Merge branch 'core/percpu' into x86/core

1 files changed, 20 insertions, 1 deletions

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 722464c520cf..2a0aad7718d5 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -19,6 +19,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/setup.h>
 #include <asm/processor-flags.h>
+#include <asm/percpu.h>
 
 /* Physical address */
 #define pa(X) ((X) - __PAGE_OFFSET)
@@ -437,8 +438,26 @@ is386:	movl $2,%ecx		# set MP
         movl $(__KERNEL_PERCPU), %eax
         movl %eax,%fs                   # set this cpu's percpu
 
-        xorl %eax,%eax                  # Clear GS and LDT
+#ifdef CONFIG_CC_STACKPROTECTOR
+        /*
+         * The linker can't handle this by relocation.  Manually set
+         * base address in stack canary segment descriptor.
+         */
+        cmpb $0,ready
+        jne 1f
+        movl $per_cpu__gdt_page,%eax
+        movl $per_cpu__stack_canary,%ecx
+        subl $20, %ecx
+        movw %cx, 8 * GDT_ENTRY_STACK_CANARY + 2(%eax)
+        shrl $16, %ecx
+        movb %cl, 8 * GDT_ENTRY_STACK_CANARY + 4(%eax)
+        movb %ch, 8 * GDT_ENTRY_STACK_CANARY + 7(%eax)
+1:
+#endif
+        movl $(__KERNEL_STACK_CANARY),%eax
         movl %eax,%gs
+
+        xorl %eax,%eax                  # Clear LDT
         lldt %ax
 
         cld                     # gcc2 wants the direction flag cleared at all times