Linux 4.9 compat: group_info changes

In Linux 4.9, torvalds/linux@81243ea, group_info changed from 2d array via
->blocks to 1d array via ->gid. We change the spl cred functions accordingly.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #581
This commit is contained in:
Chunwei Chen 2016-10-18 17:30:41 -07:00 committed by Brian Behlendorf
parent 87063d7dc3
commit ae7eda1dde
4 changed files with 41 additions and 2 deletions

View File

@ -49,6 +49,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
SPL_AC_WAIT_ON_BIT
SPL_AC_MUTEX_OWNER
SPL_AC_INODE_LOCK
SPL_AC_GROUP_INFO_GID
])
AC_DEFUN([SPL_AC_MODULE_SYMVERS], [
@ -1574,3 +1575,25 @@ AC_DEFUN([SPL_AC_INODE_LOCK], [
])
EXTRA_KCFLAGS="$tmp_flags"
])
dnl #
dnl # 4.9 API change
dnl # group_info changed from 2d array via >blocks to 1d array via ->gid
dnl #
AC_DEFUN([SPL_AC_GROUP_INFO_GID], [
AC_MSG_CHECKING([whether group_info->gid exists])
tmp_flags="$EXTRA_KCFLAGS"
EXTRA_KCFLAGS="-Werror"
SPL_LINUX_TRY_COMPILE([
#include <linux/cred.h>
],[
struct group_info *gi = groups_alloc(1);
gi->gid[0] = KGIDT_INIT(0);
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_GROUP_INFO_GID, 1, [group_info->gid exists])
],[
AC_MSG_RESULT(no)
])
EXTRA_KCFLAGS="$tmp_flags"
])

View File

@ -34,6 +34,11 @@ typedef struct cred cred_t;
#define kcred ((cred_t *)(init_task.cred))
#define CRED() ((cred_t *)current_cred())
/* Linux 4.9 API change, GROUP_AT was removed */
#ifndef GROUP_AT
#define GROUP_AT(gi, i) ((gi)->gid[i])
#endif
#ifdef HAVE_KUIDGID_T
#define KUID_TO_SUID(x) (__kuid_val(x))

View File

@ -85,7 +85,9 @@ crgetngroups(const cred_t *cr)
gi = cr->group_info;
rc = gi->ngroups;
#ifndef HAVE_GROUP_INFO_GID
/*
* For Linux <= 4.8,
* crgetgroups will only returns gi->blocks[0], which contains only
* the first NGROUPS_PER_BLOCK groups.
*/
@ -93,12 +95,16 @@ crgetngroups(const cred_t *cr)
WARN_ON_ONCE(1);
rc = NGROUPS_PER_BLOCK;
}
#endif
return rc;
}
/*
* Return an array of supplemental gids. The returned address is safe
* to use as long as the caller has taken a reference with crhold().
*
* Linux 4.9 API change, group_info changed from 2d array via ->blocks to 1d
* array via ->gid.
*/
gid_t *
crgetgroups(const cred_t *cr)
@ -107,8 +113,12 @@ crgetgroups(const cred_t *cr)
gid_t *gids = NULL;
gi = cr->group_info;
#ifdef HAVE_GROUP_INFO_GID
gids = KGIDP_TO_SGIDP(gi->gid);
#else
if (gi->nblocks > 0)
gids = KGIDP_TO_SGIDP(gi->blocks[0]);
#endif
return gids;
}

View File

@ -166,6 +166,7 @@ splat_cred_test2(struct file *file, void *arg)
return 0;
} /* splat_cred_test2() */
#define SPLAT_NGROUPS 32
/*
* Verify the groupmember() works correctly by constructing an interesting
* CRED() and checking that the expected gids are part of it.
@ -188,7 +189,7 @@ splat_cred_test3(struct file *file, void *arg)
* 1:(NGROUPS_MAX-1). Gid 0 is explicitly avoided so we can reliably
* test for its absence in the test cases.
*/
gi = groups_alloc(NGROUPS_SMALL);
gi = groups_alloc(SPLAT_NGROUPS);
if (gi == NULL) {
splat_vprint(file, SPLAT_CRED_TEST3_NAME, "Failed create "
"group_info for known gids: %d\n", -ENOMEM);
@ -196,7 +197,7 @@ splat_cred_test3(struct file *file, void *arg)
goto show_groups;
}
for (i = 0, tmp_gid = known_gid; i < NGROUPS_SMALL; i++) {
for (i = 0, tmp_gid = known_gid; i < SPLAT_NGROUPS; i++) {
splat_vprint(file, SPLAT_CRED_TEST3_NAME, "Adding gid %d "
"to current CRED() (%d/%d)\n", tmp_gid, i, gi->ngroups);
#ifdef HAVE_KUIDGID_T