x86/paravirt: don't restore second return reg
Impact: bugfix
In the 32-bit calling convention, %eax:%edx is used to return 64-bit
values. Don't save and restore %edx around wrapped functions, or they
can't return a full 64-bit result.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index b17365c..016dce3 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -1524,8 +1524,8 @@
#define PV_RESTORE_REGS "popl %edx; popl %ecx;"
/* save and restore all caller-save registers, except return value */
-#define PV_SAVE_ALL_CALLER_REGS PV_SAVE_REGS
-#define PV_RESTORE_ALL_CALLER_REGS PV_RESTORE_REGS
+#define PV_SAVE_ALL_CALLER_REGS "pushl %ecx;"
+#define PV_RESTORE_ALL_CALLER_REGS "popl %ecx;"
#define PV_FLAGS_ARG "0"
#define PV_EXTRA_CLOBBERS