summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_kprobe.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
-rw-r--r--kernel/trace/trace_kprobe.c238
1 files changed, 204 insertions, 34 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index aa515d578c5b..d8264ebb9581 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -22,7 +22,6 @@
#define KPROBE_EVENT_SYSTEM "kprobes"
#define KRETPROBE_MAXACTIVE_MAX 4096
-#define MAX_KPROBE_CMDLINE_SIZE 1024
/* Kprobe early definition from command line */
static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
@@ -902,6 +901,167 @@ static int create_or_delete_trace_kprobe(int argc, char **argv)
return ret == -ECANCELED ? -EINVAL : ret;
}
+static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
+{
+ return trace_run_command(cmd->seq.buffer, create_or_delete_trace_kprobe);
+}
+
+/**
+ * kprobe_event_cmd_init - Initialize a kprobe event command object
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @buf: A pointer to the buffer used to build the command
+ * @maxlen: The length of the buffer passed in @buf
+ *
+ * Initialize a synthetic event command object. Use this before
+ * calling any of the other kprobe_event functions.
+ */
+void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
+{
+ dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
+ trace_kprobe_run_command);
+}
+EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
+
+/**
+ * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @name: The name of the kprobe event
+ * @loc: The location of the kprobe event
+ * @kretprobe: Is this a return probe?
+ * @args: Variable number of arg (pairs), one pair for each field
+ *
+ * NOTE: Users normally won't want to call this function directly, but
+ * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
+ * adds a NULL to the end of the arg list. If this function is used
+ * directly, make sure the last arg in the variable arg list is NULL.
+ *
+ * Generate a kprobe event command to be executed by
+ * kprobe_event_gen_cmd_end(). This function can be used to generate the
+ * complete command or only the first part of it; in the latter case,
+ * kprobe_event_add_fields() can be used to add more fields following this.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
+ const char *name, const char *loc, ...)
+{
+ char buf[MAX_EVENT_NAME_LEN];
+ struct dynevent_arg arg;
+ va_list args;
+ int ret;
+
+ if (cmd->type != DYNEVENT_TYPE_KPROBE)
+ return -EINVAL;
+
+ if (kretprobe)
+ snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
+ else
+ snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
+
+ ret = dynevent_str_add(cmd, buf);
+ if (ret)
+ return ret;
+
+ dynevent_arg_init(&arg, 0);
+ arg.str = loc;
+ ret = dynevent_arg_add(cmd, &arg, NULL);
+ if (ret)
+ return ret;
+
+ va_start(args, loc);
+ for (;;) {
+ const char *field;
+
+ field = va_arg(args, const char *);
+ if (!field)
+ break;
+
+ if (++cmd->n_fields > MAX_TRACE_ARGS) {
+ ret = -EINVAL;
+ break;
+ }
+
+ arg.str = field;
+ ret = dynevent_arg_add(cmd, &arg, NULL);
+ if (ret)
+ break;
+ }
+ va_end(args);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
+
+/**
+ * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @args: Variable number of arg (pairs), one pair for each field
+ *
+ * NOTE: Users normally won't want to call this function directly, but
+ * rather use the kprobe_event_add_fields() wrapper, which
+ * automatically adds a NULL to the end of the arg list. If this
+ * function is used directly, make sure the last arg in the variable
+ * arg list is NULL.
