From d687f621c518d791b5fffde8add3112d869b0b1b Mon Sep 17 00:00:00 2001 From: Delyan Kratunov Date: Tue, 14 Jun 2022 23:10:42 +0000 Subject: [PATCH 1/5] bpf: move bpf_prog to bpf.h In order to add a version of bpf_prog_run_array which accesses the bpf_prog->aux member, bpf_prog needs to be more than a forward declaration inside bpf.h. Given that filter.h already includes bpf.h, this merely reorders the type declarations for filter.h users. bpf.h users now have access to bpf_prog internals. Signed-off-by: Delyan Kratunov Link: https://lore.kernel.org/r/3ed7824e3948f22d84583649ccac0ff0d38b6b58.1655248076.git.delyank@fb.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 36 ++++++++++++++++++++++++++++++++++++ include/linux/filter.h | 34 ---------------------------------- 2 files changed, 36 insertions(+), 34 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 8e6092d0ea95..69106ae46464 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -5,6 +5,7 @@ #define _LINUX_BPF_H 1 #include +#include #include #include @@ -22,6 +23,7 @@ #include #include #include +#include #include #include @@ -1084,6 +1086,40 @@ struct bpf_prog_aux { }; }; +struct bpf_prog { + u16 pages; /* Number of allocated pages */ + u16 jited:1, /* Is our filter JIT'ed? */ + jit_requested:1,/* archs need to JIT the prog */ + gpl_compatible:1, /* Is filter GPL compatible? */ + cb_access:1, /* Is control block accessed? */ + dst_needed:1, /* Do we need dst entry? */ + blinding_requested:1, /* needs constant blinding */ + blinded:1, /* Was blinded */ + is_func:1, /* program is a bpf function */ + kprobe_override:1, /* Do we override a kprobe? */ + has_callchain_buf:1, /* callchain buffer allocated? */ + enforce_expected_attach_type:1, /* Enforce expected_attach_type checking at attach time */ + call_get_stack:1, /* Do we call bpf_get_stack() or bpf_get_stackid() */ + call_get_func_ip:1, /* Do we call get_func_ip() */ + tstamp_type_access:1; /* Accessed __sk_buff->tstamp_type */ + enum bpf_prog_type type; /* Type of BPF program */ + enum bpf_attach_type expected_attach_type; /* For some prog types */ + u32 len; /* Number of filter blocks */ + u32 jited_len; /* Size of jited insns in bytes */ + u8 tag[BPF_TAG_SIZE]; + struct bpf_prog_stats __percpu *stats; + int __percpu *active; + unsigned int (*bpf_func)(const void *ctx, + const struct bpf_insn *insn); + struct bpf_prog_aux *aux; /* Auxiliary fields */ + struct sock_fprog_kern *orig_prog; /* Original BPF program */ + /* Instructions for interpreter */ + union { + DECLARE_FLEX_ARRAY(struct sock_filter, insns); + DECLARE_FLEX_ARRAY(struct bpf_insn, insnsi); + }; +}; + struct bpf_array_aux { /* Programs with direct jumps into programs part of this array. */ struct list_head poke_progs; diff --git a/include/linux/filter.h b/include/linux/filter.h index ed0c0ff42ad5..d0cbb31b1b4d 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -559,40 +559,6 @@ struct bpf_prog_stats { struct u64_stats_sync syncp; } __aligned(2 * sizeof(u64)); -struct bpf_prog { - u16 pages; /* Number of allocated pages */ - u16 jited:1, /* Is our filter JIT'ed? */ - jit_requested:1,/* archs need to JIT the prog */ - gpl_compatible:1, /* Is filter GPL compatible? */ - cb_access:1, /* Is control block accessed? */ - dst_needed:1, /* Do we need dst entry? */ - blinding_requested:1, /* needs constant blinding */ - blinded:1, /* Was blinded */ - is_func:1, /* program is a bpf function */ - kprobe_override:1, /* Do we override a kprobe? */ - has_callchain_buf:1, /* callchain buffer allocated? */ - enforce_expected_attach_type:1, /* Enforce expected_attach_type checking at attach time */ - call_get_stack:1, /* Do we call bpf_get_stack() or bpf_get_stackid() */ - call_get_func_ip:1, /* Do we call get_func_ip() */ - tstamp_type_access:1; /* Accessed __sk_buff->tstamp_type */ - enum bpf_prog_type type; /* Type of BPF program */ - enum bpf_attach_type