Commit 896c80be authored Dec 14, 2017 by Andy Lutomirski Committed by Ingo Molnar Dec 15, 2017

x86/power/32: Move SYSENTER MSR restoration to fix_processor_context()



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 <jarkko.nikula@linux.intel.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: http://lkml.kernel.org/r/65158f8d7ee64dd6bbc6c1c83b3b34aaa854e3ae.1513286253.git.luto@kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 090edbe2

arch/x86/power/cpu.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -174,6 +174,9 @@ 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 */
		@@ -237,12 +240,6 @@ 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));

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