From 2b0f4b4c0431f0e68a01a51b889c7935f6920765 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Mon, 4 Dec 2017 15:07:10 +0100 Subject: [PATCH 140/231] x86/irq: Remove an old outdated comment about context tracking races MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CVE-2017-5754 That race has been fixed and code cleaned up for a while now. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Reviewed-by: Borislav Petkov Reviewed-by: Thomas Gleixner Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Dave Hansen Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150605.150551639@linutronix.de Signed-off-by: Ingo Molnar (cherry picked from commit 6669a692605547892a026445e460bf233958bd7f) Signed-off-by: Andy Whitcroft Signed-off-by: Kleber Sacilotto de Souza (cherry picked from commit 7344db7580965d6f9994b6d7b1a74206d7635565) Signed-off-by: Fabian Grünbichler --- 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