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From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org, Joan Bruguera <joanbrugueram@gmail.com>
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	Juergen Gross <jgross@suse.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	xen-devel <xen-devel@lists.xenproject.org>,
	Jan Beulich <jbeulich@suse.com>,
	Roger Pau Monne <roger.pau@citrix.com>,
	Kees Cook <keescook@chromium.org>,
	mark.rutland@arm.com
Subject: [RFC][PATCH 2/6] x86/power: Inline write_cr[04]()
Date: Thu, 12 Jan 2023 15:31:43 +0100	[thread overview]
Message-ID: <20230112143825.644480983@infradead.org> (raw)
In-Reply-To: <20230112143141.645645775@infradead.org>

Since we can't do CALL/RET until GS is restored and CR[04] pinning is
of dubious value in this code path, simply write the stored values.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/power/cpu.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -208,11 +208,11 @@ static void notrace __restore_processor_
 #else
 /* CONFIG X86_64 */
 	native_wrmsrl(MSR_EFER, ctxt->efer);
-	native_write_cr4(ctxt->cr4);
+	asm volatile("mov %0,%%cr4": "+r" (ctxt->cr4) : : "memory");
 #endif
 	native_write_cr3(ctxt->cr3);
 	native_write_cr2(ctxt->cr2);
-	native_write_cr0(ctxt->cr0);
+	asm volatile("mov %0,%%cr0": "+r" (ctxt->cr0) : : "memory");
 
 	/* Restore the IDT. */
 	native_load_idt(&ctxt->idt);



  parent reply	other threads:[~2023-01-12 14:53 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-12 14:31 [RFC][PATCH 0/6] x86: Fix suspend vs retbleed=stuff Peter Zijlstra
2023-01-12 14:31 ` [RFC][PATCH 1/6] x86/power: De-paravirt restore_processor_state() Peter Zijlstra
2023-01-13  8:14   ` Juergen Gross
2023-01-12 14:31 ` Peter Zijlstra [this message]
2023-01-12 21:51   ` [RFC][PATCH 2/6] x86/power: Inline write_cr[04]() Kees Cook
2023-01-13 13:16   ` Ingo Molnar
2023-01-13 17:17     ` Peter Zijlstra
2023-01-12 14:31 ` [RFC][PATCH 3/6] x86/callthunk: No callthunk for restore_processor_state() Peter Zijlstra
2023-01-12 14:31 ` [RFC][PATCH 4/6] x86/power: Sprinkle some noinstr Peter Zijlstra
2023-01-12 14:31 ` [RFC][PATCH 5/6] PM / hibernate: Add minimal noinstr annotations Peter Zijlstra
2023-01-12 14:31 ` [RFC][PATCH 6/6] x86/power: Seal restore_processor_state() Peter Zijlstra
2023-01-13  7:39 ` [RFC][PATCH 0/6] x86: Fix suspend vs retbleed=stuff Joan Bruguera
2023-01-13  9:17   ` Peter Zijlstra
2023-01-13 12:59     ` Peter Zijlstra

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