[PATCH] uprobes: use READ_ONCE() to read mm->uprobes_state.xol_area in concurrent environment
From: linke li
Date: Sat Feb 24 2024 - 05:31:36 EST
In function get_xol_area(), mm->uprobes_state.xol_area is read using
READ_ONCE() in line 1534
1534 area = READ_ONCE(mm->uprobes_state.xol_area); /* ^^^ */
while read directly in line 1530
1530 if (!mm->uprobes_state.xol_area)
1531 __create_xol_area(0);
In the same environment, reads in two places should have the same
protection.
Signed-off-by: linke li <lilinke99@xxxxxx>
---
kernel/events/uprobes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 929e98c62965..e110941fbc6b 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1527,7 +1527,7 @@ static struct xol_area *get_xol_area(void)
struct mm_struct *mm = current->mm;
struct xol_area *area;
- if (!mm->uprobes_state.xol_area)
+ if (!READ_ONCE(mm->uprobes_state.xol_area))
__create_xol_area(0);
/* Pairs with xol_add_vma() smp_store_release() */
--
2.39.3 (Apple Git-145)