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

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, asm: If the assembler supports fxsave64, use it
  i386: Make kernel_execve() suitable for stack unwinding

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index e8c8881..b02e509 100644 (file)
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -96,8 +96,12 @@ cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_en
 # is .cfi_signal_frame supported too?
 cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
 cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
-KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections)
-KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections)
+
+# does binutils support specific instructions?
+asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)
+
+KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr)
+KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr)
 
 LDFLAGS := -m elf_$(UTS_MACHINE)
 

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index a73a8d5..70f105b 100644 (file)
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -175,7 +175,7 @@ static inline void fpu_fxsave(struct fpu *fpu)
           uses any extended registers for addressing, a second REX prefix
           will be generated (to the assembler, rex64 followed by semicolon
           is a separate instruction), and hence the 64-bitness is lost. */
-#if 0
+#ifdef CONFIG_AS_FXSAVEQ
        /* Using "fxsaveq %0" would be the ideal choice, but is only supported
           starting with gas 2.16. */
        __asm__ __volatile__("fxsaveq %0"

diff --git a/arch/x86/kernel/sys_i386_32.c b/arch/x86/kernel/sys_i386_32.c
index d5e0662..0b0cb5f 100644 (file)
--- a/arch/x86/kernel/sys_i386_32.c
+++ b/arch/x86/kernel/sys_i386_32.c
@@ -33,8 +33,8 @@ int kernel_execve(const char *filename,
                  const char *const envp[])
 {
        long __res;
-       asm volatile ("push %%ebx ; movl %2,%%ebx ; int $0x80 ; pop %%ebx"
+       asm volatile ("int $0x80"
        : "=a" (__res)
-       : "0" (__NR_execve), "ri" (filename), "c" (argv), "d" (envp) : "memory");
+       : "0" (__NR_execve), "b" (filename), "c" (argv), "d" (envp) : "memory");
        return __res;
 }