diff options
| author |   Jialin Wang <wjl.linux@gmail.com> | 2025-08-08 00:54:55 +0800 |
|---|---|---|
| committer |   Andrew Morton <akpm@linux-foundation.org> | 2025-08-11 23:01:00 -0700 |
| commit | c0e1b774f68bdbea1618e356e30672c7f1e32509 (patch) | |
| tree | c4a4f808c80ec1ee70c19f3a21f4ef725d7bdc22 | |
| parent | mm/mremap: avoid expensive folio lookup on mremap folio pte batch (diff) | |
| download | wireguard-linux-c0e1b774f68bdbea1618e356e30672c7f1e32509.tar.xz wireguard-linux-c0e1b774f68bdbea1618e356e30672c7f1e32509.zip | |
proc: proc_maps_open allow proc_mem_open to return NULL
The commit 65c66047259f ("proc: fix the issue of proc_mem_open returning
NULL") caused proc_maps_open() to return -ESRCH when proc_mem_open()
returns NULL. This breaks legitimate /proc/<pid>/maps access for kernel
threads since kernel threads have NULL mm_struct.
The regression causes perf to fail and exit when profiling a kernel
thread:
# perf record -v -g -p $(pgrep kswapd0)
...
couldn't open /proc/65/task/65/maps
This patch partially reverts the commit to fix it.
Link: https://lkml.kernel.org/r/20250807165455.73656-1-wjl.linux@gmail.com
Fixes: 65c66047259f ("proc: fix the issue of proc_mem_open returning NULL")
Signed-off-by: Jialin Wang <wjl.linux@gmail.com>
Cc: Penglei Jiang <superman.xpt@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | fs/proc/task_mmu.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index ee1e4ccd33bd..29cca0e6d0ff 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -340,8 +340,8 @@ static int proc_maps_open(struct inode *inode, struct file *file, priv->inode = inode; priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); - if (IS_ERR_OR_NULL(priv->mm)) { - int err = priv->mm ? PTR_ERR(priv->mm) : -ESRCH; + if (IS_ERR(priv->mm)) { + int err = PTR_ERR(priv->mm); seq_release_private(inode, file); return err; |