expected_attach_type; /* For some prog types */ - u32 len; /* Number of filter blocks */ - u32 jited_len; /* Size of jited insns in bytes */ - u8 tag[BPF_TAG_SIZE]; - struct bpf_prog_stats __percpu *stats; - int __percpu *active; - unsigned int (*bpf_func)(const void *ctx, - const struct bpf_insn *insn); - struct bpf_prog_aux *aux; /* Auxiliary fields */ - struct sock_fprog_kern *orig_prog; /* Original BPF program */ - /* Instructions for interpreter */ - union { - DECLARE_FLEX_ARRAY(struct sock_filter, insns); - DECLARE_FLEX_ARRAY(struct bpf_insn, insnsi); - }; -}; - struct sk_filter { refcount_t refcnt; struct rcu_head rcu; From 8c7dcb84e3b744b2b70baa7a44a9b1881c33a9c9 Mon Sep 17 00:00:00 2001 From: Delyan Kratunov Date: Tue, 14 Jun 2022 23:10:46 +0000 Subject: [PATCH 2/5] bpf: implement sleepable uprobes by chaining gps uprobes work by raising a trap, setting a task flag from within the interrupt handler, and processing the actual work for the uprobe on the way back to userspace. As a result, uprobe handlers already execute in a might_fault/_sleep context. The primary obstacle to sleepable bpf uprobe programs is therefore on the bpf side. Namely, the bpf_prog_array attached to the uprobe is protected by normal rcu. In order for uprobe bpf programs to become sleepable, it has to be protected by the tasks_trace rcu flavor instead (and kfree() called after a corresponding grace period). Therefore, the free path for bpf_prog_array now chains a tasks_trace and normal grace periods one after the other. Users who iterate under tasks_trace read section would be safe, as would users who iterate under normal read sections (from non-sleepable locations). The downside is that the tasks_trace latency affects all perf_event-attached bpf programs (and not just uprobe ones). This is deemed safe given the possible attach rates for kprobe/uprobe/tp programs. Separately, non-sleepable programs need access to dynamically sized rcu-protected maps, so bpf_run_prog_array_sleepables now conditionally takes an rcu read section, in addition to the overarching tasks_trace section. Signed-off-by: Delyan Kratunov Link: https://lore.kernel.org/r/ce844d62a2fd0443b08c5ab02e95bc7149f9aeb1.1655248076.git.delyank@fb.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 52 +++++++++++++++++++++++++++++++++++++ kernel/bpf/core.c | 15 +++++++++++ kernel/trace/bpf_trace.c | 4 +-- kernel/trace/trace_uprobe.c | 5 ++-- 4 files changed, 71 insertions(+), 5 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 69106ae46464..f3e88afdaffe 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -26,6 +26,7 @@ #include #include #include +#include struct bpf_verifier_env; struct bpf_verifier_log; @@ -1372,6 +1373,8 @@ extern struct bpf_empty_prog_array bpf_empty_prog_array; struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags); void bpf_prog_array_free(struct bpf_prog_array *progs); +/* Use when traversal over the bpf_prog_array uses tasks_trace rcu */ +void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs); int bpf_prog_array_length(struct bpf_prog_array *progs); bool bpf_prog_array_is_empty(struct bpf_prog_array *array); int bpf_prog_array_copy_to_user(struct bpf_prog_array *progs, @@ -1463,6 +1466,55 @@ bpf_prog_run_array(const struct bpf_prog_array *array, return ret; } +/* Notes on RCU design for bpf_prog_arrays containing sleepable programs: + * + * We use the tasks_trace rcu flavor read section to protect the bpf_prog_array + * overall. As a result, we must use the bpf_prog_array_free_sleepable + * in order to use the tasks_trace rcu grace period. + * + * When a non-sleepable program is inside the array, we take the rcu read + * section and disable preemption for that program alone, so it can access + * rcu-protected dynamically sized maps. + */ +static __always_inline u32 +bpf_prog_run_array_sleepable(const struct bpf_prog_array __rcu *array_rcu, + const void *ctx, bpf_prog_run_fn