diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index ec5214f39aa802ed923d10315a1672547493262d..70efcd0940f9f34b8649872b5b1ac44853a8e5f0 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -246,7 +246,7 @@ static void emit_prologue(u8 **pprog) * goto out; * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) * goto out; - * prog = array->prog[index]; + * prog = array->ptrs[index]; * if (prog == NULL) * goto out; * goto *(prog->bpf_func + prologue_size); @@ -284,9 +284,9 @@ static void emit_bpf_tail_call(u8 **pprog) EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ EMIT2_off32(0x89, 0x85, -STACKSIZE + 36); /* mov dword ptr [rbp - 516], eax */ - /* prog = array->prog[index]; */ + /* prog = array->ptrs[index]; */ EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */ - offsetof(struct bpf_array, prog)); + offsetof(struct bpf_array, ptrs)); EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */ /* if (prog == NULL) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 139d6d2e123fb0c69bbe31705b08b637c020ac8d..f57d7fed9ec3f4554609a02538f44c5f950612b6 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -10,6 +10,7 @@ #include #include #include +#include struct bpf_map; @@ -24,6 +25,10 @@ struct bpf_map_ops { void *(*map_lookup_elem)(struct bpf_map *map, void *key); int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags); int (*map_delete_elem)(struct bpf_map *map, void *key); + + /* funcs called by prog_array and perf_event_array map */ + void *(*map_fd_get_ptr) (struct bpf_map *map, int fd); + void (*map_fd_put_ptr) (void *ptr); }; struct bpf_map { @@ -142,13 +147,13 @@ struct bpf_array { bool owner_jited; union { char value[0] __aligned(8); - struct bpf_prog *prog[0] __aligned(8); + void *ptrs[0] __aligned(8); }; }; #define MAX_TAIL_CALL_CNT 32 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5); -void bpf_prog_array_map_clear(struct bpf_map *map); +void bpf_fd_array_map_clear(struct bpf_map *map); bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp); const struct bpf_func_proto *bpf_get_trace_printk_proto(void); @@ -185,6 +190,7 @@ extern const struct bpf_func_proto bpf_map_lookup_elem_proto; extern const struct bpf_func_proto bpf_map_update_elem_proto; extern const struct bpf_func_proto bpf_map_delete_elem_proto; +extern const struct bpf_func_proto bpf_perf_event_read_proto; extern const struct bpf_func_proto bpf_get_prandom_u32_proto; extern const struct bpf_func_proto bpf_get_smp_processor_id_proto; extern const struct bpf_func_proto bpf_tail_call_proto; diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 2027809433b3c86b77b832d2e7a5311021e45db3..092a0e8a479aa19569fa0704e050a853bc38883c 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -641,6 +641,8 @@ extern int perf_event_init_task(struct task_struct *child); extern void perf_event_exit_task(struct task_struct *child); extern void perf_event_free_task(struct task_struct *task); extern void perf_event_delayed_put(struct task_struct *task); +extern struct perf_event *perf_event_get(unsigned int fd); +extern const struct perf_event_attr *perf_event_attrs(struct perf_event *event); extern void perf_event_print_debug(void); extern void perf_pmu_disable(struct pmu *pmu); extern void perf_pmu_enable(struct pmu *pmu); @@ -659,6 +661,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, void *context); extern void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu); +extern u64 perf_event_read_local(struct perf_event *event); extern u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running); @@ -979,6 +982,12 @@ static inline int perf_event_init_task(struct task_struct *child) { return 0; } static inline void perf_event_exit_task(struct task_struct *child) { } static inline void perf_event_free_task(struct task_struct *task) { } static inline void perf_event_delayed_put(struct task_struct *task) { } +static inline struct perf_event *perf_event_get(unsigned int fd) { return ERR_PTR(-EINVAL); } +static inline const struct perf_event_attr *perf_event_attrs(struct perf_event *event) +{ + return ERR_PTR(-EINVAL); +} +static inline u64 perf_event_read_local(struct perf_event *event) { return -EINVAL; } static inline void perf_event_print_debug(void) { } static inline int perf_event_task_disable(void) { return -EINVAL; } static inline int perf_event_task_enable(void) { return -EINVAL; } @@ -1011,6 +1020,7 @@ static inline void perf_event_enable(struct perf_event *event) { } static inline void perf_event_disable(struct perf_event *event) { } static inline int __perf_event_disable(void *info) { return -1; } static inline void perf_event_task_tick(void) { } +static inline int perf_event_release_kernel(struct perf_event *event) { return 0; } #endif #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_NO_HZ_FULL) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 2ce13c109b006a5504946d785adaabe563a57a5e..92a48e2d54619f80113c13f9fff45f98ddfabe30 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -114,6 +114,7 @@ enum bpf_map_type { BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_ARRAY, BPF_MAP_TYPE_PROG_ARRAY, + BPF_MAP_TYPE_PERF_EVENT_ARRAY, }; enum bpf_prog_type { @@ -270,6 +271,7 @@ enum bpf_func_id { */ BPF_FUNC_skb_get_tunnel_key, BPF_FUNC_skb_set_tunnel_key, + BPF_FUNC_perf_event_read, /* u64 bpf_perf_event_read(&map, index) */ __BPF_FUNC_MAX_ID, }; diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index cb31229a6fa4ddd39c1d69038b998bc0c0dee4db..29ace107f2365c05b97f8f8aba54defeb59a6a78 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -150,15 +150,15 @@ static int __init register_array_map(void) } late_initcall(register_array_map); -static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr) +static struct bpf_map *fd_array_map_alloc(union bpf_attr *attr) { - /* only bpf_prog file descriptors can be stored in prog_array map */ + /* only file descriptors can be stored in this type of map */ if (attr->value_size != sizeof(u32)) return ERR_PTR(-EINVAL); return array_map_alloc(attr); } -static void prog_array_map_free(struct bpf_map *map) +static void fd_array_map_free(struct bpf_map *map) { struct bpf_array *array = container_of(map, struct bpf_array, map); int i; @@ -167,21 +167,21 @@ static void prog_array_map_free(struct bpf_map *map) /* make sure it's empty */ for (i = 0; i < array->map.max_entries; i++) - BUG_ON(array->prog[i] != NULL); + BUG_ON(array->ptrs[i] != NULL); kvfree(array); } -static void *prog_array_map_lookup_elem(struct bpf_map *map, void *key) +static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) { return NULL; } /* only called from syscall */ -static int prog_array_map_update_elem(struct bpf_map *map, void *key, - void *value, u64 map_flags) +static int fd_array_map_update_elem(struct bpf_map *map, void *key, + void *value, u64 map_flags) { struct bpf_array *array = container_of(map, struct bpf_array, map); - struct bpf_prog *prog, *old_prog; + void *new_ptr, *old_ptr; u32 index = *(u32 *)key, ufd; if (map_flags != BPF_ANY) @@ -191,57 +191,75 @@ static int prog_array_map_update_elem(struct bpf_map *map, void *key, return -E2BIG; ufd = *(u32 *)value; - prog = bpf_prog_get(ufd); - if (IS_ERR(prog)) - return PTR_ERR(prog); - - if (!bpf_prog_array_compatible(array, prog)) { - bpf_prog_put(prog); - return -EINVAL; - } + new_ptr = map->ops->map_fd_get_ptr(map, ufd); + if (IS_ERR(new_ptr)) + return PTR_ERR(new_ptr); - old_prog = xchg(array->prog + index, prog); - if (old_prog) - bpf_prog_put_rcu(old_prog); + old_ptr = xchg(array->ptrs + index, new_ptr); + if (old_ptr) + map->ops->map_fd_put_ptr(old_ptr); return 0; } -static int prog_array_map_delete_elem(struct bpf_map *map, void *key) +static int fd_array_map_delete_elem(struct bpf_map *map, void *key) { struct bpf_array *array = container_of(map, struct bpf_array, map); - struct bpf_prog *old_prog; + void *old_ptr; u32 index = *(u32 *)key; if (index >= array->map.max_entries) return -E2BIG; - old_prog = xchg(array->prog + index, NULL); - if (old_prog) { - bpf_prog_put_rcu(old_prog); + old_ptr = xchg(array->ptrs + index, NULL); + if (old_ptr) { + map->ops->map_fd_put_ptr(old_ptr); return 0; } else { return -ENOENT; } } +static void *prog_fd_array_get_ptr(struct bpf_map *map, int fd) +{ + struct bpf_array *array = container_of(map, struct bpf_array, map); + struct bpf_prog *prog = bpf_prog_get(fd); + if (IS_ERR(prog)) + return prog; + + if (!bpf_prog_array_compatible(array, prog)) { + bpf_prog_put(prog); + return ERR_PTR(-EINVAL); + } + return prog; +} + +static void prog_fd_array_put_ptr(void *ptr) +{ + struct bpf_prog *prog = ptr; + + bpf_prog_put_rcu(prog); +} + /* decrement refcnt of all bpf_progs that are stored in this map */ -void bpf_prog_array_map_clear(struct bpf_map *map) +void bpf_fd_array_map_clear(struct bpf_map *map) { struct bpf_array *array = container_of(map, struct bpf_array, map); int i; for (i = 0; i < array->map.max_entries; i++) - prog_array_map_delete_elem(map, &i); + fd_array_map_delete_elem(map, &i); } static const struct bpf_map_ops prog_array_ops = { - .map_alloc = prog_array_map_alloc, - .map_free = prog_array_map_free, + .map_alloc = fd_array_map_alloc, + .map_free = fd_array_map_free, .map_get_next_key = array_map_get_next_key, - .map_lookup_elem = prog_array_map_lookup_elem, - .map_update_elem = prog_array_map_update_elem, - .map_delete_elem = prog_array_map_delete_elem, + .map_lookup_elem = fd_array_map_lookup_elem, + .map_update_elem = fd_array_map_update_elem, + .map_delete_elem = fd_array_map_delete_elem, + .map_fd_get_ptr = prog_fd_array_get_ptr, + .map_fd_put_ptr = prog_fd_array_put_ptr, }; static struct bpf_map_type_list prog_array_type __read_mostly = { @@ -255,3 +273,60 @@ static int __init register_prog_array_map(void) return 0; } late_initcall(register_prog_array_map); + +static void perf_event_array_map_free(struct bpf_map *map) +{ + bpf_fd_array_map_clear(map); + fd_array_map_free(map); +} + +static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd) +{ + struct perf_event *event; + const struct perf_event_attr *attr; + + event = perf_event_get(fd); + if (IS_ERR(event)) + return event; + + attr = perf_event_attrs(event); + if (IS_ERR(attr)) + return (void *)attr; + + if (attr->type != PERF_TYPE_RAW && + attr->type != PERF_TYPE_HARDWARE) { + perf_event_release_kernel(event); + return ERR_PTR(-EINVAL); + } + return event; +} + +static void perf_event_fd_array_put_ptr(void *ptr) +{ + struct perf_event *event = ptr; + + perf_event_release_kernel(event); +} + +static const struct bpf_map_ops perf_event_array_ops = { + .map_alloc = fd_array_map_alloc, + .map_free = perf_event_array_map_free, + .map_get_next_key = array_map_get_next_key, + .map_lookup_elem = fd_array_map_lookup_elem, + .map_update_elem = fd_array_map_update_elem, + .map_delete_elem = fd_array_map_delete_elem, + .map_fd_get_ptr = perf_event_fd_array_get_ptr, + .map_fd_put_ptr = perf_event_fd_array_put_ptr, +}; + +static struct bpf_map_type_list perf_event_array_type __read_mostly = { + .ops = &perf_event_array_ops, + .