Messages in this thread Patch in this message | | | From | Denys Vlasenko <> | Subject | [PATCH 2/3] Simplify retint_kernel label usage, make retint_restore_args label local | Date | Mon, 30 Mar 2015 14:26:34 +0200 |
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Get rid of #define obfuscation of retint_kernel in CONFIG_PREEMPT case.
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: Linus Torvalds <torvalds@linux-foundation.org> CC: Steven Rostedt <rostedt@goodmis.org> CC: Ingo Molnar <mingo@kernel.org> CC: Borislav Petkov <bp@alien8.de> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Andy Lutomirski <luto@amacapital.net> CC: Oleg Nesterov <oleg@redhat.com> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Alexei Starovoitov <ast@plumgrid.com> CC: Will Drewry <wad@chromium.org> CC: Kees Cook <keescook@chromium.org> CC: x86@kernel.org CC: linux-kernel@vger.kernel.org --- 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 98edd7d..a5dc652 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 @@ -740,18 +736,18 @@ 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: -- 1.8.1.4
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