From d53ddd0181d1c284c28c0d70a3d7039db41c6f7e Mon Sep 17 00:00:00 2001
From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Tue, 14 May 2019 15:44:37 -0700
Subject: [PATCH] fs/exec.c: move ->recursion_depth out of critical sections
->recursion_depth is changed only by current, therefore decrementing can
be done without taking any locks.
Link: http://lkml.kernel.org/r/20190417213150.GA26474@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/exec.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/exec.c b/fs/exec.c
index 2e0033348d8e1..d88584ebf07f3 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1652,11 +1652,13 @@ int search_binary_handler(struct linux_binprm *bprm)
if (!try_module_get(fmt->module))
continue;
read_unlock(&binfmt_lock);
+
bprm->recursion_depth++;
retval = fmt->load_binary(bprm);
+ bprm->recursion_depth--;
+
read_lock(&binfmt_lock);
put_binfmt(fmt);
- bprm->recursion_depth--;
if (retval < 0 && !bprm->mm) {
/* we got to flush_old_exec() and failed after it */
read_unlock(&binfmt_lock);
--
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