Hi, In addition to what Breno added, When tried to debug seeing a Segmentation fault with the following scenarios.
Testing random mt-hot search: 100 threads 5 conns (5 x 100) loops... ./progs/slapd-mtread -H ldap://localhost:9011/ -D cn=Manager,dc=example,dc=com -w secret -e dc=example,dc=com -f (objectclass=*) -c 5 -m 100 -L 5 -l 100 Testing random mt-hot search: 5 threads (1 x 10000) loops... ./progs/slapd-mtread -H ldap://localhost:9011/ -D cn=Manager,dc=example,dc=com -w secret -e dc=example,dc=com -f (objectclass=*) -m 5 -L 1 -l 10000 It's been observed that there are NO array index out of bounds NO issue with the data in the array worked fine with filter "(objectclass=*)" and single thread. Segmentation fault occurs when filter is "(objectclass=*)" and multi threaded (m=5 or 100). >From gdb Core was generated by `/root/openldap-2.4.44+dfsg/debian/build/tests/progs/.libs/slapd-mtread'. Program terminated with signal SIGSEGV, Segmentation fault. #0 __strlen_power8 () at ../sysdeps/powerpc/powerpc64/power8/strlen.S:43 43 ../sysdeps/powerpc/powerpc64/power8/strlen.S: No such file or directory. [Current thread is 1 (Thread 0x3ffea4fff1a0 (LWP 14114))] (gdb) bt #0 __strlen_power8 () at ../sysdeps/powerpc/powerpc64/power8/strlen.S:43 #1 0x00003fff9ada9110 in _IO_vfprintf_internal (s=0x3ffea4ff22a0, format=0x486671b8 "Read(%d): entry=\"%s\".\n", ap=0x3ffea4ff2488 "R") at vfprintf.c:1637 #2 0x00003fff9ae764b4 in ___vsnprintf_chk (s=0x3ffea4ff24c8 "Read(1): entry=\"0 cnt: 1 (retried 0) (\220\070)", maxlen=<optimized out>, flags=<optimized out>, slen=<optimized out>, format=0x486671b8 "Read(%d): entry=\"%s\".\n", args=0x3ffea4ff2478 "\001") at vsnprintf_chk.c:63 #3 0x00003fff9ae763b8 in ___snprintf_chk (s=<optimized out>, maxlen=<optimized out>, flags=<optimized out>, slen=<optimized out>, format=<optimized out>) at snprintf_chk.c:34 #4 0x0000000048663eb0 in snprintf (__fmt=0x486671b8 "Read(%d): entry=\"%s\".\n", __n=8192, __s=0x3ffea4ff24c8 "Read(1): entry=\"0 cnt: 1 (retried 0) (\220\070)") at /usr/include/powerpc64le-linux-gnu/bits/stdio2.h:64 #5 do_read (ld=0x3ffea8001a30, entry=0x20 <error: Cannot access memory at address 0x20>, attrs=0x48680058 <srchattrs>, noattrs=<optimized out>, maxloop=<optimized out>, maxretries=<optimized out>, force=<optimized out>, idx=<optimized out>, chaserefs=<optimized out>, delay=<optimized out>, nobind=<optimized out>) at ../../../../tests/progs/slapd-mtread.c:791 #6 0x00000000486648b0 in do_random (nobind=<optimized out>, delay=<optimized out>, chaserefs=<optimized out>, idx=<optimized out>, force=0, maxretries=0, innerloop=100, noattrs=0, srchattrs=0x48680058 <srchattrs>, filter=<optimized out>, sbase=0x1002c2d0260 "dc=example,dc=com", ld=0x3ffea8001a30) at ../../../../tests/progs/slapd-mtread.c:684 #7 do_onethread (arg=<optimized out>) at ../../../../tests/progs/slapd-mtread.c:445 #8 0x00003fff9af180dc in start_thread (arg=0x3ffea4fff1a0) at pthread_create.c:335 #9 0x00003fff9ae61508 in clone () at ../sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S:85 (gdb) i r r0 0x0 0 r1 0x3ffea4ff1c70 70362922425456 r2 0x3fff9af07300 70367048659712 r3 0x20 32 r4 0x20 32 r5 0xffffffffffffffff 18446744073709551615 r6 0x0 0 r7 0x0 0 r8 0xffffffffffffffff 18446744073709551615 r9 0x20 32 r10 0x0 0 r11 0x0 0 r12 0x3fff9adfbc40 70367047564352 r13 0x3ffea5006900 70362922510592 r14 0x0 0 r15 0x3ffea4ff20d8 70362922426584 r16 0x0 0 r17 0x3fff9ada8758 70367047223128 r18 0x0 0 r19 0x73 115 r20 0x7fffffff 2147483647 r21 0x0 0 r22 0x1 1 r23 0x486671bd 1214673341 r24 0x3fff9aefc348 70367048614728 r25 0x3ffea4ff2488 70362922427528 r26 0xbd0 3024 r27 0x0 0 r28 0x486671b8 1214673336 r29 0x10 16 r30 0x3ffea4ff22a0 70362922427040 r31 0x3ffea4ff1c70 70362922425456 pc 0x3fff9adfbc5c 0x3fff9adfbc5c <__strlen_power8+28> msr 0x800000010280f033 9223372041191747635 cr 0x44004422 1140868130 lr 0x3fff9ada9110 0x3fff9ada9110 <_IO_vfprintf_internal+7936> ctr 0x3fff9adfbc40 70367047564352 xer 0x20000000 536870912 orig_r3 0x3fff9af1b900 70367048743168 trap 0x300 768 >From dmesg: slapd-mtread[13678]: unhandled signal 11 at 3d63642c656c7068 nip 00003fff7cb6bc5c lr 00003fff7cb19110 code 30003 (or) slapd-mtread[14114]: unhandled signal 11 at 0000000000000020 nip 00003fff9adfbc5c lr 00003fff9ada9110 code 30001