run_prog) +{ + const struct bpf_prog_array_item *item; + const struct bpf_prog *prog; + const struct bpf_prog_array *array; + struct bpf_run_ctx *old_run_ctx; + struct bpf_trace_run_ctx run_ctx; + u32 ret = 1; + + might_fault(); + + rcu_read_lock_trace(); + migrate_disable(); + + array = rcu_dereference_check(array_rcu, rcu_read_lock_trace_held()); + if (unlikely(!array)) + goto out; + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); + item = &array->items[0]; + while ((prog = READ_ONCE(item->prog))) { + if (!prog->aux->sleepable) + rcu_read_lock(); + + run_ctx.bpf_cookie = item->bpf_cookie; + ret &= run_prog(prog, ctx); + item++; + + if (!prog->aux->sleepable) + rcu_read_unlock(); + } + bpf_reset_run_ctx(old_run_ctx); +out: + migrate_enable(); + rcu_read_unlock_trace(); + return ret; +} + #ifdef CONFIG_BPF_SYSCALL DECLARE_PER_CPU(int, bpf_prog_active); extern struct mutex bpf_stats_enabled_mutex; diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index e78cc5eea4a5..b5ffebcce6cc 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2279,6 +2279,21 @@ void bpf_prog_array_free(struct bpf_prog_array *progs) kfree_rcu(progs, rcu); } +static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu) +{ + struct bpf_prog_array *progs; + + progs = container_of(rcu, struct bpf_prog_array, rcu); + kfree_rcu(progs, rcu); +} + +void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs) +{ + if (!progs || progs == &bpf_empty_prog_array.hdr) + return; + call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb); +} + int bpf_prog_array_length(struct bpf_prog_array *array) { struct bpf_prog_array_item *item; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 10b157a6d73e..d1c22594dbf9 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1936,7 +1936,7 @@ int perf_event_attach_bpf_prog(struct perf_event *event, event->prog = prog; event->bpf_cookie = bpf_cookie; rcu_assign_pointer(event->tp_event->prog_array, new_array); - bpf_prog_array_free(old_array); + bpf_prog_array_free_sleepable(old_array); unlock: mutex_unlock(&bpf_event_mutex); @@ -1962,7 +1962,7 @@ void perf_event_detach_bpf_prog(struct perf_event *event) bpf_prog_array_delete_safe(old_array, event->prog); } else { rcu_assign_pointer(event->tp_event->prog_array, new_array); - bpf_prog_array_free(old_array); + bpf_prog_array_free_sleepable(old_array); } bpf_prog_put(event->prog); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 9711589273cd..0282c119b1b2 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "trace_dynevent.h" #include "trace_probe.h" @@ -1346,9 +1347,7 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, if (bpf_prog_array_valid(call)) { u32 ret; - preempt_disable(); - ret = trace_call_bpf(call, regs); - preempt_enable(); + ret = bpf_prog_run_array_sleepable(call->prog_array, regs, bpf_prog_run); if (!ret) return; } From 64ad7556c75ea102eec2f5bcd60fe2d66ce70308 Mon Sep 17 00:00:00 2001 From: Delyan Kratunov Date: Tue, 14 Jun 2022 23:10:43 +0000 Subject: [PATCH 3/5] bpf: allow sleepable uprobe programs to attach uprobe and kprobe programs have the same program type, KPROBE, which is currently not allowed to load sleepable programs. To avoid adding a new UPROBE type, instead allow sleepable KPROBE programs to load and defer the is-it-actually-a-uprobe-program check to attachment time, where there's already validation of the corresponding perf_event. A corollary of this patch is that you can now load a sleepable kprobe program but cannot attach it. Acked-by: Andrii Nakryiko Signed-off-by: Delyan Kratunov Link: https://lore.kernel.org/r/fcd44a7cd204f372f6bb03ef794e829adeaef299.1655248076.git.delyank@fb.