diff options
| author | Ingo Molnar <mingo@kernel.org> | 2015-03-24 13:41:37 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-03-24 19:57:25 (GMT) |
| commit | d56fe4bf5f3cc30d455c80520f7b71da36ae00e6 (patch) | |
| tree | 387fd11f1700ccdabc517ec0a6d75d4d64fb30fc /arch/x86/kernel/cpu/common.c | |
| parent | 84f53788458c95309b88948b69ff95921e9c74a8 (diff) | |
| download | linux-d56fe4bf5f3cc30d455c80520f7b71da36ae00e6.tar.xz | |
x86/asm/entry/64: Always set up SYSENTER MSRs
On CONFIG_IA32_EMULATION=y kernels we set up
MSR_IA32_SYSENTER_CS/ESP/EIP, but on !CONFIG_IA32_EMULATION
kernels we leave them unchanged.
Clear them to make sure the instruction is disabled properly.
SYSCALL is set up properly in both cases.
Acked-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 002216ab..c928a7a 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1169,9 +1169,8 @@ void syscall_init(void) */ wrmsrl(MSR_STAR, ((u64)__USER32_CS)<<48 | ((u64)__KERNEL_CS)<<32); wrmsrl(MSR_LSTAR, system_call); -#ifndef CONFIG_IA32_EMULATION - wrmsrl(MSR_CSTAR, ignore_sysret); -#else + +#ifdef CONFIG_IA32_EMULATION wrmsrl(MSR_CSTAR, ia32_cstar_target); /* * Always load these, in case some future 64-bit CPU supports @@ -1180,6 +1179,11 @@ void syscall_init(void) wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target); +#else + wrmsrl(MSR_CSTAR, ignore_sysret); + wrmsrl_safe(MSR_IA32_SYSENTER_CS, 0); + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); + wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL); #endif /* Flags to clear on syscall */ |