This is a note to let you know that I've just added the patch titled
s390/mm: fix flush_tlb_kernel_range()
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-mm-fix-flush_tlb_kernel_range.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f6a70a07079518280022286a1dceb797d12e1edf Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Date: Mon, 4 Mar 2013 14:14:11 +0100
Subject: s390/mm: fix flush_tlb_kernel_range()
From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
commit f6a70a07079518280022286a1dceb797d12e1edf upstream.
Our flush_tlb_kernel_range() implementation calls __tlb_flush_mm() with
&init_mm as argument. __tlb_flush_mm() however will only flush tlbs
for the passed in mm if its mm_cpumask is not empty.
For the init_mm however its mm_cpumask has never any bits set. Which in
turn means that our flush_tlb_kernel_range() implementation doesn't
work at all.
This can be easily verified with a vmalloc/vfree loop which allocates
a page, writes to it and then frees the page again. A crash will follow
almost instantly.
To fix this remove the cpumask_empty() check in __tlb_flush_mm() since
there shouldn't be too many mms with a zero mm_cpumask, besides the
init_mm of course.
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/include/asm/tlbflush.h | 2 --
1 file changed, 2 deletions(-)
--- a/arch/s390/include/asm/tlbflush.h
+++ b/arch/s390/include/asm/tlbflush.h
@@ -74,8 +74,6 @@ static inline void __tlb_flush_idte(unsi
static inline void __tlb_flush_mm(struct mm_struct * mm)
{
- if (unlikely(cpumask_empty(mm_cpumask(mm))))
- return;
/*
* If the machine has IDTE we prefer to do a per mm flush
* on all cpus instead of doing a local flush if the mm
Patches currently in stable-queue which might be from heiko.carstens@xxxxxxxxxx are
queue-3.4/s390-mm-fix-flush_tlb_kernel_range.patch
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