diff options
| author | Noah Misch | 2020-10-31 15:43:28 +0000 |
|---|---|---|
| committer | Noah Misch | 2020-10-31 15:45:19 +0000 |
| commit | 0454666758209de2bdd96d5f0b9cf7aa055e4bda (patch) | |
| tree | 16dd6e6568dacbbb58efc7969a14a05a997520e3 | |
| parent | 24d769b905419992f137e9de37cd05ab8c348b12 (diff) | |
Reproduce debug_query_string==NULL on parallel workers.
Certain background workers initiate parallel queries while
debug_query_string==NULL, at which point they attempted strlen(NULL) and
died to SIGSEGV. Older debug_query_string observers allow NULL, so do
likewise in these newer ones. Back-patch to v11, where commit
7de4a1bcc56f494acbd0d6e70781df877dc8ecb5 introduced the first of these.
Discussion: https://postgr.es/m/20201014022636.GA1962668@rfd.leadboat.com
| -rw-r--r-- | src/backend/access/nbtree/nbtsort.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/src/backend/access/nbtree/nbtsort.c b/src/backend/access/nbtree/nbtsort.c index 61e00b54d03..9025c5c8c67 100644 --- a/src/backend/access/nbtree/nbtsort.c +++ b/src/backend/access/nbtree/nbtsort.c @@ -1245,7 +1245,6 @@ _bt_begin_parallel(BTBuildState *buildstate, bool isconcurrent, int request) BTLeader *btleader = (BTLeader *) palloc0(sizeof(BTLeader)); BufferUsage *bufferusage; bool leaderparticipates = true; - char *sharedquery; int querylen; #ifdef DISABLE_LEADER_PARTICIPATION @@ -1308,9 +1307,14 @@ _bt_begin_parallel(BTBuildState *buildstate, bool isconcurrent, int request) shm_toc_estimate_keys(&pcxt->estimator, 1); /* Finally, estimate PARALLEL_KEY_QUERY_TEXT space */ - querylen = strlen(debug_query_string); - shm_toc_estimate_chunk(&pcxt->estimator, querylen + 1); - shm_toc_estimate_keys(&pcxt->estimator, 1); + if (debug_query_string) + { + querylen = strlen(debug_query_string); + shm_toc_estimate_chunk(&pcxt->estimator, querylen + 1); + shm_toc_estimate_keys(&pcxt->estimator, 1); + } + else + querylen = 0; /* keep compiler quiet */ /* Everyone's had a chance to ask for space, so now create the DSM */ InitializeParallelDSM(pcxt); @@ -1372,9 +1376,14 @@ _bt_begin_parallel(BTBuildState *buildstate, bool isconcurrent, int request) } /* Store query string for workers */ - sharedquery = (char *) shm_toc_allocate(pcxt->toc, querylen + 1); - memcpy(sharedquery, debug_query_string, querylen + 1); - shm_toc_insert(pcxt->toc, PARALLEL_KEY_QUERY_TEXT, sharedquery); + if (debug_query_string) + { + char *sharedquery; + + sharedquery = (char *) shm_toc_allocate(pcxt->toc, querylen + 1); + memcpy(sharedquery, debug_query_string, querylen + 1); + shm_toc_insert(pcxt->toc, PARALLEL_KEY_QUERY_TEXT, sharedquery); + } /* Allocate space for each worker's BufferUsage; no need to initialize */ bufferusage = shm_toc_allocate(pcxt->toc, @@ -1577,7 +1586,7 @@ _bt_parallel_build_main(dsm_segment *seg, shm_toc *toc) #endif /* BTREE_BUILD_STATS */ /* Set debug_query_string for individual workers first */ - sharedquery = shm_toc_lookup(toc, PARALLEL_KEY_QUERY_TEXT, false); + sharedquery = shm_toc_lookup(toc, PARALLEL_KEY_QUERY_TEXT, true); debug_query_string = sharedquery; /* Report the query string from leader */ |