diff options
| author |   visa <visa@openbsd.org> | 2018-06-21 13:58:21 +0000 |
|---|---|---|
| committer | visa <visa@openbsd.org> | 2018-06-21 13:58:21 +0000 |
| commit | 0ff991d2469a5e6b2ec82348ccae67e31455ec55 (patch) | |
| tree | a2c3a76c752e360bc0c5b8e1bd312d11b5d02f3a /sys | |
| parent | Shuffle fields around to eliminate blanks spots resulting from (diff) | |
| download | wireguard-openbsd-0ff991d2469a5e6b2ec82348ccae67e31455ec55.tar.xz wireguard-openbsd-0ff991d2469a5e6b2ec82348ccae67e31455ec55.zip | |
Use atomic operations for updating cred structure reference counts
to make crfree() and crhold() MP-safe. Make crhold() a proper function.
Put the definition into file kern_prot.c to constrain the need of the
<sys/atomic.h> header.
While there, adjust the IPL of ucred_pool to avoid lock order problems
with the kernel lock (pointed out by kettenis@).
OK mpi@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/kern_proc.c | 4 | ||||
| -rw-r--r-- | sys/kern/kern_prot.c | 16 | ||||
| -rw-r--r-- | sys/sys/ucred.h | 4 |
3 files changed, 18 insertions, 6 deletions
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c index def3f768d89..0ce3d285796 100644 --- a/sys/kern/kern_proc.c +++ b/sys/kern/kern_proc.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_proc.c,v 1.83 2018/03/27 08:42:49 mpi Exp $ */ +/* $OpenBSD: kern_proc.c,v 1.84 2018/06/21 13:58:21 visa Exp $ */ /* $NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $ */ /* @@ -108,7 +108,7 @@ procinit(void) PR_WAITOK, "processpl", NULL); pool_init(&rusage_pool, sizeof(struct rusage), 0, IPL_NONE, PR_WAITOK, "zombiepl", NULL); - pool_init(&ucred_pool, sizeof(struct ucred), 0, IPL_NONE, + pool_init(&ucred_pool, sizeof(struct ucred), 0, IPL_MPFLOOR, PR_WAITOK, "ucredpl", NULL); pool_init(&pgrp_pool, sizeof(struct pgrp), 0, IPL_NONE, PR_WAITOK, "pgrppl", NULL); diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c index ec7ac4d4f32..5622d3b3c94 100644 --- a/sys/kern/kern_prot.c +++ b/sys/kern/kern_prot.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_prot.c,v 1.73 2018/02/20 12:38:58 mpi Exp $ */ +/* $OpenBSD: kern_prot.c,v 1.74 2018/06/21 13:58:21 visa Exp $ */ /* $NetBSD: kern_prot.c,v 1.33 1996/02/09 18:59:42 christos Exp $ */ /* @@ -43,6 +43,7 @@ #include <sys/param.h> #include <sys/acct.h> +#include <sys/atomic.h> #include <sys/systm.h> #include <sys/ucred.h> #include <sys/proc.h> @@ -948,6 +949,17 @@ crget(void) } /* + * Increment the reference count of a cred structure. + * Return the passed structure. + */ +struct ucred * +crhold(struct ucred *cr) +{ + atomic_inc_int(&cr->cr_ref); + return (cr); +} + +/* * Free a cred structure. * Throws away space when ref count gets to 0. */ @@ -955,7 +967,7 @@ void crfree(struct ucred *cr) { - if (--cr->cr_ref == 0) + if (atomic_dec_int_nv(&cr->cr_ref) == 0) pool_put(&ucred_pool, cr); } diff --git a/sys/sys/ucred.h b/sys/sys/ucred.h index 03e023dc04a..7ce0fd60b2c 100644 --- a/sys/sys/ucred.h +++ b/sys/sys/ucred.h @@ -1,4 +1,4 @@ -/* $OpenBSD: ucred.h,v 1.12 2018/02/19 08:59:53 mpi Exp $ */ +/* $OpenBSD: ucred.h,v 1.13 2018/06/21 13:58:21 visa Exp $ */ /* $NetBSD: ucred.h,v 1.12 1995/06/01 22:44:50 jtc Exp $ */ /* @@ -68,7 +68,6 @@ struct xucred { }; #ifdef _KERNEL -#define crhold(cr) (cr)->cr_ref++ int crfromxucred(struct ucred *, const struct xucred *); void crset(struct ucred *, const struct ucred *); @@ -76,6 +75,7 @@ struct ucred *crcopy(struct ucred *cr); struct ucred *crdup(struct ucred *cr); void crfree(struct ucred *cr); struct ucred *crget(void); +struct ucred *crhold(struct ucred *); int suser(struct proc *p); int suser_ucred(struct ucred *cred); |