Commit 91d44ff8 authored by Richard Weinberger's avatar Richard Weinberger
Browse files

um: Cleanup SIGTERM handling 



Richard reported that some UML processes survive if the UML
main process receives a SIGTERM.
This issue was caused by a wrongly placed signal(SIGTERM, SIG_DFL)
in init_new_thread_signals().
It disabled the UML exit handler accidently for some processes.
The correct solution is to disable the fatal handler for all
UML helper threads/processes.
Such that last_ditch_exit() does not get called multiple times
and all processes can exit due to SIGTERM.

Reported-and-tested-by: default avatarRichard W.M. Jones <rjones@redhat.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent bc1d72e7

arch/um/drivers/ubd.h

+0 −1
Original line number Diff line number Diff line
@@ -7,7 +7,6 @@ 
#ifndef __UM_UBD_USER_H

#define __UM_UBD_USER_H



extern void ignore_sigwinch_sig(void);

extern int start_io_thread(unsigned long sp, int *fds_out);

extern int io_thread(void *arg);

extern int kernel_fd;

arch/um/drivers/ubd_kern.c

+2 −1
Original line number Diff line number Diff line
@@ -1476,7 +1476,8 @@ int io_thread(void *arg) 
	struct io_thread_req *req;

	int n;



	ignore_sigwinch_sig();

	os_fix_helper_signals();



	while(1){

		n = os_read_file(kernel_fd, &req,

				 sizeof(struct io_thread_req *));

arch/um/drivers/ubd_user.c

+0 −5
Original line number Diff line number Diff line
@@ -21,11 +21,6 @@ 
#include "ubd.h"

#include <os.h>



void ignore_sigwinch_sig(void)

{

	signal(SIGWINCH, SIG_IGN);

}



int start_io_thread(unsigned long sp, int *fd_out)

{

	int pid, fds[2], err;

arch/um/include/shared/os.h

+1 −0
Original line number Diff line number Diff line
@@ -235,6 +235,7 @@ extern void setup_machinename(char *machine_out); 
extern void setup_hostinfo(char *buf, int len);

extern void os_dump_core(void) __attribute__ ((noreturn));

extern void um_early_printk(const char *s, unsigned int n);

extern void os_fix_helper_signals(void);



/* time.c */

extern void idle_sleep(unsigned long long nsecs);

arch/um/os-Linux/aio.c

+2 −3
Original line number Diff line number Diff line
@@ -104,8 +104,7 @@ static int aio_thread(void *arg) 
	struct io_event event;

	int err, n, reply_fd;



	signal(SIGWINCH, SIG_IGN);



	os_fix_helper_signals();

	while (1) {

		n = io_getevents(ctx, 1, 1, &event, NULL);

		if (n < 0) {
@@ -173,7 +172,7 @@ static int not_aio_thread(void *arg) 
	struct aio_thread_reply reply;

	int err;



	signal(SIGWINCH, SIG_IGN);

	os_fix_helper_signals();

	while (1) {

		err = read(aio_req_fd_r, &req, sizeof(req));

		if (err != sizeof(req)) {

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