From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Date: Fri, 09 Mar 2007 03:12:27 +0000 Subject: [PATCH] Fix sparc TIF_USEDFPU flag atomicity Message-Id: <20070309031227.GC9462@Krystal> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: akpm@linux-foundation.org, mbligh@google.com, linux-kernel@vger.kernel.org, wli@holomorphy.com, sparclinux@vger.kernel.org Fix sparc TIF_USEDFPU flag atomicity Non atomic update of TIF can be very dangerous, except at thread structure creation time. Here I standardize the TIF_USEDFPU usage of the sparc arch. Applies on 2.6.20. Signed-off-by: Mathieu Desnoyers --- a/arch/sparc/kernel/process.c +++ b/arch/sparc/kernel/process.c @@ -348,7 +348,7 @@ void exit_thread(void) #ifndef CONFIG_SMP if(last_task_used_math = current) { #else - if(current_thread_info()->flags & _TIF_USEDFPU) { + if(test_tsk_thread_flag(current, TIF_USEDFPU)) { #endif /* Keep process from leaving FPU in a bogon state. */ put_psr(get_psr() | PSR_EF); @@ -357,7 +357,7 @@ void exit_thread(void) #ifndef CONFIG_SMP last_task_used_math = NULL; #else - current_thread_info()->flags &= ~_TIF_USEDFPU; + clear_tsk_thread_flag(current, TIF_USEDFPU); #endif } } @@ -371,7 +371,7 @@ void flush_thread(void) #ifndef CONFIG_SMP if(last_task_used_math = current) { #else - if(current_thread_info()->flags & _TIF_USEDFPU) { + if(test_tsk_thread_flag(current, TIF_USEDFPU)) { #endif /* Clean the fpu. */ put_psr(get_psr() | PSR_EF); @@ -380,7 +380,7 @@ void flush_thread(void) #ifndef CONFIG_SMP last_task_used_math = NULL; #else - current_thread_info()->flags &= ~_TIF_USEDFPU; + clear_tsk_thread_flag(current, TIF_USEDFPU); #endif } @@ -466,13 +466,13 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, #ifndef CONFIG_SMP if(last_task_used_math = current) { #else - if(current_thread_info()->flags & _TIF_USEDFPU) { + if(test_tsk_thread_flag(current, TIF_USEDFPU)) { #endif put_psr(get_psr() | PSR_EF); fpsave(&p->thread.float_regs[0], &p->thread.fsr, &p->thread.fpqueue[0], &p->thread.fpqdepth); #ifdef CONFIG_SMP - current_thread_info()->flags &= ~_TIF_USEDFPU; + clear_tsk_thread_flag(current, TIF_USEDFPU); #endif } @@ -609,13 +609,13 @@ int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) return 1; } #ifdef CONFIG_SMP - if (current_thread_info()->flags & _TIF_USEDFPU) { + if (test_tsk_thread_flag(current, TIF_USEDFPU)) { put_psr(get_psr() | PSR_EF); fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); if (regs != NULL) { regs->psr &= ~(PSR_EF); - current_thread_info()->flags &= ~(_TIF_USEDFPU); + clear_tsk_thread_flag(current, TIF_USEDFPU); } } #else diff --git a/arch/sparc/kernel/traps.c b/arch/sparc/kernel/traps.c index 6a70d21..7a7ad05 100644 --- a/arch/sparc/kernel/traps.c +++ b/arch/sparc/kernel/traps.c @@ -259,7 +259,7 @@ void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, } else { fpload(¤t->thread.float_regs[0], ¤t->thread.fsr); } - current_thread_info()->flags |= _TIF_USEDFPU; + set_tsk_thread_flag(current, TIF_USEDFPU); #endif } @@ -290,7 +290,7 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, #ifndef CONFIG_SMP if(!fpt) { #else - if(!(task_thread_info(fpt)->flags & _TIF_USEDFPU)) { + if(!test_tsk_thread_flag(fpt, TIF_USEDFPU)) { #endif fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth); regs->psr &= ~PSR_EF; @@ -333,7 +333,7 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, /* nope, better SIGFPE the offending process... */ #ifdef CONFIG_SMP - task_thread_info(fpt)->flags &= ~_TIF_USEDFPU; + clear_tsk_thread_flag(fpt, TIF_USEDFPU); #endif if(psr & PSR_PS) { /* The first fsr store/load we tried trapped, -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030844AbXCIDMb (ORCPT ); Thu, 8 Mar 2007 22:12:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992917AbXCIDMb (ORCPT ); Thu, 8 Mar 2007 22:12:31 -0500 Received: from tomts20.bellnexxia.net ([209.226.175.74]:55529 "EHLO