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, 16 insertions, 15 deletions

diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h
index f08f9737489..022a84386de 100644
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@ -128,8 +128,6 @@ do {									\
              "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"              \
              __switch_canary                                              \
              "movq %P[thread_info](%%rsi),%%r8\n\t"                       \
@@ -157,19 +155,22 @@ extern void native_load_gs_index(unsigned);
  * Load a segment. Fall back on loading the zero
  * segment if something goes wrong..
  */
-#define loadsegment(seg, value)                 \
-        asm volatile("\n"                       \
-                     "1:\t"                     \
-                     "movl %k0,%%" #seg "\n"    \
-                     "2:\n"                     \
-                     ".section .fixup,\"ax\"\n" \
-                     "3:\t"                     \
-                     "movl %k1, %%" #seg "\n\t" \
-                     "jmp 2b\n"                 \
-                     ".previous\n"              \
-                     _ASM_EXTABLE(1b,3b)        \
-                     : :"r" (value), "r" (0) : "memory")
-
+#define loadsegment(seg, value)                                         \
+do {                                                                    \
+        unsigned short __val = (value);                                 \
+                                                                        \
+        asm volatile("                                          \n"     \
+                     "1:        movl %k0,%%" #seg "             \n"     \
+                                                                        \
+                     ".section .fixup,\"ax\"                    \n"     \
+                     "2:        xorl %k0,%k0                    \n"     \
+                     "          jmp 1b                          \n"     \
+                     ".previous                                 \n"     \
+                                                                        \
+                     _ASM_EXTABLE(1b, 2b)                               \
+                                                                        \
+                     : "+r" (__val) : : "memory");                      \
+} while (0)
 
 /*
  * Save a segment register away