From 58484ab427f147cf0d2c1ff912294ee9e001ed2e Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:43:57 -0500 Subject: [PATCH] signal/s390: Use force_sigsegv in default_trap_handler commit 9bc508cf0791c8e5a37696de1a046d746fcbd9d8 upstream. Reading the history it is unclear why default_trap_handler calls do_exit. It is not even menthioned in the commit where the change happened. My best guess is that because it is unknown why the exception happened it was desired to guarantee the process never returned to userspace. Using do_exit(SIGSEGV) has the problem that it will only terminate one thread of a process, leaving the process in an undefined state. Use force_sigsegv(SIGSEGV) instead which effectively has the same behavior except that is uses the ordinary signal mechanism and terminates all threads of a process and is generally well defined. Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: linux-s390@vger.kernel.org Fixes: ca2ab03237ec ("[PATCH] s390: core changes") History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Reviewed-by: Christian Borntraeger Link: https://lkml.kernel.org/r/20211020174406.17889-11-ebiederm@xmission.com Signed-off-by: Eric W. Biederman Cc: Thomas Backlund Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index bcefc21..51729ea 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -84,7 +84,7 @@ static void default_trap_handler(struct pt_regs *regs) { if (user_mode(regs)) { report_user_fault(regs, SIGSEGV, 0); - do_exit(SIGSEGV); + force_sigsegv(SIGSEGV); } else die(regs, "Unknown program exception"); } -- 2.7.4