groups: move code to kernel/groups.c
Alexey Dobriyan [Tue, 16 Jun 2009 22:33:40 +0000 (15:33 -0700)]
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@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/Makefile
kernel/groups.c [new file with mode: 0644]
kernel/sys.c

index 90b53f6..9df4501 100644 (file)
@@ -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 (file)
index 0000000..2b45b2e
--- /dev/null
@@ -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);
index 438d99a..b3f1097 100644 (file)
@@ -1113,289 +1113,6 @@ 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)