diff options
| author | Denys Vlasenko <dvlasenk@redhat.com> | 2015-03-22 20:48:14 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-03-24 08:20:51 +0100 |
| commit | a76c7f4604937bc781bfc411ef92c59474ddadda (patch) | |
| tree | c0e71f40fafc647dcb8ff1c834e994161f77b460 /arch/x86/kernel/cpu/common.c | |
| parent | 34061f134f70d33296fa56678cee122dd7010401 (diff) | |
x86/asm/entry/64: Fold syscall32_cpu_init() into its sole user
Having syscall32/sysenter32 initialization in a separate tiny
function, called from within a function that is already syscall
init specific, serves no real purpose.
Its existense also caused an unintended effect of having
wrmsrl(MSR_CSTAR) performed twice: once we set it to a dummy
function returning -ENOSYS, and immediately after
(if CONFIG_IA32_EMULATION), we set it to point to the proper
syscall32 entry point, ia32_cstar_target.
Signed-off-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 | 31 |
1 files changed, 10 insertions, 21 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index d79f139871e0..66d62aef7214 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -959,24 +959,6 @@ static void identify_cpu(struct cpuinfo_x86 *c) #endif } -#ifdef CONFIG_X86_64 -# ifdef CONFIG_IA32_EMULATION -/* May not be __init: called during resume */ -static void syscall32_cpu_init(void) -{ - /* - * Always load these, in case some future 64-bit CPU supports - * SYSENTER from compat mode too: - */ - 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); - - wrmsrl(MSR_CSTAR, ia32_cstar_target); -} -# endif -#endif - /* * Set up the CPU state needed to execute SYSENTER/SYSEXIT instructions * on 32-bit kernels: @@ -1187,10 +1169,17 @@ 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); - -#ifdef CONFIG_IA32_EMULATION - syscall32_cpu_init(); +#else + wrmsrl(MSR_CSTAR, ia32_cstar_target); + /* + * Always load these, in case some future 64-bit CPU supports + * SYSENTER from compat mode too: + */ + 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); #endif /* Flags to clear on syscall */ |