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Linux 3.8 compat: Use kuid_t/kgid_t when required

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When CONFIG_UIDGID_STRICT_TYPE_CHECKS is enabled uid_t/git_t are
replaced by kuid_t/kgid_t, which are structures instead of integral
types. This causes any code that uses an integral type to fail to build.
The User Namespace functionality introduced in Linux 3.8 requires
CONFIG_UIDGID_STRICT_TYPE_CHECKS, so we could not build against any
kernel that supported it.

We resolve this by converting between the new kuid_t/kgid_t structures
and the original uid_t/gid_t types.

Original-patch-by: DHE
Rewrite-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #260
This commit is contained in:
Richard Yao 2013-07-13 16:34:56 -04:00 committed by Brian Behlendorf
parent e3c4d44886
commit f7fd6ddd96
4 changed files with 87 additions and 14 deletions
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38
config/spl-build.m4
View File

@ -73,6 +73,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
SPL_AC_INODE_TRUNCATE_RANGE
SPL_AC_FS_STRUCT_SPINLOCK
SPL_AC_CRED_STRUCT
SPL_AC_KUIDGID_T
SPL_AC_GROUPS_SEARCH
SPL_AC_PUT_TASK_STRUCT
SPL_AC_5ARGS_PROC_HANDLER
@ -1866,6 +1867,36 @@ AC_DEFUN([SPL_AC_CRED_STRUCT], [
])
])
dnl #
dnl # User namespaces, use kuid_t in place of uid_t
dnl # where available. Not strictly a user namespaces thing
dnl # but it should prevent surprises
dnl #
AC_DEFUN([SPL_AC_KUIDGID_T], [
AC_MSG_CHECKING([whether kuid_t/kgid_t is available])
SPL_LINUX_TRY_COMPILE([
#include <linux/uidgid.h>
], [
kuid_t userid = KUIDT_INIT(0);
kgid_t groupid = KGIDT_INIT(0);
],[
SPL_LINUX_TRY_COMPILE([
#include <linux/uidgid.h>
], [
kuid_t userid = 0;
kgid_t groupid = 0;
],[
AC_MSG_RESULT(yes; optional)
],[
AC_MSG_RESULT(yes; mandatory)
AC_DEFINE(HAVE_KUIDGID_T, 1, [kuid_t/kgid_t in use])
])
],[
AC_MSG_RESULT(no)
])
])
dnl #
dnl # Custom SPL patch may export this symbol.
dnl #
@ -1873,8 +1904,15 @@ AC_DEFUN([SPL_AC_GROUPS_SEARCH],
[AC_MSG_CHECKING([whether groups_search() is available])
SPL_LINUX_TRY_COMPILE_SYMBOL([
#include <linux/cred.h>
#ifdef HAVE_KUIDGID_T
#include <linux/uidgid.h>
#endif
], [
#ifdef HAVE_KUIDGID_T
groups_search(NULL, KGIDT_INIT(0));
#else
groups_search(NULL, 0);
#endif
], [groups_search], [], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_GROUPS_SEARCH, 1, [groups_search() is available])

30
include/sys/cred.h
View File

@ -45,6 +45,36 @@ typedef struct task_struct cred_t;
#endif /* HAVE_CRED_STRUCT */
#ifdef HAVE_KUIDGID_T
/*
* Linux 3.8+ uses typedefs to redefine uid_t and gid_t. We have to rename the
* typedefs to recover the original types. We then can use them provided that
* we are careful about translating from k{g,u}id_t to the original versions
* and vice versa.
*/
#define uid_t xuid_t
#define gid_t xgid_t
#include <linux/uidgid.h>
#undef uid_t
#undef gid_t
#define KUID_TO_SUID(x) (__kuid_val(x))
#define KGID_TO_SGID(x) (__kgid_val(x))
#define SUID_TO_KUID(x) (KUIDT_INIT(x))
#define SGID_TO_KGID(x) (KGIDT_INIT(x))
#define KGIDP_TO_SGIDP(x) (&(x)->val)
#else /* HAVE_KUIDGID_T */
#define KUID_TO_SUID(x) (x)
#define KGID_TO_SGID(x) (x)
#define SUID_TO_KUID(x) (x)
#define SGID_TO_KGID(x) (x)
#define KGIDP_TO_SGIDP(x) (x)
#endif /* HAVE_KUIDGID_T */
extern void crhold(cred_t *cr);
extern void crfree(cred_t *cr);
extern uid_t crgetuid(const cred_t *cr);

