Messages in this thread Patch in this message | | | From | Alexander Shishkin <> | Subject | [QUEUED v20160212 14/19] stm class: Fix unlocking braino in the error path | Date | Fri, 12 Feb 2016 19:00:30 +0200 |
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If an illegal attempt is made to unlink stm source device from an stm device, the stm device's link spinlock mistakenly remains locked. While this really shouldn't happen (there's a warning in place), the locking should remain in order so that we can still recover from this situation if it indeed does happen.
This patch unifies the unlocking in the exit path of __stm_source_link_drop() to fix this.
Reported-by: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> --- drivers/hwtracing/stm/core.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index 385db65994..fb5a6a582b 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -816,10 +816,8 @@ static void __stm_source_link_drop(struct stm_source_device *src, spin_lock(&stm->link_lock); spin_lock(&src->link_lock); link = srcu_dereference_check(src->link, &stm_source_srcu, 1); - if (WARN_ON_ONCE(link != stm)) { - spin_unlock(&src->link_lock); - return; - } + if (WARN_ON_ONCE(link != stm)) + goto unlock; stm_output_free(link, &src->output); list_del_init(&src->link_entry); @@ -827,6 +825,7 @@ static void __stm_source_link_drop(struct stm_source_device *src, stm_put_device(link); rcu_assign_pointer(src->link, NULL); +unlock: spin_unlock(&src->link_lock); spin_unlock(&stm->link_lock); } -- 2.7.0
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