| Message ID | 20210916135511.3787194-4-houtao1@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3] bpf: support writable context for bare tracepoint | expand |
Hi, On 9/17/2021 7:46 AM, Yonghong Song wrote: > > > On 9/16/21 6:55 AM, Hou Tao wrote: >> 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 patch cannot be applied cleanly with bpf-next tree. > Please rebase and resubmit. Will do > >> >> Signed-off-by: Hou Tao <houtao1@huawei.com> >> --- >> .../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 | 40 ++++++++++++++++++- >> .../selftests/bpf/progs/test_module_attach.c | 14 +++++++ >> 5 files changed, 82 insertions(+), 2 deletions(-) >> >> 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 141d8da687d2..3d3fb16eaf8c 100644 >> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c >> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c >> @@ -26,6 +26,16 @@ bpf_testmod_test_read(struct file *file, struct kobject >> *kobj, >> trace_bpf_testmod_test_read(current, &ctx); >> + /* Magic number to enable writable tp */ >> + if (len == 1024) { >> + struct bpf_testmod_test_writable_ctx writable = { >> + .val = 1024, >> + }; >> + trace_bpf_testmod_test_writable_bare(&writable); >> + if (writable.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..553d94214aa6 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 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 d85a69b7ce44..5565bcab1531 100644 >> --- a/tools/testing/selftests/bpf/prog_tests/module_attach.c >> +++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c >> @@ -6,11 +6,39 @@ >> static int duration; >> +#define BPF_TESTMOD_PATH "/sys/kernel/bpf_testmod" >> + >> +static int trigger_module_test_writable(int *val) >> +{ >> + int fd, err; >> + char buf[1025]; > > Not critical, but do you need such a big stack size? > Maybe smaller one? 65 is also fine. > >> + ssize_t rd; >> + >> + fd = open(BPF_TESTMOD_PATH, O_RDONLY); >> + err = -errno; >> + if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) >> + return err; >> + >> + rd = read(fd, buf, sizeof(buf) - 1); >> + err = rd < 0 ? -errno : -EIO; >> + if (CHECK(rd <= 0, "testmod_file_read", "failed: %d\n", err)) { > > Please use ASSERT_* macros. You can take a look at other self tests. The reason using CHECK instead of ASSERT is we can output the errno if read() fails. >> + close(fd); >> + return err; >> + } > > Put one blank line here and remove the following three blank lines. Will do. > >> + buf[rd] = '\0'; >> + >> + *val = strtol(buf, NULL, 0); >> + >> + close(fd); >> + >> + return 0; >> +} >> + >> static int trigger_module_test_read(int read_sz) >> { >> int fd, err; >> - fd = open("/sys/kernel/bpf_testmod", O_RDONLY); >> + fd = open(BPF_TESTMOD_PATH, O_RDONLY); >> err = -errno; >> if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) >> return err; >> @@ -32,7 +60,7 @@ static 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_PATH, O_WRONLY); >> err = -errno; >> if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) { >> free(buf); >> @@ -58,6 +86,7 @@ void test_module_attach(void) >> struct test_module_attach__bss *bss; >> struct bpf_link *link; >> int err; >> + int writable_val; >> skel = test_module_attach__open(); >> if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) >> @@ -90,6 +119,13 @@ 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_ret = 1; >> + bss->raw_tp_writable_bare_val = 511; >> + writable_val = 0; >> + ASSERT_OK(trigger_module_test_writable(&writable_val), "trigger_writable"); >> + ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test"); >> + ASSERT_EQ(bss->raw_tp_writable_bare_val, writable_val, "writable_test"); >> + >> 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..4f5c780fcd21 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_ret = 0; >> +int raw_tp_writable_bare_val = 0; >> + >> +SEC("raw_tp_writable/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->ret = raw_tp_writable_bare_ret; >> + writable->val = raw_tp_writable_bare_val; >> + return 0; >> +} >> + >> __u32 tp_btf_read_sz = 0; >> SEC("tp_btf/bpf_testmod_test_read") >> > .
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 141d8da687d2..3d3fb16eaf8c 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -26,6 +26,16 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj, trace_bpf_testmod_test_read(current, &ctx); + /* Magic number to enable writable tp */ + if (len == 1024) { + struct bpf_testmod_test_writable_ctx writable = { + .val = 1024, + }; + trace_bpf_testmod_test_writable_bare(&writable); + if (writable.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..553d94214aa6 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 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 d85a69b7ce44..5565bcab1531 100644 --- a/tools/testing/selftests/bpf/prog_tests/module_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c @@ -6,11 +6,39 @@ static int duration; +#define BPF_TESTMOD_PATH "/sys/kernel/bpf_testmod" + +static int trigger_module_test_writable(int *val) +{ + int fd, err; + char buf[1025]; + ssize_t rd; + + fd = open(BPF_TESTMOD_PATH, O_RDONLY); + err = -errno; + if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) + return err; + + rd = read(fd, buf, sizeof(buf) - 1); + err = rd < 0 ? -errno : -EIO; + if (CHECK(rd <= 0, "testmod_file_read", "failed: %d\n", err)) { + close(fd); + return err; + } + buf[rd] = '\0'; + + *val = strtol(buf, NULL, 0); + + close(fd); + + return 0; +} + static int trigger_module_test_read(int read_sz) { int fd, err; - fd = open("/sys/kernel/bpf_testmod", O_RDONLY); + fd = open(BPF_TESTMOD_PATH, O_RDONLY); err = -errno; if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) return err; @@ -32,7 +60,7 @@ static 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_PATH, O_WRONLY); err = -errno; if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) { free(buf); @@ -58,6 +86,7 @@ void test_module_attach(void) struct test_module_attach__bss *bss; struct bpf_link *link; int err; + int writable_val; skel = test_module_attach__open(); if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) @@ -90,6 +119,13 @@ 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_ret = 1; + bss->raw_tp_writable_bare_val = 511; + writable_val = 0; + ASSERT_OK(trigger_module_test_writable(&writable_val), "trigger_writable"); + ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test"); + ASSERT_EQ(bss->raw_tp_writable_bare_val, writable_val, "writable_test"); + 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..4f5c780fcd21 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_ret = 0; +int raw_tp_writable_bare_val = 0; + +SEC("raw_tp_writable/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->ret = raw_tp_writable_bare_ret; + writable->val = raw_tp_writable_bare_val; + return 0; +} + __u32 tp_btf_read_sz = 0; SEC("tp_btf/bpf_testmod_test_read")
Add a writable bare tracepoint in bpf_testmod module, and trigger its calling when reading /sys/kernel/bpf_testmod with a specific buffer length. Signed-off-by: Hou Tao <houtao1@huawei.com> --- .../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 | 40 ++++++++++++++++++- .../selftests/bpf/progs/test_module_attach.c | 14 +++++++ 5 files changed, 82 insertions(+), 2 deletions(-)