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 4 ++-- kernel/events/core.c | 16 ++++++++++------ 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 2d2872682278..eadc23a8452c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -14829,8 +14829,8 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) } if (prog->aux->sleepable && prog->type != BPF_PROG_TYPE_TRACING && - prog->type != BPF_PROG_TYPE_LSM) { - verbose(env, "Only fentry/fexit/fmod_ret and lsm programs can be sleepable\n"); + prog->type != BPF_PROG_TYPE_LSM && prog->type != BPF_PROG_TYPE_KPROBE) { + verbose(env, "Only fentry/fexit/fmod_ret, lsm, and kprobe/uprobe programs can be sleepable\n"); return -EINVAL; } diff --git a/kernel/events/core.c b/kernel/events/core.c index 950b25c3f210..deee6815bdd3 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10069,26 +10069,30 @@ static inline bool perf_event_is_tracing(struct perf_event *event) int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie) { - bool is_kprobe, is_tracepoint, is_syscall_tp; + bool is_kprobe, is_uprobe, is_tracepoint, is_syscall_tp; if (!perf_event_is_tracing(event)) return perf_event_set_bpf_handler(event, prog, bpf_cookie); - is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; + is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_KPROBE; + is_uprobe = event->tp_event->flags & TRACE_EVENT_FL_UPROBE; is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; is_syscall_tp = is_syscall_trace_event(event->tp_event); - if (!is_kprobe && !is_tracepoint && !is_syscall_tp) + if (!is_kprobe && !is_uprobe && !is_tracepoint && !is_syscall_tp) /* bpf programs can only be attached to u/kprobe or tracepoint */ return -EINVAL; - if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) || + if (((is_kprobe || is_uprobe) && prog->type != BPF_PROG_TYPE_KPROBE) || (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) || (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) return -EINVAL; + if (prog->type == BPF_PROG_TYPE_KPROBE && prog->aux->sleepable && !is_uprobe) + /* only uprobe programs are allowed to be sleepable */ + return -EINVAL; + /* Kprobe override only works for kprobes, not uprobes. */ - if (prog->kprobe_override && - !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) + if (prog->kprobe_override && !is_kprobe) return -EINVAL; if (is_tracepoint || is_syscall_tp) { From c4cac71fc8a55cebd9abf30a3b287063be34b512 Mon Sep 17 00:00:00 2001 From: Delyan Kratunov Date: Tue, 14 Jun 2022 23:10:47 +0000 Subject: [PATCH 4/5] libbpf: add support for sleepable uprobe programs Add section mappings for u(ret)probe.s programs. Acked-by: Andrii Nakryiko Signed-off-by: Delyan Kratunov Link: https://lore.kernel.org/r/aedbc3b74f3523f00010a7b0df8f3388cca59f16.1655248076.git.delyank@fb.com Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index d989b0a17a89..49e359cd34df 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9177,8 +9177,10 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("sk_reuseport", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX), SEC_DEF("kprobe+", KPROBE, 0, SEC_NONE, attach_kprobe), SEC_DEF("uprobe+", KPROBE, 0, SEC_NONE, attach_uprobe), + SEC_DEF("uprobe.s+", KPROBE, 0, SEC_SLEEPABLE, attach_uprobe), SEC_DEF("kretprobe+", KPROBE, 0, SEC_NONE, attach_kprobe), SEC_DEF("uretprobe+", KPROBE, 0, SEC_NONE, attach_uprobe), + SEC_DEF("uretprobe.s+", KPROBE, 0, SEC_SLEEPABLE, attach_uprobe), SEC_DEF("kprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), SEC_DEF("kretprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), SEC_DEF("usdt+", KPROBE, 0, SEC_NONE, attach_usdt), @@ -11571,7 +11573,8 @@ static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf break; case 3: case 4: - opts.retprobe = strcmp(probe_type, "uretprobe") == 0; + opts.retprobe = strcmp(probe_type, "uretprobe") == 0 || + strcmp(probe_type, "uretprobe.s") == 0; if (opts.retprobe && offset != 0) { pr_warn("prog '%s': uretprobes do not support offset specification\n", prog->name); From cb3f4a4a462b46eb5487ad806d58e34824c49044 Mon Sep 17 00:00:00 2001 From: Delyan Kratunov Date: Tue, 14 Jun 2022 23:10:44 +0000 Subject: [PATCH 5/5] selftests/bpf: add