ - set = krealloc(tab->sets[hook][type], - offsetof(struct btf_id_set, ids[set_cnt + add_set->cnt]), + set = krealloc(tab->sets[hook], + offsetof(struct btf_id_set8, pairs[set_cnt + add_set->cnt]), GFP_KERNEL | __GFP_NOWARN); if (!set) { ret = -ENOMEM; @@ -7174,15 +7177,15 @@ static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, } /* For newly allocated set, initialize set->cnt to 0 */ - if (!tab->sets[hook][type]) + if (!tab->sets[hook]) set->cnt = 0; - tab->sets[hook][type] = set; + tab->sets[hook] = set; /* Concatenate the two sets */ - memcpy(set->ids + set->cnt, add_set->ids, add_set->cnt * sizeof(set->ids[0])); + memcpy(set->pairs + set->cnt, add_set->pairs, add_set->cnt * sizeof(set->pairs[0])); set->cnt += add_set->cnt; - sort(set->ids, set->cnt, sizeof(set->ids[0]), btf_id_cmp_func, NULL); + sort(set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func, NULL); return 0; end: @@ -7190,38 +7193,25 @@ end: return ret; } -static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, - const struct btf_kfunc_id_set *kset) -{ - bool vmlinux_set = !btf_is_module(btf); - int type, ret = 0; - - for (type = 0; type < ARRAY_SIZE(kset->sets); type++) { - if (!kset->sets[type]) - continue; - - ret = __btf_populate_kfunc_set(btf, hook, type, kset->sets[type], vmlinux_set); - if (ret) - break; - } - return ret; -} - -static bool __btf_kfunc_id_set_contains(const struct btf *btf, +static u32 *__btf_kfunc_id_set_contains(const struct btf *btf, enum btf_kfunc_hook hook, - enum btf_kfunc_type type, u32 kfunc_btf_id) { - struct btf_id_set *set; + struct btf_id_set8 *set; + u32 *id; - if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) - return false; + if (hook >= BTF_KFUNC_HOOK_MAX) + return NULL; if (!btf->kfunc_set_tab) - return false; - set = btf->kfunc_set_tab->sets[hook][type]; + return NULL; + set = btf->kfunc_set_tab->sets[hook]; if (!set) - return false; - return btf_id_set_contains(set, kfunc_btf_id); + return NULL; + id = btf_id_set8_contains(set, kfunc_btf_id); + if (!id) + return NULL; + /* The flags for BTF ID are located next to it */ + return id + 1; } static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) @@ -7249,14 +7239,14 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) * keeping the reference for the duration of the call provides the necessary * protection for looking up a well-formed btf->kfunc_set_tab. */ -bool btf_kfunc_id_set_contains(const struct btf *btf, +u32 *btf_kfunc_id_set_contains(const struct btf *btf, enum bpf_prog_type prog_type, - enum btf_kfunc_type type, u32 kfunc_btf_id) + u32 kfunc_btf_id) { enum btf_kfunc_hook hook; hook = bpf_prog_type_to_kfunc_hook(prog_type); - return __btf_kfunc_id_set_contains(btf, hook, type, kfunc_btf_id); + return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id); } /* This function must be invoked only from initcalls/module init functions */ @@ -7283,7 +7273,7 @@ int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, return PTR_ERR(btf); hook = bpf_prog_type_to_kfunc_hook(prog_type); - ret = btf_populate_kfunc_set(btf, hook, kset); + ret = btf_populate_kfunc_set(btf, hook, kset->set); btf_put(btf); return ret; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 7c1e056624f9..096fdac70165 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7562,6 +7562,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int err, insn_idx = *insn_idx_p; const struct btf_param *args; struct btf *desc_btf; + u32 *kfunc_flags; bool acq; /* skip for now, but return error when we find this in fixup_kfunc_call */ @@ -7577,18 +7578,16 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, func_name = btf_name_by_offset(desc_btf, func->name_off); func_proto = btf_type_by_id(desc_btf, func->type); - if (!btf_kfunc_id_set_contains(desc_btf, resolve_prog_type(env->prog), - BTF_KFUNC_TYPE_CHECK, func_id)) { + kfunc_flags = btf_kfunc_id_set_contains(desc_btf, resolve_prog_type(env->prog), func_id); + if (!kfunc_flags) { verbose(env, "calling kernel function %s is not allowed\n", func_name); return -EACCES; } - - acq = btf_kfunc_id_set_contains(desc_btf, resolve_prog_type(env->prog), - BTF_KFUNC_TYPE_ACQUIRE, func_id); + acq = *kfunc_flags & KF_ACQUIRE; /* Check the arguments */ - err = btf_check_kfunc_arg_match(env, desc_btf, func_id, regs); + err = btf_check_kfunc_arg_match(env, desc_btf, func_id, regs, *kfunc_flags); if (err < 0) return err; /* In case of release function, we get register number of refcounted @@ -7632,8 +7631,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, regs[BPF_REG_0].btf = desc_btf; regs[BPF_REG_0].type = PTR_TO_BTF_ID; regs[BPF_REG_0].btf_id = ptr_type_id; - if (btf_kfunc_id_set_contains(desc_btf, resolve_prog_type(env->prog), - BTF_KFUNC_TYPE_RET_NULL, func_id)) { + if (*kfunc_flags & KF_RET_NULL) { regs[BPF_REG_0].type |= PTR_MAYBE_NULL; /* For mark_ptr_or_null_reg, see 93c230e3f5bd6 */ regs[BPF_REG_0].id = ++env->id_gen; diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index dc9dc0bedca0..ca5b7234a350 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -695,48 +695,26 @@ __diag_pop(); ALLOW_ERROR_INJECTION(bpf_modify_return_test, ERRNO); -BTF_SET_START(test_sk_check_kfunc_ids) -BTF_ID(func, bpf_kfunc_call_test1) -BTF_ID(func, bpf_kfunc_call_test2) -BTF_ID(func, bpf_kfunc_call_test3) -BTF_ID(func, bpf_kfunc_call_test_acquire) -BTF_ID(func, bpf_kfunc_call_memb_acquire) -BTF_ID(func, bpf_kfunc_call_test_release) -BTF_ID(func, bpf_kfunc_call_memb_release) -BTF_ID(func, bpf_kfunc_call_memb1_release) -BTF_ID(func, bpf_kfunc_call_test_kptr_get) -BTF_ID(func, bpf_kfunc_call_test_pass_ctx) -BTF_ID(func, bpf_kfunc_call_test_pass1) -BTF_ID(func, bpf_kfunc_call_test_pass2) -BTF_ID(func, bpf_kfunc_call_test_fail1) -BTF_ID(func, bpf_kfunc_call_test_fail2) -BTF_ID(func, bpf_kfunc_call_test_fail3) -BTF_ID(func, bpf_kfunc_call_test_mem_len_pass1) -BTF_ID(func, bpf_kfunc_call_test_mem_len_fail1) -BTF_ID(func, bpf_kfunc_call_test_mem_len_fail2) -BTF_SET_END(test_sk_check_kfunc_ids) - -BTF_SET_START(test_sk_acquire_kfunc_ids) -BTF_ID(func, bpf_kfunc_call_test_acquire) -BTF_ID(func, bpf_kfunc_call_memb_acquire) -BTF_ID(func, bpf_kfunc_call_test_kptr_get) -BTF_SET_END(test_sk_acquire_kfunc_ids) - -BTF_SET_START(test_sk_release_kfunc_ids) -BTF_ID(func, bpf_kfunc_call_test_release) -BTF_ID(func, bpf_kfunc_call_memb_release) -BTF_ID(func, bpf_kfunc_call_memb1_release) -BTF_SET_END(test_sk_release_kfunc_ids) - -BTF_SET_START(test_sk_ret_null_kfunc_ids) -BTF_ID(func, bpf_kfunc_call_test_acquire) -BTF_ID(func, bpf_kfunc_call_memb_acquire) -BTF_ID(func, bpf_kfunc_call_test_kptr_get) -BTF_SET_END(test_sk_ret_null_kfunc_ids) - -BTF_SET_START(test_sk_kptr_acquire_kfunc_ids) -BTF_ID(func, bpf_kfunc_call_test_kptr_get) -BTF_SET_END(test_sk_kptr_acquire_kfunc_ids) +BTF_SET8_START(test_sk_check_kfunc_ids) +BTF_ID_FLAGS(func, bpf_kfunc_call_test1) +BTF_ID_FLAGS(func, bpf_kfunc_call_test2) +BTF_ID_FLAGS(func, bpf_kfunc_call_test3) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_acquire, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_kfunc_call_memb_acquire, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_release, KF_RELEASE) +BTF_ID_FLAGS(func, bpf_kfunc_call_memb_release, KF_RELEASE) +BTF_ID_FLAGS(func, bpf_kfunc_call_memb1_release, KF_RELEASE) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_kptr_get, KF_ACQUIRE | KF_RET_NULL | KF_KPTR_GET) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass_ctx) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass1) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass2) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail1) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail2) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail3) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_pass1) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail1) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail2) +BTF_SET8_END(test_sk_check_kfunc_ids) static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size, u32 size, u32 headroom, u32 tailroom) @@ -1620,12 +1598,8 @@ out: } static const struct btf_kfunc_id_set bpf_prog_test_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &test_sk_check_kfunc_ids, - .acquire_set = &test_sk_acquire_kfunc_ids, - .release_set = &test_sk_release_kfunc_ids, - .ret_null_set = &test_sk_ret_null_kfunc_ids, - .kptr_acquire_set = &test_sk_kptr_acquire_kfunc_ids + .owner = THIS_MODULE, + .set = &test_sk_check_kfunc_ids, }; BTF_ID_LIST(bpf_prog_test_dtor_kfunc_ids) diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c index 7a181631b995..85a9e500c42d 100644 --- a/net/ipv4/bpf_tcp_ca.c +++ b/net/ipv4/bpf_tcp_ca.c @@ -197,17 +197,17 @@ bpf_tcp_ca_get_func_proto(enum bpf_func_id