diff options
| author | davide <davide@FreeBSD.org> | 2013-09-20 23:16:15 +0000 |
|---|---|---|
| committer | davide <davide@FreeBSD.org> | 2013-09-20 23:16:15 +0000 |
| commit | defa3b8b8514a27c55c8c03cf37f7c8177bb3efe (patch) | |
| tree | 4594975cace99b3e3d4631da3bd59c4c78a58f58 /sys/kern/kern_timeout.c | |
| parent | 023fd8bc674b34351ef00a551db9abc16b6151e5 (diff) | |
| download | FreeBSD-src-defa3b8b8514a27c55c8c03cf37f7c8177bb3efe.zip FreeBSD-src-defa3b8b8514a27c55c8c03cf37f7c8177bb3efe.tar.gz | |
Fix callout_init_rm() in the shared case, allocating storage for 'struct
rm_priotracker' directly in the softclock thread. Now consumers can
pass CALLOUT_SHAREDLOCK flag to callout initialization routine safely.
The choice of the already existing flags instead of special casing
shared rmlocks is done to prevent consumer footshooting.
Suggested by: jhb
Reviewed by: jhb
Approved by: re (delphij)
Diffstat (limited to 'sys/kern/kern_timeout.c')
| -rw-r--r-- | sys/kern/kern_timeout.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/sys/kern/kern_timeout.c b/sys/kern/kern_timeout.c index e3580fc..507e3b0 100644 --- a/sys/kern/kern_timeout.c +++ b/sys/kern/kern_timeout.c @@ -597,11 +597,13 @@ softclock_call_cc(struct callout *c, struct callout_cpu *cc, #endif int direct) { + struct rm_priotracker tracker; void (*c_func)(void *); void *c_arg; struct lock_class *class; struct lock_object *c_lock; - int c_flags, sharedlock; + uintptr_t lock_status; + int c_flags; #ifdef SMP struct callout_cpu *new_cc; void (*new_func)(void *); @@ -620,7 +622,13 @@ softclock_call_cc(struct callout *c, struct callout_cpu *cc, (CALLOUT_PENDING | CALLOUT_ACTIVE), ("softclock_call_cc: pend|act %p %x", c, c->c_flags)); class = (c->c_lock != NULL) ? LOCK_CLASS(c->c_lock) : NULL; - sharedlock = (c->c_flags & CALLOUT_SHAREDLOCK) ? 0 : 1; + lock_status = 0; + if (c->c_flags & CALLOUT_SHAREDLOCK) { + if (class == &lock_class_rm) + lock_status = (uintptr_t)&tracker; + else + lock_status = 1; + } c_lock = c->c_lock; c_func = c->c_func; c_arg = c->c_arg; @@ -633,7 +641,7 @@ softclock_call_cc(struct callout *c, struct callout_cpu *cc, cc->cc_exec_entity[direct].cc_cancel = false; CC_UNLOCK(cc); if (c_lock != NULL) { - class->lc_lock(c_lock, sharedlock); + class->lc_lock(c_lock, lock_status); /* * The callout may have been cancelled * while we switched locks. |
