From f8b299bc6a0f8695d4005ecff29773c79a1d29af Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Mon, 6 Mar 2023 14:48:31 +0800 Subject: [PATCH 1/3] libbpf: Add support to set kprobe/uprobe attach mode By default, libbpf will attach the kprobe/uprobe BPF program in the latest mode that supported by kernel. In this patch, we add the support to let users manually attach kprobe/uprobe in legacy or perf mode. There are 3 mode that supported by the kernel to attach kprobe/uprobe: LEGACY: create perf event in legacy way and don't use bpf_link PERF: create perf event with perf_event_open() and don't use bpf_link Signed-off-by: Menglong Dong Signed-off-by: Andrii Nakryiko Reviewed-by: Biao Jiang Link: create perf event with perf_event_open() and use bpf_link Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com/ Link: https://lore.kernel.org/bpf/20230306064833.7932-2-imagedong@tencent.com Users now can manually choose the mode with bpf_program__attach_uprobe_opts()/bpf_program__attach_kprobe_opts(). --- tools/lib/bpf/libbpf.c | 48 +++++++++++++++++++++++++++++++++++++++- tools/lib/bpf/libbpf.h | 50 +++++++++++++++++++++++++++++++----------- 2 files changed, 84 insertions(+), 14 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index dacaae31b76a5..a557718401e4c 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9724,6 +9724,7 @@ struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *p char errmsg[STRERR_BUFSIZE]; struct bpf_link_perf *link; int prog_fd, link_fd = -1, err; + bool force_ioctl_attach; if (!OPTS_VALID(opts, bpf_perf_event_opts)) return libbpf_err_ptr(-EINVAL); @@ -9747,7 +9748,8 @@ struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *p link->link.dealloc = &bpf_link_perf_dealloc; link->perf_event_fd = pfd; - if (kernel_supports(prog->obj, FEAT_PERF_LINK)) { + force_ioctl_attach = OPTS_GET(opts, force_ioctl_attach, false); + if (kernel_supports(prog->obj, FEAT_PERF_LINK) && !force_ioctl_attach) { DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts, .perf_event.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0)); @@ -10106,6 +10108,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, const struct bpf_kprobe_opts *opts) { DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); + enum probe_attach_mode attach_mode; char errmsg[STRERR_BUFSIZE]; char *legacy_probe = NULL; struct bpf_link *link; @@ -10116,11 +10119,32 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, if (!OPTS_VALID(opts, bpf_kprobe_opts)) return libbpf_err_ptr(-EINVAL); + attach_mode = OPTS_GET(opts, attach_mode, PROBE_ATTACH_MODE_DEFAULT); retprobe = OPTS_GET(opts, retprobe, false); offset = OPTS_GET(opts, offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); legacy = determine_kprobe_perf_type() < 0; + switch (attach_mode) { + case PROBE_ATTACH_MODE_LEGACY: + legacy = true; + pe_opts.force_ioctl_attach = true; + break; + case PROBE_ATTACH_MODE_PERF: + if (legacy) + return libbpf_err_ptr(-ENOTSUP); + pe_opts.force_ioctl_attach = true; + break; + case PROBE_ATTACH_MODE_LINK: + if (legacy || !kernel_supports(prog->obj, FEAT_PERF_LINK)) + return libbpf_err_ptr(-ENOTSUP); + break; + case PROBE_ATTACH_MODE_DEFAULT: + break; + default: + return libbpf_err_ptr(-EINVAL); + } + if (!legacy) { pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name, offset, @@ -10852,6 +10876,7 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, const char *archive_path = NULL, *archive_sep = NULL; char errmsg[STRERR_BUFSIZE], *legacy_probe = NULL; DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); + enum probe_attach_mode attach_mode; char full_path[PATH_MAX]; struct bpf_link *link; size_t ref_ctr_off; @@ -10862,6 +10887,7 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, if (!OPTS_VALID(opts, bpf_uprobe_opts)) return libbpf_err_ptr(-EINVAL); + attach_mode = OPTS_GET(opts, attach_mode, PROBE_ATTACH_MODE_DEFAULT); retprobe = OPTS_GET(opts, retprobe, false); ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); @@ -10903,6 +10929,26 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, } legacy = determine_uprobe_perf_type() < 0; + switch (attach_mode) { + case PROBE_ATTACH_MODE_LEGACY: + legacy = true; + pe_opts.force_ioctl_attach = true; + break; + case PROBE_ATTACH_MODE_PERF: + if (legacy) + return libbpf_err_ptr(-ENOTSUP); + pe_opts.force_ioctl_attach = true; + break; + case PROBE_ATTACH_MODE_LINK: + if (legacy || !kernel_supports(prog->obj, FEAT_PERF_LINK)) + return libbpf_err_ptr(-ENOTSUP); + break; + case PROBE_ATTACH_MODE_DEFAULT: + break; + default: + return libbpf_err_ptr(-EINVAL); + } + if (!legacy) { pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path, func_offset, pid, ref_ctr_off); diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 2efd80f6f7b92..db4992a036f8b 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -447,12 +447,15 @@ LIBBPF_API struct bpf_link * bpf_program__attach(const struct bpf_program *prog); struct bpf_perf_event_opts { - /* size of this struct, for forward/backward compatiblity */ + /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; + /* don't use BPF link when attach BPF program */ + bool force_ioctl_attach; + size_t :0; }; -#define bpf_perf_event_opts__last_field bpf_cookie +#define bpf_perf_event_opts__last_field force_ioctl_attach LIBBPF_API struct bpf_link * bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd); @@ -461,8 +464,25 @@ LIBBPF_API struct bpf_link * bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, const struct bpf_perf_event_opts *opts); +/** + * enum probe_attach_mode - the mode to attach kprobe/uprobe + * + * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will + * be returned if it is not supported by the kernel. + */ +enum probe_attach_mode { + /* attach probe in latest supported mode by kernel */ + PROBE_ATTACH_MODE_DEFAULT = 0, + /* attach probe in legacy mode, using debugfs/tracefs */ + PROBE_ATTACH_MODE_LEGACY, + /* create perf event with perf_event_open() syscall */ + PROBE_ATTACH_MODE_PERF, + /* attach probe with BPF link */ + PROBE_ATTACH_MODE_LINK, +}; + struct bpf_kprobe_opts { - /* size of this struct, for forward/backward compatiblity */ + /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; @@ -470,9 +490,11 @@ struct bpf_kprobe_opts { size_t offset; /* kprobe is return probe */ bool retprobe; + /* kprobe attach mode */ + enum probe_attach_mode attach_mode; size_t :0; }; -#define bpf_kprobe_opts__last_field retprobe +#define bpf_kprobe_opts__last_field attach_mode LIBBPF_API struct bpf_link * bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, @@ -506,7 +528,7 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, const struct bpf_kprobe_multi_opts *opts); struct bpf_ksyscall_opts { - /* size of this struct, for forward/backward compatiblity */ + /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; @@ -552,7 +574,7 @@ bpf_program__attach_ksyscall(const struct bpf_program *prog, const struct bpf_ksyscall_opts *opts); struct bpf_uprobe_opts { - /* size of this struct, for forward/backward compatiblity */ + /* size of this struct, for forward/backward compatibility */ size_t sz; /* offset of kernel reference counted USDT semaphore, added in * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") @@ -570,9 +592,11 @@ struct bpf_uprobe_opts { * binary_path. */ const char *func_name; + /* uprobe attach mode */ + enum probe_attach_mode attach_mode; size_t :0; }; -#define bpf_uprobe_opts__last_field func_name +#define bpf_uprobe_opts__last_field attach_mode /** * @brief **bpf_program__attach_uprobe()** attaches a BPF program @@ -646,7 +670,7 @@ bpf_program__attach_usdt(const struct bpf_program *prog, const struct bpf_usdt_opts *opts); struct bpf_tracepoint_opts { - /* size of this struct, for