---

yaml
---
r: 136451
b: refs/heads/master
c: b4a8f7a
h: refs/heads/master
i:
  136449: 93d0612
  136447: bca31b9
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c6e50f93db5bd0895ec7c7d1b6f3886c6e1f11b6
+refs/heads/master: b4a8f7a262e79ecb0b39beb1449af524a78887f8

trunk/arch/x86/include/asm/system.h

@@ -86,17 +86,28 @@ do {									\
 	, "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
 	  "r12", "r13", "r14", "r15"
 
+#ifdef CONFIG_CC_STACKPROTECTOR
+#define __switch_canary							  \
+	"movq %P[task_canary](%%rsi),%%r8\n\t"				  \
+	"movq %%r8,%%gs:%P[pda_canary]\n\t"
+#define __switch_canary_param						  \
+	, [task_canary] "i" (offsetof(struct task_struct, stack_canary))  \
+	, [pda_canary] "i" (offsetof(struct x8664_pda, stack_canary))
+#else	/* CC_STACKPROTECTOR */
+#define __switch_canary
+#define __switch_canary_param
+#endif	/* CC_STACKPROTECTOR */
+
 /* Save restore flags to clear handle leaking NT */
 #define switch_to(prev, next, last) \
-	asm volatile(SAVE_CONTEXT						    \
+	asm volatile(SAVE_CONTEXT					  \
 	     "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */	  \
 	     "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */	  \
 	     "call __switch_to\n\t"					  \
 	     ".globl thread_return\n"					  \
 	     "thread_return:\n\t"					  \
 	     "movq "__percpu_arg([current_task])",%%rsi\n\t"		  \
-	     "movq %P[task_canary](%%rsi),%%r8\n\t"			  \
-	     "movq %%r8,%%gs:%P[pda_canary]\n\t"			  \
+	     __switch_canary						  \
 	     "movq %P[thread_info](%%rsi),%%r8\n\t"			  \
 	     LOCK_PREFIX "btr  %[tif_fork],%P[ti_flags](%%r8)\n\t"	  \
 	     "movq %%rax,%%rdi\n\t" 					  \
@@ -108,9 +119,8 @@ do {									\
 	       [ti_flags] "i" (offsetof(struct thread_info, flags)),	  \
 	       [tif_fork] "i" (TIF_FORK),			  	  \
 	       [thread_info] "i" (offsetof(struct task_struct, stack)),   \
-	       [task_canary] "i" (offsetof(struct task_struct, stack_canary)),\
-	       [current_task] "m" (per_cpu_var(current_task)),		  \
-	       [pda_canary] "i" (offsetof(struct x8664_pda, stack_canary))\
+	       [current_task] "m" (per_cpu_var(current_task))		  \
+	       __switch_canary_param					  \
 	     : "memory", "cc" __EXTRA_CLOBBER)
 #endif