Commit 33b4e38b authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google)
Browse files

tracing: kprobe-event: Allocate string buffers from heap 

Allocate temporary string buffers for parsing kprobe-events
from heap instead of stack.

Link: https://lore.kernel.org/all/175323427627.57270.5105357260879695051.stgit@devnote2/



Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent d643eaa7

kernel/trace/trace_kprobe.c

+25 −14
Original line number Diff line number Diff line
@@ -861,20 +861,20 @@ static int trace_kprobe_create_internal(int argc, const char *argv[], 
	 *  FETCHARG:TYPE : use TYPE instead of unsigned long.

	 */

	struct trace_kprobe *tk __free(free_trace_kprobe) = NULL;

	const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;

	const char **new_argv __free(kfree) = NULL;

	int i, len, new_argc = 0, ret = 0;

	bool is_return = false;

	char *symbol __free(kfree) = NULL;

	char *tmp = NULL;

	const char **new_argv __free(kfree) = NULL;

	const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;

	char *ebuf __free(kfree) = NULL;

	char *gbuf __free(kfree) = NULL;

	char *abuf __free(kfree) = NULL;

	char *dbuf __free(kfree) = NULL;

	enum probe_print_type ptype;

	bool is_return = false;

	int maxactive = 0;

	long offset = 0;

	void *addr = NULL;

	char buf[MAX_EVENT_NAME_LEN];

	char gbuf[MAX_EVENT_NAME_LEN];

	char abuf[MAX_BTF_ARGS_LEN];

	char *dbuf __free(kfree) = NULL;

	char *tmp = NULL;

	long offset = 0;



	switch (argv[0][0]) {

	case 'r':
@@ -893,6 +893,8 @@ static int trace_kprobe_create_internal(int argc, const char *argv[], 
		event++;



	if (isdigit(argv[0][1])) {

		char *buf __free(kfree) = NULL;



		if (!is_return) {

			trace_probe_log_err(1, BAD_MAXACT_TYPE);

			return -EINVAL;
@@ -905,7 +907,7 @@ static int trace_kprobe_create_internal(int argc, const char *argv[], 
			trace_probe_log_err(1, BAD_MAXACT);

			return -EINVAL;

		}

		memcpy(buf, &argv[0][1], len);

		buf = kmemdup(&argv[0][1], len + 1, GFP_KERNEL);

		buf[len] = '\0';

		ret = kstrtouint(buf, 0, &maxactive);

		if (ret || !maxactive) {
@@ -973,6 +975,9 @@ static int trace_kprobe_create_internal(int argc, const char *argv[], 


	trace_probe_log_set_index(0);

	if (event) {

		gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);

		if (!gbuf)

			return -ENOMEM;

		ret = traceprobe_parse_event_name(&event, &group, gbuf,

						  event - argv[0]);

		if (ret)
@@ -981,16 +986,22 @@ static int trace_kprobe_create_internal(int argc, const char *argv[], 


	if (!event) {

		/* Make a new event name */

		ebuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);

		if (!ebuf)

			return -ENOMEM;

		if (symbol)

			snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",

			snprintf(ebuf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",

				 is_return ? 'r' : 'p', symbol, offset);

		else

			snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",

			snprintf(ebuf, MAX_EVENT_NAME_LEN, "%c_0x%p",

				 is_return ? 'r' : 'p', addr);

		sanitize_event_name(buf);

		event = buf;

		sanitize_event_name(ebuf);

		event = ebuf;

	}



	abuf = kmalloc(MAX_BTF_ARGS_LEN, GFP_KERNEL);

	if (!abuf)

		return -ENOMEM;

	argc -= 2; argv += 2;

	ctx->funcname = symbol;

	new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc,