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| author |   Jeremy Fitzhardinge <jeremy@goop.org> | 2006-09-26 10:52:34 +0200 |
|---|---|---|
| committer |   Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:34 +0200 |
| commit | 5758d5dfef1c514200bda3f29ba700f1c3e3bc99 (patch) | |
| tree | 7d2c859f875d0d5f1eacfbec66d4a9259aaa4893 /arch/i386/kernel/cpu/common.c | |
| parent | [PATCH] Don't force frame pointers for lockdep (diff) | |
| download | linux-dev-5758d5dfef1c514200bda3f29ba700f1c3e3bc99.tar.xz linux-dev-5758d5dfef1c514200bda3f29ba700f1c3e3bc99.zip | |
[PATCH] i386: fix dubious segment register clear in cpu_init()
Fix a very dubious piece of code in
arch/i386/kernel/cpu/common.c:cpu_init(). This clears out %fs and
%gs, but clobbers %eax in the process without telling gcc. It turns
out that gcc happens to be not using %eax at that point anyway so it
doesn't matter much, but it looks like a bomb waiting to go off.
This does end up saving an instruction, because gcc wants %eax==0 for
the set_debugreg()s below.
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/i386/kernel/cpu/common.c')
| -rw-r--r-- | arch/i386/kernel/cpu/common.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c index 70c87de582c7..730a7ab75009 100644 --- a/arch/i386/kernel/cpu/common.c +++ b/arch/i386/kernel/cpu/common.c @@ -675,7 +675,7 @@ old_gdt: #endif /* Clear %fs and %gs. */ - asm volatile ("xorl %eax, %eax; movl %eax, %fs; movl %eax, %gs"); + asm volatile ("movl %0, %%fs; movl %0, %%gs" : : "r" (0)); /* Clear all 6 debug registers: */ set_debugreg(0, 0); |