lkml.org 
[lkml]   [2015]   [Sep]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v12 08/21] x86/paravirt: Add stack frame dependency to PVOP inline asm calls
Date
If a PVOP call macro is inlined at the beginning of a function, gcc can
insert the call instruction before setting up a stack frame, which
breaks frame pointer convention if CONFIG_FRAME_POINTER is enabled and
can result in a bad stack trace.

Force a stack frame to be created if CONFIG_FRAME_POINTER is enabled by
listing the stack pointer as an output operand for the PVOP inline asm
statements.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
---
arch/x86/include/asm/paravirt_types.h | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index ce029e4..1812294 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -497,8 +497,9 @@ int paravirt_disable_iospace(void);
* makes sure the incoming and outgoing types are always correct.
*/
#ifdef CONFIG_X86_32
-#define PVOP_VCALL_ARGS \
- unsigned long __eax = __eax, __edx = __edx, __ecx = __ecx
+#define PVOP_VCALL_ARGS \
+ unsigned long __eax = __eax, __edx = __edx, __ecx = __ecx; \
+ register void *__sp asm("esp")
#define PVOP_CALL_ARGS PVOP_VCALL_ARGS

#define PVOP_CALL_ARG1(x) "a" ((unsigned long)(x))
@@ -516,9 +517,10 @@ int paravirt_disable_iospace(void);
#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, __eax = __eax
+#define PVOP_VCALL_ARGS \
+ unsigned long __edi = __edi, __esi = __esi, \
+ __edx = __edx, __ecx = __ecx, __eax = __eax; \
+ register void *__sp asm("rsp")
#define PVOP_CALL_ARGS PVOP_VCALL_ARGS

#define PVOP_CALL_ARG1(x) "D" ((unsigned long)(x))
@@ -557,7 +559,7 @@ int paravirt_disable_iospace(void);
asm volatile(pre \
paravirt_alt(PARAVIRT_CALL) \
post \
- : call_clbr \
+ : "+r" (__sp), call_clbr \
: paravirt_type(op), \
paravirt_clobber(clbr), \
##__VA_ARGS__ \
@@ -567,7 +569,7 @@ int paravirt_disable_iospace(void);
asm volatile(pre \
paravirt_alt(PARAVIRT_CALL) \
post \
- : call_clbr \
+ : "+r" (__sp), call_clbr \
: paravirt_type(op), \
paravirt_clobber(clbr), \
##__VA_ARGS__ \
@@ -594,7 +596,7 @@ int paravirt_disable_iospace(void);
asm volatile(pre \
paravirt_alt(PARAVIRT_CALL) \
post \
- : call_clbr \
+ : "+r" (__sp), call_clbr \
: paravirt_type(op), \
paravirt_clobber(clbr), \
##__VA_ARGS__ \
--
2.4.3


\
 
 \ /
  Last update: 2015-09-09 15:41    [W:0.236 / U:0.128 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site