From 48f0dfd8d3e212ab27b6db147ed10407ff6aaa88 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sat, 25 Nov 2023 20:31:25 +0100 Subject: [PATCH 1/6] libbpf: Add st_type argument to elf_resolve_syms_offsets function We need to get offsets for static variables in following changes, so making elf_resolve_syms_offsets to take st_type value as argument and passing it to elf_sym_iter_new. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20231125193130.834322-2-jolsa@kernel.org --- tools/lib/bpf/elf.c | 5 +++-- tools/lib/bpf/libbpf.c | 2 +- tools/lib/bpf/libbpf_internal.h | 3 ++- tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c | 2 +- 4 files changed, 7 insertions(+), 5 deletions(-) diff --git a/tools/lib/bpf/elf.c b/tools/lib/bpf/elf.c index 2a62bf411bb3e..b02faec748a51 100644 --- a/tools/lib/bpf/elf.c +++ b/tools/lib/bpf/elf.c @@ -407,7 +407,8 @@ static int symbol_cmp(const void *a, const void *b) * size, that needs to be released by the caller. */ int elf_resolve_syms_offsets(const char *binary_path, int cnt, - const char **syms, unsigned long **poffsets) + const char **syms, unsigned long **poffsets, + int st_type) { int sh_types[2] = { SHT_DYNSYM, SHT_SYMTAB }; int err = 0, i, cnt_done = 0; @@ -438,7 +439,7 @@ int elf_resolve_syms_offsets(const char *binary_path, int cnt, struct elf_sym_iter iter; struct elf_sym *sym; - err = elf_sym_iter_new(&iter, elf_fd.elf, binary_path, sh_types[i], STT_FUNC); + err = elf_sym_iter_new(&iter, elf_fd.elf, binary_path, sh_types[i], st_type); if (err == -ENOENT) continue; if (err) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e067be95da3c0..ea9b8158c20d6 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -11447,7 +11447,7 @@ bpf_program__attach_uprobe_multi(const struct bpf_program *prog, return libbpf_err_ptr(err); offsets = resolved_offsets; } else if (syms) { - err = elf_resolve_syms_offsets(path, cnt, syms, &resolved_offsets); + err = elf_resolve_syms_offsets(path, cnt, syms, &resolved_offsets, STT_FUNC); if (err < 0) return libbpf_err_ptr(err); offsets = resolved_offsets; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index f0f08635adb0d..b5d334754e5dc 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -594,7 +594,8 @@ int elf_open(const char *binary_path, struct elf_fd *elf_fd); void elf_close(struct elf_fd *elf_fd); int elf_resolve_syms_offsets(const char *binary_path, int cnt, - const char **syms, unsigned long **poffsets); + const char **syms, unsigned long **poffsets, + int st_type); int elf_resolve_pattern_offsets(const char *binary_path, const char *pattern, unsigned long **poffsets, size_t *pcnt); diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c index cd051d3901a99..ece260cf2c0b6 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c @@ -249,7 +249,7 @@ static void __test_link_api(struct child *child) int link_extra_fd = -1; int err; - err = elf_resolve_syms_offsets(path, 3, syms, (unsigned long **) &offsets); + err = elf_resolve_syms_offsets(path, 3, syms, (unsigned long **) &offsets, STT_FUNC); if (!ASSERT_OK(err, "elf_resolve_syms_offsets")) return; From 4930b7f53a298533bc31d7540b6ea8b79a000331 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sat, 25 Nov 2023 20:31:26 +0100 Subject: [PATCH 2/6] bpf: Store ref_ctr_offsets values in bpf_uprobe array We will need to return ref_ctr_offsets values through link_info interface in following change, so we need to keep them around. Storing ref_ctr_offsets values directly into bpf_uprobe array. