[ARM] 3486/1: Mark memory as clobbered by the ARM _syscallX() macros

Patch from Markus Gutschke

In order to prevent gcc from making incorrect optimizations, all asm()
statements that define system calls should report memory as
clobbered. Recent versions of the headers for i386 have been changed
accordingly, but the ARM headers are still defective.

This patch fixes the bug tracked at
http://bugzilla.kernel.org/show_bug.cgi?id=6205

Signed-off-by: Markus Gutschke <markus@google.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 14 insertions, 7 deletions

diff --git a/include/asm-arm/unistd.h b/include/asm-arm/unistd.h
index ee8dfea549bc..26f2f4828e03 100644
--- a/include/asm-arm/unistd.h
+++ b/include/asm-arm/unistd.h
@@ -410,7 +410,8 @@ type name(void) {							\
   __asm__ __volatile__ (                                                \
   __syscall(name)                                                       \
         : "=r" (__res_r0)                                               \
-        : __SYS_REG_LIST() );                                           \
+        : __SYS_REG_LIST()                                              \
+        : "memory" );                                                   \
   __res = __res_r0;                                                     \
   __syscall_return(type,__res);                                         \
 }
@@ -424,7 +425,8 @@ type name(type1 arg1) { 						\
   __asm__ __volatile__ (                                                \
   __syscall(name)                                                       \
         : "=r" (__res_r0)                                               \
-        : __SYS_REG_LIST( "0" (__r0) ) );                               \
+        : __SYS_REG_LIST( "0" (__r0) )                                  \
+        : "memory" );                                                   \
   __res = __res_r0;                                                     \
   __syscall_return(type,__res);                                         \
 }
@@ -439,7 +441,8 @@ type name(type1 arg1,type2 arg2) {					\
   __asm__ __volatile__ (                                                \
   __syscall(name)                                                       \
         : "=r" (__res_r0)                                               \
-        : __SYS_REG_LIST( "0" (__r0), "r" (__r1) ) );                   \
+        : __SYS_REG_LIST( "0" (__r0), "r" (__r1) )                      \
+        : "memory" );                                                   \
   __res = __res_r0;                                                     \
   __syscall_return(type,__res);                                         \
 }
@@ -456,7 +459,8 @@ type name(type1 arg1,type2 arg2,type3 arg3) {				\
   __asm__ __volatile__ (                                                \
   __syscall(name)                                                       \
         : "=r" (__res_r0)                                               \
-        : __SYS_REG_LIST( "0" (__r0), "r" (__r1), "r" (__r2) ) );       \
+        : __SYS_REG_LIST( "0" (__r0), "r" (__r1), "r" (__r2) )          \
+        : "memory" );                                                   \
   __res = __res_r0;                                                     \
   __syscall_return(type,__res);                                         \
 }
@@ -474,7 +478,8 @@ type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {		\
   __asm__ __volatile__ (                                                \
   __syscall(name)                                                       \
         : "=r" (__res_r0)                                               \
-        : __SYS_REG_LIST( "0" (__r0), "r" (__r1), "r" (__r2), "r" (__r3) ) ); \
+        : __SYS_REG_LIST( "0" (__r0), "r" (__r1), "r" (__r2), "r" (__r3) ) \
+        : "memory" );                                                   \
   __res = __res_r0;                                                     \
   __syscall_return(type,__res);                                         \
 }
@@ -494,7 +499,8 @@ type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5) {	\
   __syscall(name)                                                       \
         : "=r" (__res_r0)                                               \
         : __SYS_REG_LIST( "0" (__r0), "r" (__r1), "r" (__r2),           \
-                          "r" (__r3), "r" (__r4) ) );                   \
+                          "r" (__r3), "r" (__r4) )                      \
+        : "memory" );                                                   \
   __res = __res_r0;                                                     \
   __syscall_return(type,__res);                                         \
 }
@@ -514,7 +520,8 @@ type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5, type6 arg6
   __syscall(name)                                                       \
         : "=r" (__res_r0)                                               \
         : __SYS_REG_LIST( "0" (__r0), "r" (__r1), "r" (__r2),           \
-                          "r" (__r3), "r" (__r4), "r" (__r5) ) );       \
+                          "r" (__r3), "r" (__r4), "r" (__r5) )          \
+        : "memory" );                                                   \
   __res = __res_r0;                                                     \
   __syscall_return(type,__res);                                         \
 }