[PATCH 33/38] C/R: checkpoint/restore aux groups (structy group_info)

From: Alexey Dobriyan
Date: Fri May 22 2009 - 01:03:59 EST

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
include/linux/kstate-image.h | 10 +++
include/linux/kstate.h | 5 ++
kernel/cred.c | 30 +++++++++-
kernel/groups.c | 125 ++++++++++++++++++++++++++++++++++++++++
kernel/kstate/cpt-sys.c | 6 ++
kernel/kstate/kstate-context.c | 5 ++
kernel/kstate/kstate-object.c | 3 +
7 files changed, 182 insertions(+), 2 deletions(-)

diff --git a/include/linux/kstate-image.h b/include/linux/kstate-image.h
index 3e768ca..dfd71ea 100644
--- a/include/linux/kstate-image.h
+++ b/include/linux/kstate-image.h
@@ -50,6 +50,7 @@ struct kstate_image_header {
#define KSTATE_OBJ_PID_NS 10
#define KSTATE_OBJ_NET_NS 11
#define KSTATE_OBJ_CRED 12
+#define KSTATE_OBJ_GROUP_INFO 13

struct kstate_object_header {
__u32 obj_type;
@@ -274,5 +275,14 @@ struct kstate_image_cred {
kstate_cap_t cap_permitted;
kstate_cap_t cap_effective;
kstate_cap_t cap_bset;
+
+ kstate_ref_t ref_group_info;
+} __packed;
+
+struct kstate_image_group_info {
+ struct kstate_object_header hdr;
+
+ __u32 ngroups;
+ /* __u32 gid[ngroups]; */
} __packed;
#endif
diff --git a/include/linux/kstate.h b/include/linux/kstate.h
index bbed87b..4df3bfa 100644
--- a/include/linux/kstate.h
+++ b/include/linux/kstate.h
@@ -23,6 +23,7 @@ struct kstate_object {
enum kstate_context_obj_type {
KSTATE_CTX_CRED,
KSTATE_CTX_FILE,
+ KSTATE_CTX_GROUP_INFO,
#ifdef CONFIG_IPC_NS
KSTATE_CTX_IPC_NS,
#endif
@@ -129,6 +130,10 @@ int kstate_collect_all_cred(struct kstate_context *ctx);
int kstate_dump_all_cred(struct kstate_context *ctx);
int kstate_restore_cred(struct kstate_context *ctx, kstate_ref_t *ref);

+int kstate_collect_all_group_info(struct kstate_context *ctx);
+int kstate_dump_all_group_info(struct kstate_context *ctx);
+int kstate_restore_group_info(struct kstate_context *ctx, kstate_ref_t *ref);
+
#if defined(CONFIG_X86_32) || defined(CONFIG_X86_64)
extern const __u32 kstate_kernel_arch;
int kstate_arch_check_image_header(struct kstate_image_header *i);
diff --git a/kernel/cred.c b/kernel/cred.c
index 9152c90..8543360 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -662,6 +662,7 @@ static int dump_cred(struct kstate_context *ctx, struct kstate_object *obj)
{
struct cred *cred = obj->o_obj;
struct kstate_image_cred *i;
+ struct kstate_object *tmp;
int rv;

i = kstate_prepare_image(KSTATE_OBJ_CRED, sizeof(*i));
@@ -684,6 +685,9 @@ static int dump_cred(struct kstate_context *ctx, struct kstate_object *obj)
memcpy(&i->cap_effective, &cred->cap_effective, sizeof(kstate_cap_t));
memcpy(&i->cap_bset, &cred->cap_bset, sizeof(kstate_cap_t));

+ tmp = find_kstate_obj_by_ptr(ctx, cred->group_info, KSTATE_CTX_GROUP_INFO);
+ i->ref_group_info = tmp->o_ref;
+
rv = kstate_write_image(ctx, i, sizeof(*i), obj);
kfree(i);
pr_debug("dump cred %p: ref {%llu, %u}, rv %d\n", cred, (unsigned long long)obj->o_ref.pos, obj->o_ref.id, rv);
@@ -703,6 +707,25 @@ int kstate_dump_all_cred(struct kstate_context *ctx)
return 0;
}

