+ frv-ip_fast_csum-requires-a-memory-clobber-on-its-inline-asm.patch added to -mm tree

+ frv-ip_fast_csum-requires-a-memory-clobber-on-its-inline-asm.patch added to -mm tree

[akpm]

The patch titled
     frv: ip_fast_csum() requires a memory clobber on its inline asm
has been added to the -mm tree.  Its filename is
     frv-ip_fast_csum-requires-a-memory-clobber-on-its-inline-asm.patch

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*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
Subject: frv: ip_fast_csum() requires a memory clobber on its inline asm
From: David Howells <dhowells@redhat.com>

ip_fast_csum() requires a memory clobber on its inline asm as it accesses
memory in a fashion that gcc can't predict.

The GCC manual says:

 If your assembler instructions access memory in an unpredictable
 fashion, add `memory' to the list of clobbered registers.  This will
 cause GCC to not keep memory values cached in registers across the
 assembler instruction and not optimize stores or loads to that memory.

The bug hasn't been noticed in FRV, but it has been seen in PA-RISC.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/asm-frv/checksum.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN include/asm-frv/checksum.h~frv-ip_fast_csum-requires-a-memory-clobber-on-its-inline-asm include/asm-frv/checksum.h
--- a/include/asm-frv/checksum.h~frv-ip_fast_csum-requires-a-memory-clobber-on-its-inline-asm
+++ a/include/asm-frv/checksum.h
@@ -75,7 +75,7 @@ __sum16 ip_fast_csum(const void *iph, un
 	    : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (inc), "=&r"(tmp)
 	    : "0" (sum), "1" (iph), "2" (ihl), "3" (4),
 	    "m"(*(volatile struct { int _[100]; } *)iph)
-	    : "icc0", "icc1"
+	    : "icc0", "icc1", "memory"
 	    );
 
 	return (__force __sum16)~sum;
_

Patches currently in -mm which might be from dhowells@redhat.com are

frv-dont-offer-binfmt_flat.patch
frv-ip_fast_csum-requires-a-memory-clobber-on-its-inline-asm.patch
linux-next.patch
git-unionfs.patch
security-keys-remove-unused-key_alloc_sem.patch
nommu-fix-ksize-abuse.patch
frv-use-the-common-ascii-hex-helpers.patch
mn10300-use-the-common-ascii-hex-helpers.patch
mutex-subsystem-synchro-test-module.patch