d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

locks: fix recursion support after recent changes

Browse Source 
When a relevant lockstat probe is enabled the fallback primitive is called with
a constant signifying a free lock. This works fine for typical cases but breaks
with recursion, since it checks if the passed value is that of the executing
thread.

Read the value if necessary.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@313335 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
This commit is contained in:
mjg 2017-02-06 09:40:14 +00:00
parent 23bf6bc1ed
commit 8d78da2dd4
3 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
sys/kern/kern_mutex.c
View File

@ -495,6 +495,8 @@ __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v, uintptr_t tid, int opts,
lock_delay_arg_init(&lda, NULL);
#endif
m = mtxlock2mtx(c);
if (__predict_false(v == MTX_UNOWNED))
v = MTX_READ_VALUE(m);
if (__predict_false(lv_mtx_owner(v) == (struct thread *)tid)) {
KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0 ||

2
sys/kern/kern_rwlock.c
View File

@ -812,6 +812,8 @@ __rw_wlock_hard(volatile uintptr_t *c, uintptr_t v, uintptr_t tid,
lock_delay_arg_init(&lda, NULL);
#endif
rw = rwlock2rw(c);
if (__predict_false(v == RW_UNLOCKED))
v = RW_READ_VALUE(rw);
if (__predict_false(lv_rw_wowner(v) == (struct thread *)tid)) {
KASSERT(rw->lock_object.lo_flags & LO_RECURSABLE,

3
sys/kern/kern_sx.c
View File

@ -531,6 +531,9 @@ _sx_xlock_hard(struct sx *sx, uintptr_t x, uintptr_t tid, int opts,
lock_delay_arg_init(&lda, NULL);
#endif
if (__predict_false(x == SX_LOCK_UNLOCKED))
x = SX_READ_VALUE(sx);
/* If we already hold an exclusive lock, then recurse. */
if (__predict_false(lv_sx_owner(x) == (struct thread *)tid)) {
KASSERT((sx->lock_object.lo_flags & LO_RECURSABLE) != 0,