+static int restore_group_info(struct kstate_context *ctx, kstate_ref_t *ref, struct cred *cred)
+{
+ struct group_info *gi;
+ struct kstate_object *tmp;
+ int rv;
+
+ tmp = find_kstate_obj_by_ref(ctx, ref, KSTATE_CTX_GROUP_INFO);
+ if (!tmp) {
+ rv = kstate_restore_group_info(ctx, ref);
+ if (rv < 0)
+ return rv;
+ tmp = find_kstate_obj_by_ref(ctx, ref, KSTATE_CTX_GROUP_INFO);
+ }
+ gi = tmp->o_obj;
+
+ cred->group_info = get_group_info(gi);
+ return 0;
+}
+
int kstate_restore_cred(struct kstate_context *ctx, kstate_ref_t *ref)
{
struct kstate_image_cred *i;
@@ -735,8 +758,9 @@ int kstate_restore_cred(struct kstate_context *ctx, kstate_ref_t *ref)
memcpy(&cred->cap_effective, &i->cap_effective, sizeof(i->cap_effective));
memcpy(&cred->cap_bset, &i->cap_bset, sizeof(i->cap_bset));

- /* FIXME */
- cred->group_info = get_group_info(&init_groups);
+ rv = restore_group_info(ctx, &i->ref_group_info, cred);
+ if (rv < 0)
+ goto out_group_info;
/* FIXME */
cred->user = get_uid(&root_user);
kfree(i);
@@ -747,6 +771,8 @@ int kstate_restore_cred(struct kstate_context *ctx, kstate_ref_t *ref)
pr_debug("restore cred %p: ref {%llu, %u}, rv %d\n", cred, (unsigned long long)ref->pos, ref->id, rv);
return rv;

+out_group_info:
+ kmem_cache_free(cred_jar, cred);
out_free_image:
kfree(i);
pr_debug("%s: return %d, ref {%llu, %u}\n", __func__, rv, (unsigned long long)ref->pos, ref->id);
diff --git a/kernel/groups.c b/kernel/groups.c
index 1b95b2f..706681a 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -1,5 +1,6 @@
/*
* Supplementary group IDs
+ * Copyright (C) 2000-2009 Parallels Holdings, Ltd.
*/
#include <linux/cred.h>
#include <linux/module.h>
@@ -286,3 +287,127 @@ int in_egroup_p(gid_t grp)
}

EXPORT_SYMBOL(in_egroup_p);
+
+#ifdef CONFIG_CHECKPOINT
+#include <linux/kstate.h>
+#include <linux/kstate-image.h>
+
+static int collect_group_info(struct kstate_context *ctx, struct group_info *gi)
+{
+ int rv;
+
+ rv = kstate_collect_object(ctx, gi, KSTATE_CTX_GROUP_INFO);
+ pr_debug("collect group_info %p: rv %d\n", gi, rv);
+ return rv;
+}
+
+int kstate_collect_all_group_info(struct kstate_context *ctx)
+{
+ struct kstate_object *obj;
+ int rv;
+
+ for_each_kstate_object(ctx, obj, KSTATE_CTX_CRED) {
+ struct cred *cred = obj->o_obj;
+
+ rv = collect_group_info(ctx, cred->group_info);
+ if (rv < 0)
+ return rv;
+ }
+ for_each_kstate_object(ctx, obj, KSTATE_CTX_GROUP_INFO) {
+ struct group_info *gi = obj->o_obj;
+ unsigned int cnt = atomic_read(&gi->usage);
+
+ if (obj->o_count + 1 != cnt && gi != &init_groups) {
+ pr_err("group_info %p has external references %lu:%u\n", gi, obj->o_count, cnt);
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+static int dump_group_info(struct kstate_context *ctx, struct kstate_object *obj)
+{
+ struct group_info *gi = obj->o_obj;
+ struct kstate_image_group_info *i;
+ __u32 *gid;
+ unsigned int image_len;
+ int n;
+ int rv;
+
+ image_len = sizeof(*i) + gi->ngroups * sizeof(__u32);
+ i = kstate_prepare_image(KSTATE_OBJ_GROUP_INFO, image_len);
+ if (!i)
+ return -ENOMEM;
+
+ i->ngroups = gi->ngroups;
+ gid = (__u32 *)(i + 1);
+ for (n = 0; n < gi->ngroups; n++)
+ gid[n] = GROUP_AT(gi, n);
+
+ rv = kstate_write_image(ctx, i, image_len, obj);
+ kfree(i);
+ pr_debug("dump group_info %p: ref {%llu, %u}, rv %d\n", gi, (unsigned long long)obj->o_ref.pos, obj->o_ref.id, rv);
+ return rv;
+}
+
+int kstate_dump_all_group_info(struct kstate_context *ctx)
+{
+ struct kstate_object *obj;
+ int rv;
+
+ for_each_kstate_object(ctx, obj, KSTATE_CTX_GROUP_INFO) {
+ rv = dump_group_info(ctx, obj);
+ if (rv < 0)
+ return rv;
+ }
+ return 0;
+}
+
+int kstate_restore_group_info(struct kstate_context *ctx, kstate_ref_t *ref)
+{
+ struct kstate_image_group_info *i;
+ struct group_info *gi;
+ __u32 *gid;
+ int n;
+ int rv;
+
+ i = kstate_read_image(ctx, ref, KSTATE_OBJ_GROUP_INFO, sizeof(*i));
+ if (IS_ERR(i))
+ return PTR_ERR(i);
+ if (i->ngroups > NGROUPS_MAX) {
+ rv = -EINVAL;
+ goto out_free_image;
+ }
+ if (i->hdr.obj_len != sizeof(*i) + i->ngroups * sizeof(__u32)) {
+ rv = -EINVAL;
+ goto out_free_image;
+ }
+ gid = (__u32 *)(i + 1);
+ for (n = 1; n < i->ngroups; n++) {
+ if (gid[n - 1] >= gid[n]) {
+ rv = -EINVAL;
+ goto out_free_image;
+ }
+ }
+
+ gi = groups_alloc(i->ngroups);
+ if (!gi) {
+ rv = -ENOMEM;
+ goto out_free_image;
+ }
+ for (n = 0; n < i->ngroups; n++)
+ GROUP_AT(gi, n) = gid[n];
+ kfree(i);
+
+ rv = kstate_restore_object(ctx, gi, KSTATE_CTX_GROUP_INFO, ref);
+ if (rv < 0)
+ put_group_info(gi);
+ pr_debug("restore group_info %p: ref {%llu, %u}, rv %d\n", gi, (unsigned long long)ref->pos, ref->id, rv);
+ return rv;
+
+out_free_image:
+ kfree(i);
+ pr_debug("%s: return %d, ref {%llu, %d}\n", __func__, rv, (unsigned long long)ref->pos, ref->id);
+ return rv;
+}
+#endif
diff --git a/kernel/kstate/cpt-sys.c b/kernel/kstate/cpt-sys.c
index b990fd3..1b352c8 100644
--- a/kernel/kstate/cpt-sys.c
+++ b/kernel/kstate/cpt-sys.c
@@ -92,6 +92,9 @@ static int kstate_collect(struct kstate_context *ctx)
rv = kstate_collect_all_cred(ctx);
if (rv < 0)
return rv;
+ rv = kstate_collect_all_group_info(ctx);
+ if (rv < 0)
+ return rv;
return 0;
}