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20231125193130.834322-3-jolsa@kernel.org --- kernel/trace/bpf_trace.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f0b8b7c291262..ad0323f272884 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3033,6 +3033,7 @@ struct bpf_uprobe_multi_link; struct bpf_uprobe { struct bpf_uprobe_multi_link *link; loff_t offset; + unsigned long ref_ctr_offset; u64 cookie; struct uprobe_consumer consumer; }; @@ -3172,7 +3173,6 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr { struct bpf_uprobe_multi_link *link = NULL; unsigned long __user *uref_ctr_offsets; - unsigned long *ref_ctr_offsets = NULL; struct bpf_link_primer link_primer; struct bpf_uprobe *uprobes = NULL; struct task_struct *task = NULL; @@ -3245,18 +3245,12 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (!uprobes || !link) goto error_free; - if (uref_ctr_offsets) { - ref_ctr_offsets = kvcalloc(cnt, sizeof(*ref_ctr_offsets), GFP_KERNEL); - if (!ref_ctr_offsets) - goto error_free; - } - for (i = 0; i < cnt; i++) { if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { err = -EFAULT; goto error_free; } - if (uref_ctr_offsets && __get_user(ref_ctr_offsets[i], uref_ctr_offsets + i)) { + if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { err = -EFAULT; goto error_free; } @@ -3287,7 +3281,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr for (i = 0; i < cnt; i++) { err = uprobe_register_refctr(d_real_inode(link->path.dentry), uprobes[i].offset, - ref_ctr_offsets ? ref_ctr_offsets[i] : 0, + uprobes[i].ref_ctr_offset, &uprobes[i].consumer); if (err) { bpf_uprobe_unregister(&path, uprobes, i); @@ -3299,11 +3293,9 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (err) goto error_free; - kvfree(ref_ctr_offsets); return bpf_link_settle(&link_primer); error_free: - kvfree(ref_ctr_offsets); kvfree(uprobes); kfree(link); if (task) From e56fdbfb06e26a7066b070967badef4148528df2 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sat, 25 Nov 2023 20:31:27 +0100 Subject: [PATCH 3/6] bpf: Add link_info support for uprobe multi link Adding support to get uprobe_link details through bpf_link_info interface. Adding new struct uprobe_multi to struct bpf_link_info to carry the uprobe_multi link details. The uprobe_multi.count is passed from user space to denote size of array fields (offsets/ref_ctr_offsets/cookies). The actual array size is stored back to uprobe_multi.count (allowing user to find out the actual array size) and array fields are populated up to the user passed size. All the non-array fields (path/count/flags/pid) are always set. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20231125193130.834322-4-jolsa@kernel.org --- include/uapi/linux/bpf.h | 10 +++++ kernel/trace/bpf_trace.c | 72 ++++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 10 +++++ 3 files changed, 92 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 7a5498242eaa9..e88746ba7d219 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6562,6 +6562,16 @@ struct bpf_link_info { __u32 flags; __u64 missed; } kprobe_multi; + struct { + __aligned_u64 path; + __aligned_u64 offsets; + __aligned_u64 ref_ctr_offsets; + __aligned_u64 cookies; + __u32 path_size; /* in/out: real path size on success, including zero byte */ + __u32 count; /* in/out: uprobe_multi offsets/ref_ctr_offsets/cookies count */ + __u32 flags; + __u32 pid; + } uprobe_multi; struct { __u32 type; /* enum bpf_perf_event_type */ __u32 :32; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index ad0323f272884..c284a4ad0315c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3042,6 +3042,7 @@ struct bpf_uprobe_multi_link { struct path path; struct bpf_link link; u32 cnt; + u32 flags; struct bpf_uprobe *uprobes; struct task_struct *task; }; @@ -3083,9 +3084,79 @@ static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) kfree(umulti_link); } +static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, + struct bpf_link_info *info) +{ + u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); + u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); + u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); + u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); + u32 upath_size = info->uprobe_multi.path_size; + struct bpf_uprobe_multi_link *umulti_link; + u32 ucount = info->uprobe_multi.count; + int err = 0, i; + long left; + + if (!upath ^ !upath_size) + return -EINVAL; + + if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) + return -EINVAL; + + umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); + info->uprobe_multi.count = umulti_link->cnt; + info->uprobe_multi.flags = umulti_link->flags; + info->uprobe_multi.pid = umulti_link->task ? + task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; + + if (upath) { + char *p, *buf; + + upath_size = min_t(u32, upath_size, PATH_MAX); + + buf = kmalloc(upath_size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + p = d_path(&umulti_link->path, buf, upath_size); + if (IS_ERR(p)) { + kfree(buf); + return PTR_ERR(p); + } + upath_size = buf + upath_size - p; + left = copy_to_user(upath, p, upath_size); + kfree(buf); + if (left) + return -EFAULT; + info->uprobe_multi.path_size = upath_size; + } + + if (!uoffsets && !ucookies && !uref_ctr_offsets) + return 0; + + if (ucount < umulti_link->cnt) + err = -ENOSPC; + else + ucount = umulti_link->cnt; + + for (i = 0; i < ucount; i++) { + if (uoffsets && + put_user(umulti_link->uprobes[i].offset, uoffsets + i)) + return -EFAULT; + if (uref_ctr_offsets && + put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) + return -EFAULT; + if (ucookies && + put_user(umulti_link->uprobes[i].cookie, ucookies + i)) + return -EFAULT; + } + + return err; +} + static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { .release = bpf_uprobe_multi_link_release, .dealloc = bpf_uprobe_multi_link_dealloc, + .fill_link_info = bpf_uprobe_multi_link_fill_link_info, }; static int uprobe_prog_run(struct bpf_uprobe *uprobe, @@ -3274,6 +3345,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr link->uprobes = uprobes; link->path = path; link->task = task; + link->flags = flags; bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, &bpf_uprobe_multi_link_lops, prog); diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 7a5498242eaa9..e88746ba7d219 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -6562,6 +6562,16 @@ struct bpf_link_info { __u32 flags; __u64 missed; } kprobe_multi; + struct { + __aligned_u64 path; + __aligned_u64 offsets; + __aligned_u64 ref_ctr_offsets; + __aligned_u64 cookies; + __u32 path_size; /* in/out: real path size on success, including zero byte */ + __u32 count; /* in/out: uprobe_multi offsets/ref_ctr_offsets/cookies count */ + __u32 flags; + __u32 pid; + } uprobe_multi; struct { __u32 type; /* enum bpf_perf_event_type */ __u32 :32; From 1703612885723869064f18e8816c6f3f87987748 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sat, 25 Nov 2023 20:31:28 +0100 Subject: [PATCH 4/6] selftests/bpf: Use bpf_link__destroy in fill_link_info tests The fill_link_info test keeps skeleton open and just creates various links. We are wrongly calling bpf_link__detach after each test to close them, we need to call bpf_link__destroy. