The following commit has been merged into the x86/entry branch of tip: Commit-ID: cd19bff6935f29ad06513562b59ebdfe2d34eae4 Gitweb: https://git.kernel.org/tip/cd19bff6935f29ad06513562b59ebdfe2d34eae4 Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> AuthorDate: Tue, 25 Feb 2020 23:16:08 +01:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Fri, 15 May 2020 20:03:04 +02:00 x86/entry/64: Avoid pointless code when CONTEXT_TRACKING=n GAS cannot optimize out the test and conditional jump when context tracking is disabled and CALL_enter_from_user_mode is an empty macro. Wrap it in #ifdeffery. Will go away once all this is moved to C. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx> Acked-by: Frederic Weisbecker <frederic@xxxxxxxxxx> Acked-by: Andy Lutomirski <luto@xxxxxxxxxx> Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200505134058.955968069@xxxxxxxxxxxxx --- arch/x86/entry/entry_64.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 7d40d10..f84b0f6 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -889,12 +889,14 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt TRACE_IRQS_OFF .endif +#ifdef CONFIG_CONTEXT_TRACKING .if \paranoid == 0 testb $3, CS(%rsp) jz .Lfrom_kernel_no_context_tracking_\@ CALL_enter_from_user_mode .Lfrom_kernel_no_context_tracking_\@: .endif +#endif movq %rsp, %rdi /* pt_regs pointer */
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