diff options
| -rw-r--r-- | include/linux/trace_events.h | 8 | ||||
| -rw-r--r-- | include/uapi/linux/perf_event.h | 4 | ||||
| -rw-r--r-- | kernel/events/core.c | 188 | ||||
| -rw-r--r-- | kernel/trace/trace_event_perf.c | 102 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 91 | ||||
| -rw-r--r-- | kernel/trace/trace_probe.h | 11 | ||||
| -rw-r--r-- | kernel/trace/trace_uprobe.c | 86 | ||||
| -rw-r--r-- | tools/include/uapi/linux/perf_event.h | 4 |
8 files changed, 443 insertions, 51 deletions
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 8a1442c4e513..c20acfcf647d 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -540,6 +540,14 @@ extern int perf_trace_init(struct perf_event *event); extern void perf_trace_destroy(struct perf_event *event); extern int perf_trace_add(struct perf_event *event, int flags); extern void perf_trace_del(struct perf_event *event, int flags); +#ifdef CONFIG_KPROBE_EVENTS +extern int perf_kprobe_init(struct perf_event *event, bool is_retprobe); +extern void perf_kprobe_destroy(struct perf_event *event); +#endif +#ifdef CONFIG_UPROBE_EVENTS +extern int perf_uprobe_init(struct perf_event *event, bool is_retprobe); +extern void perf_uprobe_destroy(struct perf_event *event); +#endif extern int ftrace_profile_set_filter(struct perf_event *event, int event_id, char *filter_str); extern void ftrace_profile_free_filter(struct perf_event *event); diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index e0739a1aa4b2..6f873503552d 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -380,10 +380,14 @@ struct perf_event_attr { __u32 bp_type; union { __u64 bp_addr; + __u64 kprobe_func; /* for perf_kprobe */ + __u64 uprobe_path; /* for perf_uprobe */ __u64 config1; /* extension of config */ }; union { __u64 bp_len; + __u64 kprobe_addr; /* when kprobe_func == NULL */ + __u64 probe_offset; /* for perf_[k,u]probe */ __u64 config2; /* extension of config1 */ }; __u64 branch_sample_type; /* enum perf_branch_sample_type */ diff --git a/kernel/events/core.c b/kernel/events/core.c index 96db9ae5d5af..57898102847f 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7996,9 +7996,119 @@ static struct pmu perf_tracepoint = { .read = perf_swevent_read, }; +#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS) +/* + * Flags in config, used by dynamic PMU kprobe and uprobe + * The flags should match following PMU_FORMAT_ATTR(). + * + * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe + * if not set, create kprobe/uprobe + */ +enum perf_probe_config { + PERF_PROBE_CONFIG_IS_RETPROBE = 1U << 0, /* [k,u]retprobe */ +}; + +PMU_FORMAT_ATTR(retprobe, "config:0"); + +static struct attribute *probe_attrs[] = { + &format_attr_retprobe.attr, + NULL, +}; + +static struct attribute_group probe_format_group = { + .name = "format", + .attrs = probe_attrs, +}; + +static const struct attribute_group *probe_attr_groups[] = { + &probe_format_group, + NULL, +}; +#endif + +#ifdef CONFIG_KPROBE_EVENTS +static int perf_kprobe_event_init(struct perf_event *event); +static struct pmu perf_kprobe = { + .task_ctx_nr = perf_sw_context, + .event_init = perf_kprobe_event_init, + .add = perf_trace_add, + .del = perf_trace_del, + .start = perf_swevent_start, + .stop = perf_swevent_stop, + .read = perf_swevent_read, + .attr_groups = probe_attr_groups, +}; + +static int perf_kprobe_event_init(struct perf_event *event) +{ + int err; + bool is_retprobe; + + if (event->attr.type != perf_kprobe.type) + return -ENOENT; + /* + * no branch sampling for probe events + */ + if (has_branch_stack(event)) + return -EOPNOTSUPP; + + is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE; + err = perf_kprobe_init(event, is_retprobe); + if (err) + return