[tip:x86/asm] x86/entry/64: Fix IRQ state confusion and related warning on compat syscalls with CONFIG_AUDITSYSCALL =n

From: tip-bot for Andy Lutomirski
Date: Wed Jul 08 2015 - 15:14:03 EST


Commit-ID: 8f7f06b87acd2e017d6c536f59e10045dd8d0578
Gitweb: http://git.kernel.org/tip/8f7f06b87acd2e017d6c536f59e10045dd8d0578
Author: Andy Lutomirski <luto@xxxxxxxxxx>
AuthorDate: Tue, 7 Jul 2015 10:55:28 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 8 Jul 2015 21:10:25 +0200

x86/entry/64: Fix IRQ state confusion and related warning on compat syscalls with CONFIG_AUDITSYSCALL=n

int_ret_from_sys_call now expects IRQs to be enabled. I got
this right in the real sysexit_audit and sysretl_audit asm
paths, but I missed it in the #defined-away versions when
CONFIG_AUDITSYSCALL=n. This is a straightforward fix for
CONFIG_AUDITSYSCALL=n

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: 29ea1b258b98 ("x86/entry/64: Migrate 64-bit and compat syscalls to the new exit handlers and remove old assembly code")
Link: http://lkml.kernel.org/r/25cf0a01e01c6008118dd8f8d9f043020416700c.1436291493.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/entry/entry_64_compat.S | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 25aca51..d757153 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -22,8 +22,8 @@
#define __AUDIT_ARCH_LE 0x40000000

#ifndef CONFIG_AUDITSYSCALL
-# define sysexit_audit ia32_ret_from_sys_call
-# define sysretl_audit ia32_ret_from_sys_call
+# define sysexit_audit ia32_ret_from_sys_call_irqs_off
+# define sysretl_audit ia32_ret_from_sys_call_irqs_off
#endif

.section .entry.text, "ax"
@@ -466,6 +466,10 @@ ia32_badarg:
/* And exit again. */
jmp retint_user

+ia32_ret_from_sys_call_irqs_off:
+ TRACE_IRQS_ON
+ ENABLE_INTERRUPTS(CLBR_NONE)
+
ia32_ret_from_sys_call:
xorl %eax, %eax /* Do not leak kernel information */
movq %rax, R11(%rsp)
--
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