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| author | Andy Lutomirski <luto@kernel.org> | 2019-07-01 20:43:20 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-07-02 08:45:20 +0200 |
| commit | dffb3f9db6b593f3ed6ab4c8d8f10e0aa6aa7a88 (patch) | |
| tree | 8f1baa91d005525e4a44c52886801e8978e3b54c | |
| parent | 9402eaf4c11f0b892eda7b2bcb4654ab34ce34f9 (diff) | |
| download | linux-cip-dffb3f9db6b593f3ed6ab4c8d8f10e0aa6aa7a88.tar.gz | |
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
| -rw-r--r-- | arch/x86/entry/entry_64.S | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 7f9f5119d6b11..54b1b0468b2b3 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 |