Commit-ID: d56fe4bf5f3cc30d455c80520f7b71da36ae00e6 Gitweb: http://git.kernel.org/tip/d56fe4bf5f3cc30d455c80520f7b71da36ae00e6 Author: Ingo Molnar <mingo@xxxxxxxxxx> AuthorDate: Tue, 24 Mar 2015 14:41:37 +0100 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 24 Mar 2015 20:57:25 +0100 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@xxxxxxxxxx> Acked-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Will Drewry <wad@xxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/cpu/common.c | 10 +++++++--- 1 file 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 */ -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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