Branko Čibej <br...@apache.org> writes: > On 02.04.2012 18:46, Philip Martin wrote: >> I am unable to run the Subversion regression tests for BDB and DAV with >> Apache 2.4 using the event MPM (the new default MPM in 2.4). Sometimes >> mod_dav_svn SEGVs causing tests to FAIL and sometimes the tests hang >> with mod_dav_svn spinning in a loop. The problems go away when I switch >> to the worker MPM (the old default MPM in 2.2). >> >> I'm not sure what the event MPM does that causes the problem. Here is a >> typical SEGV: >> >> #0 0x00007fb2017f8e96 in svn_error_clear (err=0x2031203920312038) >> at ../src/subversion/libsvn_subr/error.c:341 >> 341 while (err->child) >> (gdb) p err >> $1 = (svn_error_t *) 0x2031203920312038 >> (gdb) p err[0] >> Cannot access memory at address 0x2031203920312038 > > Looks like the DB_REGISTER dance biting us yet again. Pool lifetimes > most likely, it's a tricky bit of code. Hard to say for certain since I > don't know how the event MPM works.
I normally use pool debugging with valgrind as that catches more and earlier errors. This causes almost all the tests to FAIL without Subversion appearing the stack trace: ==28130== Thread 28: ==28130== Invalid read of size 8 ==28130== at 0x669CE1B: process_lingering_close (event.c:1254) ==28130== by 0x669DA9F: listener_thread (event.c:1485) ==28130== by 0x58F38C9: start_thread (pthread_create.c:300) ==28130== by 0x600486C: clone (clone.S:112) ==28130== Address 0x63c4150 is 32 bytes inside a block of size 88 free'd ==28130== at 0x4C240FD: free (vg_replace_malloc.c:366) ==28130== by 0x508D7E8: pool_clear_debug (apr_pools.c:1588) ==28130== by 0x508DA61: apr_pool_clear_debug (apr_pools.c:1625) ==28130== by 0x669CE1A: process_lingering_close (event.c:1253) ==28130== by 0x669DA9F: listener_thread (event.c:1485) ==28130== by 0x58F38C9: start_thread (pthread_create.c:300) ==28130== by 0x600486C: clone (clone.S:112) ==28130== ==28130== Invalid read of size 8 ==28130== at 0x508D0FD: pool_alloc (apr_pools.c:1482) ==28130== by 0x66A0ECD: ap_push_pool (fdqueue.c:235) ==28130== by 0x669CE2A: process_lingering_close (event.c:1254) ==28130== by 0x669DA9F: listener_thread (event.c:1485) ==28130== by 0x58F38C9: start_thread (pthread_create.c:300) ==28130== by 0x600486C: clone (clone.S:112) ==28130== Address 0x41414141414141a1 is not stack'd, malloc'd or (recently) free'd Without pool debugging valgrind gives: ==10434== Thread 15: ==10434== Invalid read of size 4 ==10434== at 0x802D5BB: svn_fs_bdb__open_internal (env.c:660) ==10434== by 0x802D679: svn_fs_bdb__open (env.c:672) ==10434== by 0x80390D7: open_databases (fs.c:536) ==10434== by 0x8039C26: base_open (fs.c:763) ==10434== by 0x77445A5: svn_fs_open (fs-loader.c:374) ==10434== by 0x752D8C6: get_repos (repos.c:1416) ==10434== by 0x752DA13: svn_repos_open2 (repos.c:1462) ==10434== by 0x72EBB1B: get_resource (repos.c:2159) ==10434== by 0x70B7B73: dav_get_resource (mod_dav.c:712) ==10434== by 0x70BC768: dav_method_options (mod_dav.c:1602) ==10434== by 0x70BDAE7: dav_handler (mod_dav.c:4706) ==10434== by 0x44BBBF: ap_run_handler (config.c:169) ==10434== Address 0x17a0b690 is 16 bytes inside a block of size 24 free'd ==10434== at 0x4C240FD: free (vg_replace_malloc.c:366) ==10434== by 0x802D0BF: svn_fs_bdb__close (env.c:539) ==10434== by 0x8038AAA: cleanup_fs (fs.c:183) ==10434== by 0x8038B36: cleanup_fs_apr (fs.c:289) ==10434== by 0x508DBCD: apr_pool_clear (apr_pools.c:2359) ==10434== by 0x669ADE3: process_lingering_close (event.c:1253) ==10434== by 0x669B987: listener_thread (event.c:1485) ==10434== by 0x58F18C9: start_thread (pthread_create.c:300) ==10434== by 0x600286C: clone (clone.S:112) ==10434== ==10434== Invalid write of size 4 ==10434== at 0x802D5C1: svn_fs_bdb__open_internal (env.c:660) ==10434== by 0x802D679: svn_fs_bdb__open (env.c:672) ==10434== by 0x80390D7: open_databases (fs.c:536) ==10434== by 0x8039C26: base_open (fs.c:763) ==10434== by 0x77445A5: svn_fs_open (fs-loader.c:374) ==10434== by 0x752D8C6: get_repos (repos.c:1416) ==10434== by 0x752DA13: svn_repos_open2 (repos.c:1462) ==10434== by 0x72EBB1B: get_resource (repos.c:2159) ==10434== by 0x70B7B73: dav_get_resource (mod_dav.c:712) ==10434== by 0x70BC768: dav_method_options (mod_dav.c:1602) ==10434== by 0x70BDAE7: dav_handler (mod_dav.c:4706) ==10434== by 0x44BBBF: ap_run_handler (config.c:169) ==10434== Address 0x17a0b690 is 16 bytes inside a block of size 24 free'd ==10434== at 0x4C240FD: free (vg_replace_malloc.c:366) ==10434== by 0x802D0BF: svn_fs_bdb__close (env.c:539) ==10434== by 0x8038AAA: cleanup_fs (fs.c:183) ==10434== by 0x8038B36: cleanup_fs_apr (fs.c:289) ==10434== by 0x508DBCD: apr_pool_clear (apr_pools.c:2359) ==10434== by 0x669ADE3: process_lingering_close (event.c:1253) ==10434== by 0x669B987: listener_thread (event.c:1485) ==10434== by 0x58F18C9: start_thread (pthread_create.c:300) ==10434== by 0x600286C: clone (clone.S:112) -- uberSVN: Apache Subversion Made Easy http://www.uberSVN.com
