pve-edge-kernel/patches/kernel/0140-x86-irq-Remove-an-old-outdated-comment-about-context.patch

From 2b0f4b4c0431f0e68a01a51b889c7935f6920765 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <[email protected]>
Date: Mon, 4 Dec 2017 15:07:10 +0100
Subject: [PATCH 140/232] x86/irq: Remove an old outdated comment about context
 tracking races
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CVE-2017-5754

That race has been fixed and code cleaned up for a while now.

Signed-off-by: Andy Lutomirski <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Borislav Petkov <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Laight <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Eduardo Valentin <[email protected]>
Cc: Greg KH <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
(cherry picked from commit 6669a692605547892a026445e460bf233958bd7f)
Signed-off-by: Andy Whitcroft <[email protected]>
Signed-off-by: Kleber Sacilotto de Souza <[email protected]>
(cherry picked from commit 7344db7580965d6f9994b6d7b1a74206d7635565)
Signed-off-by: Fabian Grünbichler <[email protected]>
---
 arch/x86/kernel/irq.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 4ed0aba8dbc8..a84142a910f3 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -222,18 +222,6 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 	/* high bit used in ret_from_ code  */
 	unsigned vector = ~regs->orig_ax;
 
-	/*
-	 * NB: Unlike exception entries, IRQ entries do not reliably
-	 * handle context tracking in the low-level entry code.  This is
-	 * because syscall entries execute briefly with IRQs on before
-	 * updating context tracking state, so we can take an IRQ from
-	 * kernel mode with CONTEXT_USER.  The low-level entry code only
-	 * updates the context if we came from user mode, so we won't
-	 * switch to CONTEXT_KERNEL.  We'll fix that once the syscall
-	 * code is cleaned up enough that we can cleanly defer enabling
-	 * IRQs.
-	 */
-
 	entering_irq();
 
 	/* entering_irq() tells RCU that we're not quiescent.  Check it. */
-- 
2.14.2