Mirrors/criu
1
0
Fork 0
mirror of https://github.com/checkpoint-restore/criu.git synced 2026-07-17 16:47:50 +00:00
Code Issues Projects Releases Wiki Activity

cr-dump: wait killed processes

Browse source 
The kill syscall queues a signal, but doesn't wait when it will be
handled.

We need to wait processes if we kill them. The user doesn't
expect to find processes after dump in this case.

PTRACE_DETACH returns errors for dead tasks, so we don't need to do it
in these cases.

Cc: Nikita Spiridonov <nspiridonov@odin.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This commit is contained in:
Andrey Vagin 2015-07-07 15:47:00 +03:00 • committed by Pavel Emelyanov
parent 679aaa56ca
commit 1fff98f76e
2 changed files with 45 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

42
cr-dump.c
View file

@ -13,6 +13,9 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/vfs.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <sys/sendfile.h>
@ -853,8 +856,42 @@ static void unseize_task_and_threads(const struct pstree_item *item, int st)
unseize_task(item->pid.real, item->state, st);
if (st == TASK_DEAD)
return;
for (i = 1; i < item->nr_threads; i++)
ptrace(PTRACE_DETACH, item->threads[i].real, NULL, NULL);
if (ptrace(PTRACE_DETACH, item->threads[i].real, NULL, NULL))
pr_perror("Unable to detach from %d", item->threads[i].real);
}
static void pstree_wait(struct pstree_item *root_item)
{
struct pstree_item *item = root_item;
int pid, status, i;
for_each_pstree_item(item) {
if (item->state == TASK_DEAD)
continue;
for (i = 0; i < item->nr_threads; i++) {
pid = wait4(-1, &status, __WALL, NULL);
if (pid < 0) {
pr_perror("wait4 failed");
break;
} else {
if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGKILL) {
pr_err("Unexpected exit code %d of %d\n", status, pid);
BUG();
}
}
}
}
pid = wait4(-1, &status, __WALL, NULL);
if (pid > 0) {
pr_err("Unexpected child %d", pid);
BUG();
}
}
static void pstree_switch_state(struct pstree_item *root_item, int st)
@ -864,6 +901,9 @@ static void pstree_switch_state(struct pstree_item *root_item, int st)
pr_info("Unfreezing tasks into %d\n", st);
for_each_pstree_item(item)
unseize_task_and_threads(item, st);
if (st == TASK_DEAD)
pstree_wait(root_item);
}
static pid_t item_ppid(const struct pstree_item *item)

6
ptrace.c
View file

@ -27,11 +27,13 @@ int unseize_task(pid_t pid, int orig_st, int st)
{
pr_debug("\tUnseizing %d into %d\n", pid, st);
if (st == TASK_DEAD)
if (st == TASK_DEAD) {
kill(pid, SIGKILL);
else if (st == TASK_STOPPED) {
return 0;
} else if (st == TASK_STOPPED) {
if (orig_st == TASK_ALIVE)
kill(pid, SIGSTOP);
/* PTRACE_SEIZE will restore state of other tasks */
} else if (st == TASK_ALIVE) {
/* do nothing */ ;
} else