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, +}; + +static int __init register_perf_event_array_map(void) +{ + bpf_register_map_type(&perf_event_array_type); + return 0; +} +late_initcall(register_perf_event_array_map); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index fafa741614453c46ec9eb90d340221dcf9c3cc85..67c380cfa9ca5b6ed8e48b69b38ba3c611d51a65 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -450,7 +450,7 @@ static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) tail_call_cnt++; - prog = READ_ONCE(array->prog[index]); + prog = READ_ONCE(array->ptrs[index]); if (unlikely(!prog)) goto out; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a1b14d197a4fc2da6acf2d812372284e78bc5af8..dc9b464fefa954a50c83e632c4ebea2ec464839e 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -72,7 +72,7 @@ static int bpf_map_release(struct inode *inode, struct file *filp) /* prog_array stores refcnt-ed bpf_prog pointers * release them all when user space closes prog_array_fd */ - bpf_prog_array_map_clear(map); + bpf_fd_array_map_clear(map); bpf_map_put(map); return 0; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index cd307df98cb33fca49c2e02704336f0bdd7c736d..48e1c719256038563c691653387428613d580214 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -238,6 +238,14 @@ static const char * const reg_type_str[] = { [CONST_IMM] = "imm", }; +static const struct { + int map_type; + int func_id; +} func_limit[] = { + {BPF_MAP_TYPE_PROG_ARRAY, BPF_FUNC_tail_call}, + {BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_read}, +}; + static void print_verifier_state(struct verifier_env *env) { enum bpf_reg_type t; @@ -837,6 +845,28 @@ static int check_func_arg(struct verifier_env *env, u32 regno, return err; } +static int check_map_func_compatibility(struct bpf_map *map, int func_id) +{ + bool bool_map, bool_func; + int i; + + if (!map) + return 0; + + for (i = 0; i <= ARRAY_SIZE(func_limit); i++) { + bool_map = (map->map_type == func_limit[i].map_type); + bool_func = (func_id == func_limit[i].func_id); + /* only when map & func pair match it can continue. + * don't allow any other map type to be passed into + * the special func; + */ + if (bool_map != bool_func) + return -EINVAL; + } + + return 0; +} + static int check_call(struct verifier_env *env, int func_id) { struct verifier_state *state = &env->cur_state; @@ -912,21 +942,9 @@ static int check_call(struct verifier_env *env, int func_id) return -EINVAL; } - if (map && map->map_type == BPF_MAP_TYPE_PROG_ARRAY && - func_id != BPF_FUNC_tail_call) - /* prog_array map type needs extra care: - * only allow to pass it into bpf_tail_call() for now. - * bpf_map_delete_elem() can be allowed in the future, - * while bpf_map_update_elem() must only be done via syscall - */ - return -EINVAL; - - if (func_id == BPF_FUNC_tail_call && - map->map_type != BPF_MAP_TYPE_PROG_ARRAY) - /* don't allow any other map type to be passed into - * bpf_tail_call() - */ - return -EINVAL; + err = check_map_func_compatibility(map, func_id); + if (err) + return err; return 0; } diff --git a/kernel/events/core.c b/kernel/events/core.c index d3dae3419b99566c127f1682b29f39bb184bbdb1..e2c6a8886d4d376450b61f8a3347427484ab392d 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3212,6 +3212,59 @@ static inline u64 perf_event_count(struct perf_event *event) return __perf_event_count(event); } +/* + * NMI-safe method to read a local event, that is an event that + * is: + * - either for the current task, or