Commit-ID: a76c7f4604937bc781bfc411ef92c59474ddadda
Gitweb: http://git.kernel.org/tip/a76c7f4604937bc781bfc411ef92c59474ddadda
Author: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
AuthorDate: Sun, 22 Mar 2015 20:48:14 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 24 Mar 2015 08:20:51 +0100
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@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 | 31 ++++++++++---------------------
1 file changed, 10 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index d79f139..66d62ae 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 */
--
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