[PATCH 5/5] tracing: uprobe-event: Allocate string buffers from heap

Masami Hiramatsu (Google)
2025-07-18T11:34:56Z

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

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

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/trace_uprobe.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 1fd479718d03..17124769e254 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -7,6 +7,7 @@
*/
#define pr_fmt(fmt) "trace_uprobe: " fmt

+#include <linux/cleanup.h>
#include <linux/bpf-cgroup.h>
#include <linux/security.h>
#include <linux/ctype.h>
@@ -19,6 +20,7 @@
#include <linux/filter.h>
#include <linux/percpu.h>

+#include "trace.h"
#include "trace_dynevent.h"
#include "trace_probe.h"
#include "trace_probe_tmpl.h"
@@ -538,15 +540,15 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
static int __trace_uprobe_create(int argc, const char **argv)
{
struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) = NULL;
- struct trace_uprobe *tu;
const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
char *arg, *filename, *rctr, *rctr_end, *tmp;
- char buf[MAX_EVENT_NAME_LEN];
- char gbuf[MAX_EVENT_NAME_LEN];
- enum probe_print_type ptype;
- struct path path;
unsigned long offset, ref_ctr_offset;
+ char *gbuf __free(kfree) = NULL;
+ char *buf __free(kfree) = NULL;
+ enum probe_print_type ptype;
+ struct trace_uprobe *tu;
bool is_return = false;
+ struct path path;
int i, ret;

ref_ctr_offset = 0;
@@ -654,6 +656,11 @@ static int __trace_uprobe_create(int argc, const char **argv)
/* setup a probe */
trace_probe_log_set_index(0);
if (event) {
+ gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
+ if (!gbuf) {
+ ret = -ENOMEM;
+ goto fail_address_parse;
+ }
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
@@ -674,6 +681,11 @@ static int __trace_uprobe_create(int argc, const char **argv)
if (ptr)
*ptr = '\0';

+ buf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto fail_address_parse;
+ }
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
event = buf;
kfree(tail);