28
module/spl/spl-cred.c
View File

@ -38,7 +38,11 @@
#else
/* Implementation from 2.6.30 kernel */
static int
#ifdef HAVE_KUIDGID_T
cr_groups_search(const struct group_info *group_info, kgid_t grp)
#else
cr_groups_search(const struct group_info *group_info, gid_t grp)
#endif
{
unsigned int left, right;
@ -49,7 +53,7 @@ cr_groups_search(const struct group_info *group_info, gid_t grp)
right = group_info->ngroups;
while (left < right) {
unsigned int mid = (left+right)/2;
int cmp = grp - GROUP_AT(group_info, mid);
int cmp = KGID_TO_SGID(grp) - KGID_TO_SGID(GROUP_AT(group_info, mid));
if (cmp > 0)
left = mid + 1;
else if (cmp < 0)
@ -110,7 +114,7 @@ crgetgroups(const cred_t *cr)
gid_t *gids;
gi = get_group_info(cr->group_info);
gids = gi->blocks[0];
gids = KGIDP_TO_SGIDP(gi->blocks[0]);
put_group_info(gi);
return gids;
@ -124,7 +128,7 @@ groupmember(gid_t gid, const cred_t *cr)
int rc;
gi = get_group_info(cr->group_info);
rc = cr_groups_search(cr->group_info, gid);
rc = cr_groups_search(cr->group_info, SGID_TO_KGID(gid));
put_group_info(gi);
return rc;
@ -180,7 +184,7 @@ crgetgroups(const cred_t *cr)
task_lock((struct task_struct *)cr);
get_group_info(cr->group_info);
gids = cr->group_info->blocks[0];
gids = KGID_TO_SGID(cr->group_info->blocks[0]);
put_group_info(cr->group_info);
if (lock)
@ -215,56 +219,56 @@ groupmember(gid_t gid, const cred_t *cr)
uid_t
crgetuid(const cred_t *cr)
{
return cr->euid;
return KUID_TO_SUID(cr->euid);
}
/* Return the real user id */
uid_t
crgetruid(const cred_t *cr)
{
return cr->uid;
return KUID_TO_SUID(cr->uid);
}
/* Return the saved user id */
uid_t
crgetsuid(const cred_t *cr)
{
return cr->suid;
return KUID_TO_SUID(cr->suid);
}
/* Return the filesystem user id */
uid_t
crgetfsuid(const cred_t *cr)
{
return cr->fsuid;
return KUID_TO_SUID(cr->fsuid);
}
/* Return the effective group id */
gid_t
crgetgid(const cred_t *cr)
{
return cr->egid;
return KGID_TO_SGID(cr->egid);
}
/* Return the real group id */
gid_t
crgetrgid(const cred_t *cr)
{
return cr->gid;
return KGID_TO_SGID(cr->gid);
}
/* Return the saved group id */
gid_t
crgetsgid(const cred_t *cr)
{
return cr->sgid;
return KGID_TO_SGID(cr->sgid);
}
/* Return the filesystem group id */
gid_t
crgetfsgid(const cred_t *cr)
{
return cr->fsgid;
return KGID_TO_SGID(cr->fsgid);
}
EXPORT_SYMBOL(crhold);

5
module/spl/spl-vnode.c
View File

@ -24,6 +24,7 @@
* Solaris Porting Layer (SPL) Vnode Implementation.
\*****************************************************************************/
#include <sys/cred.h>
#include <sys/vnode.h>
#include <linux/falloc.h>
#include <spl-debug.h>
@ -616,8 +617,8 @@ vn_getattr(vnode_t *vp, vattr_t *vap, int flags, void *x3, void *x4)
vap->va_type = vn_mode_to_vtype(stat.mode);
vap->va_mode = stat.mode;
vap->va_uid = stat.uid;
vap->va_gid = stat.gid;
vap->va_uid = KUID_TO_SUID(stat.uid);
vap->va_gid = KGID_TO_SGID(stat.gid);
vap->va_fsid = 0;
vap->va_nodeid = stat.ino;
vap->va_nlink = stat.nlink;