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Convert the MAC Framework from using rwlocks to rmlocks to stabilize

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framework registration for non-sleepable entry points.

Obtained from:	TrustedBSD Project
This commit is contained in:
Robert Watson 2009-05-27 09:41:58 +00:00
parent cff5821a61
commit 81fee06f9c
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=192881
2 changed files with 32 additions and 21 deletions
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22
sys/security/mac/mac_framework.c
View File

@ -78,7 +78,7 @@ __FBSDID("$FreeBSD$");
#include <sys/lock.h>
#include <sys/mac.h>
#include <sys/module.h>
#include <sys/rwlock.h>
#include <sys/rmlock.h>
#include <sys/sdt.h>
#include <sys/sx.h>
#include <sys/systm.h>
@ -165,7 +165,7 @@ MALLOC_DEFINE(M_MACTEMP, "mactemp", "MAC temporary label storage");
*
* The dynamic policy list is protected by two locks: modifying the list
* requires both locks to be held exclusively. One of the locks,
* mac_policy_rw, is acquired over policy entry points that will never sleep;
* mac_policy_rm, is acquired over policy entry points that will never sleep;
* the other, mac_policy_sx, is acquire over policy entry points that may
* sleep. The former category will be used when kernel locks may be held
* over calls to the MAC Framework, during network processing in ithreads,
@ -173,7 +173,7 @@ MALLOC_DEFINE(M_MACTEMP, "mactemp", "MAC temporary label storage");
* allocations, extended attribute I/O, etc.
*/
#ifndef MAC_STATIC
static struct rwlock mac_policy_rw; /* Non-sleeping entry points. */
static struct rmlock mac_policy_rm; /* Non-sleeping entry points. */
static struct sx mac_policy_sx; /* Sleeping entry points. */
#endif
@ -185,14 +185,14 @@ static void mac_policy_xlock_assert(void);
static void mac_policy_xunlock(void);
void
mac_policy_slock_nosleep(void)
mac_policy_slock_nosleep(struct rm_priotracker *tracker)
{
#ifndef MAC_STATIC
if (!mac_late)
return;
rw_rlock(&mac_policy_rw);
rm_rlock(&mac_policy_rm, tracker);
#endif
}
@ -212,14 +212,14 @@ mac_policy_slock_sleep(void)
}
void
mac_policy_sunlock_nosleep(void)
mac_policy_sunlock_nosleep(struct rm_priotracker *tracker)
{
#ifndef MAC_STATIC
if (!mac_late)
return;
rw_runlock(&mac_policy_rw);
rm_runlock(&mac_policy_rm, tracker);
#endif
}
@ -247,7 +247,7 @@ mac_policy_xlock(void)
return;
sx_xlock(&mac_policy_sx);
rw_wlock(&mac_policy_rw);
rm_wlock(&mac_policy_rm);
#endif
}
@ -259,7 +259,7 @@ mac_policy_xunlock(void)
if (!mac_late)
return;
rw_wunlock(&mac_policy_rw);
rm_wunlock(&mac_policy_rm);
sx_xunlock(&mac_policy_sx);
#endif
}
@ -272,7 +272,7 @@ mac_policy_xlock_assert(void)
if (!mac_late)
return;
rw_assert(&mac_policy_rw, RA_WLOCKED);
/* XXXRW: rm_assert(&mac_policy_rm, RA_WLOCKED); */
sx_assert(&mac_policy_sx, SA_XLOCKED);
#endif
}
@ -289,7 +289,7 @@ mac_init(void)
mac_labelzone_init();
#ifndef MAC_STATIC
rw_init(&mac_policy_rw, "mac_policy_rw");
rm_init(&mac_policy_rm, "mac_policy_rm", 0);
sx_init(&mac_policy_sx, "mac_policy_sx");
#endif
}

31
sys/security/mac/mac_internal.h
View File

@ -55,6 +55,9 @@
#error "no user-serviceable parts inside"
#endif
#include <sys/lock.h>
#include <sys/rmlock.h>
/*
* MAC Framework sysctl namespace.
*/
@ -194,9 +197,9 @@ extern struct mtx mac_ifnet_mtx;
*/
int mac_error_select(int error1, int error2);
void mac_policy_slock_nosleep(void);
void mac_policy_slock_nosleep(struct rm_priotracker *tracker);
void mac_policy_slock_sleep(void);
void mac_policy_sunlock_nosleep(void);
void mac_policy_sunlock_nosleep(struct rm_priotracker *tracker);
void mac_policy_sunlock_sleep(void);
struct label *mac_labelzone_alloc(int flags);
@ -294,14 +297,16 @@ int vn_setlabel(struct vnode *vp, struct label *intlabel,
error); \
} \
if (!LIST_EMPTY(&mac_policy_list)) { \
mac_policy_slock_nosleep(); \
struct rm_priotracker tracker; \
\
mac_policy_slock_nosleep(&tracker); \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## check != NULL) \
error = mac_error_select( \
mpc->mpc_ops->mpo_ ## check (args), \
error); \
} \
mac_policy_sunlock_nosleep(); \
mac_policy_sunlock_nosleep(&tracker); \
} \
} while (0)
@ -323,7 +328,9 @@ int vn_setlabel(struct vnode *vp, struct label *intlabel,
} \
} \
if (!LIST_EMPTY(&mac_policy_list)) { \
mac_policy_slock_nosleep(); \
struct rm_priotracker tracker; \
\
mac_policy_slock_nosleep(&tracker); \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## check != NULL) { \
if (mpc->mpc_ops->mpo_ ## check (args) \
@ -331,7 +338,7 @@ int vn_setlabel(struct vnode *vp, struct label *intlabel,
error = 0; \
} \
} \
mac_policy_sunlock_nosleep(); \
mac_policy_sunlock_nosleep(&tracker); \
} \
} while (0)
@ -371,14 +378,16 @@ int vn_setlabel(struct vnode *vp, struct label *intlabel,
mpc->mpc_ops->mpo_ ## operation (args); \
} \
if (!LIST_EMPTY(&mac_policy_list)) { \
mac_policy_slock_nosleep(); \
struct rm_priotracker tracker; \
\
mac_policy_slock_nosleep(&tracker); \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
result = result composition \
mpc->mpc_ops->mpo_ ## operation \
(args); \
} \
mac_policy_sunlock_nosleep(); \
mac_policy_sunlock_nosleep(&tracker); \
} \
} while (0)
@ -492,12 +501,14 @@ int vn_setlabel(struct vnode *vp, struct label *intlabel,
mpc->mpc_ops->mpo_ ## operation (args); \
} \
if (!LIST_EMPTY(&mac_policy_list)) { \
mac_policy_slock_nosleep(); \
struct rm_priotracker tracker; \
\
mac_policy_slock_nosleep(&tracker); \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
mpc->mpc_ops->mpo_ ## operation (args); \
} \
mac_policy_sunlock_nosleep(); \
mac_policy_sunlock_nosleep(&tracker); \
} \
} while (0)