From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:37297 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030575AbcDLVBV (ORCPT ); Tue, 12 Apr 2016 17:01:21 -0400 Subject: Patch "powerpc/process: Fix altivec SPR not being saved" has been added to the 4.5-stable tree To: oohall@gmail.com, anton@samba.org, gregkh@linuxfoundation.org, mpe@ellerman.id.au Cc: , From: Date: Tue, 12 Apr 2016 14:01:20 -0700 Message-ID: <14604948802073@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 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 powerpc/process: Fix altivec SPR not being saved to the 4.5-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: powerpc-process-fix-altivec-spr-not-being-saved.patch and it can be found in the queue-4.5 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 01d7c2a2de47890934faba91a71d183795e4348d Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran Date: Tue, 8 Mar 2016 09:08:47 +1100 Subject: powerpc/process: Fix altivec SPR not being saved From: Oliver O'Halloran commit 01d7c2a2de47890934faba91a71d183795e4348d upstream. In save_sprs() in process.c contains the following test: if (cpu_has_feature(cpu_has_feature(CPU_FTR_ALTIVEC))) t->vrsave = mfspr(SPRN_VRSAVE); CPU feature with the mask 0x1 is CPU_FTR_COHERENT_ICACHE so the test is equivilent to: if (cpu_has_feature(CPU_FTR_ALTIVEC) && cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) On CPUs without support for both (i.e G5) this results in vrsave not being saved between context switches. The vector register save/restore code doesn't use VRSAVE to determine which registers to save/restore, but the value of VRSAVE is used to determine if altivec is being used in several code paths. Fixes: 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") Signed-off-by: Oliver O'Halloran Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/process.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -854,7 +854,7 @@ void restore_tm_state(struct pt_regs *re static inline void save_sprs(struct thread_struct *t) { #ifdef CONFIG_ALTIVEC - if (cpu_has_feature(cpu_has_feature(CPU_FTR_ALTIVEC))) + if (cpu_has_feature(CPU_FTR_ALTIVEC)) t->vrsave = mfspr(SPRN_VRSAVE); #endif #ifdef CONFIG_PPC_BOOK3S_64 Patches currently in stable-queue which might be from oohall@gmail.com are queue-4.5/powerpc-process-fix-altivec-spr-not-being-saved.patch