Hello Tejun, On 2013/9/9 22:14, Tejun Heo wrote: > On Mon, Sep 09, 2013 at 01:12:14PM +0800, Libin wrote: >> From: Li Bin <[email protected]> >> >> When one work starts execution, the high bits of work's data contain >> pool ID. It can represent a maximum of WORK_OFFQ_POOL_NONE. Pool ID >> is assigned WORK_OFFQ_POOL_NONE when the work being initialized >> indicating that no pool is associated and get_work_pool() uses it to >> check the associated pool. So if worker_pool_assign_id() assigns a >> ID greater than or equal WORK_OFFQ_POOL_NONE to a pool, it may break >> the non-reentrance guarantee. >> >> This patch fix this issue by modifying the worker_pool_assign_id() >> function to add the WORK_OFFQ_POOL_NONE check condition. >> >> Signed-off-by: Li Bin <[email protected]> >> --- >> kernel/workqueue.c | 11 ++++++++++- >> 1 file changed, 10 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/workqueue.c b/kernel/workqueue.c >> index 41019b1..97d9ff7 100644 >> --- a/kernel/workqueue.c >> +++ b/kernel/workqueue.c >> @@ -518,7 +518,14 @@ static inline void debug_work_activate(struct >> work_struct *work) { } >> static inline void debug_work_deactivate(struct work_struct *work) { } >> #endif >> >> -/* allocate ID and assign it to @pool */ >> +/** >> + * worker_pool_assign_id - allocate ID and assing it to @pool >> + * @pool: the pool pointer of interest >> + * >> + * Return 0 if ID assigned successful. >> + * Return non-zero if the allocation fails or the ID number out of >> + * %WORK_OFFQ_POOL_NONE range. >> + */ >> static int worker_pool_assign_id(struct worker_pool *pool) >> { >> int ret; >> @@ -526,6 +533,8 @@ static int worker_pool_assign_id(struct worker_pool >> *pool) >> lockdep_assert_held(&wq_pool_mutex); >> >> ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL); >> + if (ret >= WORK_OFFQ_POOL_NONE) >> + return ret; > > Hmmm.... this would leak the allocated ID. Just setting @end param to > idr_alloc to WORK_OFFQ_POOL_NONE would work, right? >
Yes, I will update it with the last patch. Thanks! Libin > Thanks. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
