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Message-Id: <1242968132-1044-17-git-send-email-adobriyan@gmail.com>
Date: Fri, 22 May 2009 08:55:11 +0400
From: Alexey Dobriyan <adobriyan@...il.com>
To: akpm@...ux-foundation.org
Cc: linux-kernel@...r.kernel.org,
containers@...ts.linux-foundation.org,
torvalds@...ux-foundation.org, xemul@...allels.com,
orenl@...columbia.edu, serue@...ibm.com, dave@...ux.vnet.ibm.com,
mingo@...e.hu, Alexey Dobriyan <adobriyan@...il.com>
Subject: [PATCH 17/38] groups: move code to kernel/groups.c
Move supplementary groups implementation to kernel/groups.c .
kernel/sys.c already accumulated quite a few random stuff.
Do strictly copy/paste + add required headers to compile.
Compile-tested on many configs and archs.
Signed-off-by: Alexey Dobriyan <adobriyan@...il.com>
---
kernel/Makefile | 1 +
kernel/groups.c | 288 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
kernel/sys.c | 283 ------------------------------------------------------
3 files changed, 289 insertions(+), 283 deletions(-)
create mode 100644 kernel/groups.c
diff --git a/kernel/Makefile b/kernel/Makefile
index 4242366..705ad3d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -11,6 +11,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \
hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \
async.o
+obj-y += groups.o
ifdef CONFIG_FUNCTION_TRACER
# Do not trace debug files and internal ftrace files
diff --git a/kernel/groups.c b/kernel/groups.c
new file mode 100644
index 0000000..1b95b2f
--- /dev/null
+++ b/kernel/groups.c
@@ -0,0 +1,288 @@
+/*
+ * Supplementary group IDs
+ */
+#include <linux/cred.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <asm/uaccess.h>
+
+/* init to 2 - one for init_task, one to ensure it is never freed */
+struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
+
+struct group_info *groups_alloc(int gidsetsize)
+{
+ struct group_info *group_info;
+ int nblocks;
+ int i;
+
+ nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
+ /* Make sure we always allocate at least one indirect block pointer */
+ nblocks = nblocks ? : 1;
+ group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
+ if (!group_info)
+ return NULL;
+ group_info->ngroups = gidsetsize;
+ group_info->nblocks = nblocks;
+ atomic_set(&group_info->usage, 1);
+
+ if (gidsetsize <= NGROUPS_SMALL)
+ group_info->blocks[0] = group_info->small_block;
+ else {
+ for (i = 0; i < nblocks; i++) {
+ gid_t *b;
+ b = (void *)__get_free_page(GFP_USER);
+ if (!b)
+ goto out_undo_partial_alloc;
+ group_info->blocks[i] = b;
+ }
+ }
+ return group_info;
+
+out_undo_partial_alloc:
+ while (--i >= 0) {
+ free_page((unsigned long)group_info->blocks[i]);
+ }
+ kfree(group_info);
+ return NULL;
+}
+
+EXPORT_SYMBOL(groups_alloc);
+
+void groups_free(struct group_info *group_info)
+{
+ if (group_info->blocks[0] != group_info->small_block) {
+ int i;
+ for (i = 0; i < group_info->nblocks; i++)
+ free_page((unsigned long)group_info->blocks[i]);
+ }
+ kfree(group_info);
+}
+
+EXPORT_SYMBOL(groups_free);
+
+/* export the group_info to a user-space array */
+static int groups_to_user(gid_t __user *grouplist,
+ const struct group_info *group_info)
+{
+ int i;
+ unsigned int count = group_info->ngroups;
+
+ for (i = 0; i < group_info->nblocks; i++) {
+ unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
+ unsigned int len = cp_count * sizeof(*grouplist);
+
+ if (copy_to_user(grouplist, group_info->blocks[i], len))
+ return -EFAULT;
+
+ grouplist += NGROUPS_PER_BLOCK;
+ count -= cp_count;
+ }
+ return 0;
+}
+
+/* fill a group_info from a user-space array - it must be allocated already */
+static int groups_from_user(struct group_info *group_info,
+ gid_t __user *grouplist)
+{
