mir/criu
2
0
Fork 0
mirror of https://github.com/checkpoint-restore/criu synced 2025-08-31 14:25:49 +00:00
Code Issues Releases Wiki Activity

parasite: unmap itself (v2)

Browse Source 
This patch adds a new parasite command, which unmaps the parasite blob.
This command never returns and the criu process traps the target process
on the exit from the munmap syscall.

v2: rename the function for unmaping a parasite blob to not intersects
with criu's functions.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This commit is contained in:
Andrey Vagin
2013-09-23 14:33:36 +04:00
committed by Pavel Emelyanov
parent 89d8b20186
commit c900bf74b0
3 changed files with 30 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/parasite.h
View File

@@ -25,6 +25,7 @@ enum {
PARASITE_CMD_INIT_DAEMON,
PARASITE_CMD_DUMP_THREAD,
PARASITE_CMD_UNMAP,
/*
* These two must be greater than INITs.
@@ -70,6 +71,11 @@ struct parasite_init_args {
struct rt_sigframe *sigframe;
};
struct parasite_unmap_args {
void *parasite_start;
unsigned long parasite_len;
};
struct parasite_vma_entry
{
unsigned long start;

19
parasite-syscall.c
View File

@@ -307,14 +307,6 @@ int parasite_execute_daemon(unsigned int cmd, struct parasite_ctl *ctl)
return ret;
}
static int munmap_seized(struct parasite_ctl *ctl, void *addr, size_t length)
{
unsigned long x;
return syscall_seized(ctl, __NR_munmap, &x,
(unsigned long)addr, length, 0, 0, 0, 0);
}
static int gen_parasite_saddr(struct sockaddr_un *saddr, int key)
{
int sun_len;
@@ -850,10 +842,15 @@ int parasite_cure_remote(struct parasite_ctl *ctl)
close_safe(&ctl->tsock);
if (ctl->remote_map) {
if (munmap_seized(ctl, (void *)ctl->remote_map, ctl->map_length)) {
pr_err("munmap_seized failed (pid: %d)\n", ctl->pid.real);
struct parasite_unmap_args *args;
*ctl->addr_cmd = PARASITE_CMD_UNMAP;
args = parasite_args(ctl, struct parasite_unmap_args);
args->parasite_start = ctl->remote_map;
args->parasite_len = ctl->map_length;
if (parasite_unmap(ctl, ctl->parasite_ip))
ret = -1;
}
}
return ret;

16
pie/parasite.c
View File

@@ -478,6 +478,20 @@ out:
return 0;
}
static noinline int unmap_itself(void *data)
{
struct parasite_unmap_args *args = data;
sys_munmap(args->parasite_start, args->parasite_len);
/*
* sys_munmap never return back. The controll process must
* trap us on the exit from munmap
*/
BUG();
return -1;
}
static noinline __used int parasite_init_daemon(void *data)
{
struct parasite_init_args *args = data;
@@ -523,6 +537,8 @@ int __used parasite_service(unsigned int cmd, void *args)
return dump_thread(args);
case PARASITE_CMD_INIT_DAEMON:
return parasite_init_daemon(args);
case PARASITE_CMD_UNMAP:
return unmap_itself(args);
}
pr_err("Unknown command to parasite: %d\n", cmd);