err; + + event->destroy = perf_kprobe_destroy; + + return 0; +} +#endif /* CONFIG_KPROBE_EVENTS */ + +#ifdef CONFIG_UPROBE_EVENTS +static int perf_uprobe_event_init(struct perf_event *event); +static struct pmu perf_uprobe = { + .task_ctx_nr = perf_sw_context, + .event_init = perf_uprobe_event_init, + .add = perf_trace_add, + .del = perf_trace_del, + .start = perf_swevent_start, + .stop = perf_swevent_stop, + .read = perf_swevent_read, + .attr_groups = probe_attr_groups, +}; + +static int perf_uprobe_event_init(struct perf_event *event) +{ + int err; + bool is_retprobe; + + if (event->attr.type != perf_uprobe.type) + return -ENOENT; + /* + * no branch sampling for probe events + */ + if (has_branch_stack(event)) + return -EOPNOTSUPP; + + is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE; + err = perf_uprobe_init(event, is_retprobe); + if (err) + return err; + + event->destroy = perf_uprobe_destroy; + + return 0; +} +#endif /* CONFIG_UPROBE_EVENTS */ + static inline void perf_tp_register(void) { perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT); +#ifdef CONFIG_KPROBE_EVENTS + perf_pmu_register(&perf_kprobe, "kprobe", -1); +#endif +#ifdef CONFIG_UPROBE_EVENTS + perf_pmu_register(&perf_uprobe, "uprobe", -1); +#endif } static void perf_event_free_filter(struct perf_event *event) @@ -8075,13 +8185,32 @@ static void perf_event_free_bpf_handler(struct perf_event *event) } #endif +/* + * returns true if the event is a tracepoint, or a kprobe/upprobe created + * with perf_event_open() + */ +static inline bool perf_event_is_tracing(struct perf_event *event) +{ + if (event->pmu == &perf_tracepoint) + return true; +#ifdef CONFIG_KPROBE_EVENTS + if (event->pmu == &perf_kprobe) + return true; +#endif +#ifdef CONFIG_UPROBE_EVENTS + if (event->pmu == &perf_uprobe) + return true; +#endif + return false; +} + static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) { bool is_kprobe, is_tracepoint, is_syscall_tp; struct bpf_prog *prog; int ret; - if (event->attr.type != PERF_TYPE_TRACEPOINT) + if (!perf_event_is_tracing(event)) return perf_event_set_bpf_handler(event, prog_fd); is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; @@ -8127,7 +8256,7 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) static void perf_event_free_bpf_prog(struct perf_event *event) { - if (event->attr.type != PERF_TYPE_TRACEPOINT) { + if (!perf_event_is_tracing(event)) { perf_event_free_bpf_handler(event); return; } @@ -8546,47 +8675,36 @@ fail_clear_files: return ret; } -static int -perf_tracepoint_set_filter(struct perf_event *event, char *filter_str) -{ - struct perf_event_context *ctx = event->ctx; - int ret; - - /* - * Beware, here be dragons!! - * - * the tracepoint muck will deadlock against ctx->mutex, but the tracepoint - * stuff does not actually need it. So temporarily drop ctx->mutex. As per - * perf_event_ctx_lock() we already have a reference on ctx. - * - * This can result in event getting moved to a different ctx, but that - * does not affect the tracepoint state. - */ - mutex_unlock(&ctx->mutex); - ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); - mutex_lock(&ctx->mutex); - - return ret; -} - static int perf_event_set_filter(struct perf_event *event, void __user *arg) { - char *filter_str; int ret = -EINVAL; - - if ((event->attr.type != PERF_TYPE_TRACEPOINT || - !IS_ENABLED(CONFIG_EVENT_TRACING)) && - !has_addr_filter(event)) - return -EINVAL; + char *filter_str; filter_str = strndup_user(arg, PAGE_SIZE); if (IS_ERR(filter_str)) return PTR_ERR(filter_str); - if (IS_ENABLED(CONFIG_EVENT_TRACING) && - event->attr.type == PERF_TYPE_TRACEPOINT) - ret = perf_tracepoint_set_filter(event, filter_str); - else if (has_addr_filter(event)) +#ifdef