+ int i;
+ unsigned int count = group_info->ngroups;
+
+ for (i = 0; i < group_info->nblocks; i++) {
+ unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
+ unsigned int len = cp_count * sizeof(*grouplist);
+
+ if (copy_from_user(group_info->blocks[i], grouplist, len))
+ return -EFAULT;
+
+ grouplist += NGROUPS_PER_BLOCK;
+ count -= cp_count;
+ }
+ return 0;
+}
+
+/* a simple Shell sort */
+static void groups_sort(struct group_info *group_info)
+{
+ int base, max, stride;
+ int gidsetsize = group_info->ngroups;
+
+ for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
+ ; /* nothing */
+ stride /= 3;
+
+ while (stride) {
+ max = gidsetsize - stride;
+ for (base = 0; base < max; base++) {
+ int left = base;
+ int right = left + stride;
+ gid_t tmp = GROUP_AT(group_info, right);
+
+ while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
+ GROUP_AT(group_info, right) =
+ GROUP_AT(group_info, left);
+ right = left;
+ left -= stride;
+ }
+ GROUP_AT(group_info, right) = tmp;
+ }
+ stride /= 3;
+ }
+}
+
+/* a simple bsearch */
+int groups_search(const struct group_info *group_info, gid_t grp)
+{
+ unsigned int left, right;
+
+ if (!group_info)
+ return 0;
+
+ left = 0;
+ right = group_info->ngroups;
+ while (left < right) {
+ unsigned int mid = (left+right)/2;
+ int cmp = grp - GROUP_AT(group_info, mid);
+ if (cmp > 0)
+ left = mid + 1;
+ else if (cmp < 0)
+ right = mid;
+ else
+ return 1;
+ }
+ return 0;
+}
+
+/**
+ * set_groups - Change a group subscription in a set of credentials
+ * @new: The newly prepared set of credentials to alter
+ * @group_info: The group list to install
+ *
+ * Validate a group subscription and, if valid, insert it into a set
+ * of credentials.
+ */
+int set_groups(struct cred *new, struct group_info *group_info)
+{
+ int retval;
+
+ retval = security_task_setgroups(group_info);
+ if (retval)
+ return retval;
+
+ put_group_info(new->group_info);
+ groups_sort(group_info);
+ get_group_info(group_info);
+ new->group_info = group_info;
+ return 0;
+}
+
+EXPORT_SYMBOL(set_groups);
+
+/**
+ * set_current_groups - Change current's group subscription
+ * @group_info: The group list to impose
+ *
+ * Validate a group subscription and, if valid, impose it upon current's task
+ * security record.
+ */
+int set_current_groups(struct group_info *group_info)
+{
+ struct cred *new;
+ int ret;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+
+ ret = set_groups(new, group_info);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret;
+ }
+
+ return commit_creds(new);
+}
+
+EXPORT_SYMBOL(set_current_groups);
+
+SYSCALL_DEFINE2(getgroups, int, gidsetsize, gid_t __user *, grouplist)
+{
+ const struct cred *cred = current_cred();
+ int i;
+
+ if (gidsetsize < 0)
+ return -EINVAL;
+
+ /* no need to grab task_lock here; it cannot change */
+ i = cred->group_info->ngroups;
+ if (gidsetsize) {
+ if (i > gidsetsize) {
+ i = -EINVAL;
+ goto out;
+ }
+ if (groups_to_user(grouplist, cred->group_info)) {
+ i = -EFAULT;
+ goto out;
+ }
+ }
+out:
+ return i;
+}
+
+/*
+ * SMP: Our groups are copy-on-write. We can set them safely
+ * without another task interfering.
+ */
+
+SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
+{
+ struct group_info *group_info;
+ int retval;
+
+ if (!capable(CAP_SETGID))
+ return -EPERM;
+ if ((unsigned)gidsetsize > NGROUPS_MAX)
+ return -EINVAL;
+
+ group_info = groups_alloc(gidsetsize);
+ if (!group_info)
+ return -ENOMEM;
+ retval = groups_from_user(group_info, grouplist);
+ if (retval) {
+ put_group_info(group_info);
+ return retval;
+ }
+
+ retval = set_current_groups(group_info);
+ put_group_info(group_info);
+
+ return retval;
+}
+
+/*
+ * Check whether we're fsgid/egid or in the supplemental group..
