x86/ptrace: Remove checks for TIF_IA32 when changing CS and SS
The ability for modified CS and/or SS to be useful has nothing
to do with TIF_IA32. Similarly, if there's an exploit involving
changing CS or SS, it's exploitable with or without a TIF_IA32
check.
So just delete the check.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Link: http://lkml.kernel.org/r/71c7ab36456855d11ae07edd4945a7dfe80f9915.1424822291.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index e510618..1e12581 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -364,18 +364,12 @@
case offsetof(struct user_regs_struct,cs):
if (unlikely(value == 0))
return -EIO;
-#ifdef CONFIG_IA32_EMULATION
- if (test_tsk_thread_flag(task, TIF_IA32))
- task_pt_regs(task)->cs = value;
-#endif
+ task_pt_regs(task)->cs = value;
break;
case offsetof(struct user_regs_struct,ss):
if (unlikely(value == 0))
return -EIO;
-#ifdef CONFIG_IA32_EMULATION
- if (test_tsk_thread_flag(task, TIF_IA32))
- task_pt_regs(task)->ss = value;
-#endif
+ task_pt_regs(task)->ss = value;
break;
}