From b053b439b72ad152257ecc3f71cfb4c619b0137e Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 7 Dec 2018 16:42:32 -0800 Subject: bpf: libbpf: bpftool: Print bpf_line_info during prog dump This patch adds print bpf_line_info function in 'prog dump jitted' and 'prog dump xlated': [root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool prog dump jited pinned /sys/fs/bpf/test_btf_haskv [...] int test_long_fname_2(struct dummy_tracepoint_args * arg): bpf_prog_44a040bf25481309_test_long_fname_2: ; static int test_long_fname_2(struct dummy_tracepoint_args *arg) 0: push %rbp 1: mov %rsp,%rbp 4: sub $0x30,%rsp b: sub $0x28,%rbp f: mov %rbx,0x0(%rbp) 13: mov %r13,0x8(%rbp) 17: mov %r14,0x10(%rbp) 1b: mov %r15,0x18(%rbp) 1f: xor %eax,%eax 21: mov %rax,0x20(%rbp) 25: xor %esi,%esi ; int key = 0; 27: mov %esi,-0x4(%rbp) ; if (!arg->sock) 2a: mov 0x8(%rdi),%rdi ; if (!arg->sock) 2e: cmp $0x0,%rdi 32: je 0x0000000000000070 34: mov %rbp,%rsi ; counts = bpf_map_lookup_elem(&btf_map, &key); 37: add $0xfffffffffffffffc,%rsi 3b: movabs $0xffff8881139d7480,%rdi 45: add $0x110,%rdi 4c: mov 0x0(%rsi),%eax 4f: cmp $0x4,%rax 53: jae 0x000000000000005e 55: shl $0x3,%rax 59: add %rdi,%rax 5c: jmp 0x0000000000000060 5e: xor %eax,%eax ; if (!counts) 60: cmp $0x0,%rax 64: je 0x0000000000000070 ; counts->v6++; 66: mov 0x4(%rax),%edi 69: add $0x1,%rdi 6d: mov %edi,0x4(%rax) 70: mov 0x0(%rbp),%rbx 74: mov 0x8(%rbp),%r13 78: mov 0x10(%rbp),%r14 7c: mov 0x18(%rbp),%r15 80: add $0x28,%rbp 84: leaveq 85: retq [...] With linum: [root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool prog dump jited pinned /sys/fs/bpf/test_btf_haskv linum int _dummy_tracepoint(struct dummy_tracepoint_args * arg): bpf_prog_b07ccb89267cf242__dummy_tracepoint: ; return test_long_fname_1(arg); [file:/data/users/kafai/fb-kernel/linux/tools/testing/selftests/bpf/test_btf_haskv.c line_num:54 line_col:9] 0: push %rbp 1: mov %rsp,%rbp 4: sub $0x28,%rsp b: sub $0x28,%rbp f: mov %rbx,0x0(%rbp) 13: mov %r13,0x8(%rbp) 17: mov %r14,0x10(%rbp) 1b: mov %r15,0x18(%rbp) 1f: xor %eax,%eax 21: mov %rax,0x20(%rbp) 25: callq 0x000000000000851e ; return test_long_fname_1(arg); [file:/data/users/kafai/fb-kernel/linux/tools/testing/selftests/bpf/test_btf_haskv.c line_num:54 line_col:2] 2a: xor %eax,%eax 2c: mov 0x0(%rbp),%rbx 30: mov 0x8(%rbp),%r13 34: mov 0x10(%rbp),%r14 38: mov 0x18(%rbp),%r15 3c: add $0x28,%rbp 40: leaveq 41: retq [...] Signed-off-by: Martin KaFai Lau Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/Build | 2 +- tools/lib/bpf/bpf_prog_linfo.c | 253 +++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 13 +++ tools/lib/bpf/libbpf.map | 4 + 4 files changed, 271 insertions(+), 1 deletion(-) create mode 100644 tools/lib/bpf/bpf_prog_linfo.c (limited to 'tools/lib/bpf') diff --git a/tools/lib/bpf/Build b/tools/lib/bpf/Build index 7bc31c905018..197b40f5b5c6 100644 --- a/tools/lib/bpf/Build +++ b/tools/lib/bpf/Build @@ -1 +1 @@ -libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o netlink.o +libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o netlink.o bpf_prog_linfo.o diff --git a/tools/lib/bpf/bpf_prog_linfo.c b/tools/lib/bpf/bpf_prog_linfo.c new file mode 100644 index 000000000000..b8af65145408 --- /dev/null +++ b/tools/lib/bpf/bpf_prog_linfo.c @@ -0,0 +1,253 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) +/* Copyright (c) 2018 Facebook */ + +#include +#include +#include +#include +#include "libbpf.h" + +#ifndef min +#define min(x, y) ((x) < (y) ? (x) : (y)) +#endif + +struct bpf_prog_linfo { + void *raw_linfo; + void *raw_jited_linfo; + __u32 *nr_jited_linfo_per_func; + __u32 *jited_linfo_func_idx; + __u32 nr_linfo; + __u32 nr_jited_func; + __u32 rec_size; + __u32 jited_rec_size; +}; + +static int dissect_jited_func(struct bpf_prog_linfo *prog_linfo, + const __u64 *ksym_func, const __u32 *ksym_len) +{ + __u32 nr_jited_func, nr_linfo; + const void *raw_jited_linfo; + const __u64 *jited_linfo; + __u64 last_jited_linfo; + /* + * Index to raw_jited_linfo: + * i: Index for searching the next ksym_func + * prev_i: Index to the last found ksym_func + */ + __u32 i, prev_i; + __u32 f; /* Index to ksym_func */ + + raw_jited_linfo = prog_linfo->raw_jited_linfo; + jited_linfo = raw_jited_linfo; + if (ksym_func[0] != *jited_linfo) + goto errout; + + prog_linfo->jited_linfo_func_idx[0] = 0; + nr_jited_func = prog_linfo->nr_jited_func; + nr_linfo = prog_linfo->nr_linfo; + + for (prev_i = 0, i = 1, f = 1; + i < nr_linfo && f < nr_jited_func; + i++) { + raw_jited_linfo += prog_linfo->jited_rec_size; + last_jited_linfo = *jited_linfo; + jited_linfo = raw_jited_linfo; + + if (ksym_func[f] == *jited_linfo) { + prog_linfo->jited_linfo_func_idx[f] = i; + + /* Sanity check */ + if (last_jited_linfo - ksym_func[f - 1] + 1 > + ksym_len[f - 1]) + goto errout; + + prog_linfo->nr_jited_linfo_per_func[f - 1] = + i - prev_i; + prev_i = i; + + /* + * The ksym_func[f] is found in jited_linfo. + * Look for the next one. + */ + f++; + } else if (*jited_linfo <= last_jited_linfo) { + /* Ensure the addr is increasing _within_ a func */ + goto errout; + } + } + + if (f != nr_jited_func) + goto errout; + + prog_linfo->nr_jited_linfo_per_func[nr_jited_func - 1] = + nr_linfo - prev_i; + + return 0; + +errout: + return -EINVAL; +} + +void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo) +{ + if (!prog_linfo) + return; + + free(prog_linfo->raw_linfo); + free(prog_linfo->raw_jited_linfo); + free(prog_linfo->nr_jited_linfo_per_func); + free(prog_linfo->jited_linfo_func_idx); + free(prog_linfo); +} + +struct bpf_prog_linfo *bpf_prog_linfo__new(const struct bpf_prog_info *info) +{ + struct bpf_prog_linfo *prog_linfo; + __u32 nr_linfo, nr_jited_func; + + nr_linfo = info->line_info_cnt; + + /* + * Test !info->line_info because the kernel may NULL + * the ptr if kernel.kptr_restrict is set. + */ + if (!nr_linfo || !info->line_info) + return NULL; + + /* + * The min size that bpf_prog_linfo has to access for + * searching purpose. + */ + if (info->line_info_rec_size < + offsetof(struct bpf_line_info, file_name_off)) + return NULL; + + prog_linfo = calloc(1, sizeof(*prog_linfo)); + if (!prog_linfo) + return NULL; + + /* Copy xlated line_info */ + prog_linfo->nr_linfo = nr_linfo; + prog_linfo->rec_size = info->line_info_rec_size; + prog_linfo->raw_linfo = malloc(nr_linfo * prog_linfo->rec_size); + if (!prog_linfo->raw_linfo) + goto err_free; + memcpy(prog_linfo->raw_linfo, (void *)(long)info->line_info, + nr_linfo * prog_linfo->rec_size); + + nr_jited_func = info->nr_jited_ksyms; + if (!nr_jited_func || + !info->jited_line_info || + info->jited_line_info_cnt != nr_linfo || + info->jited_line_info_rec_size < sizeof(__u64) || + info->nr_jited_func_lens != nr_jited_func || + !info->jited_ksyms || + !info->jited_func_lens) + /* Not enough info to provide jited_line_info */ + return prog_linfo; + + /* Copy jited_line_info */ + prog_linfo->nr_jited_func = nr_jited_func; + prog_linfo->jited_rec_size = info->jited_line_info_rec_size; + prog_linfo->raw_jited_linfo = malloc(nr_linfo * + prog_linfo->jited_rec_size); + if (!prog_linfo->raw_jited_linfo) + goto err_free; + memcpy(prog_linfo->raw_jited_linfo, + (void *)(long)info->jited_line_info, + nr_linfo * prog_linfo->jited_rec_size); + + /* Number of jited_line_info per jited func */ + prog_linfo->nr_jited_linfo_per_func = malloc(nr_jited_func * + sizeof(__u32)); + if (!prog_linfo->nr_jited_linfo_per_func) + goto err_free; + + /* + * For each jited func, + * the start idx to the "linfo" and "jited_linfo" array, + */ + prog_linfo->jited_linfo_func_idx = malloc(nr_jited_func * + sizeof(__u32)); + if (!prog_linfo->jited_linfo_func_idx) + goto err_free; + + if (dissect_jited_func(prog_linfo, + (__u64 *)(long)info->jited_ksyms, + (__u32 *)(long)info->jited_func_lens)) + goto err_free; + + return prog_linfo; + +err_free: + bpf_prog_linfo__free(prog_linfo); + return NULL; +} + +const struct bpf_line_info * +bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, + __u64 addr, __u32 func_idx, __u32 nr_skip) +{ + __u32 jited_rec_size, rec_size, nr_linfo, start, i; + const void *raw_jited_linfo, *raw_linfo; + const __u64 *jited_linfo; + + if (func_idx >= prog_linfo->nr_jited_func) + return NULL; + + nr_linfo = prog_linfo->nr_jited_linfo_per_func[func_idx]; + if (nr_skip >= nr_linfo) + return NULL; + + start = prog_linfo->jited_linfo_func_idx[func_idx] + nr_skip; + jited_rec_size = prog_linfo->jited_rec_size; + raw_jited_linfo = prog_linfo->raw_jited_linfo + + (start * jited_rec_size); + jited_linfo = raw_jited_linfo; + if (addr < *jited_linfo) + return NULL; + + nr_linfo -= nr_skip; + rec_size = prog_linfo->rec_size; + raw_linfo = prog_linfo->raw_linfo + (start * rec_size); + for (i = 0; i < nr_linfo; i++) { + if (addr < *jited_linfo) + break; + + raw_linfo += rec_size; + raw_jited_linfo += jited_rec_size; + jited_linfo = raw_jited_linfo; + } + + return raw_linfo - rec_size; +} + +const struct bpf_line_info * +bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, + __u32 insn_off, __u32 nr_skip) +{ + const struct bpf_line_info *linfo; + __u32 rec_size, nr_linfo, i; + const void *raw_linfo; + + nr_linfo = prog_linfo->nr_linfo; + if (nr_skip >= nr_linfo) + return NULL; + + rec_size = prog_linfo->rec_size; + raw_linfo = prog_linfo->raw_linfo + (nr_skip * rec_size); + linfo = raw_linfo; + if (insn_off < linfo->insn_off) + return NULL; + + nr_linfo -= nr_skip; + for (i = 0; i < nr_linfo; i++) { + if (insn_off < linfo->insn_off) + break; + + raw_linfo += rec_size; + linfo = raw_linfo; + } + + return raw_linfo - rec_size; +} diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index f30c3d07bb7d..5f68d7b75215 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -342,6 +342,19 @@ int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex, int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie); +struct bpf_prog_linfo; +struct bpf_prog_info; + +LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); +LIBBPF_API struct bpf_prog_linfo * +bpf_prog_linfo__new(const struct bpf_prog_info *info); +LIBBPF_API const struct bpf_line_info * +bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, + __u64 addr, __u32 func_idx, __u32 nr_skip); +LIBBPF_API const struct bpf_line_info * +bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, + __u32 insn_off, __u32 nr_skip); + #ifdef __cplusplus } /* extern "C" */ #endif diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 8deff22d61bb..cd02cd4e2cc3 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -99,6 +99,10 @@ LIBBPF_0.0.1 { bpf_program__unload; bpf_program__unpin; bpf_program__unpin_instance; + bpf_prog_linfo__free; + bpf_prog_linfo__new; + bpf_prog_linfo__lfind_addr_func; + bpf_prog_linfo__lfind; bpf_raw_tracepoint_open; bpf_set_link_xdp_fd; bpf_task_fd_query; 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