CONFIG_EVENT_TRACING + if (perf_event_is_tracing(event)) { + struct perf_event_context *ctx = event->ctx; + + /* + * Beware, here be dragons!! + * + * the tracepoint muck will deadlock against ctx->mutex, but + * the tracepoint stuff does not actually need it. So + * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we + * already have a reference on ctx. + * + * This can result in event getting moved to a different ctx, + * but that does not affect the tracepoint state. + */ + mutex_unlock(&ctx->mutex); + ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); + mutex_lock(&ctx->mutex); + } else +#endif + if (has_addr_filter(event)) ret = perf_event_set_addr_filter(event, filter_str); kfree(filter_str); diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 55d6dff37daf..2c416509b834 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -8,6 +8,7 @@ #include <linux/module.h> #include <linux/kprobes.h> #include "trace.h" +#include "trace_probe.h" static char __percpu *perf_trace_buf[PERF_NR_CONTEXTS]; @@ -237,6 +238,107 @@ void perf_trace_destroy(struct perf_event *p_event) mutex_unlock(&event_mutex); } +#ifdef CONFIG_KPROBE_EVENTS +int perf_kprobe_init(struct perf_event *p_event, bool is_retprobe) +{ + int ret; + char *func = NULL; + struct trace_event_call *tp_event; + + if (p_event->attr.kprobe_func) { + func = kzalloc(KSYM_NAME_LEN, GFP_KERNEL); + if (!func) + return -ENOMEM; + ret = strncpy_from_user( + func, u64_to_user_ptr(p_event->attr.kprobe_func), + KSYM_NAME_LEN); + if (ret < 0) + goto out; + + if (func[0] == '\0') { + kfree(func); + func = NULL; + } + } + + tp_event = create_local_trace_kprobe( + func, (void *)(unsigned long)(p_event->attr.kprobe_addr), + p_event->attr.probe_offset, is_retprobe); + if (IS_ERR(tp_event)) { + ret = PTR_ERR(tp_event); + goto out; + } + + ret = perf_trace_event_init(tp_event, p_event); + if (ret) + destroy_local_trace_kprobe(tp_event); +out: + kfree(func); + return ret; +} + +void perf_kprobe_destroy(struct perf_event *p_event) +{ + perf_trace_event_close(p_event); + perf_trace_event_unreg(p_event); + + destroy_local_trace_kprobe(p_event->tp_event); +} +#endif /* CONFIG_KPROBE_EVENTS */ + +#ifdef CONFIG_UPROBE_EVENTS +int perf_uprobe_init(struct perf_event *p_event, bool is_retprobe) +{ + int ret; + char *path = NULL; + struct trace_event_call *tp_event; + + if (!p_event->attr.uprobe_path) + return -EINVAL; + path = kzalloc(PATH_MAX, GFP_KERNEL); + if (!path) + return -ENOMEM; + ret = strncpy_from_user( + path, u64_to_user_ptr(p_event->attr.uprobe_path), PATH_MAX); + if (ret < 0) + goto out; + if (path[0] == '\0') { + ret = -EINVAL; + goto out; + } + + tp_event = create_local_trace_uprobe( + path, p_event->attr.probe_offset, is_retprobe); + if (IS_ERR(tp_event)) { + ret = PTR_ERR(tp_event); + goto out; + } + + /* + * local trace_uprobe need to hold event_mutex to call + * uprobe_buffer_enable() and uprobe_buffer_disable(). + * event_mutex is not required for local trace_kprobes. + */ + mutex_lock(&event_mutex); + ret = perf_trace_event_init(tp_event, p_event); + if (ret) + destroy_local_trace_uprobe(tp_event); + mutex_unlock(&event_mutex); +out: + kfree(path); + return ret; +} + +void perf_uprobe_destroy(struct perf_event *p_event) +{ + mutex_lock(&event_mutex); + perf_trace_event_close(p_event); + perf_trace_event_unreg(p_event); + mutex_unlock(&event_mutex); + destroy_local_trace_uprobe(p_event->tp_event); +} +#endif /* CONFIG_UPROBE_EVENTS */ + int perf_trace_add(struct perf_event *p_event, int flags) { struct trace_event_call *tp_event = p_event->tp_event; diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 1fad24acd444..5ce9b8cf7be3 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -462,6 +462,14 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) disable_kprobe(&tk->rp.kp); wait = 1; } + + /* + * if tk is not added to any list, it must be a local trace_kprobe + * created with perf_event_open. We don't need to wait for these + * trace_kprobes + */ + if (list_empty(&tk->list)) + wait = 0; out: if (wait) { /* @@ -1358,12 +1366,9 @@ static struct trace_event_functions kprobe_funcs = { .trace = print_kprobe_event }; -static int register_kprobe_event(struct trace_kprobe *tk) +static inline void init_trace_event_call(struct trace_kprobe *tk, + struct trace_event_call *call) { - struct trace_event_call *call = &tk->tp.call; - int ret; - - /* Initialize trace_event_call */ INIT_LIST_HEAD(&call->class->fields); if (trace_kprobe_is_return(tk)) { call->event.funcs = &kretprobe_funcs; @@ -1372,6 +1377,19 @@ static int register_kprobe_event(struct trace_kprobe *tk) call->event.funcs = &kprobe_funcs; call->class->define_fields = kprobe_event_define_fields; } + + call->flags = TRACE_EVENT_FL_KPROBE; + call->class->reg = kprobe_register; + call->data = tk; +} + +static int register_kprobe_event(struct trace_kprobe *tk) +{ + struct trace_event_call *call = &tk->tp.call; + int ret = 0; + + init_trace_event_call(tk, call); + if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) return -ENOMEM; ret = register_trace_event(&call->event); @@ -1379,9 +1397,6 @@ static int register_kprobe_event(struct trace_kprobe *tk) kfree(call->print_fmt); return -ENODEV; } - call->flags = TRACE_EVENT_FL_KPROBE; - call->class->reg = kprobe_register; - call->data = tk; ret = trace_add_event_call(call); if (ret) { pr_info("Failed to register kprobe event: %s\n", @@ -1403,6 +1418,66 @@ static int unregister_kprobe_event(struct trace_kprobe *tk) return ret; } +#ifdef CONFIG_PERF_EVENTS +/* create a trace_kprobe, but don't add it to global lists */ +struct trace_event_call * +create_local_trace_kprobe(char *func, void *addr, unsigned long offs, + bool is_return) +{ + struct trace_kprobe *tk; + int ret; + char *event; + + /* + * local trace_kprobes are not added to probe_list, so they are never + * searched in find_trace_kprobe(). Therefore, there is no concern of + * duplicated name here. + */ + event = func ? func : "DUMMY_EVENT"; + + tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, + offs, 0 /* maxactive */, 0 /* nargs */, + is_return); + + if (IS_ERR(tk)) { + pr_info("Failed to allocate trace_probe.(%d)\n", + (int)PTR_ERR(tk)); + return ERR_CAST(tk); + } + + init_trace_event_call(tk, &tk->tp.call); + + if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { + ret = -ENOMEM; + goto error; + } + + ret = __register_trace_kprobe(tk); + if (ret < 0) + goto error; + + return &tk->tp.call; +error: + free_trace_kprobe(tk); + return ERR_PTR(ret); +} + +void destroy_local_trace_kprobe(struct trace_event_call *event_call) +{ + struct trace_kprobe *tk; + + tk = container_of(event_call, struct trace_kprobe, tp.call); + + if (trace_probe_is_enabled(&tk->tp)) { + WARN_ON(1); + return; + } + + __unregister_trace_kprobe(tk); + free_trace_kprobe(tk); +} +#endif /* CONFIG_PERF_EVENTS */ + /* Make a tracefs interface for controlling probe points */ static __init int init_kprobe_trace(void) { diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index e101c5bb9eda..0745f895f780 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -416,3 +416,14 @@ store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, } extern int set_print_fmt(struct trace_probe *tp, bool is_return); + +#ifdef CONFIG_PERF_EVENTS +extern struct trace_event_call * +create_local_trace_kprobe(char *func, void *addr, unsigned long offs, + bool