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| author | Ingo Molnar <mingo@kernel.org> | 2015-04-30 10:09:26 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-05-19 16:48:03 +0300 |
| commit | 5e907bb0459399b0d1cc8d4c7e9f363a995b748a (patch) | |
| tree | 7a0ba64607b1e538740ef6f5d6b95a91c80418fc /arch/x86/include/asm/alternative.h | |
| parent | 2e85591a6ca2ad84741d2859753be5497d74bd42 (diff) | |
| download | linux-5e907bb0459399b0d1cc8d4c7e9f363a995b748a.tar.xz | |
x86/alternatives, x86/fpu: Add 'alternatives_patched' debug flag and use it in xsave_state()
We'd like to use xsave_state() earlier, but its SYSTEM_BOOTING check
is too imprecise.
The real condition that xsave_state() would like to check is whether
alternative XSAVE instructions were patched into the kernel image
already.
Add such a (read-mostly) debug flag and use it in xsave_state().
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/alternative.h')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index ba32af062f61..7bfc85bbb8ff 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -52,6 +52,12 @@ struct alt_instr { u8 padlen; /* length of build-time padding */ } __packed; +/* + * Debug flag that can be tested to see whether alternative + * instructions were patched in already: + */ +extern int alternatives_patched; + extern void alternative_instructions(void); extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); |