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Acked-by: Yafang Shao Link: https://lore.kernel.org/bpf/20231125193130.834322-5-jolsa@kernel.org --- .../selftests/bpf/prog_tests/fill_link_info.c | 44 ++++++++++--------- 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c index 97142a4db3747..9294cb8d7743e 100644 --- a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c +++ b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c @@ -140,14 +140,14 @@ static void test_kprobe_fill_link_info(struct test_fill_link_info *skel, .retprobe = type == BPF_PERF_EVENT_KRETPROBE, ); ssize_t entry_offset = 0; + struct bpf_link *link; int link_fd, err; - skel->links.kprobe_run = bpf_program__attach_kprobe_opts(skel->progs.kprobe_run, - KPROBE_FUNC, &opts); - if (!ASSERT_OK_PTR(skel->links.kprobe_run, "attach_kprobe")) + link = bpf_program__attach_kprobe_opts(skel->progs.kprobe_run, KPROBE_FUNC, &opts); + if (!ASSERT_OK_PTR(link, "attach_kprobe")) return; - link_fd = bpf_link__fd(skel->links.kprobe_run); + link_fd = bpf_link__fd(link); if (!invalid) { /* See also arch_adjust_kprobe_addr(). */ if (skel->kconfig->CONFIG_X86_KERNEL_IBT) @@ -157,39 +157,41 @@ static void test_kprobe_fill_link_info(struct test_fill_link_info *skel, } else { kprobe_fill_invalid_user_buffer(link_fd); } - bpf_link__detach(skel->links.kprobe_run); + bpf_link__destroy(link); } static void test_tp_fill_link_info(struct test_fill_link_info *skel) { + struct bpf_link *link; int link_fd, err; - skel->links.tp_run = bpf_program__attach_tracepoint(skel->progs.tp_run, TP_CAT, TP_NAME); - if (!ASSERT_OK_PTR(skel->links.tp_run, "attach_tp")) + link = bpf_program__attach_tracepoint(skel->progs.tp_run, TP_CAT, TP_NAME); + if (!ASSERT_OK_PTR(link, "attach_tp")) return; - link_fd = bpf_link__fd(skel->links.tp_run); + link_fd = bpf_link__fd(link); err = verify_perf_link_info(link_fd, BPF_PERF_EVENT_TRACEPOINT, 0, 0, 0); ASSERT_OK(err, "verify_perf_link_info"); - bpf_link__detach(skel->links.tp_run); + bpf_link__destroy(link); } static void test_uprobe_fill_link_info(struct test_fill_link_info *skel, enum bpf_perf_event_type type) { + struct bpf_link *link; int link_fd, err; - skel->links.uprobe_run = bpf_program__attach_uprobe(skel->progs.uprobe_run, - type == BPF_PERF_EVENT_URETPROBE, - 0, /* self pid */ - UPROBE_FILE, uprobe_offset); - if (!ASSERT_OK_PTR(skel->links.uprobe_run, "attach_uprobe")) + link = bpf_program__attach_uprobe(skel->progs.uprobe_run, + type == BPF_PERF_EVENT_URETPROBE, + 0, /* self pid */ + UPROBE_FILE, uprobe_offset); + if (!ASSERT_OK_PTR(link, "attach_uprobe")) return; - link_fd = bpf_link__fd(skel->links.uprobe_run); + link_fd = bpf_link__fd(link); err = verify_perf_link_info(link_fd, type, 0, uprobe_offset, 0); ASSERT_OK(err, "verify_perf_link_info"); - bpf_link__detach(skel->links.uprobe_run); + bpf_link__destroy(link); } static int verify_kmulti_link_info(int fd, bool retprobe) @@ -278,24 +280,24 @@ static void test_kprobe_multi_fill_link_info(struct test_fill_link_info *skel, bool retprobe, bool invalid) { LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + struct bpf_link *link; int link_fd, err; opts.syms = kmulti_syms; opts.cnt = KMULTI_CNT; opts.retprobe = retprobe; - skel->links.kmulti_run = bpf_program__attach_kprobe_multi_opts(skel->progs.kmulti_run, - NULL, &opts); - if (!ASSERT_OK_PTR(skel->links.kmulti_run, "attach_kprobe_multi")) + link = bpf_program__attach_kprobe_multi_opts(skel->progs.kmulti_run, NULL, &opts); + if (!ASSERT_OK_PTR(link, "attach_kprobe_multi")) return; - link_fd = bpf_link__fd(skel->links.kmulti_run); + link_fd = bpf_link__fd(link); if (!invalid) { err = verify_kmulti_link_info(link_fd, retprobe); ASSERT_OK(err, "verify_kmulti_link_info"); } else { verify_kmulti_invalid_user_buffer(link_fd); } - bpf_link__detach(skel->links.kmulti_run); + bpf_link__destroy(link); } void test_fill_link_info(void) From 147c69307bcf67f1f01246f9acb794da9837f299 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sat, 25 Nov 2023 20:31:29 +0100 Subject: [PATCH 5/6] selftests/bpf: Add link_info test for uprobe_multi link Adding fill_link_info test for uprobe_multi link. Setting up uprobes with bogus ref_ctr_offsets and cookie values to test all the bpf_link_info::uprobe_multi fields. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20231125193130.834322-6-jolsa@kernel.org --- .../selftests/bpf/prog_tests/fill_link_info.c | 198 ++++++++++++++++++ .../selftests/bpf/progs/test_fill_link_info.c | 6 + 2 files changed, 204 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c index 9294cb8d7743e..d4b1901f7879a 100644 --- a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c +++ b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c @@ -7,6 +7,7 @@ #include #include "trace_helpers.h" #include "test_fill_link_info.skel.h" +#include "bpf/libbpf_internal.h" #define TP_CAT "sched" #define TP_NAME "sched_switch" @@ -300,6 +301,196 @@ static void test_kprobe_multi_fill_link_info(struct test_fill_link_info *skel, bpf_link__destroy(link); } +#define SEC(name) __attribute__((section(name), used)) + +static short uprobe_link_info_sema_1 SEC(".probes"); +static short uprobe_link_info_sema_2 SEC(".probes"); +static short uprobe_link_info_sema_3 SEC(".probes"); + +noinline void uprobe_link_info_func_1(void) +{ + asm volatile (""); + uprobe_link_info_sema_1++; +} + +noinline void uprobe_link_info_func_2(void) +{ + asm volatile (""); + uprobe_link_info_sema_2++; +} + +noinline void uprobe_link_info_func_3(void) +{ + asm volatile (""); + uprobe_link_info_sema_3++; +} + +static int +verify_umulti_link_info(int fd, bool retprobe, __u64 *offsets, + __u64 *cookies, __u64 *ref_ctr_offsets) +{ + char path[PATH_MAX], path_buf[PATH_MAX]; + struct bpf_link_info info; + __u32 len = sizeof(info); + __u64 ref_ctr_offsets_buf[3]; + __u64 offsets_buf[3]; + __u64 cookies_buf[3]; + int i, err, bit; + __u32 count = 0; + + memset(path, 0, sizeof(path)); + err = readlink("/proc/self/exe", path, sizeof(path)); + if (!ASSERT_NEQ(err, -1, "readlink")) + return -1; + + for (bit = 0; bit < 8; bit++) { + memset(&info, 0, sizeof(info)); + info.uprobe_multi.path = ptr_to_u64(path_buf); + info.uprobe_multi.path_size = sizeof(path_buf); + info.uprobe_multi.count = count; + + if (bit & 0x1) + info.uprobe_multi.offsets = ptr_to_u64(offsets_buf); + if (bit & 0x2) + info.uprobe_multi.cookies = ptr_to_u64(cookies_buf); + if (bit & 0x4) + info.uprobe_multi.ref_ctr_offsets = ptr_to_u64(ref_ctr_offsets_buf); + + err = bpf_link_get_info_by_fd(fd, &info, &len); + if (!ASSERT_OK(err, "bpf_link_get_info_by_fd")) + return -1; + + if (!ASSERT_EQ(info.type, BPF_LINK_TYPE_UPROBE_MULTI, "info.type")) + return -1; + + ASSERT_EQ(info.uprobe_multi.pid, getpid(), "info.uprobe_multi.pid"); + ASSERT_EQ(info.uprobe_multi.count, 3, "info.uprobe_multi.count"); + ASSERT_EQ(info.uprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN, + retprobe, "info.uprobe_multi.flags.retprobe"); + ASSERT_EQ(info.uprobe_multi.path_size, strlen(path) + 1, "info.uprobe_multi.path_size"); + ASSERT_STREQ(path_buf, path, "info.uprobe_multi.path"); + + for (i = 0; i < info.uprobe_multi.count; i++) { + if (info.uprobe_multi.offsets) + ASSERT_EQ(offsets_buf[i], offsets[i], "info.uprobe_multi.offsets"); + if (info.uprobe_multi.cookies) + ASSERT_EQ(cookies_buf[i], cookies[i], "info.uprobe_multi.cookies"); + if (info.uprobe_multi.ref_ctr_offsets) { + ASSERT_EQ(ref_ctr_offsets_buf[i], ref_ctr_offsets[i], + "info.uprobe_multi.ref_ctr_offsets"); + } + } + count = count ?: info.uprobe_multi.count; + } + + return 0; +} + +static void verify_umulti_invalid_user_buffer(int fd) +{ + struct bpf_link_info info; + __u32 len = sizeof(info); + __u64 buf[3]; + int err; + + /* upath_size defined, not path */ + memset(&info, 0, sizeof(info)); + info.uprobe_multi.path_size = 3; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "failed_upath_size"); + + /* path defined, but small */ + memset(&info, 0, sizeof(info)); + info.uprobe_multi.path = ptr_to_u64(buf); + info.uprobe_multi.path_size = 3; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_LT(err, 0, "failed_upath_small"); + + /* path has wrong pointer */ + memset(&info, 0, sizeof(info)); + info.uprobe_multi.path_size = PATH_MAX; + info.uprobe_multi.path = 123; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EFAULT, "failed_bad_path_ptr"); + + /* count zero, with offsets */ + memset(&info, 0, sizeof(info)); + info.uprobe_multi.offsets = ptr_to_u64(buf); + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "failed_count"); + + /* offsets not big enough */ + memset(&info, 0, sizeof(info)); + info.uprobe_multi.offsets = ptr_to_u64(buf); + info.uprobe_multi.count = 2; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -ENOSPC, "failed_small_count"); + + /* offsets has wrong pointer */ + memset(&info, 0, sizeof(info)); + info.uprobe_multi.offsets = 123; + info.uprobe_multi.count = 3; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EFAULT, "failed_wrong_offsets"); +} + +static void test_uprobe_multi_fill_link_info(struct test_fill_link_info *skel, + bool retprobe, bool invalid) +{ + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, + .retprobe = retprobe, + ); + const char *syms[3] = { + "uprobe_link_info_func_1", + "uprobe_link_info_func_2", + "uprobe_link_info_func_3", + }; + __u64 cookies[3] = { + 0xdead, + 0xbeef, + 0xcafe, + }; + const char *sema[3] = { + "uprobe_link_info_sema_1", + "uprobe_link_info_sema_2", + "uprobe_link_info_sema_3", + }; + __u64 *offsets = NULL, *ref_ctr_offsets; + struct bpf_link *link; + int link_fd, err; + + err = elf_resolve_syms_offsets("/proc/self/exe", 3, sema, + (unsigned long **) &ref_ctr_offsets, STT_OBJECT); + if (!ASSERT_OK(err, "elf_resolve_syms_offsets_object")) + return; + + err = elf_resolve_syms_offsets("/proc/self/exe", 3, syms, + (unsigned long **) &offsets, STT_FUNC); + if (!ASSERT_OK(err, "elf_resolve_syms_offsets_func")) + goto out; + + opts.syms = syms; + opts.cookies = &cookies[0]; + opts.ref_ctr_offsets = (unsigned long *) &ref_ctr_offsets[0]; + opts.cnt = ARRAY_SIZE(syms); + + link = bpf_program__attach_uprobe_multi(skel->progs.umulti_run, 