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-rw-r--r--arch/um/os-Linux/util.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index 7cbcf484e13..ef095436a78 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -105,6 +105,44 @@ int setjmp_wrapper(void (*proc)(void *, void *), ...)
void os_dump_core(void)
{
+ int pid;
+
signal(SIGSEGV, SIG_DFL);
+
+ /*
+ * We are about to SIGTERM this entire process group to ensure that
+ * nothing is around to run after the kernel exits. The
+ * kernel wants to abort, not die through SIGTERM, so we
+ * ignore it here.
+ */
+
+ signal(SIGTERM, SIG_IGN);
+ kill(0, SIGTERM);
+ /*
+ * Most of the other processes associated with this UML are
+ * likely sTopped, so give them a SIGCONT so they see the
+ * SIGTERM.
+ */
+ kill(0, SIGCONT);
+
+ /*
+ * Now, having sent signals to everyone but us, make sure they
+ * die by ptrace. Processes can survive what's been done to
+ * them so far - the mechanism I understand is receiving a
+ * SIGSEGV and segfaulting immediately upon return. There is
+ * always a SIGSEGV pending, and (I'm guessing) signals are
+ * processed in numeric order so the SIGTERM (signal 15 vs
+ * SIGSEGV being signal 11) is never handled.
+ *
+ * Run a waitpid loop until we get some kind of error.
+ * Hopefully, it's ECHILD, but there's not a lot we can do if
+ * it's something else. Tell os_kill_ptraced_process not to
+ * wait for the child to report its death because there's
+ * nothing reasonable to do if that fails.
+ */
+
+ while ((pid = waitpid(-1, NULL, WNOHANG)) > 0)
+ os_kill_ptraced_process(pid, 0);
+
abort();
}