func_id, } } -BTF_SET_START(bpf_tcp_ca_check_kfunc_ids) -BTF_ID(func, tcp_reno_ssthresh) -BTF_ID(func, tcp_reno_cong_avoid) -BTF_ID(func, tcp_reno_undo_cwnd) -BTF_ID(func, tcp_slow_start) -BTF_ID(func, tcp_cong_avoid_ai) -BTF_SET_END(bpf_tcp_ca_check_kfunc_ids) +BTF_SET8_START(bpf_tcp_ca_check_kfunc_ids) +BTF_ID_FLAGS(func, tcp_reno_ssthresh) +BTF_ID_FLAGS(func, tcp_reno_cong_avoid) +BTF_ID_FLAGS(func, tcp_reno_undo_cwnd) +BTF_ID_FLAGS(func, tcp_slow_start) +BTF_ID_FLAGS(func, tcp_cong_avoid_ai) +BTF_SET8_END(bpf_tcp_ca_check_kfunc_ids) static const struct btf_kfunc_id_set bpf_tcp_ca_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &bpf_tcp_ca_check_kfunc_ids, + .owner = THIS_MODULE, + .set = &bpf_tcp_ca_check_kfunc_ids, }; static const struct bpf_verifier_ops bpf_tcp_ca_verifier_ops = { diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c index 075e744bfb48..54eec33c6e1c 100644 --- a/net/ipv4/tcp_bbr.c +++ b/net/ipv4/tcp_bbr.c @@ -1154,24 +1154,24 @@ static struct tcp_congestion_ops tcp_bbr_cong_ops __read_mostly = { .set_state = bbr_set_state, }; -BTF_SET_START(tcp_bbr_check_kfunc_ids) +BTF_SET8_START(tcp_bbr_check_kfunc_ids) #ifdef CONFIG_X86 #ifdef CONFIG_DYNAMIC_FTRACE -BTF_ID(func, bbr_init) -BTF_ID(func, bbr_main) -BTF_ID(func, bbr_sndbuf_expand) -BTF_ID(func, bbr_undo_cwnd) -BTF_ID(func, bbr_cwnd_event) -BTF_ID(func, bbr_ssthresh) -BTF_ID(func, bbr_min_tso_segs) -BTF_ID(func, bbr_set_state) +BTF_ID_FLAGS(func, bbr_init) +BTF_ID_FLAGS(func, bbr_main) +BTF_ID_FLAGS(func, bbr_sndbuf_expand) +BTF_ID_FLAGS(func, bbr_undo_cwnd) +BTF_ID_FLAGS(func, bbr_cwnd_event) +BTF_ID_FLAGS(func, bbr_ssthresh) +BTF_ID_FLAGS(func, bbr_min_tso_segs) +BTF_ID_FLAGS(func, bbr_set_state) #endif #endif -BTF_SET_END(tcp_bbr_check_kfunc_ids) +BTF_SET8_END(tcp_bbr_check_kfunc_ids) static const struct btf_kfunc_id_set tcp_bbr_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &tcp_bbr_check_kfunc_ids, + .owner = THIS_MODULE, + .set = &tcp_bbr_check_kfunc_ids, }; static int __init bbr_register(void) diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c index 68178e7280ce..768c10c1f649 100644 --- a/net/ipv4/tcp_cubic.c +++ b/net/ipv4/tcp_cubic.c @@ -485,22 +485,22 @@ static struct tcp_congestion_ops cubictcp __read_mostly = { .name = "cubic", }; -BTF_SET_START(tcp_cubic_check_kfunc_ids) +BTF_SET8_START(tcp_cubic_check_kfunc_ids) #ifdef CONFIG_X86 #ifdef CONFIG_DYNAMIC_FTRACE -BTF_ID(func, cubictcp_init) -BTF_ID(func, cubictcp_recalc_ssthresh) -BTF_ID(func, cubictcp_cong_avoid) -BTF_ID(func, cubictcp_state) -BTF_ID(func, cubictcp_cwnd_event) -BTF_ID(func, cubictcp_acked) +BTF_ID_FLAGS(func, cubictcp_init) +BTF_ID_FLAGS(func, cubictcp_recalc_ssthresh) +BTF_ID_FLAGS(func, cubictcp_cong_avoid) +BTF_ID_FLAGS(func, cubictcp_state) +BTF_ID_FLAGS(func, cubictcp_cwnd_event) +BTF_ID_FLAGS(func, cubictcp_acked) #endif #endif -BTF_SET_END(tcp_cubic_check_kfunc_ids) +BTF_SET8_END(tcp_cubic_check_kfunc_ids) static const struct btf_kfunc_id_set tcp_cubic_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &tcp_cubic_check_kfunc_ids, + .owner = THIS_MODULE, + .set = &tcp_cubic_check_kfunc_ids, }; static int __init cubictcp_register(void) diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c index ab034a4e9324..2a6c0dd665a4 100644 --- a/net/ipv4/tcp_dctcp.c +++ b/net/ipv4/tcp_dctcp.c @@ -239,22 +239,22 @@ static struct tcp_congestion_ops dctcp_reno __read_mostly = { .name = "dctcp-reno", }; -BTF_SET_START(tcp_dctcp_check_kfunc_ids) +BTF_SET8_START(tcp_dctcp_check_kfunc_ids) #ifdef CONFIG_X86 #ifdef CONFIG_DYNAMIC_FTRACE -BTF_ID(func, dctcp_init) -BTF_ID(func, dctcp_update_alpha) -BTF_ID(func, dctcp_cwnd_event) -BTF_ID(func, dctcp_ssthresh) -BTF_ID(func, dctcp_cwnd_undo) -BTF_ID(func, dctcp_state) +BTF_ID_FLAGS(func, dctcp_init) +BTF_ID_FLAGS(func, dctcp_update_alpha) +BTF_ID_FLAGS(func, dctcp_cwnd_event) +BTF_ID_FLAGS(func, dctcp_ssthresh) +BTF_ID_FLAGS(func, dctcp_cwnd_undo) +BTF_ID_FLAGS(func, dctcp_state) #endif #endif -BTF_SET_END(tcp_dctcp_check_kfunc_ids) +BTF_SET8_END(tcp_dctcp_check_kfunc_ids) static const struct btf_kfunc_id_set tcp_dctcp_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &tcp_dctcp_check_kfunc_ids, + .owner = THIS_MODULE, + .set = &tcp_dctcp_check_kfunc_ids, }; static int __init dctcp_register(void) diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c index bc4d5cd63a94..cf2096f65d0e 100644 --- a/net/netfilter/nf_conntrack_bpf.c +++ b/net/netfilter/nf_conntrack_bpf.c @@ -219,48 +219,21 @@ void bpf_ct_release(struct nf_conn *nfct) __diag_pop() -BTF_SET_START(nf_ct_xdp_check_kfunc_ids) -BTF_ID(func, bpf_xdp_ct_lookup) -BTF_ID(func, bpf_ct_release) -BTF_SET_END(nf_ct_xdp_check_kfunc_ids) - -BTF_SET_START(nf_ct_tc_check_kfunc_ids) -BTF_ID(func, bpf_skb_ct_lookup) -BTF_ID(func, bpf_ct_release) -BTF_SET_END(nf_ct_tc_check_kfunc_ids) - -BTF_SET_START(nf_ct_acquire_kfunc_ids) -BTF_ID(func, bpf_xdp_ct_lookup) -BTF_ID(func, bpf_skb_ct_lookup) -BTF_SET_END(nf_ct_acquire_kfunc_ids) - -BTF_SET_START(nf_ct_release_kfunc_ids) -BTF_ID(func, bpf_ct_release) -BTF_SET_END(nf_ct_release_kfunc_ids) - -/* Both sets are identical */ -#define nf_ct_ret_null_kfunc_ids nf_ct_acquire_kfunc_ids - -static const struct btf_kfunc_id_set nf_conntrack_xdp_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &nf_ct_xdp_check_kfunc_ids, - .acquire_set = &nf_ct_acquire_kfunc_ids, - .release_set = &nf_ct_release_kfunc_ids, - .ret_null_set = &nf_ct_ret_null_kfunc_ids, -}; - -static const struct btf_kfunc_id_set nf_conntrack_tc_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &nf_ct_tc_check_kfunc_ids, - .acquire_set = &nf_ct_acquire_kfunc_ids, - .release_set = &nf_ct_release_kfunc_ids, - .ret_null_set = &nf_ct_ret_null_kfunc_ids, +BTF_SET8_START(nf_ct_kfunc_set) +BTF_ID_FLAGS(func, bpf_xdp_ct_lookup, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_skb_ct_lookup, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_ct_release, KF_RELEASE) +BTF_SET8_END(nf_ct_kfunc_set) + +static const struct btf_kfunc_id_set nf_conntrack_kfunc_set = { + .owner = THIS_MODULE, + .set = &nf_ct_kfunc_set, }; int register_nf_conntrack_bpf(void) { int ret; - ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &nf_conntrack_xdp_kfunc_set); - return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &nf_conntrack_tc_kfunc_set); + ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &nf_conntrack_kfunc_set); + return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &nf_conntrack_kfunc_set); } diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index e585e1cefc77..792cb15bac40 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -148,13 +148,13 @@ static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = { .write = bpf_testmod_test_write, }; -BTF_SET_START(bpf_testmod_check_kfunc_ids) -BTF_ID(func, bpf_testmod_test_mod_kfunc) -BTF_SET_END(bpf_testmod_check_kfunc_ids) +BTF_SET8_START(bpf_testmod_check_kfunc_ids) +BTF_ID_FLAGS(func, bpf_testmod_test_mod_kfunc) +BTF_SET8_END(bpf_testmod_check_kfunc_ids) static const struct btf_kfunc_id_set bpf_testmod_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &bpf_testmod_check_kfunc_ids, + .owner = THIS_MODULE, + .set = &bpf_testmod_check_kfunc_ids, }; extern int bpf_fentry_test1(int a); -- cgit v1.3-18-gd494 From 8dd5e75683f713c155880c30ea545f2360c9bf46 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 21 Jul 2022 15:42:42 +0200 Subject: selftests/bpf: Add verifier tests for trusted kfunc args Make sure verifier rejects the bad cases and ensure the good case keeps working. The selftests make use of the bpf_kfunc_call_test_ref kfunc added in the previous patch only for verification. Acked-by: Yonghong Song Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20220721134245.2450-11-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/verifier/calls.c | 53 ++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index 743ed34c1238..3fb4f69b1962 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -218,6 +218,59 @@ .result = REJECT, .errstr = "variable ptr_ access var_off=(0x0; 0x7) disallowed", }, +{ + "calls: invalid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 16), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .fixup_kfunc_btf_id = { + { "bpf_kfunc_call_test_acquire", 3 }, + { "bpf_kfunc_call_test_ref", 8 }, + { "bpf_kfunc_call_test_ref", 10 }, + }, + .result_unpriv = REJECT, + .result = REJECT, + .errstr = "R1 must be referenced", +}, +{ + "calls: valid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .fixup_kfunc_btf_id = { + { "bpf_kfunc_call_test_acquire", 3 }, + { "bpf_kfunc_call_test_ref", 8 }, + { "bpf_kfunc_call_test_release", 10 }, + }, + .result_unpriv = REJECT, + .result = ACCEPT, +}, { "calls: basic sanity", .insns = { -- cgit v1.3-18-gd494 From 6eb7fba007a728e8701be11e93e9da40c95ffad3 Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Thu, 21 Jul 2022 15:42:43 +0200 Subject: selftests/bpf: Add tests for new nf_conntrack kfuncs Introduce selftests for the following kfunc helpers: - bpf_xdp_ct_alloc - bpf_skb_ct_alloc - bpf_ct_insert_entry - bpf_ct_set_timeout - bpf_ct_change_timeout - bpf_ct_set_status - bpf_ct_change_status Signed-off-by: Lorenzo Bianconi Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20220721134245.2450-12-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/bpf_nf.c | 8 +++ tools/testing/selftests/bpf/progs/test_bpf_nf.c | 85 +++++++++++++++++++++---- 2 files changed, 81 insertions(+), 12 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_nf.c b/tools/testing/selftests/bpf/prog_tests/bpf_nf.c index dd30b1e3a67c..cbada73a61f8 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_nf.