Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932945AbZJPR2j (ORCPT ); Fri, 16 Oct 2009 13:28:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758138AbZJPR2i (ORCPT ); Fri, 16 Oct 2009 13:28:38 -0400 Received: from kroah.org ([198.145.64.141]:48446 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752474AbZJPRSP (ORCPT ); Fri, 16 Oct 2009 13:18:15 -0400 X-Mailbox-Line: From linux@linux.site Fri Oct 16 10:11:49 2009 Message-Id: <20091016171149.406810626@linux.site> User-Agent: quilt/0.47-14.9 Date: Fri, 16 Oct 2009 10:09:59 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jeremy Fitzhardinge , Xen-devel , Ingo Molnar , Greg Kroah-Hartman Subject: [06/46] x86/paravirt: Use normal calling sequences for irq enable/disable References: <20091016170953.128828149@linux.site> Content-Disposition: inline; filename=x86-paravirt-use-normal-calling-sequences-for-irq-enable-disable.patch In-Reply-To: <20091016171422.GA13339@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4075 Lines: 111 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jeremy Fitzhardinge commit 71999d9862e667f1fd14f8fbfa0cce6d855bad3f upstream. Bastian Blank reported a boot crash with stackprotector enabled, and debugged it back to edx register corruption. For historical reasons irq enable/disable/save/restore had special calling sequences to make them more efficient. With the more recent introduction of higher-level and more general optimisations this is no longer necessary so we can just use the normal PVOP_ macros. This fixes some residual bugs in the old implementations which left edx liable to inadvertent clobbering. Also, fix some bugs in __PVOP_VCALLEESAVE which were revealed by actual use. Reported-by: Bastian Blank Signed-off-by: Jeremy Fitzhardinge Cc: Xen-devel LKML-Reference: <4AD3BC9B.7040501@goop.org> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/paravirt.h | 38 ++++++++++---------------------------- 1 file changed, 10 insertions(+), 28 deletions(-) --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -528,10 +528,11 @@ int paravirt_disable_iospace(void); #define EXTRA_CLOBBERS #define VEXTRA_CLOBBERS #else /* CONFIG_X86_64 */ +/* [re]ax isn't an arg, but the return val */ #define PVOP_VCALL_ARGS \ unsigned long __edi = __edi, __esi = __esi, \ - __edx = __edx, __ecx = __ecx -#define PVOP_CALL_ARGS PVOP_VCALL_ARGS, __eax + __edx = __edx, __ecx = __ecx, __eax = __eax +#define PVOP_CALL_ARGS PVOP_VCALL_ARGS #define PVOP_CALL_ARG1(x) "D" ((unsigned long)(x)) #define PVOP_CALL_ARG2(x) "S" ((unsigned long)(x)) @@ -543,6 +544,7 @@ int paravirt_disable_iospace(void); "=c" (__ecx) #define PVOP_CALL_CLOBBERS PVOP_VCALL_CLOBBERS, "=a" (__eax) +/* void functions are still allowed [re]ax for scratch */ #define PVOP_VCALLEE_CLOBBERS "=a" (__eax) #define PVOP_CALLEE_CLOBBERS PVOP_VCALLEE_CLOBBERS @@ -617,8 +619,8 @@ int paravirt_disable_iospace(void); VEXTRA_CLOBBERS, \ pre, post, ##__VA_ARGS__) -#define __PVOP_VCALLEESAVE(rettype, op, pre, post, ...) \ - ____PVOP_CALL(rettype, op.func, CLBR_RET_REG, \ +#define __PVOP_VCALLEESAVE(op, pre, post, ...) \ + ____PVOP_VCALL(op.func, CLBR_RET_REG, \ PVOP_VCALLEE_CLOBBERS, , \ pre, post, ##__VA_ARGS__) @@ -1565,42 +1567,22 @@ extern struct paravirt_patch_site __para static inline unsigned long __raw_local_save_flags(void) { - unsigned long f; - - asm volatile(paravirt_alt(PARAVIRT_CALL) - : "=a"(f) - : paravirt_type(pv_irq_ops.save_fl), - paravirt_clobber(CLBR_EAX) - : "memory", "cc"); - return f; + return PVOP_CALLEE0(unsigned long, pv_irq_ops.save_fl); } static inline void raw_local_irq_restore(unsigned long f) { - asm volatile(paravirt_alt(PARAVIRT_CALL) - : "=a"(f) - : PV_FLAGS_ARG(f), - paravirt_type(pv_irq_ops.restore_fl), - paravirt_clobber(CLBR_EAX) - : "memory", "cc"); + PVOP_VCALLEE1(pv_irq_ops.restore_fl, f); } static inline void raw_local_irq_disable(void) { - asm volatile(paravirt_alt(PARAVIRT_CALL) - : - : paravirt_type(pv_irq_ops.irq_disable), - paravirt_clobber(CLBR_EAX) - : "memory", "eax", "cc"); + PVOP_VCALLEE0(pv_irq_ops.irq_disable); } static inline void raw_local_irq_enable(void) { - asm volatile(paravirt_alt(PARAVIRT_CALL) - : - : paravirt_type(pv_irq_ops.irq_enable), - paravirt_clobber(CLBR_EAX) - : "memory", "eax", "cc"); + PVOP_VCALLEE0(pv_irq_ops.irq_enable); } static inline unsigned long __raw_local_irq_save(void) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/