From e2f447c6bbaef62fbd820f2892721c7c64871847 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 14 Dec 2017 13:19:06 -0800 Subject: [PATCH 3/4] x86/power/32: Move SYSENTER MSR restoration to fix_processor_context() commit 896c80bef4d3b357814a476663158aaf669d0fb3 upstream x86_64 restores system call MSRs in fix_processor_context(), and x86_32 restored them along with segment registers. The 64-bit variant makes more sense, so move the 32-bit code to match the 64-bit code. No side effects are expected to runtime behavior. Tested-by: Jarkko Nikula Signed-off-by: Andy Lutomirski Acked-by: Rafael J. Wysocki Acked-by: Thomas Gleixner Cc: Borislav Petkov Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Zhang Rui Link: http://lkml.kernel.org/r/65158f8d7ee64dd6bbc6c1c83b3b34aaa854e3ae.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Sudip Mukherjee --- arch/x86/power/cpu.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index cba2e2c3f89e..8e1668470b23 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -176,6 +176,9 @@ static void fix_processor_context(void) write_gdt_entry(desc, GDT_ENTRY_TSS, &tss, DESC_TSS); syscall_init(); /* This sets MSR_*STAR and related */ +#else + if (boot_cpu_has(X86_FEATURE_SEP)) + enable_sep_cpu(); #endif load_TR_desc(); /* This does ltr */ load_mm_ldt(current->active_mm); /* This does lldt */ @@ -239,12 +242,6 @@ static void notrace __restore_processor_state(struct saved_context *ctxt) loadsegment(fs, ctxt->fs); loadsegment(gs, ctxt->gs); loadsegment(ss, ctxt->ss); - - /* - * sysenter MSRs - */ - if (boot_cpu_has(X86_FEATURE_SEP)) - enable_sep_cpu(); #else /* CONFIG_X86_64 */ asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds)); -- 2.11.0