[PATCH] i386: PARAVIRT: Fix patch site clobbers to include return register

Fix a few clobbers to include the return register.  The clobbers set
is the set of all registers modified (or may be modified) by the code
snippet, regardless of whether it was deliberate or accidental.

Also, make sure that callsites which are used in contexts which don't
allow clobbers actually save and restore all clobberable registers.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>

diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index e901952..e07473c 100644 (file)
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -338,7 +338,7 @@ sysenter_past_esp:
        jae syscall_badsys
        call *sys_call_table(,%eax,4)
        movl %eax,PT_EAX(%esp)
-       DISABLE_INTERRUPTS(CLBR_ECX|CLBR_EDX)
+       DISABLE_INTERRUPTS(CLBR_ANY)
        TRACE_IRQS_OFF
        movl TI_flags(%ebp), %ecx
        testw $_TIF_ALLWORK_MASK, %cx

diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h
index 1dbc01f..87fd431 100644 (file)
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -535,7 +535,7 @@ static inline unsigned long __raw_local_save_flags(void)
                                  "popl %%edx; popl %%ecx")
                     : "=a"(f)
                     : paravirt_type(save_fl),
-                      paravirt_clobber(CLBR_NONE)
+                      paravirt_clobber(CLBR_EAX)
                     : "memory", "cc");
        return f;
 }
@@ -620,27 +620,29 @@ static inline unsigned long __raw_local_irq_save(void)
        .popsection
 
 #define INTERRUPT_RETURN                                       \
-       PARA_SITE(PARA_PATCH(PARAVIRT_iret), CLBR_ANY,          \
+       PARA_SITE(PARA_PATCH(PARAVIRT_iret), CLBR_NONE,         \
                  jmp *%cs:paravirt_ops+PARAVIRT_iret)
 
 #define DISABLE_INTERRUPTS(clobbers)                                   \
        PARA_SITE(PARA_PATCH(PARAVIRT_irq_disable), clobbers,           \
-                 pushl %ecx; pushl %edx;                               \
+                 pushl %eax; pushl %ecx; pushl %edx;                   \
                  call *%cs:paravirt_ops+PARAVIRT_irq_disable;          \
-                 popl %edx; popl %ecx)                                 \
+                 popl %edx; popl %ecx; popl %eax)                      \
 
 #define ENABLE_INTERRUPTS(clobbers)                                    \
        PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable), clobbers,            \
-                 pushl %ecx; pushl %edx;                               \
+                 pushl %eax; pushl %ecx; pushl %edx;                   \
                  call *%cs:paravirt_ops+PARAVIRT_irq_enable;           \
-                 popl %edx; popl %ecx)
+                 popl %edx; popl %ecx; popl %eax)
 
 #define ENABLE_INTERRUPTS_SYSEXIT                                      \
-       PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable_sysexit), CLBR_ANY,    \
+       PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable_sysexit), CLBR_NONE,   \
                  jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
 
 #define GET_CR0_INTO_EAX                       \
-       call *paravirt_ops+PARAVIRT_read_cr0
+       push %ecx; push %edx;                   \
+       call *paravirt_ops+PARAVIRT_read_cr0;   \
+       pop %edx; pop %ecx
 
 #endif /* __ASSEMBLY__ */
 #endif /* CONFIG_PARAVIRT */