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_nf.c @@ -39,6 +39,14 @@ void test_bpf_nf_ct(int mode) ASSERT_EQ(skel->bss->test_enonet_netns_id, -ENONET, "Test ENONET for bad but valid netns_id"); ASSERT_EQ(skel->bss->test_enoent_lookup, -ENOENT, "Test ENOENT for failed lookup"); ASSERT_EQ(skel->bss->test_eafnosupport, -EAFNOSUPPORT, "Test EAFNOSUPPORT for invalid len__tuple"); + ASSERT_EQ(skel->data->test_alloc_entry, 0, "Test for alloc new entry"); + ASSERT_EQ(skel->data->test_insert_entry, 0, "Test for insert new entry"); + ASSERT_EQ(skel->data->test_succ_lookup, 0, "Test for successful lookup"); + /* allow some tolerance for test_delta_timeout value to avoid races. */ + ASSERT_GT(skel->bss->test_delta_timeout, 8, "Test for min ct timeout update"); + ASSERT_LE(skel->bss->test_delta_timeout, 10, "Test for max ct timeout update"); + /* expected status is IPS_SEEN_REPLY */ + ASSERT_EQ(skel->bss->test_status, 2, "Test for ct status update "); end: test_bpf_nf__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/test_bpf_nf.c b/tools/testing/selftests/bpf/progs/test_bpf_nf.c index f00a9731930e..196cd8dfe42a 100644 --- a/tools/testing/selftests/bpf/progs/test_bpf_nf.c +++ b/tools/testing/selftests/bpf/progs/test_bpf_nf.c @@ -8,6 +8,8 @@ #define EINVAL 22 #define ENOENT 2 +extern unsigned long CONFIG_HZ __kconfig; + int test_einval_bpf_tuple = 0; int test_einval_reserved = 0; int test_einval_netns_id = 0; @@ -16,6 +18,11 @@ int test_eproto_l4proto = 0; int test_enonet_netns_id = 0; int test_enoent_lookup = 0; int test_eafnosupport = 0; +int test_alloc_entry = -EINVAL; +int test_insert_entry = -EAFNOSUPPORT; +int test_succ_lookup = -ENOENT; +u32 test_delta_timeout = 0; +u32 test_status = 0; struct nf_conn; @@ -26,31 +33,44 @@ struct bpf_ct_opts___local { u8 reserved[3]; } __attribute__((preserve_access_index)); +struct nf_conn *bpf_xdp_ct_alloc(struct xdp_md *, struct bpf_sock_tuple *, u32, + struct bpf_ct_opts___local *, u32) __ksym; struct nf_conn *bpf_xdp_ct_lookup(struct xdp_md *, struct bpf_sock_tuple *, u32, struct bpf_ct_opts___local *, u32) __ksym; +struct nf_conn *bpf_skb_ct_alloc(struct __sk_buff *, struct bpf_sock_tuple *, u32, + struct bpf_ct_opts___local *, u32) __ksym; struct nf_conn *bpf_skb_ct_lookup(struct __sk_buff *, struct bpf_sock_tuple *, u32, struct bpf_ct_opts___local *, u32) __ksym; +struct nf_conn *bpf_ct_insert_entry(struct nf_conn *) __ksym; void bpf_ct_release(struct nf_conn *) __ksym; +void bpf_ct_set_timeout(struct nf_conn *, u32) __ksym; +int bpf_ct_change_timeout(struct nf_conn *, u32) __ksym; +int bpf_ct_set_status(struct nf_conn *, u32) __ksym; +int bpf_ct_change_status(struct nf_conn *, u32) __ksym; static __always_inline void -nf_ct_test(struct nf_conn *(*func)(void *, struct bpf_sock_tuple *, u32, - struct bpf_ct_opts___local *, u32), +nf_ct_test(struct nf_conn *(*lookup_fn)(void *, struct bpf_sock_tuple *, u32, + struct bpf_ct_opts___local *, u32), + struct nf_conn *(*alloc_fn)(void *, struct bpf_sock_tuple *, u32, + struct bpf_ct_opts___local *, u32), void *ctx) { struct bpf_ct_opts___local opts_def = { .l4proto = IPPROTO_TCP, .netns_id = -1 }; struct bpf_sock_tuple bpf_tuple; struct nf_conn *ct; + int err; __builtin_memset(&bpf_tuple, 0, sizeof(bpf_tuple.ipv4)); - ct = func(ctx, NULL, 0, &opts_def, sizeof(opts_def)); + ct = lookup_fn(ctx, NULL, 0, &opts_def, sizeof(opts_def)); if (ct) bpf_ct_release(ct); else test_einval_bpf_tuple = opts_def.error; opts_def.reserved[0] = 1; - ct = func(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, sizeof(opts_def)); + ct = lookup_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, + sizeof(opts_def)); opts_def.reserved[0] = 0; opts_def.l4proto = IPPROTO_TCP; if (ct) @@ -59,21 +79,24 @@ nf_ct_test(struct nf_conn *(*func)(void *, struct bpf_sock_tuple *, u32, test_einval_reserved = opts_def.error; opts_def.netns_id = -2; - ct = func(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, sizeof(opts_def)); + ct = lookup_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, + sizeof(opts_def)); opts_def.netns_id = -1; if (ct) bpf_ct_release(ct); else test_einval_netns_id = opts_def.error; - ct = func(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, sizeof(opts_def) - 1); + ct = lookup_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, + sizeof(opts_def) - 1); if (ct) bpf_ct_release(ct); else test_einval_len_opts = opts_def.error; opts_def.l4proto = IPPROTO_ICMP; - ct = func(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, sizeof(opts_def)); + ct = lookup_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, + sizeof(opts_def)); opts_def.l4proto = IPPROTO_TCP; if (ct) bpf_ct_release(ct); @@ -81,37 +104,75 @@ nf_ct_test(struct nf_conn *(*func)(void *, struct bpf_sock_tuple *, u32, test_eproto_l4proto = opts_def.error; opts_def.netns_id = 0xf00f; - ct = func(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, sizeof(opts_def)); + ct = lookup_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, + sizeof(opts_def)); opts_def.netns_id = -1; if (ct) bpf_ct_release(ct); else test_enonet_netns_id = opts_def.error; - ct = func(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, sizeof(opts_def)); + ct = lookup_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, + sizeof(opts_def)); if (ct) bpf_ct_release(ct); else test_enoent_lookup = opts_def.error; - ct = func(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4) - 1, &opts_def, sizeof(opts_def)); + ct = lookup_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4) - 1, &opts_def, + sizeof(opts_def)); if (ct) bpf_ct_release(ct); else test_eafnosupport = opts_def.error; + + bpf_tuple.ipv4.saddr = bpf_get_prandom_u32(); /* src IP */ + bpf_tuple.ipv4.daddr = bpf_get_prandom_u32(); /* dst IP */ + bpf_tuple.ipv4.sport = bpf_get_prandom_u32(); /* src port */ + bpf_tuple.ipv4.dport = bpf_get_prandom_u32(); /* dst port */ + + ct = alloc_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), &opts_def, + sizeof(opts_def)); + if (ct) { + struct nf_conn *ct_ins; + + bpf_ct_set_timeout(ct, 10000); + bpf_ct_set_status(ct, IPS_CONFIRMED); + + ct_ins = bpf_ct_insert_entry(ct); + if (ct_ins) { + struct nf_conn *ct_lk; + + ct_lk = lookup_fn(ctx, &bpf_tuple, sizeof(bpf_tuple.ipv4), + &opts_def, sizeof(opts_def)); + if (ct_lk) { + /* update ct entry timeout */ + bpf_ct_change_timeout(ct_lk, 10000); + test_delta_timeout = ct_lk->timeout - bpf_jiffies64(); + test_delta_timeout /= CONFIG_HZ; + test_status = IPS_SEEN_REPLY; + bpf_ct_change_status(ct_lk, IPS_SEEN_REPLY); + bpf_ct_release(ct_lk); + test_succ_lookup = 0; + } + bpf_ct_release(ct_ins); + test_insert_entry = 0; + } + test_alloc_entry = 0; + } } SEC("xdp") int nf_xdp_ct_test(struct xdp_md *ctx) { - nf_ct_test((void *)bpf_xdp_ct_lookup, ctx); + nf_ct_test((void *)bpf_xdp_ct_lookup, (void *)bpf_xdp_ct_alloc, ctx); return 0; } SEC("tc") int nf_skb_ct_test(struct __sk_buff *ctx) { - nf_ct_test((void *)bpf_skb_ct_lookup, ctx); + nf_ct_test((void *)bpf_skb_ct_lookup, (void *)bpf_skb_ct_alloc, ctx); return 0; } -- cgit v1.3-18-gd494 From c6f420ac9d251f694d030ed4ea43262f3f3ef39e Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 21 Jul 2022 15:42:44 +0200 Subject: selftests/bpf: Add negative tests for new nf_conntrack kfuncs Test cases we care about and ensure improper usage is caught and rejected by the verifier. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20220721134245.2450-13-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/bpf_nf.c | 56 ++++++++- .../testing/selftests/bpf/progs/test_bpf_nf_fail.c | 134 +++++++++++++++++++++ 2 files changed, 189 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/progs/test_bpf_nf_fail.c (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_nf.c b/tools/testing/selftests/bpf/prog_tests/bpf_nf.c index cbada73a61f8..7a74a1579076 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_nf.