+ */
+int in_group_p(gid_t grp)
+{
+ const struct cred *cred = current_cred();
+ int retval = 1;
+
+ if (grp != cred->fsgid)
+ retval = groups_search(cred->group_info, grp);
+ return retval;
+}
+
+EXPORT_SYMBOL(in_group_p);
+
+int in_egroup_p(gid_t grp)
+{
+ const struct cred *cred = current_cred();
+ int retval = 1;
+
+ if (grp != cred->egid)
+ retval = groups_search(cred->group_info, grp);
+ return retval;
+}
+
+EXPORT_SYMBOL(in_egroup_p);
diff --git a/kernel/sys.c b/kernel/sys.c
index e7998cf..4edcf51 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1112,289 +1112,6 @@ out:
return err;
}
-/*
- * Supplementary group IDs
- */
-
-/* init to 2 - one for init_task, one to ensure it is never freed */
-struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
-
-struct group_info *groups_alloc(int gidsetsize)
-{
- struct group_info *group_info;
- int nblocks;
- int i;
-
- nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
- /* Make sure we always allocate at least one indirect block pointer */
- nblocks = nblocks ? : 1;
- group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
- if (!group_info)
- return NULL;
- group_info->ngroups = gidsetsize;
- group_info->nblocks = nblocks;
- atomic_set(&group_info->usage, 1);
-
- if (gidsetsize <= NGROUPS_SMALL)
- group_info->blocks[0] = group_info->small_block;
- else {
- for (i = 0; i < nblocks; i++) {
- gid_t *b;
- b = (void *)__get_free_page(GFP_USER);
- if (!b)
- goto out_undo_partial_alloc;
- group_info->blocks[i] = b;
- }
- }
- return group_info;
-
-out_undo_partial_alloc:
- while (--i >= 0) {
- free_page((unsigned long)group_info->blocks[i]);
- }
- kfree(group_info);
- return NULL;
-}
-
-EXPORT_SYMBOL(groups_alloc);
-
-void groups_free(struct group_info *group_info)
-{
- if (group_info->blocks[0] != group_info->small_block) {
- int i;
- for (i = 0; i < group_info->nblocks; i++)
- free_page((unsigned long)group_info->blocks[i]);
- }
- kfree(group_info);
-}
-
-EXPORT_SYMBOL(groups_free);
-
-/* export the group_info to a user-space array */
-static int groups_to_user(gid_t __user *grouplist,
- const struct group_info *group_info)
-{
- int i;
- unsigned int count = group_info->ngroups;
-
- for (i = 0; i < group_info->nblocks; i++) {
- unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
- unsigned int len = cp_count * sizeof(*grouplist);
-
- if (copy_to_user(grouplist, group_info->blocks[i], len))
- return -EFAULT;
-
- grouplist += NGROUPS_PER_BLOCK;
- count -= cp_count;
- }
- return 0;
-}
-
-/* fill a group_info from a user-space array - it must be allocated already */
-static int groups_from_user(struct group_info *group_info,
- gid_t __user *grouplist)
-{
- int i;
- unsigned int count = group_info->ngroups;
-
- for (i = 0; i < group_info->nblocks; i++) {
- unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
- unsigned int len = cp_count * sizeof(*grouplist);
-
- if (copy_from_user(group_info->blocks[i], grouplist, len))
- return -EFAULT;
-
- grouplist += NGROUPS_PER_BLOCK;
- count -= cp_count;
- }
- return 0;
-}
-
-/* a simple Shell sort */
-static void groups_sort(struct group_info *group_info)
-{
- int base, max, stride;
- int gidsetsize = group_info->ngroups;
-
- for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
- ; /* nothing */
- stride /= 3;
-
- while (stride) {
- max = gidsetsize - stride;
- for (base = 0; base < max; base++) {
- int left = base;
- int right = left + stride;
- gid_t tmp = GROUP_AT(group_info, right);
-
- while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
- GROUP_AT(group_info, right) =
- GROUP_AT(group_info, left);
- right = left;
- left -= stride;
- }
- GROUP_AT(group_info, right) = tmp;
- }
- stride /= 3;
- }
-}
-
-/* a simple bsearch */
-int groups_search(const struct group_info *group_info, gid_t grp)
-{
- unsigned int left, right;
-
- if (!group_info)
- return 0;
-
- left = 0;
- right = group_info->ngroups;
- while (left < right) {
- unsigned int mid = (left+right)/2;
- int cmp = grp - GROUP_AT(group_info, mid);
- if (cmp > 0)
- left = mid + 1;
- else if (cmp < 0)
- right = mid;
- else
- return 1;
- }
- return 0;
-}
-
-/**
- * set_groups - Change a group subscription in a set of credentials
- * @new: The newly prepared set of credentials to alter
- * @group_info: The group list to install
- *
- * Validate a group subscription and, if valid, insert it into a set
- * of credentials.
