[PATCH] MM: kmemleak: Removed coding style warnings and added a NULL check

From: Omkar Wagle
Date: Wed Nov 08 2023 - 01:28:16 EST


Fixed most of the coding style warnings
Added a NULL check to "object" pointer before accessing its members

Signed-off-by: Omkar Wagle <ov.wagle@xxxxxxxxx>
---
mm/kmemleak.c | 50 +++++++++++++++++++++++++++-----------------------
1 file changed, 27 insertions(+), 23 deletions(-)

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 1eacca03bedd..a7b74dc3ff01 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1,6 +1,5 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * mm/kmemleak.c
*
* Copyright (C) 2008 ARM Limited
* Written by Catalin Marinas <catalin.marinas@xxxxxxx>
@@ -97,7 +96,7 @@
#include <linux/crc32.h>

#include <asm/sections.h>
-#include <asm/processor.h>
+#include <linux/processor.h>
#include <linux/atomic.h>

#include <linux/kasan.h>
@@ -368,6 +367,7 @@ static void print_unreferenced(struct seq_file *seq,

for (i = 0; i < nr_entries; i++) {
void *ptr = (void *)entries[i];
+
warn_or_seq_printf(seq, " [<%pK>] %pS\n", ptr, ptr);
}
}
@@ -406,10 +406,13 @@ static struct kmemleak_object *__lookup_object(unsigned long ptr, int alias,
unsigned long untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr);

while (rb) {
- struct kmemleak_object *object;
+ struct kmemleak_object *object = NULL;
unsigned long untagged_objp;

object = rb_entry(rb, struct kmemleak_object, rb_node);
+ if (!object)
+ break;
+
untagged_objp = (unsigned long)kasan_reset_tag((void *)object->pointer);

if (untagged_ptr < untagged_objp)
@@ -674,10 +677,10 @@ static int __link_object(struct kmemleak_object *object, unsigned long ptr,
/* task information */
if (in_hardirq()) {
object->pid = 0;
- strncpy(object->comm, "hardirq", sizeof(object->comm));
+ strscpy(object->comm, "hardirq", sizeof(object->comm));
} else if (in_serving_softirq()) {
object->pid = 0;
- strncpy(object->comm, "softirq", sizeof(object->comm));
+ strscpy(object->comm, "softirq", sizeof(object->comm));
} else {
object->pid = current->pid;
/*
@@ -686,7 +689,7 @@ static int __link_object(struct kmemleak_object *object, unsigned long ptr,
* dependency issues with current->alloc_lock. In the worst
* case, the command line is not correct.
*/
- strncpy(object->comm, current->comm, sizeof(object->comm));
+ strscpy(object->comm, current->comm, sizeof(object->comm));
}

/* kernel backtrace */
@@ -1027,7 +1030,7 @@ static void object_no_scan(unsigned long ptr)
void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count,
gfp_t gfp)
{
- pr_debug("%s(0x%px, %zu, %d)\n", __func__, ptr, size, min_count);
+ pr_debug("%s(0x%p, %zu, %d)\n", __func__, ptr, size, min_count);

if (kmemleak_enabled && ptr && !IS_ERR(ptr))
create_object((unsigned long)ptr, size, min_count, gfp);
@@ -1048,7 +1051,7 @@ void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size,
{
unsigned int cpu;

- pr_debug("%s(0x%px, %zu)\n", __func__, ptr, size);
+ pr_debug("%s(0x%p, %zu)\n", __func__, ptr, size);

/*
* Percpu allocations are only scanned and not reported as leaks
@@ -1072,7 +1075,7 @@ EXPORT_SYMBOL_GPL(kmemleak_alloc_percpu);
*/
void __ref kmemleak_vmalloc(const struct vm_struct *area, size_t size, gfp_t gfp)
{
- pr_debug("%s(0x%px, %zu)\n", __func__, area, size);
+ pr_debug("%s(0x%p, %zu)\n", __func__, area, size);

/*
* A min_count = 2 is needed because vm_struct contains a reference to
@@ -1095,7 +1098,7 @@ EXPORT_SYMBOL_GPL(kmemleak_vmalloc);
*/
void __ref kmemleak_free(const void *ptr)
{
- pr_debug("%s(0x%px)\n", __func__, ptr);
+ pr_debug("%s(0x%p)\n", __func__, ptr);

if (kmemleak_free_enabled && ptr && !IS_ERR(ptr))
delete_object_full((unsigned long)ptr);
@@ -1113,7 +1116,7 @@ EXPORT_SYMBOL_GPL(kmemleak_free);
*/
void __ref kmemleak_free_part(const void *ptr, size_t size)
{
- pr_debug("%s(0x%px)\n", __func__, ptr);
+ pr_debug("%s(0x%p)\n", __func__, ptr);

if (kmemleak_enabled && ptr && !IS_ERR(ptr))
delete_object_part((unsigned long)ptr, size, false);
@@ -1131,7 +1134,7 @@ void __ref kmemleak_free_percpu(const void __percpu *ptr)
{
unsigned int cpu;

