ubsan: no need to unset panic_on_warn in ubsan_epilogue()

stable inclusion
from stable-v5.10.166
commit b857b42a8c0992256d3129bce141724e4eb2b438
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7TH9O

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b857b42a8c0992256d3129bce141724e4eb2b438

--------------------------------

commit d83ce027 upstream.

panic_on_warn is unset inside panic(), so no need to unset it before
calling panic() in ubsan_epilogue().

Link: https://lkml.kernel.org/r/1644324666-15947-5-git-send-email-yangtiezhu@loongson.cnSigned-off-by: NTiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: Nsanglipeng <sanglipeng1@jd.com>

lib/ubsan.c

@@ -151,16 +151,8 @@ static void ubsan_epilogue(void)
 
 	current->in_ubsan--;
 
-	if (panic_on_warn) {
-		/*
-		 * This thread may hit another WARN() in the panic path.
-		 * Resetting this prevents additional WARN() from panicking the
-		 * system on this thread.  Other threads are blocked by the
-		 * panic_mutex in panic().
-		 */
-		panic_on_warn = 0;
+	if (panic_on_warn)
 		panic("panic_on_warn set ...\n");
-	}
 }
 
 static void handle_overflow(struct overflow_data *data, void *lhs,