[tip:x86/asm] x86/syscalls/64: Mark sys_iopl() as using ptregs

[tip-bot for Andy Lutomirski]

Commit-ID:  bb56968a37a44070de92d5690c4b08dd98a5d3f1
Gitweb:     http://git.kernel.org/tip/bb56968a37a44070de92d5690c4b08dd98a5d3f1
Author:     Andy Lutomirski <luto@xxxxxxxxxx>
AuthorDate: Sun, 31 Jan 2016 09:33:28 -0800
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 1 Feb 2016 08:53:25 +0100

x86/syscalls/64: Mark sys_iopl() as using ptregs

sys_iopl() both reads and writes pt_regs->flags.  Mark it as using ptregs.

This isn't strictly necessary, as pt_regs->flags is available
even in the fast path, but this is very lightweight now that we
have syscall qualifiers and it could avoid some pain down the
road.

Reported-and-tested-by: Borislav Petkov <bp@xxxxxxx>
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>
Link: http://lkml.kernel.org/r/3de0ca692fa8bf414c5e3d7afe3e6195d1a10e1f.1454261517.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/entry/syscalls/syscall_64.tbl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index dcf107c..2e5b565 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -178,7 +178,7 @@
 169	common	reboot			sys_reboot
 170	common	sethostname		sys_sethostname
 171	common	setdomainname		sys_setdomainname
-172	common	iopl			sys_iopl
+172	common	iopl			sys_iopl/ptregs
 173	common	ioperm			sys_ioperm
 174	64	create_module
 175	common	init_module		sys_init_module