patches/kernel/0140-x86-irq-Remove-an-old-outdated-comment-about-context.patch

   1 From 2b0f4b4c0431f0e68a01a51b889c7935f6920765 Mon Sep 17 00:00:00 2001
   2 From: Andy Lutomirski <luto@kernel.org>
   3 Date: Mon, 4 Dec 2017 15:07:10 +0100
   4 Subject: [PATCH 140/233] x86/irq: Remove an old outdated comment about context
   5  tracking races
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 CVE-2017-5754
  11
  12 That race has been fixed and code cleaned up for a while now.
  13
  14 Signed-off-by: Andy Lutomirski <luto@kernel.org>
  15 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  16 Reviewed-by: Borislav Petkov <bp@suse.de>
  17 Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
  18 Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
  19 Cc: Borislav Petkov <bp@alien8.de>
  20 Cc: Borislav Petkov <bpetkov@suse.de>
  21 Cc: Brian Gerst <brgerst@gmail.com>
  22 Cc: Dave Hansen <dave.hansen@intel.com>
  23 Cc: Dave Hansen <dave.hansen@linux.intel.com>
  24 Cc: David Laight <David.Laight@aculab.com>
  25 Cc: Denys Vlasenko <dvlasenk@redhat.com>
  26 Cc: Eduardo Valentin <eduval@amazon.com>
  27 Cc: Greg KH <gregkh@linuxfoundation.org>
  28 Cc: H. Peter Anvin <hpa@zytor.com>
  29 Cc: Josh Poimboeuf <jpoimboe@redhat.com>
  30 Cc: Juergen Gross <jgross@suse.com>
  31 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  32 Cc: Peter Zijlstra <peterz@infradead.org>
  33 Cc: Rik van Riel <riel@redhat.com>
  34 Cc: Will Deacon <will.deacon@arm.com>
  35 Cc: aliguori@amazon.com
  36 Cc: daniel.gruss@iaik.tugraz.at
  37 Cc: hughd@google.com
  38 Cc: keescook@google.com
  39 Link: https://lkml.kernel.org/r/20171204150605.150551639@linutronix.de
  40 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  41 (cherry picked from commit 6669a692605547892a026445e460bf233958bd7f)
  42 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  43 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  44 (cherry picked from commit 7344db7580965d6f9994b6d7b1a74206d7635565)
  45 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  46 ---
  47  arch/x86/kernel/irq.c | 12 ------------
  48  1 file changed, 12 deletions(-)
  49
  50 diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
  51 index 4ed0aba8dbc8..a84142a910f3 100644
  52 --- a/arch/x86/kernel/irq.c
  53 +++ b/arch/x86/kernel/irq.c
  54 @@ -222,18 +222,6 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
  55         /* high bit used in ret_from_ code  */
  56         unsigned vector = ~regs->orig_ax;
  57
  58 -       /*
  59 -        * NB: Unlike exception entries, IRQ entries do not reliably
  60 -        * handle context tracking in the low-level entry code.  This is
  61 -        * because syscall entries execute briefly with IRQs on before
  62 -        * updating context tracking state, so we can take an IRQ from
  63 -        * kernel mode with CONTEXT_USER.  The low-level entry code only
  64 -        * updates the context if we came from user mode, so we won't
  65 -        * switch to CONTEXT_KERNEL.  We'll fix that once the syscall
  66 -        * code is cleaned up enough that we can cleanly defer enabling
  67 -        * IRQs.
  68 -        */
  69 -
  70         entering_irq();
  71
  72         /* entering_irq() tells RCU that we're not quiescent.  Check it. */
  73 --
  74 2.14.2
  75