mirror of
https://git.yoctoproject.org/meta-ti
synced 2026-07-26 22:07:51 +00:00
Koen Kooi
189ce92b4c
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net> Signed-off-by: Denys Dmytriyenko <denys@ti.com>
46 lines
1.6 KiB
Diff
46 lines
1.6 KiB
Diff
From bf1dbf3f545a79e9ac5ff460053283f2760f095b Mon Sep 17 00:00:00 2001
|
|
From: Dima Zavin <dima@android.com>
|
|
Date: Mon, 30 Apr 2012 10:26:14 +0100
|
|
Subject: [PATCH 073/117] ARM: 7409/1: Do not call flush_cache_user_range with
|
|
mmap_sem held
|
|
|
|
commit 435a7ef52db7d86e67a009b36cac1457f8972391 upstream.
|
|
|
|
We can't be holding the mmap_sem while calling flush_cache_user_range
|
|
because the flush can fault. If we fault on a user address, the
|
|
page fault handler will try to take mmap_sem again. Since both places
|
|
acquire the read lock, most of the time it succeeds. However, if another
|
|
thread tries to acquire the write lock on the mmap_sem (e.g. mmap) in
|
|
between the call to flush_cache_user_range and the fault, the down_read
|
|
in do_page_fault will deadlock.
|
|
|
|
[will: removed drop of vma parameter as already queued by rmk (7365/1)]
|
|
|
|
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
|
|
Signed-off-by: Dima Zavin <dima@android.com>
|
|
Signed-off-by: John Stultz <john.stultz@linaro.org>
|
|
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
|
|
---
|
|
arch/arm/kernel/traps.c | 2 ++
|
|
1 file changed, 2 insertions(+)
|
|
|
|
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
|
|
index f363ad9..160cb16 100644
|
|
--- a/arch/arm/kernel/traps.c
|
|
+++ b/arch/arm/kernel/traps.c
|
|
@@ -488,7 +488,9 @@ do_cache_op(unsigned long start, unsigned long end, int flags)
|
|
if (end > vma->vm_end)
|
|
end = vma->vm_end;
|
|
|
|
+ up_read(&mm->mmap_sem);
|
|
flush_cache_user_range(start, end);
|
|
+ return;
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
}
|
|
--
|
|
1.7.9.5
|
|
|