tests for sleepable (uk)probes Add tests that ensure sleepable uprobe programs work correctly. Add tests that ensure sleepable kprobe programs cannot attach. Also add tests that attach both sleepable and non-sleepable uprobe programs to the same location (i.e. same bpf_prog_array). Acked-by: Andrii Nakryiko Signed-off-by: Delyan Kratunov Link: https://lore.kernel.org/r/c744e5bb7a5c0703f05444dc41f2522ba3579a48.1655248076.git.delyank@fb.com Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/prog_tests/attach_probe.c | 49 ++++++++++++++- .../selftests/bpf/progs/test_attach_probe.c | 60 +++++++++++++++++++ 2 files changed, 108 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index 08c0601b3e84..0b899d2d8ea7 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -17,6 +17,14 @@ static void trigger_func2(void) asm volatile (""); } +/* attach point for byname sleepable uprobe */ +static void trigger_func3(void) +{ + asm volatile (""); +} + +static char test_data[] = "test_data"; + void test_attach_probe(void) { DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); @@ -49,9 +57,17 @@ void test_attach_probe(void) if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset")) return; - skel = test_attach_probe__open_and_load(); + 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; @@ -151,6 +167,30 @@ void test_attach_probe(void) if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2")) 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; + + /* 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; + + 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; + + 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; + + 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; + + skel->bss->user_ptr = test_data; + /* trigger & validate kprobe && kretprobe */ usleep(1); @@ -164,6 +204,9 @@ void test_attach_probe(void) /* 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"); @@ -174,6 +217,10 @@ void test_attach_probe(void) 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"); cleanup: test_attach_probe__destroy(skel); diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c index ce9acf4db8d2..f1c88ad368ef 100644 --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -5,6 +5,7 @@ #include #include #include +#include #include "bpf_misc.h" int kprobe_res = 0; @@ -17,6 +18,11 @@ int uprobe_byname_res = 0; int uretprobe_byname_res = 0; int uprobe_byname2_res = 0; int uretprobe_byname2_res = 0; +int uprobe_byname3_sleepable_res = 0; +int uprobe_byname3_res = 0; +int uretprobe_byname3_sleepable_res = 0; +int uretprobe_byname3_res = 0; +void *user_ptr = 0; SEC("kprobe") int handle_kprobe(struct pt_regs *ctx) @@ -32,6 +38,17 @@ int BPF_KPROBE(handle_kprobe_auto) 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) { @@ -93,4 +110,47 @@ int handle_uretprobe_byname2(struct pt_regs *ctx) return 0; } +static __always_inline bool verify_sleepable_user_copy(void) +{ + char data[9]; + + bpf_copy_from_user(data, sizeof(data), user_ptr); + return bpf_strncmp(data, sizeof(data), "test_data") == 0; +} + +SEC("uprobe.s//proc/self/exe:trigger_func3") +int handle_uprobe_byname3_sleepable(struct pt_regs *ctx) +{ + if (verify_sleepable_user_copy()) + uprobe_byname3_sleepable_res = 9; + return 0; +} + +/** + * same target as the uprobe.s above to force sleepable and non-sleepable + * programs in the same bpf_prog_array + */ +SEC("uprobe//proc/self/exe:trigger_func3") +int handle_uprobe_byname3(struct pt_regs *ctx) +{ + uprobe_byname3_res = 10; + return 0; +} + +SEC("uretprobe.s//proc/self/exe:trigger_func3") +int handle_uretprobe_byname3_sleepable(struct pt_regs *ctx) +{ + if (verify_sleepable_user_copy()) + uretprobe_byname3_sleepable_res = 11; + return 0; +} + +SEC("uretprobe//proc/self/exe:trigger_func3") +int handle_uretprobe_byname3(struct pt_regs *ctx) +{ + uretprobe_byname3_res = 12; + return 0; +} + + char _license[] SEC("license") = "GPL";