for this CPU + * - does not have inherit set, for inherited task events + * will not be local and we cannot read them atomically + * - must not have a pmu::count method + */ +u64 perf_event_read_local(struct perf_event *event) +{ + unsigned long flags; + u64 val; + + /* + * Disabling interrupts avoids all counter scheduling (context + * switches, timer based rotation and IPIs). + */ + local_irq_save(flags); + + /* If this is a per-task event, it must be for current */ + WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) && + event->hw.target != current); + + /* If this is a per-CPU event, it must be for this CPU */ + WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) && + event->cpu != smp_processor_id()); + + /* + * It must not be an event with inherit set, we cannot read + * all child counters from atomic context. + */ + WARN_ON_ONCE(event->attr.inherit); + + /* + * It must not have a pmu::count method, those are not + * NMI safe. + */ + WARN_ON_ONCE(event->pmu->count); + + /* + * If the event is currently on this CPU, its either a per-task event, + * or local to this CPU. Furthermore it means its ACTIVE (otherwise + * oncpu == -1). + */ + if (event->oncpu == smp_processor_id()) + event->pmu->read(event); + + val = local64_read(&event->count); + local_irq_restore(flags); + + return val; +} + static u64 perf_event_read(struct perf_event *event) { /* @@ -8574,6 +8627,31 @@ void perf_event_delayed_put(struct task_struct *task) WARN_ON_ONCE(task->perf_event_ctxp[ctxn]); } +struct perf_event *perf_event_get(unsigned int fd) +{ + int err; + struct fd f; + struct perf_event *event; + + err = perf_fget_light(fd, &f); + if (err) + return ERR_PTR(err); + + event = f.file->private_data; + atomic_long_inc(&event->refcount); + fdput(f); + + return event; +} + +const struct perf_event_attr *perf_event_attrs(struct perf_event *event) +{ + if (!event) + return ERR_PTR(-EINVAL); + + return &event->attr; +} + /* * inherit a event from parent task to child task: */ diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 88a041adee901f5109c50e560cb5e13fc96f0357..ef9936df1b0491b5621501a495e5a20991aac4a7 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -158,6 +158,35 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void) return &bpf_trace_printk_proto; } +static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5) +{ + struct bpf_map *map = (struct bpf_map *) (unsigned long) r1; + struct bpf_array *array = container_of(map, struct bpf_array, map); + struct perf_event *event; + + if (unlikely(index >= array->map.max_entries)) + return -E2BIG; + + event = (struct perf_event *)array->ptrs[index]; + if (!event) + return -ENOENT; + + /* + * we don't know if the function is run successfully by the + * return value. It can be judged in other places, such as + * eBPF programs. + */ + return perf_event_read_local(event); +} + +const struct bpf_func_proto bpf_perf_event_read_proto = { + .func = bpf_perf_event_read, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func_id) { switch (func_id) { @@ -183,6 +212,8 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func return bpf_get_trace_printk_proto(); case BPF_FUNC_get_smp_processor_id: return &bpf_get_smp_processor_id_proto; + case BPF_FUNC_perf_event_read: + return &bpf_perf_event_read_proto; default: return NULL; } diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 4450fed91ab40f61306ab1af8bf38d470b1f4114..63e7d50e6a4fe3ca46cbd3b7ae064600bf6696ff 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -12,6 +12,7 @@ hostprogs-y += tracex2 hostprogs-y += tracex3 hostprogs-y += tracex4 hostprogs-y += tracex5 +hostprogs-y += tracex6 hostprogs-y += lathist test_verifier-objs := test_verifier.o libbpf.o @@ -25,6 +26,7 @@ tracex2-objs := bpf_load.o libbpf.o tracex2_user.o tracex3-objs := bpf_load.o libbpf.o tracex3_user.o tracex4-objs := bpf_load.o libbpf.o tracex4_user.o tracex5-objs := bpf_load.o libbpf.o tracex5_user.o +tracex6-objs := bpf_load.o libbpf.o tracex6_user.o lathist-objs := bpf_load.o libbpf.o lathist_user.o # Tell kbuild to always build the programs @@ -37,6 +39,7 @@ always += tracex2_kern.o always += tracex3_kern.o always += tracex4_kern.o always += tracex5_kern.o +always += tracex6_kern.o always += tcbpf1_kern.o always += lathist_kern.o @@ -51,6 +54,7 @@ HOSTLOADLIBES_tracex2 += -lelf HOSTLOADLIBES_tracex3 += -lelf HOSTLOADLIBES_tracex4 += -lelf -lrt HOSTLOADLIBES_tracex5 += -lelf +HOSTLOADLIBES_tracex6 += -lelf HOSTLOADLIBES_lathist += -lelf # point this to your LLVM backend with bpf support diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h index c77c872fe8ee477c7cfabf5fd539824fc676b173..3a44d3a272af40119b379fe1930244909499fd8d 100644 --- a/samples/bpf/bpf_helpers.h +++ b/samples/bpf/bpf_helpers.h @@ -31,6 +31,8 @@ static unsigned long long (*bpf_get_current_uid_gid)(void) = (void *) BPF_FUNC_get_current_uid_gid; static int (*bpf_get_current_comm)(void *buf, int buf_size) = (void *) BPF_FUNC_get_current_comm; +static int (*bpf_perf_event_read)(void *map, int index) = + (void *) BPF_FUNC_perf_event_read; /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c new file mode 100644 index 0000000000000000000000000000000000000000..23d1cffaf2497311386a1d4758eb6ccb22ae6109 --- /dev/null +++ b/samples/bpf/tracex6_kern.c @@ -0,0 +1,26 @@ +#include +#include +#include "bpf_helpers.h" + +struct bpf_map_def SEC("maps") my_map = { + .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(u32), + .max_entries = 32, +}; + +SEC("kprobe/sys_write") +int bpf_prog1(struct pt_regs *ctx) +{ + u64 count; + u32 key = bpf_get_smp_processor_id(); + char fmt[] = "CPU-%d %llu\n"; + + count = bpf_perf_event_read(&my_map, key); + bpf_trace_printk(fmt, sizeof(fmt), key, count); + + return 0; +} + +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = LINUX_VERSION_CODE; diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c new file mode 100644 index 0000000000000000000000000000000000000000..928f05eaa304ed5e47d2d2ed3312616efd7fbcd4 --- /dev/null +++ b/samples/bpf/tracex6_user.c @@ -0,0 +1,68 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "libbpf.h" +#include "bpf_load.h" + +#define SAMPLE_PERIOD 0x7fffffffffffffffULL + +static void test_bpf_perf_event(void) +{ + int nr_cpus = sysconf(_SC_NPROCESSORS_CONF); + int *pmu_fd = malloc(nr_cpus * sizeof(int)); + unsigned long value; + int i; + + struct perf_event_attr attr_insn_pmu = { + .freq = 0, + .sample_period = SAMPLE_PERIOD, + .inherit = 0, + .type = PERF_TYPE_HARDWARE, + .read_format = 0, + .sample_type = 0, + .config = 0,/* PMU: cycles */ + }; + + for (i = 0; i < nr_cpus; i++) { + pmu_fd[i] = perf_event_open(&attr_insn_pmu, -1/*pid*/, i/*cpu*/, -1/*group_fd*/, 0); + if (pmu_fd[i] < 0) + printf("event syscall failed\n"); + + bpf_update_elem(map_fd[0], &i, &pmu_fd[i], BPF_ANY); + ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0); + } + + system("ls"); + system("pwd"); + system("sleep 2"); + + for (i = 0; i < nr_cpus; i++) + close(pmu_fd[i]); + + close(map_fd); + + free(pmu_fd); +} + +int main(int argc, char **argv) +{ + char filename[256]; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + + if (load_bpf_file(filename)) { + printf("%s", bpf_log_buf); + return 1; + } + + test_bpf_perf_event(); + + return 0; +}