From 6ba71b7617f1fa65f19bd34f4484a0694ef9a520 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 31 Mar 2015 19:00:05 +0200 Subject: [PATCH] x86/asm/entry/64: Simplify retint_kernel label usage, make retint_restore_args label local Get rid of #define obfuscation of retint_kernel in CONFIG_PREEMPT case by defining retint_kernel label always, not only for CONFIG_PREEMPT. Strip retint_kernel of .global-ness (ENTRY macro) - it has no users outside of this file. This looks like cosmetics, but it is not: "je LABEL" can be optimized to short jump by assember only if LABEL is not global, for global labels jump is always a near one with relocation. Convert retint_restore_args to a local numeric label, making it clearer that it is not used elsewhere in the file. Signed-off-by: Denys Vlasenko Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Steven Rostedt Cc: Will Drewry Link: http://lkml.kernel.org/r/1427821211-25099-3-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/entry_64.S | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index f6e37de02ba7..1879c55bf0f7 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -57,10 +57,6 @@ .section .entry.text, "ax" -#ifndef CONFIG_PREEMPT -#define retint_kernel retint_restore_args -#endif - #ifdef CONFIG_PARAVIRT ENTRY(native_usergs_sysret64) swapgs @@ -741,18 +737,18 @@ opportunistic_sysret_failed: jmp restore_args /* Returning to kernel space */ +retint_kernel: #ifdef CONFIG_PREEMPT /* Interrupts are off */ /* Check if we need preemption */ -ENTRY(retint_kernel) cmpl $0,PER_CPU_VAR(__preempt_count) - jnz retint_restore_args + jnz 1f bt $9,EFLAGS(%rsp) /* interrupts were off? */ - jnc retint_restore_args + jnc 1f call preempt_schedule_irq jmp exit_intr +1: #endif -retint_restore_args: DISABLE_INTERRUPTS(CLBR_ANY) /* * The iretq could re-enable interrupts: -- 2.20.1