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| author | Denys Vlasenko <dvlasenk@redhat.com> | 2015-03-31 19:00:05 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-04-01 13:17:38 +0200 |
| commit | 6ba71b7617f1fa65f19bd34f4484a0694ef9a520 (patch) | |
| tree | c5eeb1fb9c84a819d83f4ab8b25eda7801d35f3d /arch | |
| parent | x86/asm/entry/32: Use smaller PUSH instructions instead of MOV, to build 'pt_... (diff) | |
| download | linux-6ba71b7617f1fa65f19bd34f4484a0694ef9a520.tar.xz linux-6ba71b7617f1fa65f19bd34f4484a0694ef9a520.zip | |
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 <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-3-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 12 |
1 files 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: |