diff options
| author | Noah Misch <noah@leadboat.com> | 2020-10-31 08:43:28 -0700 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2020-10-31 08:44:13 -0700 |
| commit | 741b84e9f74726fbc97f63ddb46ab5675de98bdf (patch) | |
| tree | ffab30e3674c35dc153f29c552515527ec2d587f /src | |
| parent | 25b587f03a8372786ec06fbd033fdf49750be0e5 (diff) | |
| download | postgresql-741b84e9f74726fbc97f63ddb46ab5675de98bdf.tar.gz postgresql-741b84e9f74726fbc97f63ddb46ab5675de98bdf.zip | |
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
Diffstat (limited to 'src')
| -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 1aa2363f1a5..286d2cc93f1 100644 --- a/src/backend/access/nbtree/nbtsort.c +++ b/src/backend/access/nbtree/nbtsort.c @@ -1341,7 +1341,6 @@ _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 @@ -1404,9 +1403,14 @@ _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); @@ -1470,9 +1474,14 @@ _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, @@ -1669,7 +1678,7 @@ _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 */ |