forward/backward compatiblity */ + /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; @@ -1110,7 +1134,7 @@ struct user_ring_buffer; typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size); struct ring_buffer_opts { - size_t sz; /* size of this struct, for forward/backward compatiblity */ + size_t sz; /* size of this struct, for forward/backward compatibility */ }; #define ring_buffer_opts__last_field sz @@ -1475,7 +1499,7 @@ LIBBPF_API void bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s); struct gen_loader_opts { - size_t sz; /* size of this struct, for forward/backward compatiblity */ + size_t sz; /* size of this struct, for forward/backward compatibility */ const char *data; const char *insns; __u32 data_sz; @@ -1493,13 +1517,13 @@ enum libbpf_tristate { }; struct bpf_linker_opts { - /* size of this struct, for forward/backward compatiblity */ + /* size of this struct, for forward/backward compatibility */ size_t sz; }; #define bpf_linker_opts__last_field sz struct bpf_linker_file_opts { - /* size of this struct, for forward/backward compatiblity */ + /* size of this struct, for forward/backward compatibility */ size_t sz; }; #define bpf_linker_file_opts__last_field sz @@ -1542,7 +1566,7 @@ typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cook struct bpf_link **link); struct libbpf_prog_handler_opts { - /* size of this struct, for forward/backward compatiblity */ + /* size of this struct, for forward/backward compatibility */ size_t sz; /* User-provided value that is passed to prog_setup_fn, * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to From 7391ec6391e2b129aeaee5462487c404f61157aa Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Mon, 6 Mar 2023 14:48:32 +0800 Subject: [PATCH 2/3] selftests/bpf: Split test_attach_probe into multi subtests In order to adapt to the older kernel, now we split the "attach_probe" testing into multi subtests: manual // manual attach tests for kprobe/uprobe auto // auto-attach tests for kprobe and uprobe kprobe-sleepable // kprobe sleepable test uprobe-lib // uprobe tests for library function by name uprobe-sleepable // uprobe sleepable test uprobe-ref_ctr // uprobe ref_ctr test As sleepable kprobe needs to set BPF_F_SLEEPABLE flag before loading, we need to move it to a stand alone skel file, in case of it is not supported by kernel and make the whole loading fail. Therefore, we can only enable part of the subtests for older kernel. Signed-off-by: Menglong Dong Signed-off-by: Andrii Nakryiko Reviewed-by: Biao Jiang Link: https://lore.kernel.org/bpf/20230306064833.7932-3-imagedong@tencent.com --- .../selftests/bpf/prog_tests/attach_probe.c | 260 ++++++++++++------ .../bpf/progs/test_attach_kprobe_sleepable.c | 23 ++ .../selftests/bpf/progs/test_attach_probe.c | 23 +- 3 files changed, 205 insertions(+), 101 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/test_attach_kprobe_sleepable.c diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index 56374c8b5436d..c374759f39ce0 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include "test_attach_kprobe_sleepable.skel.h" #include "test_attach_probe.skel.h" /* this is how USDT semaphore is actually defined, except volatile modifier */ @@ -23,52 +24,24 @@ static noinline void trigger_func3(void) asm volatile (""); } +/* attach point for ref_ctr */ +static noinline void trigger_func4(void) +{ + asm volatile (""); +} + static char test_data[] = "test_data"; -void test_attach_probe(void) +/* manual attach kprobe/kretprobe/uprobe/uretprobe testings */ +static void test_attach_probe_manual(struct test_attach_probe *skel) { DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); struct bpf_link *kprobe_link, *kretprobe_link; 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; - FILE *devnull; - bool legacy; - - /* Check if new-style kprobe/uprobe API is supported. - * Kernels that support