+ *
+ * Add probe fields to an existing kprobe command using a variable
+ * list of args. Fields are added in the same order they're listed.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
+{
+ struct dynevent_arg arg;
+ va_list args;
+ int ret;
+
+ if (cmd->type != DYNEVENT_TYPE_KPROBE)
+ return -EINVAL;
+
+ dynevent_arg_init(&arg, 0);
+
+ va_start(args, cmd);
+ for (;;) {
+ const char *field;
+
+ field = va_arg(args, const char *);
+ if (!field)
+ break;
+
+ if (++cmd->n_fields > MAX_TRACE_ARGS) {
+ ret = -EINVAL;
+ break;
+ }
+
+ arg.str = field;
+ ret = dynevent_arg_add(cmd, &arg, NULL);
+ if (ret)
+ break;
+ }
+ va_end(args);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
+
+/**
+ * kprobe_event_delete - Delete a kprobe event
+ * @name: The name of the kprobe event to delete
+ *
+ * Delete a kprobe event with the give @name from kernel code rather
+ * than directly from the command line.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int kprobe_event_delete(const char *name)
+{
+ char buf[MAX_EVENT_NAME_LEN];
+
+ snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
+
+ return trace_run_command(buf, create_or_delete_trace_kprobe);
+}
+EXPORT_SYMBOL_GPL(kprobe_event_delete);
+
static int trace_kprobe_release(struct dyn_event *ev)
{
struct trace_kprobe *tk = to_trace_kprobe(ev);
@@ -1175,35 +1335,35 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
struct trace_event_file *trace_file)
{
struct kprobe_trace_entry_head *entry;
- struct ring_buffer_event *event;
- struct ring_buffer *buffer;
- int size, dsize, pc;
- unsigned long irq_flags;
struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+ struct trace_event_buffer fbuffer;
+ int dsize;
WARN_ON(call != trace_file->event_call);
if (trace_trigger_soft_disabled(trace_file))
return;
- local_save_flags(irq_flags);
- pc = preempt_count();
+ local_save_flags(fbuffer.flags);
+ fbuffer.pc = preempt_count();
+ fbuffer.trace_file = trace_file;
dsize = __get_data_size(&tk->tp, regs);
- size = sizeof(*entry) + tk->tp.size + dsize;
- event = trace_event_buffer_lock_reserve(&buffer, trace_file,
- call->event.type,
- size, irq_flags, pc);
- if (!event)
+ fbuffer.event =
+ trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
+ call->event.type,
+ sizeof(*entry) + tk->tp.size + dsize,
+ fbuffer.flags, fbuffer.pc);
+ if (!fbuffer.event)
return;
- entry = ring_buffer_event_data(event);
+ fbuffer.regs = regs;
+ entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
entry->ip = (unsigned long)tk->rp.kp.addr;
store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
- event_trigger_unlock_commit_regs(trace_file, buffer, event,
- entry, irq_flags, pc, regs);
+ trace_event_buffer_commit(&fbuffer);
}
static void
@@ -1223,36 +1383,35 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
struct trace_event_file *trace_file)
{
struct kretprobe_trace_entry_head *entry;
- struct ring_buffer_event *event;
- struct ring_buffer *buffer;
- int size, pc, dsize;
- unsigned long irq_flags;
+ struct trace_event_buffer fbuffer;
struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+ int dsize;
WARN_ON(call != trace_file->event_call);
if (trace_trigger_soft_disabled(trace_file))
return;
- local_save_flags(irq_flags);
- pc = preempt_count();
+ local_save_flags(fbuffer.flags);
+ fbuffer.pc = preempt_count();
+ fbuffer.trace_file = trace_file;
dsize = __get_data_size(&tk->tp, regs);
- size = sizeof(*entry) + tk->tp.size + dsize;
-
- event = trace_event_buffer_lock_reserve(&buffer, trace_file,
- call->event.type,
- size, irq_flags, pc);
- if (!event)
+ fbuffer.event =
+ trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
+ call->event.type,
+ sizeof(*entry) + tk->tp.size + dsize,
+ fbuffer.flags, fbuffer.pc);
+ if (!fbuffer.event)
return;
- entry = ring_buffer_event_data(event);
+ fbuffer.regs = regs;
+ entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
entry->func = (unsigned long)tk->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
- event_trigger_unlock_commit_regs(trace_file, buffer, event,
- entry, irq_flags, pc, regs);
+ trace_event_buffer_commit(&fbuffer);
}
static void
@@ -1698,11 +1857,12 @@ static __init void setup_boot_kprobe_events(void)
enable_boot_kprobe_events();
}
-/* Make a tracefs interface for controlling probe points */
-static __init int init_kprobe_trace(void)
+/*
+ * Register dynevent at subsys_initcall. This allows kernel to setup kprobe
+ * events in fs_initcall without tracefs.
+ */
+static __init int init_kprobe_trace_early(void)
{
- struct dentry *d_tracer;
- struct dentry *entry;
int ret;
ret = dyn_event_register(&trace_kprobe_ops);
@@ -1712,6 +1872,16 @@ static __init int init_kprobe_trace(void)
if (register_module_notifier(&trace_kprobe_module_nb))
return -EINVAL;
+ return 0;
+}
+subsys_initcall(init_kprobe_trace_early);
+
+/* Make a tracefs interface for controlling probe points */
+static __init int init_kprobe_trace(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *entry;
+
d_tracer = tracing_init_dentry();
if (IS_ERR(d_tracer))
return 0;