- pr_debug("%s(0x%px)\n", __func__, ptr);
+ pr_debug("%s(0x%p)\n", __func__, ptr);

if (kmemleak_free_enabled && ptr && !IS_ERR(ptr))
for_each_possible_cpu(cpu)
@@ -1152,7 +1155,7 @@ void __ref kmemleak_update_trace(const void *ptr)
struct kmemleak_object *object;
unsigned long flags;

- pr_debug("%s(0x%px)\n", __func__, ptr);
+ pr_debug("%s(0x%p)\n", __func__, ptr);

if (!kmemleak_enabled || IS_ERR_OR_NULL(ptr))
return;
@@ -1183,7 +1186,7 @@ EXPORT_SYMBOL(kmemleak_update_trace);
*/
void __ref kmemleak_not_leak(const void *ptr)
{
- pr_debug("%s(0x%px)\n", __func__, ptr);
+ pr_debug("%s(0x%p)\n", __func__, ptr);

if (kmemleak_enabled && ptr && !IS_ERR(ptr))
make_gray_object((unsigned long)ptr);
@@ -1201,7 +1204,7 @@ EXPORT_SYMBOL(kmemleak_not_leak);
*/
void __ref kmemleak_ignore(const void *ptr)
{
- pr_debug("%s(0x%px)\n", __func__, ptr);
+ pr_debug("%s(0x%p)\n", __func__, ptr);

if (kmemleak_enabled && ptr && !IS_ERR(ptr))
make_black_object((unsigned long)ptr, false);
@@ -1221,7 +1224,7 @@ EXPORT_SYMBOL(kmemleak_ignore);
*/
void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp)
{
- pr_debug("%s(0x%px)\n", __func__, ptr);
+ pr_debug("%s(0x%p)\n", __func__, ptr);

if (kmemleak_enabled && ptr && size && !IS_ERR(ptr))
add_scan_area((unsigned long)ptr, size, gfp);
@@ -1239,7 +1242,7 @@ EXPORT_SYMBOL(kmemleak_scan_area);
*/
void __ref kmemleak_no_scan(const void *ptr)
{
- pr_debug("%s(0x%px)\n", __func__, ptr);
+ pr_debug("%s(0x%p)\n", __func__, ptr);

if (kmemleak_enabled && ptr && !IS_ERR(ptr))
object_no_scan((unsigned long)ptr);
@@ -1255,7 +1258,7 @@ EXPORT_SYMBOL(kmemleak_no_scan);
*/
void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, gfp_t gfp)
{
- pr_debug("%s(0x%px, %zu)\n", __func__, &phys, size);
+ pr_debug("%s(0x%p, %zu)\n", __func__, &phys, size);

if (kmemleak_enabled)
/*
@@ -1275,7 +1278,7 @@ EXPORT_SYMBOL(kmemleak_alloc_phys);
*/
void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size)
{
- pr_debug("%s(0x%px)\n", __func__, &phys);
+ pr_debug("%s(0x%p)\n", __func__, &phys);

if (kmemleak_enabled)
delete_object_part((unsigned long)phys, size, true);
@@ -1289,7 +1292,7 @@ EXPORT_SYMBOL(kmemleak_free_part_phys);
*/
void __ref kmemleak_ignore_phys(phys_addr_t phys)
{
- pr_debug("%s(0x%px)\n", __func__, &phys);
+ pr_debug("%s(0x%p)\n", __func__, &phys);

if (kmemleak_enabled)
make_black_object((unsigned long)phys, true);
@@ -1662,6 +1665,7 @@ static void kmemleak_scan(void)
rcu_read_lock();
for_each_process_thread(g, p) {
void *stack = try_get_task_stack(p);
+
if (stack) {
scan_block(stack, stack + THREAD_SIZE, NULL);
put_task_stack(p);
@@ -1768,6 +1772,7 @@ static int kmemleak_scan_thread(void *arg)
*/
if (first_run) {
signed long timeout = msecs_to_jiffies(SECS_FIRST_SCAN * 1000);
+
first_run = 0;
while (timeout && !kthread_should_stop())
timeout = schedule_timeout_interruptible(timeout);
@@ -2013,7 +2018,7 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
else if (strncmp(buf, "scan=off", 8) == 0)
stop_scan_thread();
else if (strncmp(buf, "scan=", 5) == 0) {
- unsigned secs;
+ unsigned int secs;
unsigned long msecs;

ret = kstrtouint(buf + 5, 0, &secs);
@@ -2130,8 +2135,7 @@ static int __init kmemleak_boot_config(char *str)
else if (strcmp(str, "on") == 0) {
kmemleak_skip_disable = 1;
stack_depot_request_early_init();
- }
- else
+ } else
return -EINVAL;
return 0;
}
--
2.34.1