- */
-int set_groups(struct cred *new, struct group_info *group_info)
-{
- int retval;
-
- retval = security_task_setgroups(group_info);
- if (retval)
- return retval;
-
- put_group_info(new->group_info);
- groups_sort(group_info);
- get_group_info(group_info);
- new->group_info = group_info;
- return 0;
-}
-
-EXPORT_SYMBOL(set_groups);
-
-/**
- * set_current_groups - Change current's group subscription
- * @group_info: The group list to impose
- *
- * Validate a group subscription and, if valid, impose it upon current's task
- * security record.
- */
-int set_current_groups(struct group_info *group_info)
-{
- struct cred *new;
- int ret;
-
- new = prepare_creds();
- if (!new)
- return -ENOMEM;
-
- ret = set_groups(new, group_info);
- if (ret < 0) {
- abort_creds(new);
- return ret;
- }
-
- return commit_creds(new);
-}
-
-EXPORT_SYMBOL(set_current_groups);
-
-SYSCALL_DEFINE2(getgroups, int, gidsetsize, gid_t __user *, grouplist)
-{
- const struct cred *cred = current_cred();
- int i;
-
- if (gidsetsize < 0)
- return -EINVAL;
-
- /* no need to grab task_lock here; it cannot change */
- i = cred->group_info->ngroups;
- if (gidsetsize) {
- if (i > gidsetsize) {
- i = -EINVAL;
- goto out;
- }
- if (groups_to_user(grouplist, cred->group_info)) {
- i = -EFAULT;
- goto out;
- }
- }
-out:
- return i;
-}
-
-/*
- * SMP: Our groups are copy-on-write. We can set them safely
- * without another task interfering.
- */
-
-SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
-{
- struct group_info *group_info;
- int retval;
-
- if (!capable(CAP_SETGID))
- return -EPERM;
- if ((unsigned)gidsetsize > NGROUPS_MAX)
- return -EINVAL;
-
- group_info = groups_alloc(gidsetsize);
- if (!group_info)
- return -ENOMEM;
- retval = groups_from_user(group_info, grouplist);
- if (retval) {
- put_group_info(group_info);
- return retval;
- }
-
- retval = set_current_groups(group_info);
- put_group_info(group_info);
-
- return retval;
-}
-
-/*
- * Check whether we're fsgid/egid or in the supplemental group..
- */
-int in_group_p(gid_t grp)
-{
- const struct cred *cred = current_cred();
- int retval = 1;
-
- if (grp != cred->fsgid)
- retval = groups_search(cred->group_info, grp);
- return retval;
-}
-
-EXPORT_SYMBOL(in_group_p);
-
-int in_egroup_p(gid_t grp)
-{
- const struct cred *cred = current_cred();
- int retval = 1;
-
- if (grp != cred->egid)
- retval = groups_search(cred->group_info, grp);
- return retval;
-}
-
-EXPORT_SYMBOL(in_egroup_p);
-
DECLARE_RWSEM(uts_sem);
SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
--
1.5.6.5
--
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