fix the leak of alloc/free traces debugfs interface, reported
by kmemleak like below,
unreferenced object 0xffff00091ae1b540 (size 64):
comm "lsbug", pid 1607, jiffies 4294958291 (age 1476.340s)
hex dump (first 32 bytes):
02 00 00 00 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b ........kkkkkkkk
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
backtrace:
[<ffff8000106b06b8>] slab_post_alloc_hook+0xa0/0x418
[<ffff8000106b5c7c>] kmem_cache_alloc_trace+0x1e4/0x378
[<ffff8000106b5e40>] slab_debugfs_start+0x30/0x50
slab_debugfs_start at mm/slub.c:5831
[<ffff8000107b3dbc>] seq_read_iter+0x214/0xd50
[<ffff8000107b4b84>] seq_read+0x28c/0x418
[<ffff8000109560b4>] full_proxy_read+0xdc/0x148
[<ffff800010738f24>] vfs_read+0x104/0x340
[<ffff800010739ee0>] ksys_read+0xf8/0x1e0
[<ffff80001073a03c>] __arm64_sys_read+0x74/0xa8
[<ffff8000100358d4>] invoke_syscall.constprop.0+0xdc/0x1d8
[<ffff800010035ab4>] do_el0_svc+0xe4/0x298
[<ffff800011138528>] el0_svc+0x20/0x30
[<ffff800011138b08>] el0t_64_sync_handler+0xb0/0xb8
[<ffff80001001259c>] el0t_64_sync+0x178/0x17c
Fixes: 84a2bdb1b458fc968d6d9e07dab388dc679bd747 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Link: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/mm/slub.c?h=next-20210617&id=84a2bdb1b458fc968d6d9e07dab388dc679bd747
Signed-off-by: Faiyaz Mohammed <faiyazm@xxxxxxxxxxxxxx>
---
mm/slub.c | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index fcb0c50..f006766 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5785,31 +5785,24 @@ static int slab_debugfs_show(struct seq_file *seq, void *v)
static void slab_debugfs_stop(struct seq_file *seq, void *v)
{
- kfree(v);
}
static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
{
- loff_t *spos = v;
struct loc_track *t = seq->private;
+ v = ppos;
if (*ppos < t->count) {
- *ppos = ++*spos;
- return spos;
+ ++*ppos;
+ return v;
}
- *ppos = ++*spos;
+ ++*ppos;
return NULL;
}
static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
{
- loff_t *spos = kmalloc(sizeof(loff_t), GFP_KERNEL);
-
- if (!spos)
- return NULL;
-
- *spos = *ppos;
- return spos;
+ return ppos;
}
static const struct seq_operations slab_debugfs_sops = {
--
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