| Message ID | 1643645554-28723-5-git-send-email-alan.maguire@oracle.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | libbpf: name-based u[ret]probe attach | expand |
On Mon, Jan 31, 2022 at 8:13 AM Alan Maguire <alan.maguire@oracle.com> wrote: > > add tests that verify attaching by name for > > 1. local functions in a program > 2. library functions in a shared object; and > 3. library functions in a program > > ...succeed for uprobe and uretprobes using new "func_name" > option for bpf_program__attach_uprobe_opts(). Also verify > auto-attach works where uprobe, path to binary and function > name are specified, but fails with -ESRCH when the format > does not match (the latter is to support backwards-compatibility). > > Signed-off-by: Alan Maguire <alan.maguire@oracle.com> > --- > .../selftests/bpf/prog_tests/attach_probe.c | 89 +++++++++++++++++++++- > .../selftests/bpf/progs/test_attach_probe.c | 37 +++++++++ > 2 files changed, 123 insertions(+), 3 deletions(-) > [...] > if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res", > "wrong uprobe res: %d\n", skel->bss->uprobe_res)) > goto cleanup; > @@ -110,7 +179,21 @@ void test_attach_probe(void) > "wrong uretprobe res: %d\n", skel->bss->uretprobe_res)) > goto cleanup; > > + if (CHECK(skel->bss->uprobe_byname_res != 5, "check_uprobe_byname_res", > + "wrong uprobe byname res: %d\n", skel->bss->uprobe_byname_res)) > + goto cleanup; > + if (CHECK(skel->bss->uretprobe_byname_res != 6, "check_uretprobe_byname_res", > + "wrong uretprobe byname res: %d\n", skel->bss->uretprobe_byname_res)) > + goto cleanup; > + if (CHECK(skel->bss->uprobe_byname2_res != 7, "check_uprobe_byname2_res", > + "wrong uprobe byname2 res: %d\n", skel->bss->uprobe_byname2_res)) > + goto cleanup; > + if (CHECK(skel->bss->uretprobe_byname2_res != 8, "check_uretprobe_byname2_res", > + "wrong uretprobe byname2 res: %d\n", skel->bss->uretprobe_byname2_res)) > + goto cleanup; > + Please don't use CHECK()s for new code, only ASSERT_xxx() for new code. > cleanup: > + free(libc_path); > test_attach_probe__destroy(skel); > ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup"); > } > diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c > index 8056a4c..9942461c 100644 > --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c > +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c > @@ -10,6 +10,10 @@ > int kretprobe_res = 0; > int uprobe_res = 0; > int uretprobe_res = 0; > +int uprobe_byname_res = 0; > +int uretprobe_byname_res = 0; > +int uprobe_byname2_res = 0; > +int uretprobe_byname2_res = 0; > > SEC("kprobe/sys_nanosleep") > int handle_kprobe(struct pt_regs *ctx) > @@ -39,4 +43,37 @@ int handle_uretprobe(struct pt_regs *ctx) > return 0; > } > > +SEC("uprobe/trigger_func_byname") > +int handle_uprobe_byname(struct pt_regs *ctx) > +{ > + uprobe_byname_res = 5; > + return 0; > +} > + > +/* use auto-attach format for section definition. */ > +SEC("uretprobe//proc/self/exe:trigger_func2") > +int handle_uretprobe_byname(struct pt_regs *ctx) > +{ > + uretprobe_byname_res = 6; > + return 0; > +} > + > +SEC("uprobe/trigger_func_byname2") > +int handle_uprobe_byname2(struct pt_regs *ctx) this one is for malloc, so why SEC() doesn't reflect this? It would be great to also have (probably separate) selftest for auto-attach logic of skeleton for uprobes. I'd add a separate uprobe-specific selftests, there is plenty to test without having kprobes intermingled. > +{ > + unsigned int size = PT_REGS_PARM1(ctx); > + > + /* verify malloc size */ > + if (size == 1) > + uprobe_byname2_res = 7; > + return 0; > +} > + > +SEC("uretprobe/trigger_func_byname2") > +int handle_uretprobe_byname2(struct pt_regs *ctx) > +{ > + uretprobe_byname2_res = 8; > + return 0; > +} > + > char _license[] SEC("license") = "GPL"; > -- > 1.8.3.1 >
