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

shmem: Turn shmem-info into shared objects from shremap ones

Browse source 
We have a nasty issue with it. Current code allocates these
entries in shremap area one by one. We do NOT allocate any
OTHER entries in this region, but if we will this array will
be spoiled.

Fortunately we no longer need shmem-infos as plain array,
neither we need one in restorer. So just turn this into plain
shared objects and collect them in a list.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This commit is contained in:
Pavel Emelyanov 2014-12-30 18:42:03 +03:00
parent b246ccb181
commit a1b1959dd1
4 changed files with 13 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

6
cr-restore.c
View file

@ -168,9 +168,6 @@ static int root_prepare_shared(void)
if (prepare_shared_reg_files())
return -1;
if (prepare_shmem_restore())
return -1;
for (i = 0; i < ARRAY_SIZE(cinfos); i++) {
ret = collect_image(cinfos[i]);
if (ret)
@ -2788,9 +2785,6 @@ static int sigreturn_restore(pid_t pid, CoreEntry *core)
task_args->premmapped_addr = (unsigned long)rsti(current)->premmapped_addr;
task_args->premmapped_len = rsti(current)->premmapped_len;
task_args->shmems = rst_mem_remap_ptr(rst_shmems, RM_SHREMAP);
task_args->nr_shmems = nr_shmems;
task_args->nr_vmas = vmas->nr;
task_args->tgt_vmas = rst_mem_remap_ptr(tgt_vmas, RM_PRIVATE);

2
include/restorer.h
View file

@ -106,8 +106,6 @@ struct task_restore_args {
int nr_zombies;
thread_restore_fcall_t clone_restore_fn; /* helper address for clone() call */
struct thread_restore_args *thread_args; /* array of thread arguments */
struct shmem_info *shmems;
unsigned int nr_shmems;
struct task_entries *task_entries;
void *rst_mem;
unsigned long rst_mem_size;

4
include/shmem.h
View file

@ -6,13 +6,9 @@
struct _VmaEntry;
extern int collect_shmem(int pid, struct _VmaEntry *vi);
extern int prepare_shmem_restore(void);
extern void show_saved_shmems(void);
extern int get_shmem_fd(int pid, VmaEntry *vi);
extern unsigned long nr_shmems;
extern unsigned long rst_shmems;
extern int cr_dump_shmem(void);
extern int add_shmem_area(pid_t pid, VmaEntry *vma);

40
shmem.c
View file

@ -46,51 +46,38 @@ struct shmem_info {
*/
int count; /* the number of regions */
int self_count; /* the number of regions, which belongs to "pid" */
struct list_head l;
};
unsigned long nr_shmems;
unsigned long rst_shmems;
int prepare_shmem_restore(void)
{
rst_shmems = rst_mem_cpos(RM_SHREMAP);
return 0;
}
/*
* This list is filled with shared objects before we fork
* any tasks. Thus the head is private (COW-ed) and the
* entries are all in shmem.
*/
static LIST_HEAD(shmems); /* XXX hash? tree? */
void show_saved_shmems(void)
{
int i;
struct shmem_info *si;
pr_info("\tSaved shmems:\n");
si = rst_mem_remap_ptr(rst_shmems, RM_SHREMAP);
for (i = 0; i < nr_shmems; i++, si++)
list_for_each_entry(si, &shmems, l)
pr_info("\t\tstart: 0x%016lx shmid: 0x%lx pid: %d\n",
si->start, si->shmid, si->pid);
}
static struct shmem_info *find_shmem(struct shmem_info *shmems,
int nr, unsigned long shmid)
static struct shmem_info *find_shmem_by_id(unsigned long shmid)
{
struct shmem_info *si;
int i;
for (i = 0, si = shmems; i < nr; i++, si++)
list_for_each_entry(si, &shmems, l)
if (si->shmid == shmid)
return si;
return NULL;
}
static struct shmem_info *find_shmem_by_id(unsigned long id)
{
struct shmem_info *si;
si = rst_mem_remap_ptr(rst_shmems, RM_SHREMAP);
return find_shmem(si, nr_shmems, id);
}
int collect_shmem(int pid, VmaEntry *vi)
{
unsigned long size = vi->pgoff + vi->end - vi->start;
@ -124,7 +111,7 @@ int collect_shmem(int pid, VmaEntry *vi)
return 0;
}
si = rst_mem_alloc(sizeof(struct shmem_info), RM_SHREMAP);
si = shmalloc(sizeof(struct shmem_info));
if (!si)
return -1;
@ -139,9 +126,8 @@ int collect_shmem(int pid, VmaEntry *vi)
si->fd = -1;
si->count = 1;
si->self_count = 1;
nr_shmems++;
futex_init(&si->lock);
list_add_tail(&si->l, &shmems);
return 0;
}