From 4d655281eb1bb59fad021c0f68afd033f8d0320d Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 11 Jan 2020 01:06:41 +0900 Subject: [PATCH] tracing/boot Add kprobe event support Add kprobe event support on event node to boot-time tracing. If the group name of event is "kprobes", the boot-time tracing defines new probe event according to "probes" values. - ftrace.event.kprobes.EVENT.probes = PROBE[, PROBE2...] Defines new kprobe event based on PROBEs. It is able to define multiple probes on one event, but those must have same type of arguments. For example, ftrace.events.kprobes.myevent { probes = "vfs_read $arg1 $arg2"; enable; } This will add kprobes:myevent on vfs_read with the 1st and the 2nd arguments. Link: http://lkml.kernel.org/r/157867240104.17873.9712052065426433111.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 46 +++++++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace_kprobe.c | 5 +++++ 2 files changed, 51 insertions(+) diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 3752403..a11dc60 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -76,6 +76,48 @@ trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node) } } +#ifdef CONFIG_KPROBE_EVENTS +extern int trace_kprobe_run_command(const char *command); + +static int __init +trace_boot_add_kprobe_event(struct xbc_node *node, const char *event) +{ + struct xbc_node *anode; + char buf[MAX_BUF_LEN]; + const char *val; + char *p; + int len; + + len = snprintf(buf, ARRAY_SIZE(buf) - 1, "p:kprobes/%s ", event); + if (len >= ARRAY_SIZE(buf)) { + pr_err("Event name is too long: %s\n", event); + return -E2BIG; + } + p = buf + len; + len = ARRAY_SIZE(buf) - len; + + xbc_node_for_each_array_value(node, "probes", anode, val) { + if (strlcpy(p, val, len) >= len) { + pr_err("Probe definition is too long: %s\n", val); + return -E2BIG; + } + if (trace_kprobe_run_command(buf) < 0) { + pr_err("Failed to add probe: %s\n", buf); + return -EINVAL; + } + } + + return 0; +} +#else +static inline int __init +trace_boot_add_kprobe_event(struct xbc_node *node, const char *event) +{ + pr_err("Kprobe event is not supported.\n"); + return -ENOTSUPP; +} +#endif + static void __init trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, struct xbc_node *enode) @@ -88,6 +130,10 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, group = xbc_node_get_data(gnode); event = xbc_node_get_data(enode); + if (!strcmp(group, "kprobes")) + if (trace_boot_add_kprobe_event(enode, event) < 0) + return; + mutex_lock(&event_mutex); file = find_event_file(tr, group, event); if (!file) { diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 8113d6a..283b7c4 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -902,6 +902,11 @@ static int create_or_delete_trace_kprobe(int argc, char **argv) return ret == -ECANCELED ? -EINVAL : ret; } +int trace_kprobe_run_command(const char *command) +{ + return trace_run_command(command, create_or_delete_trace_kprobe); +} + static int trace_kprobe_release(struct dyn_event *ev) { struct trace_kprobe *tk = to_trace_kprobe(ev); -- 2.7.4