Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  include/linux/compiler-gcc4.h: Fix build bug - gcc-4.0.2 doesn't understand __builtin_object_size
  x86/alternatives: No need for alternatives-asm.h to re-invent stuff already in asm.h
  x86/alternatives: Check replacementlen <= instrlen at build time
  x86, 64-bit: Set data segments to null after switching to 64-bit mode
  x86: Clean up the loadsegment() macro
  x86: Optimize loadsegment()
  x86: Add missing might_fault() checks to copy_{to,from}_user()
  x86-64: __copy_from_user_inatomic() adjustments
  x86: Remove unused thread_return label from switch_to()
  x86, 64-bit: Fix bstep_iret jump
  x86: Don't use the strict copy checks when branch profiling is in use
  x86, 64-bit: Move K8 B step iret fixup to fault entry asm
  x86: Generate cmpxchg build failures
  x86: Add a Kconfig option to turn the copy_from_user warnings into errors
  x86: Turn the copy_from_user check into an (optional) compile time warning
  x86: Use __builtin_memset and __builtin_memcpy for memset/memcpy
  x86: Use __builtin_object_size() to validate the buffer size for copy_from_user()

1 files changed, 8 insertions, 3 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 722df1b1152d..4deb8fc849dd 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1499,12 +1499,17 @@ error_kernelspace:
         leaq irq_return(%rip),%rcx
         cmpq %rcx,RIP+8(%rsp)
         je error_swapgs
-        movl %ecx,%ecx  /* zero extend */
-        cmpq %rcx,RIP+8(%rsp)
-        je error_swapgs
+        movl %ecx,%eax  /* zero extend */
+        cmpq %rax,RIP+8(%rsp)
+        je bstep_iret
         cmpq $gs_change,RIP+8(%rsp)
         je error_swapgs
         jmp error_sti
+
+bstep_iret:
+        /* Fix truncated RIP */
+        movq %rcx,RIP+8(%rsp)
+        jmp error_swapgs
 END(error_entry)