When BTF encoding thread aborts because of an error, dwarf loader
worker threads get stuck in cus_queue__enqdeq_job() at:
pthread_cond_wait(&cus_processing_queue.job_added, &cus_processing_queue.mutex);
To avoid this, introduce an abort flag into cus_processing_queue, and
atomically check for it in the deq loop. The flag is only set in case
of a worker thread exiting on error. Make sure to pthread_cond_signal
to the waiting threads to let them exit too.
In cus__process_file fix the check of an error returned from
dwfl_getmodules: it may return a positive number when a
callback (cus__process_dwflmod in our case) returns an error.
Link: https://lore.kernel.org/dwarves/Z-JzFrXaopQCYd6h@localhost/
Reported-by: Domenico Andreoli <domenico.andreoli@xxxxxxxxx>
Signed-off-by: Ihor Solodrai <ihor.solodrai@xxxxxxxxx>
---
dwarf_loader.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/dwarf_loader.c b/dwarf_loader.c
index 84122d0..e1ba7bc 100644
--- a/dwarf_loader.c
+++ b/dwarf_loader.c
@@ -3459,6 +3459,7 @@ static struct {
*/
uint32_t next_cu_id;
struct list_head jobs;
+ bool abort;
} cus_processing_queue;
enum job_type {
@@ -3479,6 +3480,7 @@ static void cus_queue__init(void)
pthread_cond_init(&cus_processing_queue.job_added, NULL);
INIT_LIST_HEAD(&cus_processing_queue.jobs);
cus_processing_queue.next_cu_id = 0;
+ cus_processing_queue.abort = false;
}
static void cus_queue__destroy(void)
@@ -3535,8 +3537,9 @@ static struct cu_processing_job *cus_queue__enqdeq_job(struct cu_processing_job
pthread_cond_signal(&cus_processing_queue.job_added);
}
for (;;) {
+ bool abort = __atomic_load_n(&cus_processing_queue.abort, __ATOMIC_SEQ_CST);
job = cus_queue__try_dequeue();
- if (job)
+ if (job || abort)
break;
/* No jobs or only steals out of order */
pthread_cond_wait(&cus_processing_queue.job_added, &cus_processing_queue.mutex);
@@ -3653,6 +3656,9 @@ static void *dwarf_loader__worker_thread(void *arg)
while (!stop) {
job = cus_queue__enqdeq_job(job);
+ if (!job)
+ goto out_abort;
+
switch (job->type) {
case JOB_DECODE:
@@ -3688,6 +3694,8 @@ static void *dwarf_loader__worker_thread(void *arg)
return (void *)DWARF_CB_OK;
out_abort:
+ __atomic_store_n(&cus_processing_queue.abort, true, __ATOMIC_SEQ_CST);
+ pthread_cond_signal(&cus_processing_queue.job_added);
return (void *)DWARF_CB_ABORT;
}
@@ -4028,7 +4036,7 @@ static int cus__process_file(struct cus *cus, struct conf_load *conf, int fd,
/* Process the one or more modules gleaned from this file. */
int err = dwfl_getmodules(dwfl, cus__process_dwflmod, &parms, 0);
- if (err < 0)
+ if (err)
return -1;
// We can't call dwfl_end(dwfl) here, as we keep pointers to strings
--
2.48.1