new FD-based kprobe and uprobe BPF attachment - * through perf_event_open() syscall expose - * /sys/bus/event_source/devices/kprobe/type and - * /sys/bus/event_source/devices/uprobe/type files, respectively. They - * contain magic numbers that are passed as "type" field of - * perf_event_attr. Lack of such file in the system indicates legacy - * kernel with old-style kprobe/uprobe attach interface through - * creating per-probe event through tracefs. For such cases - * ref_ctr_offset feature is not supported, so we don't test it. - */ - legacy = access("/sys/bus/event_source/devices/kprobe/type", F_OK) != 0; + ssize_t uprobe_offset; uprobe_offset = get_uprobe_offset(&trigger_func); if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset")) - return; - - ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr); - if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset")) - return; - - skel = test_attach_probe__open(); - if (!ASSERT_OK_PTR(skel, "skel_open")) - return; - - /* sleepable kprobe test case needs flags set before loading */ - if (!ASSERT_OK(bpf_program__set_flags(skel->progs.handle_kprobe_sleepable, - BPF_F_SLEEPABLE), "kprobe_sleepable_flags")) - goto cleanup; - - if (!ASSERT_OK(test_attach_probe__load(skel), "skel_load")) - goto cleanup; - if (!ASSERT_OK_PTR(skel->bss, "check_bss")) goto cleanup; /* manual-attach kprobe/kretprobe */ @@ -86,18 +59,9 @@ void test_attach_probe(void) goto cleanup; skel->links.handle_kretprobe = kretprobe_link; - /* auto-attachable kprobe and kretprobe */ - skel->links.handle_kprobe_auto = bpf_program__attach(skel->progs.handle_kprobe_auto); - ASSERT_OK_PTR(skel->links.handle_kprobe_auto, "attach_kprobe_auto"); - - skel->links.handle_kretprobe_auto = bpf_program__attach(skel->progs.handle_kretprobe_auto); - ASSERT_OK_PTR(skel->links.handle_kretprobe_auto, "attach_kretprobe_auto"); - - if (!legacy) - ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before"); - + /* manual-attach uprobe/uretprobe */ + uprobe_opts.ref_ctr_offset = 0; uprobe_opts.retprobe = false; - uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset; uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, 0 /* self pid */, "/proc/self/exe", @@ -107,12 +71,7 @@ void test_attach_probe(void) goto cleanup; skel->links.handle_uprobe = uprobe_link; - if (!legacy) - ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after"); - - /* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */ uprobe_opts.retprobe = true; - uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset; uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe, -1 /* any pid */, "/proc/self/exe", @@ -121,12 +80,7 @@ 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), -EOPNOTSUPP, - "auto-attach should fail for old-style name")) - goto cleanup; - + /* attach uprobe by function name manually */ uprobe_opts.func_name = "trigger_func2"; uprobe_opts.retprobe = false; uprobe_opts.ref_ctr_offset = 0; @@ -138,11 +92,62 @@ void test_attach_probe(void) if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname")) goto cleanup; + /* trigger & validate kprobe && kretprobe */ + usleep(1); + + /* trigger & validate uprobe & uretprobe */ + trigger_func(); + + /* trigger & validate uprobe attached by name */ + trigger_func2(); + + ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res"); + ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res"); + ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res"); + ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res"); + ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res"); + +cleanup: +} + +static void test_attach_probe_auto(struct test_attach_probe *skel) +{ + struct bpf_link *uprobe_err_link; + + /* auto-attachable kprobe and kretprobe */ + skel->links.handle_kprobe_auto = bpf_program__attach(skel->progs.handle_kprobe_auto); + ASSERT_OK_PTR(skel->links.handle_kprobe_auto, "attach_kprobe_auto"); + + skel->links.handle_kretprobe_auto = bpf_program__attach(skel->progs.handle_kretprobe_auto); + ASSERT_OK_PTR(skel->links.handle_kretprobe_auto, "attach_kretprobe_auto"); + + /* 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), -EOPNOTSUPP, + "auto-attach should fail for old-style name")) + return; + /* 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; + return; + + /* trigger & validate kprobe && kretprobe */ + usleep(1); + + /* trigger & validate uprobe attached by name */ + trigger_func2(); + + ASSERT_EQ(skel->bss->kprobe2_res, 11, "check_kprobe_auto_res"); + ASSERT_EQ(skel->bss->kretprobe2_res, 22, "check_kretprobe_auto_res"); + ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res"); +} + +static void test_uprobe_lib(struct test_attach_probe *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); + FILE *devnull; /* test attach by name for a library function, using the library * as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo(). @@ -155,7 +160,7 @@ void test_attach_probe(void) "libc.so.6", 0, &uprobe_opts); if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2")) - goto cleanup; + return; uprobe_opts.func_name = "fclose"; uprobe_opts.retprobe = true; @@ -165,62 +170,137 @@ void test_attach_probe(void) "libc.so.6", 0, &uprobe_opts); if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2")) + return; + + /* trigger & validate shared library u[ret]probes attached by name */ + devnull = fopen("/dev/null", "r"); + fclose(devnull); + + ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res"); + ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res"); +} + +static void test_uprobe_ref_ctr(struct test_attach_probe *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); + struct bpf_link *uprobe_link, *uretprobe_link; + ssize_t uprobe_offset, ref_ctr_offset; + + uprobe_offset = get_uprobe_offset(&trigger_func4); + if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset_ref_ctr")) + return; + + ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr); + if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset")) + return; + + ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before"); + + uprobe_opts.retprobe = false; + uprobe_opts.ref_ctr_offset = ref_ctr_offset; + uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_ref_ctr, + 0 /* self pid */, + "/proc/self/exe", + uprobe_offset, + &uprobe_opts); + if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe_ref_ctr")) + return; + skel->links.handle_uprobe_ref_ctr = uprobe_link; + + ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after"); + + /* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */ + uprobe_opts.retprobe = true; + uprobe_opts.ref_ctr_offset = ref_ctr_offset; + uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_ref_ctr, + -1 /* any pid */, + "/proc/self/exe", + uprobe_offset, &uprobe_opts); + if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe_ref_ctr")) + return; + skel->links.handle_uretprobe_ref_ctr = uretprobe_link; +} + +static void test_kprobe_sleepable(void) +{ + struct test_attach_kprobe_sleepable *skel; + + skel = test_attach_kprobe_sleepable__open(); + if (!ASSERT_OK_PTR(skel, "skel_kprobe_sleepable_open")) + return; + + /* sleepable kprobe test case needs flags set before loading */ + if (!ASSERT_OK(bpf_program__set_flags(skel->progs.handle_kprobe_sleepable, + BPF_F_SLEEPABLE), "kprobe_sleepable_flags")) + goto cleanup; + + if (!ASSERT_OK(test_attach_kprobe_sleepable__load(skel), + "skel_kprobe_sleepable_load")) goto cleanup; /* sleepable kprobes should not attach successfully */ skel->links.handle_kprobe_sleepable = bpf_program__attach(skel->progs.handle_kprobe_sleepable); - if (!ASSERT_ERR_PTR(skel->links.handle_kprobe_sleepable, "attach_kprobe_sleepable")) - goto cleanup; + ASSERT_ERR_PTR(skel->links.handle_kprobe_sleepable, "attach_kprobe_sleepable"); +cleanup: + test_attach_kprobe_sleepable__destroy(skel); +} + +static void test_uprobe_sleepable(struct test_attach_probe *skel) +{ /* test sleepable uprobe and uretprobe variants */ skel->links.handle_uprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uprobe_byname3_sleepable); if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3_sleepable, "attach_uprobe_byname3_sleepable")) - goto cleanup; + return; skel->links.handle_uprobe_byname3 = bpf_program__attach(skel->progs.handle_uprobe_byname3); if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3, "attach_uprobe_byname3")) - goto cleanup; + return; skel->links.handle_uretprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uretprobe_byname3_sleepable); if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3_sleepable, "attach_uretprobe_byname3_sleepable")) - goto cleanup; + return; skel->links.handle_uretprobe_byname3 = bpf_program__attach(skel->progs.handle_uretprobe_byname3); if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3, "attach_uretprobe_byname3")) - goto cleanup; + return; skel->bss->user_ptr = test_data; - /* trigger & validate kprobe && kretprobe */ - usleep(1); - - /* trigger & validate shared library u[ret]probes attached by name */ - devnull = fopen("/dev/null", "r"); - fclose(devnull); - - /* trigger & validate uprobe & uretprobe */ - trigger_func(); - - /* trigger & validate uprobe attached by name */ - trigger_func2(); - /* trigger & validate sleepable uprobe attached by name */ trigger_func3(); - ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res"); - ASSERT_EQ(skel->bss->kprobe2_res, 11, "check_kprobe_auto_res"); - ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res"); - ASSERT_EQ(skel->bss->kretprobe2_res, 22, "check_kretprobe_auto_res"); - ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res"); - ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res"); - ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res"); - ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res"); - ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res"); - ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res"); ASSERT_EQ(skel->bss->uprobe_byname3_sleepable_res, 9, "check_uprobe_byname3_sleepable_res"); ASSERT_EQ(skel->bss->uprobe_byname3_res, 10, "check_uprobe_byname3_res"); ASSERT_EQ(skel->bss->uretprobe_byname3_sleepable_res, 11, "check_uretprobe_byname3_sleepable_res"); ASSERT_EQ(skel->bss->uretprobe_byname3_res, 12, "check_uretprobe_byname3_res"); +} + +void test_attach_probe(void) +{ + struct test_attach_probe *skel; + + skel = test_attach_probe__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + if (!ASSERT_OK(test_attach_probe__load(skel), "skel_load")) + goto cleanup; + if (!ASSERT_OK_PTR(skel->bss, "check_bss")) + goto cleanup; + + if (test__start_subtest("manual")) + test_attach_probe_manual(skel); + if (test__start_subtest("auto")) + test_attach_probe_auto(skel); + if (test__start_subtest("kprobe-sleepable")) + test_kprobe_sleepable(); + if (test__start_subtest("uprobe-lib")) + test_uprobe_lib(skel); + if (test__start_subtest("uprobe-sleepable")) + test_uprobe_sleepable(skel); + if (test__start_subtest("uprobe-ref_ctr")) + test_uprobe_ref_ctr(skel); cleanup: test_attach_probe__destroy(skel); diff --git a/tools/testing/selftests/bpf/progs/test_attach_kprobe_sleepable.c b/tools/testing/selftests/bpf/progs/test_attach_kprobe_sleepable.c new file mode 100644 index 0000000000000..f548b74462189 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_attach_kprobe_sleepable.c @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2017 Facebook + +#include "vmlinux.h" +#include +#include +#include +#include "bpf_misc.h" + +int kprobe_res = 0; + +/** + * This program will be manually made sleepable on the userspace side + * and should thus be unattachable. + */ +SEC("kprobe/" SYS_PREFIX "sys_nanosleep") +int handle_kprobe_sleepable(struct pt_regs *ctx) +{ + kprobe_res = 1; + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c index 3b5dc34d23e99..9e1e7163bb676 100644 --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -37,17 +37,6 @@ int BPF_KSYSCALL(handle_kprobe_auto, struct __kernel_timespec *req, struct __ker return 0; } -/** - * This program will be manually made sleepable on the userspace side - * and should thus be unattachable. - */ -SEC("kprobe/" SYS_PREFIX "sys_nanosleep") -int handle_kprobe_sleepable(struct pt_regs *ctx) -{ - kprobe_res = 2; - return 0; -} - SEC("kretprobe") int handle_kretprobe(struct pt_regs *ctx) { @@ -76,6 +65,18 @@ int handle_uretprobe(struct pt_regs *ctx) return 0; } +SEC("uprobe") +int handle_uprobe_ref_ctr(struct pt_regs *ctx) +{ + return 0; +} + +SEC("uretprobe") +int handle_uretprobe_ref_ctr(struct pt_regs *ctx) +{ + return 0; +} + SEC("uprobe") int handle_uprobe_byname(struct pt_regs *ctx) { From c7aec81b31e43a0aa94ee55d9bb33d70b1046f76 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Mon, 6 Mar 2023 14:48:33 +0800 Subject: [PATCH 3/3] selftests/bpf: Add test for legacy/perf kprobe/uprobe attach mode Add the testing for kprobe/uprobe attaching in default, legacy, perf and link mode. And the testing passed: ./test_progs -t attach_probe $5/1 attach_probe/manual-default:OK $5/2 attach_probe/manual-legacy:OK $5/3 attach_probe/manual-perf:OK $5/4 attach_probe/manual-link:OK $5/5 attach_probe/auto:OK $5/6 attach_probe/kprobe-sleepable:OK $5/7 attach_probe/uprobe-lib:OK $5/8 attach_probe/uprobe-sleepable:OK $5/9 attach_probe/uprobe-ref_ctr:OK $5 attach_probe:OK Summary: 1/9 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Menglong Dong Signed-off-by: Andrii Nakryiko Reviewed-by: Biao Jiang Link: https://lore.kernel.org/bpf/20230306064833.7932-4-imagedong@tencent.com --- .../selftests/bpf/prog_tests/attach_probe.c | 37 +++++++++---- .../selftests/bpf/progs/test_attach_probe.c | 32 ----------- .../bpf/progs/test_attach_probe_manual.c | 53 +++++++++++++++++++ 3 files changed, 81 insertions(+), 41 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/test_attach_probe_manual.c diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index c374759f39ce0..7175af39134f3 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include #include "test_attach_kprobe_sleepable.skel.h" +#include "test_attach_probe_manual.skel.h" #include "test_attach_probe.skel.h" /* this is how USDT semaphore is actually defined, except volatile modifier */ @@ -33,33 +34,43 @@ static noinline void trigger_func4(void) static char test_data[] = "test_data"; /* manual attach kprobe/kretprobe/uprobe/uretprobe testings */ -static void test_attach_probe_manual(struct test_attach_probe *skel) +static void test_attach_probe_manual(enum probe_attach_mode attach_mode) { DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); + DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts); struct bpf_link *kprobe_link, *kretprobe_link; struct bpf_link *uprobe_link, *uretprobe_link; + struct test_attach_probe_manual *skel; ssize_t uprobe_offset; + skel = test_attach_probe_manual__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_kprobe_manual_open_and_load")) + return; + uprobe_offset = get_uprobe_offset(&trigger_func); if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset")) goto cleanup; /* manual-attach kprobe/kretprobe */ - kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe, - false /* retprobe */, - SYS_NANOSLEEP_KPROBE_NAME); + kprobe_opts.attach_mode = attach_mode; + kprobe_opts.retprobe = false; + kprobe_link = bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe, + SYS_NANOSLEEP_KPROBE_NAME, + &kprobe_opts); if (!ASSERT_OK_PTR(kprobe_link, "attach_kprobe")) goto cleanup; skel->links.handle_kprobe = kprobe_link; - kretprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kretprobe, - true /* retprobe */, - SYS_NANOSLEEP_KPROBE_NAME); + kprobe_opts.retprobe = true; + kretprobe_link = bpf_program__attach_kprobe_opts(skel->progs.handle_kretprobe, + SYS_NANOSLEEP_KPROBE_NAME, + &kprobe_opts); if (!ASSERT_OK_PTR(kretprobe_link, "attach_kretprobe")) goto cleanup; skel->links.handle_kretprobe = kretprobe_link; /* manual-attach uprobe/uretprobe */ + uprobe_opts.attach_mode = attach_mode; uprobe_opts.ref_ctr_offset = 0; uprobe_opts.retprobe = false; uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, @@ -108,6 +119,7 @@ static void test_attach_probe_manual(struct test_attach_probe *skel) ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res"); cleanup: + test_attach_probe_manual__destroy(skel); } static void test_attach_probe_auto(struct test_attach_probe *skel) @@ -289,8 +301,15 @@ void test_attach_probe(void) if (!ASSERT_OK_PTR(skel->bss, "check_bss")) goto cleanup; - if (test__start_subtest("manual")) - test_attach_probe_manual(skel); + if (test__start_subtest("manual-default")) + test_attach_probe_manual(PROBE_ATTACH_MODE_DEFAULT); + if (test__start_subtest("manual-legacy")) + test_attach_probe_manual(PROBE_ATTACH_MODE_LEGACY); + if (test__start_subtest("manual-perf")) + test_attach_probe_manual(PROBE_ATTACH_MODE_PERF); + if (test__start_subtest("manual-link")) + test_attach_probe_manual(PROBE_ATTACH_MODE_LINK); + if (test__start_subtest("auto")) test_attach_probe_auto(skel); if (test__start_subtest("kprobe-sleepable")) diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c index 9e1e7163bb676..68466a6ad18c7 100644 --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -7,12 +7,8 @@ #include #include "bpf_misc.h" -int kprobe_res = 0; int kprobe2_res = 0; -int kretprobe_res = 0; int kretprobe2_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; @@ -23,13 +19,6 @@ int uretprobe_byname3_sleepable_res = 0; int uretprobe_byname3_res = 0; void *user_ptr = 0; -SEC("kprobe") -int handle_kprobe(struct pt_regs *ctx) -{ - kprobe_res = 1; - return 0; -} - SEC("ksyscall/nanosleep") int BPF_KSYSCALL(handle_kprobe_auto, struct __kernel_timespec *req, struct __kernel_timespec *rem) { @@ -37,13 +26,6 @@ int BPF_KSYSCALL(handle_kprobe_auto, struct __kernel_timespec *req, struct __ker return 0; } -SEC("kretprobe") -int handle_kretprobe(struct pt_regs *ctx) -{ - kretprobe_res = 2; - return 0; -} - SEC("kretsyscall/nanosleep") int BPF_KRETPROBE(handle_kretprobe_auto, int ret) { @@ -51,20 +33,6 @@ int BPF_KRETPROBE(handle_kretprobe_auto, int ret) return ret; } -SEC("uprobe") -int handle_uprobe(struct pt_regs *ctx) -{ - uprobe_res = 3; - return 0; -} - -SEC("uretprobe") -int handle_uretprobe(struct pt_regs *ctx) -{ - uretprobe_res = 4; - return 0; -} - SEC("uprobe") int handle_uprobe_ref_ctr(struct pt_regs *ctx) { diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe_manual.c b/tools/testing/selftests/bpf/progs/test_attach_probe_manual.c new file mode 100644 index 0000000000000..7f08bce94596f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_attach_probe_manual.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2017 Facebook + +#include "vmlinux.h" +#include +#include +#include +#include "bpf_misc.h" + +int kprobe_res = 0; +int kretprobe_res = 0; +int uprobe_res = 0; +int uretprobe_res = 0; +int uprobe_byname_res = 0; +void *user_ptr = 0; + +SEC("kprobe") +int handle_kprobe(struct pt_regs *ctx) +{ + kprobe_res = 1; + return 0; +} + +SEC("kretprobe") +int handle_kretprobe(struct pt_regs *ctx) +{ + kretprobe_res = 2; + return 0; +} + +SEC("uprobe") +int handle_uprobe(struct pt_regs *ctx) +{ + uprobe_res = 3; + return 0; +} + +SEC("uretprobe") +int handle_uretprobe(struct pt_regs *ctx) +{ + uretprobe_res = 4; + return 0; +} + +SEC("uprobe") +int handle_uprobe_byname(struct pt_regs *ctx) +{ + uprobe_byname_res = 5; + return 0; +} + + +char _license[] SEC("license") = "GPL";