Commit 627276cb authored Mar 30, 2015 by Denys Vlasenko Committed by Ingo Molnar Mar 31, 2015

x86/asm/entry/64: Move retint_kernel code block closer to its user



The "retint_kernel" code block is misplaced. Since its logical
continuation is "retint_restore_args", it is more natural to
place it above that label. This also makes two jumps "short".

This change only moves code block around, without changing
logic.

This enables the next simplification: making
"retint_restore_args" label a local numeric one.

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/1427738975-7391-2-git-send-email-dvlasenk@redhat.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 4ee8ec17

arch/x86/kernel/entry_64.S

+13 −12

Original line number	Diff line number	Diff line
		@@ -740,7 +740,19 @@ opportunistic_sysret_failed:
		SWAPGS
		jmp restore_args

		retint_restore_args: /* return to kernel space */
		/* Returning to kernel space */
		#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
		bt $9,EFLAGS(%rsp) /* interrupts were off? */
		jnc retint_restore_args
		call preempt_schedule_irq
		jmp exit_intr
		#endif
		retint_restore_args:
		DISABLE_INTERRUPTS(CLBR_ANY)
		/*
		* The iretq could re-enable interrupts:
		@@ -830,17 +842,6 @@ retint_signal:
		GET_THREAD_INFO(%rcx)
		jmp retint_with_reschedule

		#ifdef CONFIG_PREEMPT
		/* Returning to kernel space. Check if we need preemption */
		/* rcx: threadinfo. interrupts off. */
		ENTRY(retint_kernel)
		cmpl $0,PER_CPU_VAR(__preempt_count)
		jnz retint_restore_args
		bt $9,EFLAGS(%rsp) /* interrupts off? */
		jnc retint_restore_args
		call preempt_schedule_irq
		jmp exit_intr
		#endif
		CFI_ENDPROC
		END(common_interrupt)

Admin message