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_nf.c @@ -2,13 +2,29 @@ #include #include #include "test_bpf_nf.skel.h" +#include "test_bpf_nf_fail.skel.h" + +static char log_buf[1024 * 1024]; + +struct { + const char *prog_name; + const char *err_msg; +} test_bpf_nf_fail_tests[] = { + { "alloc_release", "kernel function bpf_ct_release args#0 expected pointer to STRUCT nf_conn but" }, + { "insert_insert", "kernel function bpf_ct_insert_entry args#0 expected pointer to STRUCT nf_conn___init but" }, + { "lookup_insert", "kernel function bpf_ct_insert_entry args#0 expected pointer to STRUCT nf_conn___init but" }, + { "set_timeout_after_insert", "kernel function bpf_ct_set_timeout args#0 expected pointer to STRUCT nf_conn___init but" }, + { "set_status_after_insert", "kernel function bpf_ct_set_status args#0 expected pointer to STRUCT nf_conn___init but" }, + { "change_timeout_after_alloc", "kernel function bpf_ct_change_timeout args#0 expected pointer to STRUCT nf_conn but" }, + { "change_status_after_alloc", "kernel function bpf_ct_change_status args#0 expected pointer to STRUCT nf_conn but" }, +}; enum { TEST_XDP, TEST_TC_BPF, }; -void test_bpf_nf_ct(int mode) +static void test_bpf_nf_ct(int mode) { struct test_bpf_nf *skel; int prog_fd, err; @@ -51,10 +67,48 @@ end: test_bpf_nf__destroy(skel); } +static void test_bpf_nf_ct_fail(const char *prog_name, const char *err_msg) +{ + LIBBPF_OPTS(bpf_object_open_opts, opts, .kernel_log_buf = log_buf, + .kernel_log_size = sizeof(log_buf), + .kernel_log_level = 1); + struct test_bpf_nf_fail *skel; + struct bpf_program *prog; + int ret; + + skel = test_bpf_nf_fail__open_opts(&opts); + if (!ASSERT_OK_PTR(skel, "test_bpf_nf_fail__open")) + return; + + prog = bpf_object__find_program_by_name(skel->obj, prog_name); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto end; + + bpf_program__set_autoload(prog, true); + + ret = test_bpf_nf_fail__load(skel); + if (!ASSERT_ERR(ret, "test_bpf_nf_fail__load must fail")) + goto end; + + if (!ASSERT_OK_PTR(strstr(log_buf, err_msg), "expected error message")) { + fprintf(stderr, "Expected: %s\n", err_msg); + fprintf(stderr, "Verifier: %s\n", log_buf); + } + +end: + test_bpf_nf_fail__destroy(skel); +} + void test_bpf_nf(void) { + int i; if (test__start_subtest("xdp-ct")) test_bpf_nf_ct(TEST_XDP); if (test__start_subtest("tc-bpf-ct")) test_bpf_nf_ct(TEST_TC_BPF); + for (i = 0; i < ARRAY_SIZE(test_bpf_nf_fail_tests); i++) { + if (test__start_subtest(test_bpf_nf_fail_tests[i].prog_name)) + test_bpf_nf_ct_fail(test_bpf_nf_fail_tests[i].prog_name, + test_bpf_nf_fail_tests[i].err_msg); + } } diff --git a/tools/testing/selftests/bpf/progs/test_bpf_nf_fail.c b/tools/testing/selftests/bpf/progs/test_bpf_nf_fail.c new file mode 100644 index 000000000000..bf79af15c808 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_bpf_nf_fail.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +struct nf_conn; + +struct bpf_ct_opts___local { + s32 netns_id; + s32 error; + u8 l4proto; + u8 reserved[3]; +} __attribute__((preserve_access_index)); + +struct nf_conn *bpf_skb_ct_alloc(struct __sk_buff *, struct bpf_sock_tuple *, u32, + struct bpf_ct_opts___local *, u32) __ksym; +struct nf_conn *bpf_skb_ct_lookup(struct __sk_buff *, struct bpf_sock_tuple *, u32, + struct bpf_ct_opts___local *, u32) __ksym; +struct nf_conn *bpf_ct_insert_entry(struct nf_conn *) __ksym; +void bpf_ct_release(struct nf_conn *) __ksym; +void bpf_ct_set_timeout(struct nf_conn *, u32) __ksym; +int bpf_ct_change_timeout(struct nf_conn *, u32) __ksym; +int bpf_ct_set_status(struct nf_conn *, u32) __ksym; +int bpf_ct_change_status(struct nf_conn *, u32) __ksym; + +SEC("?tc") +int alloc_release(struct __sk_buff *ctx) +{ + struct bpf_ct_opts___local opts = {}; + struct bpf_sock_tuple tup = {}; + struct nf_conn *ct; + + ct = bpf_skb_ct_alloc(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts)); + if (!ct) + return 0; + bpf_ct_release(ct); + return 0; +} + +SEC("?tc") +int insert_insert(struct __sk_buff *ctx) +{ + struct bpf_ct_opts___local opts = {}; + struct bpf_sock_tuple tup = {}; + struct nf_conn *ct; + + ct = bpf_skb_ct_alloc(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts)); + if (!ct) + return 0; + ct = bpf_ct_insert_entry(ct); + if (!ct) + return 0; + ct = bpf_ct_insert_entry(ct); + return 0; +} + +SEC("?tc") +int lookup_insert(struct __sk_buff *ctx) +{ + struct bpf_ct_opts___local opts = {}; + struct bpf_sock_tuple tup = {}; + struct nf_conn *ct; + + ct = bpf_skb_ct_lookup(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts)); + if (!ct) + return 0; + bpf_ct_insert_entry(ct); + return 0; +} + +SEC("?tc") +int set_timeout_after_insert(struct __sk_buff *ctx) +{ + struct bpf_ct_opts___local opts = {}; + struct bpf_sock_tuple tup = {}; + struct nf_conn *ct; + + ct = bpf_skb_ct_alloc(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts)); + if (!ct) + return 0; + ct = bpf_ct_insert_entry(ct); + if (!ct) + return 0; + bpf_ct_set_timeout(ct, 0); + return 0; +} + +SEC("?tc") +int set_status_after_insert(struct __sk_buff *ctx) +{ + struct bpf_ct_opts___local opts = {}; + struct bpf_sock_tuple tup = {}; + struct nf_conn *ct; + + ct = bpf_skb_ct_alloc(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts)); + if (!ct) + return 0; + ct = bpf_ct_insert_entry(ct); + if (!ct) + return 0; + bpf_ct_set_status(ct, 0); + return 0; +} + +SEC("?tc") +int change_timeout_after_alloc(struct __sk_buff *ctx) +{ + struct bpf_ct_opts___local opts = {}; + struct bpf_sock_tuple tup = {}; + struct nf_conn *ct; + + ct = bpf_skb_ct_alloc(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts)); + if (!ct) + return 0; + bpf_ct_change_timeout(ct, 0); + return 0; +} + +SEC("?tc") +int change_status_after_alloc(struct __sk_buff *ctx) +{ + struct bpf_ct_opts___local opts = {}; + struct bpf_sock_tuple tup = {}; + struct nf_conn *ct; + + ct = bpf_skb_ct_alloc(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts)); + if (!ct) + return 0; + bpf_ct_change_status(ct, 0); + return 0; +} + +char _license[] SEC("license") = "GPL"; -- cgit v1.3-18-gd494 From e3fa4735f04dcebd49c78544eb6c363efdd6385f Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 21 Jul 2022 15:42:45 +0200 Subject: selftests/bpf: Fix test_verifier failed test in unprivileged mode Loading the BTF won't be permitted without privileges, hence only test for privileged mode by setting the prog type. This makes the test_verifier show 0 failures when unprivileged BPF is enabled. Fixes: 41188e9e9def ("selftest/bpf: Test for use-after-free bug fix in inline_bpf_loop") Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20220721134245.2450-14-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/verifier/bpf_loop_inline.c | 1 + 1 file changed, 1 insertion(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c b/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c index 2d0023659d88..a535d41dc20d 100644 --- a/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c +++ b/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c @@ -251,6 +251,7 @@ .expected_insns = { PSEUDO_CALL_INSN() }, .unexpected_insns = { HELPER_CALL_INSN() }, .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, .func_info = { { 0, MAIN_TYPE }, { 16, CALLBACK_TYPE } }, .func_info_cnt = 2, BTF_TYPES -- cgit v1.3-18-gd494 From f664f9c6b4a1bb9a10af812df0fbbf6aac28fcc6 Mon Sep 17 00:00:00 2001 From: Jie2x Zhou Date: Tue, 19 Jul 2022 16:24:30 +0800 Subject: bpf/selftests: Fix couldn't retrieve pinned program in xdp veth test Before change: selftests: bpf: test_xdp_veth.sh Couldn't retrieve pinned program '/sys/fs/bpf/test_xdp_veth/progs/redirect_map_0': No such file or directory selftests: xdp_veth [SKIP] ok 20 selftests: bpf: test_xdp_veth.sh # SKIP After change: PING 10.1.1.33 (10.1.1.33) 56(84) bytes of data. 64 bytes from 10.1.1.33: icmp_seq=1 ttl=64 time=0.320 ms --- 10.1.1.33 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.320/0.320/0.320/0.000 ms selftests: xdp_veth [PASS] For the test case, the following can be found: ls /sys/fs/bpf/test_xdp_veth/progs/redirect_map_0 ls: cannot access '/sys/fs/bpf/test_xdp_veth/progs/redirect_map_0': No such file or directory ls /sys/fs/bpf/test_xdp_veth/progs/ xdp_redirect_map_0 xdp_redirect_map_1 xdp_redirect_map_2 Reported-by: kernel test robot Signed-off-by: Jie2x Zhou Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220719082430.9916-1-jie2x.zhou@intel.com --- tools/testing/selftests/bpf/test_xdp_veth.sh | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/test_xdp_veth.sh b/tools/testing/selftests/bpf/test_xdp_veth.sh index 392d28cc4e58..49936c4c8567 100755 --- a/tools/testing/selftests/bpf/test_xdp_veth.sh +++ b/tools/testing/selftests/bpf/test_xdp_veth.sh @@ -106,9 +106,9 @@ bpftool prog loadall \ bpftool map update pinned $BPF_DIR/maps/tx_port key 0 0 0 0 value 122 0 0 0 bpftool map update pinned $BPF_DIR/maps/tx_port key 1 0 0 0 value 133 0 0 0 bpftool map update pinned $BPF_DIR/maps/tx_port key 2 0 0 0 value 111 0 0 0 -ip link set dev veth1 xdp pinned $BPF_DIR/progs/redirect_map_0 -ip link set dev veth2 xdp pinned $BPF_DIR/progs/redirect_map_1 -ip link set dev veth3 xdp pinned $BPF_DIR/progs/redirect_map_2 +ip link set dev veth1 xdp pinned $BPF_DIR/progs/xdp_redirect_map_0 +ip link set dev veth2 xdp pinned $BPF_DIR/progs/xdp_redirect_map_1 +ip link set dev veth3 xdp pinned $BPF_DIR/progs/xdp_redirect_map_2 ip -n ${NS1} link set dev veth11 xdp obj xdp_dummy.o sec xdp ip -n ${NS2} link set dev veth22 xdp obj xdp_tx.o sec xdp -- cgit v1.3-18-gd494