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Subject[PATCH] powerpc/mm: Fix missing mmap_sem release
Date
The commit b5c8f0fd595d ("powerpc/mm: Rework mm_fault_error()") reviewed
the way the error path is managed in __do_page_fault() but it was a bit too
agressive when handling a case by returning without releasing the mmap_sem.

By the way, replacing current->mm->mmap_sem by mm->mmap_sem as mm is set to
current->mm.

Fixes: b5c8f0fd595d ("powerpc/mm: Rework mm_fault_error()")
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Laurent Dufour <laurent.du4@free.fr>
---
arch/powerpc/mm/fault.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 4797d08581ce..f799ccf37d27 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -521,10 +521,11 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
* User mode? Just return to handle the fatal exception otherwise
* return to bad_page_fault
*/
+ up_read(&mm->mmap_sem);
return is_user ? 0 : SIGBUS;
}

- up_read(&current->mm->mmap_sem);
+ up_read(&mm->mmap_sem);

if (unlikely(fault & VM_FAULT_ERROR))
return mm_fault_error(regs, address, fault);
--
2.7.4
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