[PATCH 09/20] signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON

[Eric W. Biederman]

The function save_v86_state is only called when userspace was
operating in vm86 mode before entering the kernel.  Not having vm86
state in the task_struct should never happen.  So transform the hand
rolled BUG_ON into an actual BUG_ON to make it clear what is
happening.

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: H Peter Anvin <hpa@xxxxxxxxx>
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
 arch/x86/kernel/vm86_32.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index e5a7a10a0164..63486da77272 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -106,10 +106,8 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval)
 	 */
 	local_irq_enable();
 
-	if (!vm86 || !vm86->user_vm86) {
-		pr_alert("no user_vm86: BAD\n");
-		do_exit(SIGSEGV);
-	}
+	BUG_ON(!vm86 || !vm86->user_vm86);
+
 	set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | vm86->veflags_mask);
 	user = vm86->user_vm86;
 
-- 
2.20.1