um: Fix wait_stub_done() error handling

If we die within a stub handler we only way to reliable kill the (obviously) dying uml guest process is killing it's host twin on the host side. Signed-off-by: Richard Weinberger <richard@nod.at>

um: Fix wait_stub_done() error handling
If we die within a stub handler we only way to reliable kill the (obviously) dying uml guest process is killing it's host twin on the host side. Signed-off-by: Richard Weinberger <richard@nod.at>
Richard Weinberger · Eric Lee · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent dee20035b4
Showing 1 changed file with 7 additions and 2 deletions Side-by-side Diff
arch/um/os-Linux/skas/process.c
@@ -54,7 +54,7 @@
  
 void wait_stub_done(int pid)
 {
-	int n, status, err;
+	int n, status, err, bad_stop = 0;
  
 	while (1) {
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
@@ -74,6 +74,8 @@
  
 	if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0)
 		return;
+	else
+		bad_stop = 1;
  
 bad_wait:
 	err = ptrace_dump_regs(pid);
@@ -83,7 +85,10 @@
 	printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, "
 	       "pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno,
 	       status);
-	fatal_sigsegv();
+	if (bad_stop)
+		kill(pid, SIGKILL);
+	else
+		fatal_sigsegv();
 }
  
 extern unsigned long current_stub_stack(void);
...	...	@@ -54,7 +54,7 @@
54	54
55	55	void wait_stub_done(int pid)
56	56	{
57		- int n, status, err;
	57	+ int n, status, err, bad_stop = 0;
58	58
59	59	while (1) {
60	60	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED \| __WALL));
...	...	@@ -74,6 +74,8 @@
74	74
75	75	if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0)
76	76	return;
	77	+ else
	78	+ bad_stop = 1;
77	79
78	80	bad_wait:
79	81	err = ptrace_dump_regs(pid);
...	...	@@ -83,7 +85,10 @@
83	85	printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, "
84	86	"pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno,
85	87	status);
86		- fatal_sigsegv();
	88	+ if (bad_stop)
	89	+ kill(pid, SIGKILL);
	90	+ else
	91	+ fatal_sigsegv();
87	92	}
88	93
89	94	extern unsigned long current_stub_stack(void);