[PATCH] fix kexec asm
Michael Matz [Wed, 8 Mar 2006 05:55:48 +0000 (21:55 -0800)]
While testing kexec and kdump we hit problems where the new kernel would
freeze or instantly reboot.  The easiest way to trigger it was to kexec a
kernel compiled for CONFIG_M586 on an athlon cpu.  Compiling for CONFIG_MK7
instead would work fine.

The patch fixes a few problems with the kexec inline asm.

Signed-off-by: Chris Mason <mason@suse.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/machine_kexec.c
arch/x86_64/kernel/machine_kexec.c
include/asm-powerpc/kexec.h

index a912fed..f73d737 100644 (file)
@@ -116,13 +116,13 @@ static void load_segments(void)
        __asm__ __volatile__ (
                "\tljmp $"STR(__KERNEL_CS)",$1f\n"
                "\t1:\n"
-               "\tmovl $"STR(__KERNEL_DS)",%eax\n"
-               "\tmovl %eax,%ds\n"
-               "\tmovl %eax,%es\n"
-               "\tmovl %eax,%fs\n"
-               "\tmovl %eax,%gs\n"
-               "\tmovl %eax,%ss\n"
-               );
+               "\tmovl $"STR(__KERNEL_DS)",%%eax\n"
+               "\tmovl %%eax,%%ds\n"
+               "\tmovl %%eax,%%es\n"
+               "\tmovl %%eax,%%fs\n"
+               "\tmovl %%eax,%%gs\n"
+               "\tmovl %%eax,%%ss\n"
+               ::: "eax", "memory");
 #undef STR
 #undef __STR
 }
index 89fab51..25ac8a3 100644 (file)
@@ -140,7 +140,7 @@ static void load_segments(void)
                "\tmovl %0,%%ss\n"
                "\tmovl %0,%%fs\n"
                "\tmovl %0,%%gs\n"
-               : : "a" (__KERNEL_DS)
+               : : "a" (__KERNEL_DS) : "memory"
                );
 }
 
index bda2f21..6a2af2f 100644 (file)
@@ -93,7 +93,8 @@ static inline void crash_setup_regs(struct pt_regs *newregs,
                        "mfxer  %0\n"
                        "std    %0, 296(%2)\n"
                        : "=&r" (tmp1), "=&r" (tmp2)
-                       : "b" (newregs));
+                       : "b" (newregs)
+                       : "memory");
        }
 }
 #else