From fa7f17d066bd0996b930b664aa0ed1f213fc1828 Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Mon, 4 Oct 2021 17:48:57 +0800 Subject: bpf/selftests: Add test for writable bare tracepoint Add a writable bare tracepoint in bpf_testmod module, and trigger its calling when reading /sys/kernel/bpf_testmod with a specific buffer length. The reading will return the value in writable context if the early return flag is enabled in writable context. Signed-off-by: Hou Tao Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211004094857.30868-4-hotforest@gmail.com --- .../selftests/bpf/bpf_testmod/bpf_testmod-events.h | 15 ++++++++++ .../selftests/bpf/bpf_testmod/bpf_testmod.c | 10 +++++++ .../selftests/bpf/bpf_testmod/bpf_testmod.h | 5 ++++ .../selftests/bpf/prog_tests/module_attach.c | 35 ++++++++++++++++++++++ .../selftests/bpf/progs/test_module_attach.c | 14 +++++++++ tools/testing/selftests/bpf/test_progs.c | 4 +-- tools/testing/selftests/bpf/test_progs.h | 2 ++ 7 files changed, 83 insertions(+), 2 deletions(-) (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h index 89c6d58e5dd6..11ee801e75e7 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h @@ -34,6 +34,21 @@ DECLARE_TRACE(bpf_testmod_test_write_bare, TP_ARGS(task, ctx) ); +#undef BPF_TESTMOD_DECLARE_TRACE +#ifdef DECLARE_TRACE_WRITABLE +#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \ + DECLARE_TRACE_WRITABLE(call, PARAMS(proto), PARAMS(args), size) +#else +#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \ + DECLARE_TRACE(call, PARAMS(proto), PARAMS(args)) +#endif + +BPF_TESTMOD_DECLARE_TRACE(bpf_testmod_test_writable_bare, + TP_PROTO(struct bpf_testmod_test_writable_ctx *ctx), + TP_ARGS(ctx), + sizeof(struct bpf_testmod_test_writable_ctx) +); + #endif /* _BPF_TESTMOD_EVENTS_H */ #undef TRACE_INCLUDE_PATH diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index b892948dc134..5d52ea2768df 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -50,6 +50,16 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj, if (bpf_testmod_loop_test(101) > 100) trace_bpf_testmod_test_read(current, &ctx); + /* Magic number to enable writable tp */ + if (len == 64) { + struct bpf_testmod_test_writable_ctx writable = { + .val = 1024, + }; + trace_bpf_testmod_test_writable_bare(&writable); + if (writable.early_ret) + return snprintf(buf, len, "%d\n", writable.val); + } + return -EIO; /* always fail */ } EXPORT_SYMBOL(bpf_testmod_test_read); diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h index b3892dc40111..0d71e2607832 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h @@ -17,4 +17,9 @@ struct bpf_testmod_test_write_ctx { size_t len; }; +struct bpf_testmod_test_writable_ctx { + bool early_ret; + int val; +}; + #endif /* _BPF_TESTMOD_H */ diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c b/tools/testing/selftests/bpf/prog_tests/module_attach.c index 1797a6e4d6d8..6d0e50dcf47c 100644 --- a/tools/testing/selftests/bpf/prog_tests/module_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c @@ -2,10 +2,36 @@ /* Copyright (c) 2020 Facebook */ #include +#include #include "test_module_attach.skel.h" static int duration; +static int trigger_module_test_writable(int *val) +{ + int fd, err; + char buf[65]; + ssize_t rd; + + fd = open(BPF_TESTMOD_TEST_FILE, O_RDONLY); + err = -errno; + if (!ASSERT_GE(fd, 0, "testmode_file_open")) + return err; + + rd = read(fd, buf, sizeof(buf) - 1); + err = -errno; + if (!ASSERT_GT(rd, 0, "testmod_file_rd_val")) { + close(fd); + return err; + } + + buf[rd] = '\0'; + *val = strtol(buf, NULL, 0); + close(fd); + + return 0; +} + static int delete_module(const char *name, int flags) { return syscall(__NR_delete_module, name, flags); @@ -19,6 +45,7 @@ void test_module_attach(void) struct test_module_attach__bss *bss; struct bpf_link *link; int err; + int writable_val = 0; skel = test_module_attach__open(); if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) @@ -51,6 +78,14 @@ void test_module_attach(void) ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet"); ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret"); + bss->raw_tp_writable_bare_early_ret = true; + bss->raw_tp_writable_bare_out_val = 0xf1f2f3f4; + ASSERT_OK(trigger_module_test_writable(&writable_val), + "trigger_writable"); + ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test_in"); + ASSERT_EQ(bss->raw_tp_writable_bare_out_val, writable_val, + "writable_test_out"); + test_module_attach__detach(skel); /* attach fentry/fexit and make sure it get's module reference */ diff --git a/tools/testing/selftests/bpf/progs/test_module_attach.c b/tools/testing/selftests/bpf/progs/test_module_attach.c index bd37ceec5587..b36857093f71 100644 --- a/tools/testing/selftests/bpf/progs/test_module_attach.c +++ b/tools/testing/selftests/bpf/progs/test_module_attach.c @@ -27,6 +27,20 @@ int BPF_PROG(handle_raw_tp_bare, return 0; } +int raw_tp_writable_bare_in_val = 0; +int raw_tp_writable_bare_early_ret = 0; +int raw_tp_writable_bare_out_val = 0; + +SEC("raw_tp.w/bpf_testmod_test_writable_bare") +int BPF_PROG(handle_raw_tp_writable_bare, + struct bpf_testmod_test_writable_ctx *writable) +{ + raw_tp_writable_bare_in_val = writable->val; + writable->early_ret = raw_tp_writable_bare_early_ret; + writable->val = raw_tp_writable_bare_out_val; + return 0; +} + __u32 tp_btf_read_sz = 0; SEC("tp_btf/bpf_testmod_test_read") diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index 2ed01f615d20..007b4ff85fea 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -747,7 +747,7 @@ int trigger_module_test_read(int read_sz) { int fd, err; - fd = open("/sys/kernel/bpf_testmod", O_RDONLY); + fd = open(BPF_TESTMOD_TEST_FILE, O_RDONLY); err = -errno; if (!ASSERT_GE(fd, 0, "testmod_file_open")) return err; @@ -769,7 +769,7 @@ int trigger_module_test_write(int write_sz) memset(buf, 'a', write_sz); buf[write_sz-1] = '\0'; - fd = open("/sys/kernel/bpf_testmod", O_WRONLY); + fd = open(BPF_TESTMOD_TEST_FILE, O_WRONLY); err = -errno; if (!ASSERT_GE(fd, 0, "testmod_file_open")) { free(buf); diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h index 94bef0aa74cf..9b8a1810b700 100644 --- a/tools/testing/selftests/bpf/test_progs.h +++ b/tools/testing/selftests/bpf/test_progs.h @@ -301,3 +301,5 @@ int trigger_module_test_write(int write_sz); #else #define SYS_NANOSLEEP_KPROBE_NAME "sys_nanosleep" #endif + +#define BPF_TESTMOD_TEST_FILE "/sys/kernel/bpf_testmod" -- cgit v1.2.3-59-g8ed1b