On Mon, Jan 31, 2022 at 04:12:34PM +0000, Alan Maguire wrote: SNIP > + /* verify auto-attach fails for old-style uprobe definition */ > + uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname); > + if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -ESRCH, > + "auto-attach should fail for old-style name")) > + goto cleanup; > + > + uprobe_opts.func_name = "trigger_func2"; > + uprobe_opts.retprobe = false; > + uprobe_opts.ref_ctr_offset = 0; > + skel->links.handle_uprobe_byname = > + bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname, > + 0 /* this pid */, > + "/proc/self/exe", > + 0, &uprobe_opts); > + if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname")) > + goto cleanup; > + > + /* verify auto-attach works */ > + skel->links.handle_uretprobe_byname = > + bpf_program__attach(skel->progs.handle_uretprobe_byname); > + if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname")) > + goto cleanup; > + > + /* test attach by name for a library function, using the library > + * as the binary argument. To do this, find path to libc used > + * by test_progs via /proc/self/maps. > + */ > + libc_path = get_lib_path("libc-"); hi, I'm getting crash in here because the libc line in maps for me looks like: /usr/lib64/libc.so.6 plus the check below will let through null pointer > + if (!ASSERT_OK_PTR(libc_path, "get path to libc")) > + goto cleanup; > + if (!ASSERT_NEQ(strstr(libc_path, "libc-"), NULL, "find libc path in /proc/self/maps")) > + goto cleanup; and when I tried to use 'libc' in here, it does not crash but libc_path holds the whole maps line: 7fdbef31d000-7fdbef349000 r--p 00000000 fd:01 201656665 /usr/lib64/libc.so.6 so it fails, I guess there's some issue in get_lib_path jirka
diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index d48f6e5..127c347 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -11,6 +11,12 @@ static void trigger_func(void) asm volatile (""); } +/* attach point for byname uprobe */ +static void trigger_func2(void) +{ + asm volatile (""); +} + void test_attach_probe(void) { DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); @@ -19,7 +25,10 @@ void test_attach_probe(void) struct bpf_link *uprobe_link, *uretprobe_link; struct test_attach_probe* skel; ssize_t uprobe_offset, ref_ctr_offset; + struct bpf_link *uprobe_err_link; + char *libc_path; bool legacy; + char *mem; /* Check if new-style kprobe/uprobe API is supported. * Kernels that support new FD-based kprobe and uprobe BPF attachment @@ -90,9 +99,72 @@ void test_attach_probe(void) goto cleanup; skel->links.handle_uretprobe = uretprobe_link; + /* verify auto-attach fails for old-style uprobe definition */ + uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname); + if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -ESRCH, + "auto-attach should fail for old-style name")) + goto cleanup; + + uprobe_opts.func_name = "trigger_func2"; + uprobe_opts.retprobe = false; + uprobe_opts.ref_ctr_offset = 0; + skel->links.handle_uprobe_byname = + bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname, + 0 /* this pid */, + "/proc/self/exe", + 0, &uprobe_opts); + if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname")) + goto cleanup; + + /* verify auto-attach works */ + skel->links.handle_uretprobe_byname = + bpf_program__attach(skel->progs.handle_uretprobe_byname); + if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname")) + goto cleanup; + + /* test attach by name for a library function, using the library + * as the binary argument. To do this, find path to libc used + * by test_progs via /proc/self/maps. + */ + libc_path = get_lib_path("libc-"); + if (!ASSERT_OK_PTR(libc_path, "get path to libc")) + goto cleanup; + if (!ASSERT_NEQ(strstr(libc_path, "libc-"), NULL, "find libc path in /proc/self/maps")) + goto cleanup; + + uprobe_opts.func_name = "malloc"; + uprobe_opts.retprobe = false; + skel->links.handle_uprobe_byname2 = + bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2, + 0 /* this pid */, + libc_path, + 