From 1b36ba815bd91f17e31277a44dd5c6b6a5a8d97e Mon Sep 17 00:00:00 2001
From: Namhyung Kim <namhyung@gmail.com>
Date: Tue, 26 Oct 2010 14:22:00 -0700
Subject: [PATCH] mm: wrap follow_pte() using __cond_lock()
The follow_pte() conditionally grabs *@ptlp in case of returning 0.
Rename and wrap it using __cond_lock() removes following warnings:
mm/memory.c:2337:9: warning: context imbalance in 'do_wp_page' - unexpected unlock
mm/memory.c:3142:19: warning: context imbalance in 'handle_mm_fault' - different lock contexts for basic block
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/memory.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c
index 01bdf9dbbfac..861f7982dd54 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3351,7 +3351,7 @@ int in_gate_area_no_task(unsigned long addr)
#endif /* __HAVE_ARCH_GATE_AREA */
-static int follow_pte(struct mm_struct *mm, unsigned long address,
+static int __follow_pte(struct mm_struct *mm, unsigned long address,
pte_t **ptepp, spinlock_t **ptlp)
{
pgd_t *pgd;
@@ -3388,6 +3388,17 @@ out:
return -EINVAL;
}
+static inline int follow_pte(struct mm_struct *mm, unsigned long address,
+ pte_t **ptepp, spinlock_t **ptlp)
+{
+ int res;
+
+ /* (void) is needed to make gcc happy */
+ (void) __cond_lock(*ptlp,
+ !(res = __follow_pte(mm, address, ptepp, ptlp)));
+ return res;
+}
+
/**
* follow_pfn - look up PFN at a user virtual address
* @vma: memory mapping
--
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