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x86/vdso: Fix lsl operand order

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commit e78e5a91456fcecaa2efbb3706572fe043766f4d upstream.

In the __getcpu function, lsl is using the wrong target and destination
registers. Luckily, the compiler tends to choose %eax for both variables,
so it has been working so far.

Fixes: a582c540ac1b ("x86/vdso: Use RDPID in preference to LSL when available")
Signed-off-by: Samuel Neves <sneves@dei.uc.pt>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180901201452.27828-1-sneves@dei.uc.pt
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Samuel Neves 2018-09-01 21:14:52 +01:00 committed by Greg Kroah-Hartman
parent 42228037aa
commit fbd5b82d30
1 changed files with 1 additions and 1 deletions
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2
arch/x86/include/asm/vgtod.h
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@ -93,7 +93,7 @@ static inline unsigned int __getcpu(void)
*
* If RDPID is available, use it.
*/
alternative_io ("lsl %[p],%[seg]",
alternative_io ("lsl %[seg],%[p]",
".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */
X86_FEATURE_RDPID,
[p] "=a" (p), [seg] "r" (__PER_CPU_SEG));