tomts20-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030844AbXCIDM3 (ORCPT ); Thu, 8 Mar 2007 22:12:29 -0500 Date: Thu, 8 Mar 2007 22:12:27 -0500 From: Mathieu Desnoyers To: akpm@linux-foundation.org, mbligh@google.com, linux-kernel@vger.kernel.org, wli@holomorphy.com, sparclinux@vger.kernel.org Subject: [PATCH] Fix sparc TIF_USEDFPU flag atomicity Message-ID: <20070309031227.GC9462@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.4.34-grsec (i686) X-Uptime: 22:10:05 up 34 days, 17:17, 6 users, load average: 1.30, 1.38, 1.34 User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Fix sparc TIF_USEDFPU flag atomicity Non atomic update of TIF can be very dangerous, except at thread structure creation time. Here I standardize the TIF_USEDFPU usage of the sparc arch. Applies on 2.6.20. Signed-off-by: Mathieu Desnoyers --- a/arch/sparc/kernel/process.c +++ b/arch/sparc/kernel/process.c @@ -348,7 +348,7 @@ void exit_thread(void) #ifndef CONFIG_SMP if(last_task_used_math == current) { #else - if(current_thread_info()->flags & _TIF_USEDFPU) { + if(test_tsk_thread_flag(current, TIF_USEDFPU)) { #endif /* Keep process from leaving FPU in a bogon state. */ put_psr(get_psr() | PSR_EF); @@ -357,7 +357,7 @@ void exit_thread(void) #ifndef CONFIG_SMP last_task_used_math = NULL; #else - current_thread_info()->flags &= ~_TIF_USEDFPU; + clear_tsk_thread_flag(current, TIF_USEDFPU); #endif } } @@ -371,7 +371,7 @@ void flush_thread(void) #ifndef CONFIG_SMP if(last_task_used_math == current) { #else - if(current_thread_info()->flags & _TIF_USEDFPU) { + if(test_tsk_thread_flag(current, TIF_USEDFPU)) { #endif /* Clean the fpu. */ put_psr(get_psr() | PSR_EF); @@ -380,7 +380,7 @@ void flush_thread(void) #ifndef CONFIG_SMP last_task_used_math = NULL; #else - current_thread_info()->flags &= ~_TIF_USEDFPU; + clear_tsk_thread_flag(current, TIF_USEDFPU); #endif } @@ -466,13 +466,13 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, #ifndef CONFIG_SMP if(last_task_used_math == current) { #else - if(current_thread_info()->flags & _TIF_USEDFPU) { + if(test_tsk_thread_flag(current, TIF_USEDFPU)) { #endif put_psr(get_psr() | PSR_EF); fpsave(&p->thread.float_regs[0], &p->thread.fsr, &p->thread.fpqueue[0], &p->thread.fpqdepth); #ifdef CONFIG_SMP - current_thread_info()->flags &= ~_TIF_USEDFPU; + clear_tsk_thread_flag(current, TIF_USEDFPU); #endif } @@ -609,13 +609,13 @@ int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) return 1; } #ifdef CONFIG_SMP - if (current_thread_info()->flags & _TIF_USEDFPU) { + if (test_tsk_thread_flag(current, TIF_USEDFPU)) { put_psr(get_psr() | PSR_EF); fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); if (regs != NULL) { regs->psr &= ~(PSR_EF); - current_thread_info()->flags &= ~(_TIF_USEDFPU); + clear_tsk_thread_flag(current, TIF_USEDFPU); } } #else diff --git a/arch/sparc/kernel/traps.c b/arch/sparc/kernel/traps.c index 6a70d21..7a7ad05 100644 --- a/arch/sparc/kernel/traps.c +++ b/arch/sparc/kernel/traps.c @@ -259,7 +259,7 @@ void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, } else { fpload(¤t->thread.float_regs[0], ¤t->thread.fsr); } - current_thread_info()->flags |= _TIF_USEDFPU; + set_tsk_thread_flag(current, TIF_USEDFPU); #endif } @@ -290,7 +290,7 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, #ifndef CONFIG_SMP if(!fpt) { #else - if(!(task_thread_info(fpt)->flags & _TIF_USEDFPU)) { + if(!test_tsk_thread_flag(fpt, TIF_USEDFPU)) { #endif fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth); regs->psr &= ~PSR_EF; @@ -333,7 +333,7 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, /* nope, better SIGFPE the offending process... */ #ifdef CONFIG_SMP - task_thread_info(fpt)->flags &= ~_TIF_USEDFPU; + clear_tsk_thread_flag(fpt, TIF_USEDFPU); #endif if(psr & PSR_PS) { /* The first fsr store/load we tried trapped, -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68