| From e78e5a91456fcecaa2efbb3706572fe043766f4d Mon Sep 17 00:00:00 2001 |
| From: Samuel Neves <sneves@dei.uc.pt> |
| Date: Sat, 1 Sep 2018 21:14:52 +0100 |
| Subject: x86/vdso: Fix lsl operand order |
| |
| From: Samuel Neves <sneves@dei.uc.pt> |
| |
| 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> |
| |
| --- |
| arch/x86/include/asm/vgtod.h | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/arch/x86/include/asm/vgtod.h |
| +++ b/arch/x86/include/asm/vgtod.h |
| @@ -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)); |
