Commit d643eaa7 authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google)
Browse files

tracing: fprobe-event: Allocate string buffers from heap 

Allocate temporary string buffers for fprobe-event from heap
instead of stack. This fixes the stack frame exceed limit error.

Link: https://lore.kernel.org/all/175323426643.57270.6657152008331160704.stgit@devnote2/



Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506240416.nZIhDXoO-lkp@intel.com/


Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 43beb5e8

kernel/trace/trace_fprobe.c

+26 −13
Original line number Diff line number Diff line
@@ -1235,18 +1235,18 @@ static int trace_fprobe_create_internal(int argc, const char *argv[], 
	 *  FETCHARG:TYPE : use TYPE instead of unsigned long.

	 */

	struct trace_fprobe *tf __free(free_trace_fprobe) = NULL;

	struct module *mod __free(module_put) = NULL;

	int i, new_argc = 0, ret = 0;

	bool is_return = false;

	char *symbol __free(kfree) = NULL;

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

	struct module *mod __free(module_put) = NULL;

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

	char buf[MAX_EVENT_NAME_LEN];

	char gbuf[MAX_EVENT_NAME_LEN];

	char sbuf[KSYM_NAME_LEN];

	char abuf[MAX_BTF_ARGS_LEN];

	char *symbol __free(kfree) = NULL;

	char *ebuf __free(kfree) = NULL;

	char *gbuf __free(kfree) = NULL;

	char *sbuf __free(kfree) = NULL;

	char *abuf __free(kfree) = NULL;

	char *dbuf __free(kfree) = NULL;

	int i, new_argc = 0, ret = 0;

	bool is_tracepoint = false;

	bool is_return = false;



	if ((argv[0][0] != 'f' && argv[0][0] != 't') || argc < 2)

		return -ECANCELED;
@@ -1274,6 +1274,9 @@ static int trace_fprobe_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)
@@ -1281,15 +1284,18 @@ static int trace_fprobe_create_internal(int argc, const char *argv[], 
	}



	if (!event) {

		ebuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);

		if (!ebuf)

			return -ENOMEM;

		/* Make a new event name */

		if (is_tracepoint)

			snprintf(buf, MAX_EVENT_NAME_LEN, "%s%s",

			snprintf(ebuf, MAX_EVENT_NAME_LEN, "%s%s",

				 isdigit(*symbol) ? "_" : "", symbol);

		else

			snprintf(buf, MAX_EVENT_NAME_LEN, "%s__%s", symbol,

			snprintf(ebuf, MAX_EVENT_NAME_LEN, "%s__%s", symbol,

				 is_return ? "exit" : "entry");

		sanitize_event_name(buf);

		event = buf;

		sanitize_event_name(ebuf);

		event = ebuf;

	}



	if (is_return)
@@ -1305,13 +1311,20 @@ static int trace_fprobe_create_internal(int argc, const char *argv[], 
		ctx->flags |= TPARG_FL_TPOINT;

		mod = NULL;

		tpoint = find_tracepoint(symbol, &mod);

		if (tpoint)

		if (tpoint) {

			sbuf = kmalloc(KSYM_NAME_LEN, GFP_KERNEL);

			if (!sbuf)

				return -ENOMEM;

			ctx->funcname = kallsyms_lookup((unsigned long)tpoint->probestub,

							NULL, NULL, NULL, sbuf);

		}

	}

	if (!ctx->funcname)

		ctx->funcname = symbol;



	abuf = kmalloc(MAX_BTF_ARGS_LEN, GFP_KERNEL);

	if (!abuf)

		return -ENOMEM;

	argc -= 2; argv += 2;

	new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc,

					       abuf, MAX_BTF_ARGS_LEN, ctx);