[tip:x86/x32] x32: Make sure TS_COMPAT is cleared for x32 tasks

[tip-bot for Bobby Powers <bobbypowers@gmail.com>]

Commit-ID:  ce5f7a99df87918b5be4618a9386213a8e9a7146
Gitweb:     http://git.kernel.org/tip/ce5f7a99df87918b5be4618a9386213a8e9a7146
Author:     Bobby Powers <bobbypowers@gmail.com>
AuthorDate: Sat, 25 Feb 2012 23:25:38 -0500
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Sat, 25 Feb 2012 20:42:18 -0800

x32: Make sure TS_COMPAT is cleared for x32 tasks

If a process has a non-x32 ia32 personality and changes to x32, the
process would keep its TS_COMPAT flag. x32 uses the presence of the
x32 flag on a syscall to determine compat status, so make sure
TS_COMPAT is cleared.

Signed-off-by: Bobby Powers <bobbypowers@gmail.com>
Link: http://lkml.kernel.org/r/1330230338-25077-1-git-send-email-bobbypowers@gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/kernel/process_64.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index a0701da..32e0412 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -540,6 +540,9 @@ void set_personality_ia32(bool x32)
 		clear_thread_flag(TIF_IA32);
 		set_thread_flag(TIF_X32);
 		current->personality &= ~READ_IMPLIES_EXEC;
+		/* is_compat_task() uses the presence of the x32
+		   syscall bit flag to determine compat status */
+		current_thread_info()->status &= ~TS_COMPAT;
 	} else {
 		set_thread_flag(TIF_IA32);
 		clear_thread_flag(TIF_X32);