0, + "/proc/self/exe", NULL, &opts); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi")) + goto out; + + link_fd = bpf_link__fd(link); + if (invalid) + verify_umulti_invalid_user_buffer(link_fd); + else + verify_umulti_link_info(link_fd, retprobe, offsets, cookies, ref_ctr_offsets); + + bpf_link__destroy(link); +out: + free(ref_ctr_offsets); + free(offsets); +} + void test_fill_link_info(void) { struct test_fill_link_info *skel; @@ -339,6 +530,13 @@ void test_fill_link_info(void) if (test__start_subtest("kprobe_multi_invalid_ubuff")) test_kprobe_multi_fill_link_info(skel, true, true); + if (test__start_subtest("uprobe_multi_link_info")) + test_uprobe_multi_fill_link_info(skel, false, false); + if (test__start_subtest("uretprobe_multi_link_info")) + test_uprobe_multi_fill_link_info(skel, true, false); + if (test__start_subtest("uprobe_multi_invalid")) + test_uprobe_multi_fill_link_info(skel, false, true); + cleanup: test_fill_link_info__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/test_fill_link_info.c b/tools/testing/selftests/bpf/progs/test_fill_link_info.c index 564f402d56fef..69509f8bb680f 100644 --- a/tools/testing/selftests/bpf/progs/test_fill_link_info.c +++ b/tools/testing/selftests/bpf/progs/test_fill_link_info.c @@ -39,4 +39,10 @@ int BPF_PROG(kmulti_run) return 0; } +SEC("uprobe.multi") +int BPF_PROG(umulti_run) +{ + return 0; +} + char _license[] SEC("license") = "GPL"; From a7795698f8b6c48283fa4334eb313bc1350b2864 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sat, 25 Nov 2023 20:31:30 +0100 Subject: [PATCH 6/6] bpftool: Add support to display uprobe_multi links Adding support to display details for uprobe_multi links, both plain: # bpftool link -p ... 24: uprobe_multi prog 126 uprobe.multi path /home/jolsa/bpf/test_progs func_cnt 3 pid 4143 offset ref_ctr_offset cookies 0xd1f88 0xf5d5a8 0xdead 0xd1f8f 0xf5d5aa 0xbeef 0xd1f96 0xf5d5ac 0xcafe and json: # bpftool link -p [{ ... },{ "id": 24, "type": "uprobe_multi", "prog_id": 126, "retprobe": false, "path": "/home/jolsa/bpf/test_progs", "func_cnt": 3, "pid": 4143, "funcs": [{ "offset": 860040, "ref_ctr_offset": 16111016, "cookie": 57005 },{ "offset": 860047, "ref_ctr_offset": 16111018, "cookie": 48879 },{ "offset": 860054, "ref_ctr_offset": 16111020, "cookie": 51966 } ] } ] Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20231125193130.834322-7-jolsa@kernel.org --- tools/bpf/bpftool/link.c | 105 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 103 insertions(+), 2 deletions(-) diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index a1528cde81abf..cb46667a6b2e7 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -294,6 +294,37 @@ show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr) jsonw_end_array(json_wtr); } +static __u64 *u64_to_arr(__u64 val) +{ + return (__u64 *) u64_to_ptr(val); +} + +static void +show_uprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + __u32 i; + + jsonw_bool_field(json_wtr, "retprobe", + info->uprobe_multi.flags & BPF_F_UPROBE_MULTI_RETURN); + jsonw_string_field(json_wtr, "path", (char *) u64_to_ptr(info->uprobe_multi.path)); + jsonw_uint_field(json_wtr, "func_cnt", info->uprobe_multi.count); + jsonw_int_field(json_wtr, "pid", (int) info->uprobe_multi.pid); + jsonw_name(json_wtr, "funcs"); + jsonw_start_array(json_wtr); + + for (i = 0; i < info->uprobe_multi.count; i++) { + jsonw_start_object(json_wtr); + jsonw_uint_field(json_wtr, "offset", + u64_to_arr(info->uprobe_multi.offsets)[i]); + jsonw_uint_field(json_wtr, "ref_ctr_offset", + u64_to_arr(info->uprobe_multi.ref_ctr_offsets)[i]); + jsonw_uint_field(json_wtr, "cookie", + u64_to_arr(info->uprobe_multi.cookies)[i]); + jsonw_end_object(json_wtr); + } + jsonw_end_array(json_wtr); +} + static void show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr) { @@ -465,6 +496,9 @@ static int show_link_close_json(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_KPROBE_MULTI: show_kprobe_multi_json(info, json_wtr); break; + case BPF_LINK_TYPE_UPROBE_MULTI: + show_uprobe_multi_json(info, json_wtr); + break; case BPF_LINK_TYPE_PERF_EVENT: switch (info->perf_event.type) { case BPF_PERF_EVENT_EVENT: @@ -674,6 +708,33 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info) } } +static void show_uprobe_multi_plain(struct bpf_link_info *info) +{ + __u32 i; + + if (!info->uprobe_multi.count) + return; + + if (info->uprobe_multi.flags & BPF_F_UPROBE_MULTI_RETURN) + printf("\n\turetprobe.multi "); + else + printf("\n\tuprobe.multi "); + + printf("path %s ", (char *) u64_to_ptr(info->uprobe_multi.path)); + printf("func_cnt %u ", info->uprobe_multi.count); + + if (info->uprobe_multi.pid) + printf("pid %d ", info->uprobe_multi.pid); + + printf("\n\t%-16s %-16s %-16s", "offset", "ref_ctr_offset", "cookies"); + for (i = 0; i < info->uprobe_multi.count; i++) { + printf("\n\t0x%-16llx 0x%-16llx 0x%-16llx", + u64_to_arr(info->uprobe_multi.offsets)[i], + u64_to_arr(info->uprobe_multi.ref_ctr_offsets)[i], + u64_to_arr(info->uprobe_multi.cookies)[i]); + } +} + static void show_perf_event_kprobe_plain(struct bpf_link_info *info) { const char *buf; @@ -807,6 +868,9 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_KPROBE_MULTI: show_kprobe_multi_plain(info); break; + case BPF_LINK_TYPE_UPROBE_MULTI: + show_uprobe_multi_plain(info); + break; case BPF_LINK_TYPE_PERF_EVENT: switch (info->perf_event.type) { case BPF_PERF_EVENT_EVENT: @@ -846,8 +910,10 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) static int do_show_link(int fd) { + __u64 *ref_ctr_offsets = NULL, *offsets = NULL, *cookies = NULL; struct bpf_link_info info; __u32 len = sizeof(info); + char path_buf[PATH_MAX]; __u64 *addrs = NULL; char buf[PATH_MAX]; int count; @@ -889,6 +955,39 @@ static int do_show_link(int fd) goto again; } } + if (info.type == BPF_LINK_TYPE_UPROBE_MULTI && + !info.uprobe_multi.offsets) { + count = info.uprobe_multi.count; + if (count) { + offsets = calloc(count, sizeof(__u64)); + if (!offsets) { + p_err("mem alloc failed"); + close(fd); + return -ENOMEM; + } + info.uprobe_multi.offsets = ptr_to_u64(offsets); + ref_ctr_offsets = calloc(count, sizeof(__u64)); + if (!ref_ctr_offsets) { + p_err("mem alloc failed"); + free(offsets); + close(fd); + return -ENOMEM; + } + info.uprobe_multi.ref_ctr_offsets = ptr_to_u64(ref_ctr_offsets); + cookies = calloc(count, sizeof(__u64)); + if (!cookies) { + p_err("mem alloc failed"); + free(cookies); + free(offsets); + close(fd); + return -ENOMEM; + } + info.uprobe_multi.cookies = ptr_to_u64(cookies); + info.uprobe_multi.path = ptr_to_u64(path_buf); + info.uprobe_multi.path_size = sizeof(path_buf); + goto again; + } + } if (info.type == BPF_LINK_TYPE_PERF_EVENT) { switch (info.perf_event.type) { case BPF_PERF_EVENT_TRACEPOINT: @@ -924,8 +1023,10 @@ static int do_show_link(int fd) else show_link_close_plain(fd, &info); - if (addrs) - free(addrs); + free(ref_ctr_offsets); + free(cookies); + free(offsets); + free(addrs); close(fd); return 0; }