@@ -145,6 +148,9 @@ static int kstate_dump(struct kstate_context *ctx)
rv = kstate_dump_all_pid_ns(ctx);
if (rv < 0)
return rv;
+ rv = kstate_dump_all_group_info(ctx);
+ if (rv < 0)
+ return rv;
rv = kstate_dump_all_cred(ctx);
if (rv < 0)
return rv;
diff --git a/kernel/kstate/kstate-context.c b/kernel/kstate/kstate-context.c
index 01b6e5f..51b28c0 100644
--- a/kernel/kstate/kstate-context.c
+++ b/kernel/kstate/kstate-context.c
@@ -46,6 +46,11 @@ void kstate_context_destroy(struct kstate_context *ctx)
list_del(&obj->o_list);
kfree(obj);
}
+ for_each_kstate_object_safe(ctx, obj, tmp, KSTATE_CTX_GROUP_INFO) {
+ put_group_info((struct group_info *)obj->o_obj);
+ list_del(&obj->o_list);
+ kfree(obj);
+ }
#ifdef CONFIG_IPC_NS
for_each_kstate_object_safe(ctx, obj, tmp, KSTATE_CTX_IPC_NS) {
put_ipc_ns((struct ipc_namespace *)obj->o_obj);
diff --git a/kernel/kstate/kstate-object.c b/kernel/kstate/kstate-object.c
index 8000124..f6ce7a2 100644
--- a/kernel/kstate/kstate-object.c
+++ b/kernel/kstate/kstate-object.c
@@ -41,6 +41,9 @@ int kstate_collect_object(struct kstate_context *ctx, void *p, enum kstate_conte
case KSTATE_CTX_FILE:
get_file((struct file *)obj->o_obj);
break;
+ case KSTATE_CTX_GROUP_INFO:
+ get_group_info((struct group_info *)obj->o_obj);
+ break;
#ifdef CONFIG_IPC_NS
case KSTATE_CTX_IPC_NS:
get_ipc_ns((struct ipc_namespace *)obj->o_obj);
--
1.5.6.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/