Commit dffb3f9d authored Jul 01, 2019 by Andy Lutomirski Committed by Thomas Gleixner Jul 02, 2019

x86/entry/64: Don't compile ignore_sysret if 32-bit emulation is enabled



It's only used if !CONFIG_IA32_EMULATION, so disable it in normal
configs.  This will save a few bytes of text and reduce confusion.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc:  "BaeChang Seok" <chang.seok.bae@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Bae, Chang Seok" <chang.seok.bae@intel.com>
Link: https://lkml.kernel.org/r/0f7dafa72fe7194689de5ee8cfe5d83509fabcf5.1562035429.git.luto@kernel.org

parent 9402eaf4

arch/x86/entry/entry_64.S

+6 −0

Original line number	Diff line number	Diff line
		@@ -1743,11 +1743,17 @@ nmi_restore:
		iretq
		END(nmi)

		#ifndef CONFIG_IA32_EMULATION
		/*
		* This handles SYSCALL from 32-bit code. There is no way to program
		* MSRs to fully disable 32-bit SYSCALL.
		*/
		ENTRY(ignore_sysret)
		UNWIND_HINT_EMPTY
		mov $-ENOSYS, %eax
		sysret
		END(ignore_sysret)
		#endif

		ENTRY(rewind_stack_do_exit)
		UNWIND_HINT_FUNC

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