0, &uprobe_opts); + if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2")) + goto cleanup; + + uprobe_opts.func_name = "free"; + uprobe_opts.retprobe = true; + skel->links.handle_uretprobe_byname2 = + bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2, + -1 /* any pid */, + "/proc/self/exe", + 0, &uprobe_opts); + if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2")) + goto cleanup; + /* trigger & validate kprobe && kretprobe */ usleep(1); + /* trigger & validate shared library u[ret]probes attached by name */ + mem = malloc(1); + free(mem); + + /* trigger & validate uprobe & uretprobe */ + trigger_func(); + + /* trigger & validate uprobe attached by name */ + trigger_func2(); + if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res", "wrong kprobe res: %d\n", skel->bss->kprobe_res)) goto cleanup; @@ -100,9 +172,6 @@ void test_attach_probe(void) "wrong kretprobe res: %d\n", skel->bss->kretprobe_res)) goto cleanup; - /* trigger & validate uprobe & uretprobe */ - trigger_func(); - if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res", "wrong uprobe res: %d\n", skel->bss->uprobe_res)) goto cleanup; @@ -110,7 +179,21 @@ void test_attach_probe(void) "wrong uretprobe res: %d\n", skel->bss->uretprobe_res)) goto cleanup; + if (CHECK(skel->bss->uprobe_byname_res != 5, "check_uprobe_byname_res", + "wrong uprobe byname res: %d\n", skel->bss->uprobe_byname_res)) + goto cleanup; + if (CHECK(skel->bss->uretprobe_byname_res != 6, "check_uretprobe_byname_res", + "wrong uretprobe byname res: %d\n", skel->bss->uretprobe_byname_res)) + goto cleanup; + if (CHECK(skel->bss->uprobe_byname2_res != 7, "check_uprobe_byname2_res", + "wrong uprobe byname2 res: %d\n", skel->bss->uprobe_byname2_res)) + goto cleanup; + if (CHECK(skel->bss->uretprobe_byname2_res != 8, "check_uretprobe_byname2_res", + "wrong uretprobe byname2 res: %d\n", skel->bss->uretprobe_byname2_res)) + goto cleanup; + cleanup: + free(libc_path); test_attach_probe__destroy(skel); ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup"); } diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c index 8056a4c..9942461c 100644 --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -10,6 +10,10 @@ int kretprobe_res = 0; int uprobe_res = 0; int uretprobe_res = 0; +int uprobe_byname_res = 0; +int uretprobe_byname_res = 0; +int uprobe_byname2_res = 0; +int uretprobe_byname2_res = 0; SEC("kprobe/sys_nanosleep") int handle_kprobe(struct pt_regs *ctx) @@ -39,4 +43,37 @@ int handle_uretprobe(struct pt_regs *ctx) return 0; } +SEC("uprobe/trigger_func_byname") +int handle_uprobe_byname(struct pt_regs *ctx) +{ + uprobe_byname_res = 5; + return 0; +} + +/* use auto-attach format for section definition. */ +SEC("uretprobe//proc/self/exe:trigger_func2") +int handle_uretprobe_byname(struct pt_regs *ctx) +{ + uretprobe_byname_res = 6; + return 0; +} + +SEC("uprobe/trigger_func_byname2") +int handle_uprobe_byname2(struct pt_regs *ctx) +{ + unsigned int size = PT_REGS_PARM1(ctx); + + /* verify malloc size */ + if (size == 1) + uprobe_byname2_res = 7; + return 0; +} + +SEC("uretprobe/trigger_func_byname2") +int handle_uretprobe_byname2(struct pt_regs *ctx) +{ + uretprobe_byname2_res = 8; + return 0; +} + char _license[] SEC("license") = "GPL";
add tests that verify attaching by name for 1. local functions in a program 2. library functions in a shared object; and 3. library functions in a program ...succeed for uprobe and uretprobes using new "func_name" option for bpf_program__attach_uprobe_opts(). Also verify auto-attach works where uprobe, path to binary and function name are specified, but fails with -ESRCH when the format does not match (the latter is to support backwards-compatibility). Signed-off-by: Alan Maguire <alan.maguire@oracle.com> --- .../selftests/bpf/prog_tests/attach_probe.c | 89 +++++++++++++++++++++- .../selftests/bpf/progs/test_attach_probe.c | 37 +++++++++ 2 files changed, 123 insertions(+), 3 deletions(-)