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authorJeremy Fitzhardinge2009-10-13 01:32:43 +0200
committerIngo Molnar2009-10-13 09:22:01 +0200
commit71999d9862e667f1fd14f8fbfa0cce6d855bad3f (patch)
treeb228a66c29154a446dc3adaf6f0dae8ee4b908d3 /arch/x86/include/asm/paravirt_types.h
parentx86: fix kernel panic on 32 bits when profiling (diff)
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x86/paravirt: Use normal calling sequences for irq enable/disable
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 <bastian@waldi.eu.org> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org> Cc: Xen-devel <xen-devel@lists.xensource.com> LKML-Reference: <4AD3BC9B.7040501@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include/asm/paravirt_types.h')
-rw-r--r--arch/x86/include/asm/paravirt_types.h10
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index dd0f5b32489d..9357473c8da0 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -494,10 +494,11 @@ 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))
@@ -509,6 +510,7 @@ 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
@@ -583,8 +585,8 @@ 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__)