From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49206 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751022AbdHaF5n (ORCPT ); Thu, 31 Aug 2017 01:57:43 -0400 Subject: Patch "x86/io: Add "memory" clobber to insb/insw/insl/outsb/outsw/outsl" has been added to the 3.18-stable tree To: arnd@arndb.de, bp@suse.de, gregkh@linuxfoundation.org, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, thomas.lendacky@amd.com, torvalds@linux-foundation.org Cc: , From: Date: Thu, 31 Aug 2017 07:57:41 +0200 Message-ID: <15041590619143@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/io: Add "memory" clobber to insb/insw/insl/outsb/outsw/outsl to the 3.18-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: x86-io-add-memory-clobber-to-insb-insw-insl-outsb-outsw-outsl.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 7206f9bf108eb9513d170c73f151367a1bdf3dbf Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 19 Jul 2017 14:53:02 +0200 Subject: x86/io: Add "memory" clobber to insb/insw/insl/outsb/outsw/outsl MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Arnd Bergmann commit 7206f9bf108eb9513d170c73f151367a1bdf3dbf upstream. The x86 version of insb/insw/insl uses an inline assembly that does not have the target buffer listed as an output. This can confuse the compiler, leading it to think that a subsequent access of the buffer is uninitialized: drivers/net/wireless/wl3501_cs.c: In function ‘wl3501_mgmt_scan_confirm’: drivers/net/wireless/wl3501_cs.c:665:9: error: ‘sig.status’ is used uninitialized in this function [-Werror=uninitialized] drivers/net/wireless/wl3501_cs.c:668:12: error: ‘sig.cap_info’ may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/net/sb1000.c: In function 'sb1000_rx': drivers/net/sb1000.c:775:9: error: 'st[0]' is used uninitialized in this function [-Werror=uninitialized] drivers/net/sb1000.c:776:10: error: 'st[1]' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/net/sb1000.c:784:11: error: 'st[1]' may be used uninitialized in this function [-Werror=maybe-uninitialized] I tried to mark the exact input buffer as an output here, but couldn't figure it out. As suggested by Linus, marking all memory as clobbered however is good enough too. For the outs operations, I also add the memory clobber, to force the input to be written to local variables. This is probably already guaranteed by the "asm volatile", but it can't hurt to do this for symmetry. Suggested-by: Linus Torvalds Signed-off-by: Arnd Bergmann Acked-by: Linus Torvalds Cc: Borislav Petkov Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tom Lendacky Link: http://lkml.kernel.org/r/20170719125310.2487451-5-arnd@arndb.de Link: https://lkml.org/lkml/2017/7/12/605 Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/io.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -297,13 +297,13 @@ static inline unsigned type in##bwl##_p( static inline void outs##bwl(int port, const void *addr, unsigned long count) \ { \ asm volatile("rep; outs" #bwl \ - : "+S"(addr), "+c"(count) : "d"(port)); \ + : "+S"(addr), "+c"(count) : "d"(port) : "memory"); \ } \ \ static inline void ins##bwl(int port, void *addr, unsigned long count) \ { \ asm volatile("rep; ins" #bwl \ - : "+D"(addr), "+c"(count) : "d"(port)); \ + : "+D"(addr), "+c"(count) : "d"(port) : "memory"); \ } BUILDIO(b, b, char) Patches currently in stable-queue which might be from arnd@arndb.de are queue-3.18/x86-io-add-memory-clobber-to-insb-insw-insl-outsb-outsw-outsl.patch queue-3.18/scsi-isci-avoid-array-subscript-warning.patch