is_return); +extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); + +extern struct trace_event_call * +create_local_trace_uprobe(char *name, unsigned long offs, bool is_return); +extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); +#endif diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 268029ae1be6..2014f4351ae0 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1292,16 +1292,25 @@ static struct trace_event_functions uprobe_funcs = { .trace = print_uprobe_event }; -static int register_uprobe_event(struct trace_uprobe *tu) +static inline void init_trace_event_call(struct trace_uprobe *tu, + struct trace_event_call *call) { - struct trace_event_call *call = &tu->tp.call; - int ret; - - /* Initialize trace_event_call */ INIT_LIST_HEAD(&call->class->fields); call->event.funcs = &uprobe_funcs; call->class->define_fields = uprobe_event_define_fields; + call->flags = TRACE_EVENT_FL_UPROBE; + call->class->reg = trace_uprobe_register; + call->data = tu; +} + +static int register_uprobe_event(struct trace_uprobe *tu) +{ + struct trace_event_call *call = &tu->tp.call; + int ret = 0; + + init_trace_event_call(tu, call); + if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) return -ENOMEM; @@ -1311,9 +1320,6 @@ static int register_uprobe_event(struct trace_uprobe *tu) return -ENODEV; } - call->flags = TRACE_EVENT_FL_UPROBE; - call->class->reg = trace_uprobe_register; - call->data = tu; ret = trace_add_event_call(call); if (ret) { @@ -1339,6 +1345,70 @@ static int unregister_uprobe_event(struct trace_uprobe *tu) return 0; } +#ifdef CONFIG_PERF_EVENTS +struct trace_event_call * +create_local_trace_uprobe(char *name, unsigned long offs, bool is_return) +{ + struct trace_uprobe *tu; + struct inode *inode; + struct path path; + int ret; + + ret = kern_path(name, LOOKUP_FOLLOW, &path); + if (ret) + return ERR_PTR(ret); + + inode = igrab(d_inode(path.dentry)); + path_put(&path); + + if (!inode || !S_ISREG(inode->i_mode)) { + iput(inode); + return ERR_PTR(-EINVAL); + } + + /* + * local trace_kprobes are not added to probe_list, so they are never + * searched in find_trace_kprobe(). Therefore, there is no concern of + * duplicated name "DUMMY_EVENT" here. + */ + tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, + is_return); + + if (IS_ERR(tu)) { + pr_info("Failed to allocate trace_uprobe.(%d)\n", + (int)PTR_ERR(tu)); + return ERR_CAST(tu); + } + + tu->offset = offs; + tu->inode = inode; + tu->filename = kstrdup(name, GFP_KERNEL); + init_trace_event_call(tu, &tu->tp.call); + + if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { + ret = -ENOMEM; + goto error; + } + + return &tu->tp.call; +error: + free_trace_uprobe(tu); + return ERR_PTR(ret); +} + +void destroy_local_trace_uprobe(struct trace_event_call *event_call) +{ + struct trace_uprobe *tu; + + tu = container_of(event_call, struct trace_uprobe, tp.call); + + kfree(tu->tp.call.print_fmt); + tu->tp.call.print_fmt = NULL; + + free_trace_uprobe(tu); +} +#endif /* CONFIG_PERF_EVENTS */ + /* Make a trace interface for controling probe points */ static __init int init_uprobe_trace(void) { diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h index e0739a1aa4b2..6f873503552d 100644 --- a/tools/include/uapi/linux/perf_event.h +++ b/tools/include/uapi/linux/perf_event.h @@ -380,10 +380,14 @@ struct perf_event_attr { __u32 bp_type; union { __u64 bp_addr; + __u64 kprobe_func; /* for perf_kprobe */ + __u64 uprobe_path; /* for perf_uprobe */ __u64 config1; /* extension of config */ }; union { __u64 bp_len; + __u64 kprobe_addr; /* when kprobe_func == NULL */ + __u64 probe_offset; /* for perf_[k,u]probe */ __u64 config2; /* extension of config1 */ }; __u64 branch_sample_type; /* enum perf_branch_sample_type */ |