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From: Andy Lutomirski <luto@kernel.org>
To: X86 ML <x86@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Pavel Machek <pavel@ucw.cz>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Zhang Rui <rui.zhang@intel.com>,
	Jarkko Nikula <jarkko.nikula@linux.intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Andy Lutomirski <luto@kernel.org>
Subject: [PATCH urgent 2/3] x86/power/32: Move SYSENTER MSR restoration to fix_processor_context()
Date: Thu, 14 Dec 2017 13:19:06 -0800
Message-ID: <65158f8d7ee64dd6bbc6c1c83b3b34aaa854e3ae.1513286253.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1513286253.git.luto@kernel.org>
In-Reply-To: <cover.1513286253.git.luto@kernel.org>

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.

Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 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 472bc8c8212b..033c61e6891b 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -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));
-- 
2.13.6

  parent reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-14 21:19 [PATCH urgent 0/3] __restore_processor_state() fixes Andy Lutomirski
2017-12-14 21:19 ` [PATCH urgent 1/3] x86/power/64: Use struct desc_ptr for the IDT in struct saved_context Andy Lutomirski
2017-12-15 14:37   ` [tip:x86/urgent] " tip-bot for Andy Lutomirski
2017-12-14 21:19 ` Andy Lutomirski [this message]
2017-12-15 14:38   ` [tip:x86/urgent] x86/power/32: Move SYSENTER MSR restoration to fix_processor_context() tip-bot for Andy Lutomirski
2017-12-14 21:19 ` [PATCH urgent 3/3] x86/power: Make restore_processor_context() sane Andy Lutomirski
2017-12-14 22:32   ` Pavel Machek
2017-12-15 14:38   ` [tip:x86/urgent] " tip-bot for Andy Lutomirski
2017-12-15  1:28 ` [PATCH urgent 0/3] __restore_processor_state() fixes Rafael J. Wysocki
2017-12-15  1:35   ` Linus Torvalds
2017-12-15 11:21     ` Ingo Molnar
2017-12-15  9:18   ` Jarkko Nikula
2017-12-15 11:31     ` Ingo Molnar

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