signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON

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 <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: [email protected] Cc: H Peter Anvin <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Eric W. Biederman <[email protected]>
smaeul · Oct 25, 2021 · 1a4d21a · 1a4d21a
1 parent 984bd71
commit 1a4d21a
Showing 1 changed file with 2 additions and 4 deletions.
diff --git 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;