From 1528f231b559670445cfc427937174535981917d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= Date: Fri, 18 Sep 2020 14:46:02 +0200 Subject: [PATCH] Fix isc_atomic_xadd symbol missing Squashed commit of the following: commit d8afe85342f05d8fec8ee0255451568e936b7eb2 Author: Mark Andrews Date: Mon Sep 7 16:12:31 2020 +1000 Update 'init_count' atomically to silence tsan errors. (cherry picked from commit 90185b225f4c7acde2fbb04697d857fe496725a2) commit f166c7fb7cc262a688ed511e40c9b0d551d5992d Author: Mark Andrews Date: Thu Sep 3 12:53:53 2020 +1000 The node lock was released too early. NEGATIVE needs to be call with the node lock held. WARNING: ThreadSanitizer: data race Write of size 2 at 0x000000000001 by thread T1 (mutexes: write M1): #0 mark_stale_header lib/dns/rbtdb.c:1802:21 #1 add32 lib/dns/rbtdb.c:6559:5 #2 addrdataset lib/dns/rbtdb.c:6975:12 #3 dns_db_addrdataset lib/dns/db.c:783:10 #4 cache_name lib/dns/resolver.c:5829:13 #5 cache_message lib/dns/resolver.c:5926:14 #6 resquery_response lib/dns/resolver.c:8618:12 #7 dispatch lib/isc/task.c:1157:7 #8 run lib/isc/task.c:1331:2 Previous read of size 2 at 0x000000000001 by thread T2: #0 cache_findrdataset lib/dns/rbtdb.c:5932:6 #1 dns_db_findrdataset lib/dns/db.c:739:10 #2 query_addadditional2 bin/named/query.c:2196:11 #3 additionaldata_ns lib/dns/./rdata/generic/ns_2.c:198:10 #4 dns_rdata_additionaldata lib/dns/rdata.c:1246:2 #5 dns_rdataset_additionaldata lib/dns/rdataset.c:629:12 #6 query_addrdataset bin/named/query.c:2411:8 #7 query_addrrset bin/named/query.c:2802:2 #8 query_addbestns bin/named/query.c:3501:2 #9 query_find bin/named/query.c:9165:4 #10 query_resume bin/named/query.c:4164:12 #11 dispatch lib/isc/task.c:1157:7 #12 run lib/isc/task.c:1331:2 (cherry picked from commit a1dcb73f677969d99df3ccff2acf4737e18a72b1) commit 591a80fa95b8f3f3e716c45ceb9c5e4ccfa551c8 Author: Mark Andrews Date: Mon Aug 24 17:34:58 2020 +1000 increment header->count atomically (cherry picked from commit 121837aa75ced489e28f8ce1dd20315487d199fa) --- lib/dns/rbtdb.c | 43 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 35 insertions(+), 8 deletions(-) diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c index 88c39bf714..31ced8e73a 100644 --- a/lib/dns/rbtdb.c +++ b/lib/dns/rbtdb.c @@ -399,6 +399,23 @@ typedef isc_mutex_t nodelock_t; #define NODE_WEAKDOWNGRADE(l) ((void)0) #endif +#if defined(ISC_PLATFORM_HAVESTDATOMIC) +#if defined(__cplusplus) +#include +#else +#include +#endif +#define DNS_RBTDB_STDATOMIC 1 +#define DNS_RBTDB_INC(x) atomic_fetch_add(&(x), (1)) +#define DNS_RBTDB_LOAD(x) atomic_load(&(x)) +#elif defined(ISC_PLATFORM_HAVEXADD) +#define DNS_RBTDB_INC(x) isc_atomic_xadd((int *)&(x), 1); +#define DNS_RBTDB_LOAD(x) isc_atomic_xadd((int *)&(x), 0); +#else +#define DNS_RBTDB_INC(x) ((x)++) +#define DNS_RBTDB_LOAD(x) (x) +#endif + /*% * Whether to rate-limit updating the LRU to avoid possible thread contention. * Our performance measurement has shown the cost is marginal, so it's defined @@ -457,7 +474,11 @@ typedef struct rdatasetheader { * this rdataset. */ - uint32_t count; +#ifdef DNS_RBTDB_STDATOMIC + _Atomic(uint32_t) count; +#else + uint32_t count; +#endif /*%< * Monotonously increased every time this rdataset is bound so that * it is used as the base of the starting point in DNS responses @@ -952,7 +973,11 @@ static char FILE_VERSION[32] = "\0"; * that indicates that the database does not implement cyclic * processing. */ +#ifdef DNS_RBTDB_STDATOMIC +static _Atomic(unsigned int) init_count; +#else static unsigned int init_count; +#endif /* * Locking @@ -3322,7 +3347,7 @@ bind_rdataset(dns_rbtdb_t *rbtdb, dns_rbtnode_t *node, rdatasetheader_t *header, rdataset->private2 = node; raw = (unsigned char *)header + sizeof(*header); rdataset->private3 = raw; - rdataset->count = header->count++; + rdataset->count = DNS_RBTDB_INC(header->count); if (rdataset->count == UINT32_MAX) rdataset->count = 0; @@ -5924,10 +5949,10 @@ cache_findrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, } } - NODE_UNLOCK(lock, locktype); - - if (found == NULL) + if (found == NULL) { + NODE_UNLOCK(lock, locktype); return (ISC_R_NOTFOUND); + } if (NEGATIVE(found)) { /* @@ -5939,6 +5964,8 @@ cache_findrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, result = DNS_R_NCACHENXRRSET; } + NODE_UNLOCK(lock, locktype); + update_cachestats(rbtdb, result); return (result); @@ -6839,7 +6866,7 @@ addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, newheader->attributes |= RDATASET_ATTR_ZEROTTL; newheader->noqname = NULL; newheader->closest = NULL; - newheader->count = isc_atomic_xadd((int32_t*)&init_count, 1); + newheader->count = DNS_RBTDB_INC(init_count); newheader->trust = rdataset->trust; newheader->additional_auth = NULL; newheader->additional_glue = NULL; @@ -7035,7 +7062,7 @@ subtractrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, newheader->trust = 0; newheader->noqname = NULL; newheader->closest = NULL; - newheader->count = isc_atomic_xadd((int32_t*)&init_count, 1); + newheader->count = DNS_RBTDB_INC(init_count); newheader->additional_auth = NULL; newheader->additional_glue = NULL; newheader->last_used = 0; @@ -7481,7 +7508,7 @@ loading_addrdataset(void *arg, dns_name_t *name, dns_rdataset_t *rdataset) { newheader->serial = 1; newheader->noqname = NULL; newheader->closest = NULL; - newheader->count = isc_atomic_xadd((int32_t*)&init_count, 1); + newheader->count = DNS_RBTDB_INC(init_count); newheader->additional_auth = NULL; newheader->additional_glue = NULL; newheader->last_used = 0; -- 2.26.2