Patch "parisc: Ensure volatile space register %sr1 is not clobbered" has been added to the 3.10-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    parisc: Ensure volatile space register %sr1 is not clobbered

to the 3.10-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:
     parisc-ensure-volatile-space-register-sr1-is-not-clobbered.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From e8d8fc219f9a0e63e7fb927881e6f4db8e7d34df Mon Sep 17 00:00:00 2001
From: John David Anglin <dave.anglin@xxxxxxxx>
Date: Sat, 29 Jun 2013 16:42:12 -0400
Subject: parisc: Ensure volatile space register %sr1 is not clobbered

From: John David Anglin <dave.anglin@xxxxxxxx>

commit e8d8fc219f9a0e63e7fb927881e6f4db8e7d34df upstream.

I still see the occasional random segv on rp3440.  Looking at one of
these (a code 15), it appeared the problem must be with the cache
handling of anonymous pages.  Reviewing this, I noticed that the space
register %sr1 might be being clobbered when we flush an anonymous page.

Register %sr1 is used for TLB purges in a couple of places.  These
purges are needed on PA8800 and PA8900 processors to ensure cache
consistency of flushed cache lines.

The solution here is simply to move the %sr1 load into the TLB lock
region needed to ensure that one purge executes at a time on SMP
systems.  This was already the case for one use.  After a few days of
operation, I haven't had a random segv on my rp3440.

Signed-off-by: John David Anglin <dave.anglin@xxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/parisc/include/asm/tlbflush.h |    5 +++--
 arch/parisc/kernel/cache.c         |    2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

--- a/arch/parisc/include/asm/tlbflush.h
+++ b/arch/parisc/include/asm/tlbflush.h
@@ -63,13 +63,14 @@ static inline void flush_tlb_mm(struct m
 static inline void flush_tlb_page(struct vm_area_struct *vma,
 	unsigned long addr)
 {
-	unsigned long flags;
+	unsigned long flags, sid;
 
 	/* For one page, it's not worth testing the split_tlb variable */
 
 	mb();
-	mtsp(vma->vm_mm->context,1);
+	sid = vma->vm_mm->context;
 	purge_tlb_start(flags);
+	mtsp(sid, 1);
 	pdtlb(addr);
 	pitlb(addr);
 	purge_tlb_end(flags);
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -440,8 +440,8 @@ void __flush_tlb_range(unsigned long sid
 	else {
 		unsigned long flags;
 
-		mtsp(sid, 1);
 		purge_tlb_start(flags);
+		mtsp(sid, 1);
 		if (split_tlb) {
 			while (npages--) {
 				pdtlb(start);


Patches currently in stable-queue which might be from dave.anglin@xxxxxxxx are

queue-3.10/parisc-ensure-volatile-space-register-sr1-is-not-clobbered.patch
queue-3.10/parisc-fix-gcc-miscompilation-in-pa_memcpy.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]