Commit-ID: dffb3f9db6b593f3ed6ab4c8d8f10e0aa6aa7a88 Gitweb: https://git.kernel.org/tip/dffb3f9db6b593f3ed6ab4c8d8f10e0aa6aa7a88 Author: Andy Lutomirski <luto@xxxxxxxxxx> AuthorDate: Mon, 1 Jul 2019 20:43:20 -0700 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Tue, 2 Jul 2019 08:45:20 +0200 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@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: "BaeChang Seok" <chang.seok.bae@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: "Bae, Chang Seok" <chang.seok.bae@xxxxxxxxx> Link: https://lkml.kernel.org/r/0f7dafa72fe7194689de5ee8cfe5d83509fabcf5.1562035429.git.luto@xxxxxxxxxx --- arch/x86/entry/entry_64.S | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 7f9f5119d6b1..54b1b0468b2b 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -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
|