Re: Segmentation fault of probed program during probing.

[Srikar Dronamraju <srikar at linux dot vnet dot ibm dot com>]

Hi Daniel, 

Do you see any hints from output of 'dmesg'?

Also if you have enabled core, then running gdb with core file can
give us more hints.

-- 
Thanks and Regards
Srikar

> Hello,
> 
> I am trying to execute the following test script:
> 
> probe process("/usr/bin/find").function("*")
> {
>     printf("%s\n", pp())
> }
> 
> 
> When I execute the script and run find ('find ./'), find crashes with 
> segfault (script itself continues to run).
> 
> What is the problem here? Did I ran against some systemtap's safety limit?
> 
> 
> Here is output from script's execution:
> 
> 
> root@laptop:~/a/systemtap# /opt/systemtap-01feb2010/bin/stap -v test.stp 
> Pass 1: parsed user script and 75 library script(s) using 77776virt/21980res/2324shr kb, in 160usr/10sys/169real ms.
> Pass 2: analyzed script: 953 probe(s), 1 function(s), 3 embed(s), 0 global(s) using 208944virt/26836res/3628shr kb, in 140usr/720sys/864real ms.
> Pass 3: using cached /root/.systemtap/cache/34/stap_34f7f1ae4b5b2093cc71f987d03d63be_188965.c
> Pass 4: using cached /root/.systemtap/cache/34/stap_34f7f1ae4b5b2093cc71f987d03d63be_188965.ko
> Pass 5: starting run.
> process("/usr/bin/find").function("main@/build/buildd/findutils-4.4.2/find/ftsfind.c:657")
> process("/usr/bin/find").function("set_option_defaults@/build/buildd/findutils-4.4.2/find/util.c:890")
> process("/usr/bin/find").function("check_nofollow@/build/buildd/findutils-4.4.2/find/util.c:252")
> process("/usr/bin/find").function("atof@/usr/include/stdlib.h:279")
> process("/usr/bin/find").function("now@/build/buildd/findutils-4.4.2/find/util.c:870")
> process("/usr/bin/find").function("set_follow_state@/build/buildd/findutils-4.4.2/find/parser.c:438")
> process("/usr/bin/find").function("process_leading_options@/build/buildd/findutils-4.4.2/find/util.c:820")
> process("/usr/bin/find").function("process_optimisation_option@/build/buildd/findutils-4.4.2/find/util.c:766")
> process("/usr/bin/find").function("process_debug_options@/build/buildd/findutils-4.4.2/find/util.c:726")
> process("/usr/bin/find").function("build_expression_tree@/build/buildd/findutils-4.4.2/find/tree.c:1190")
> process("/usr/bin/find").function("looks_like_expression@/build/buildd/findutils-4.4.2/find/util.c:692")
> process("/usr/bin/find").function("find_parser@/build/buildd/findutils-4.4.2/find/parser.c:562")
> process("/usr/bin/find").function("found_parser@/build/buildd/findutils-4.4.2/find/parser.c:501")
> process("/usr/bin/find").function("find_parser@/build/buildd/findutils-4.4.2/find/parser.c:562")
> process("/usr/bin/find").function("found_parser@/build/buildd/findutils-4.4.2/find/parser.c:501")
> process("/usr/bin/find").function("find_parser@/build/buildd/findutils-4.4.2/find/parser.c:562")
> process("/usr/bin/find").function("found_parser@/build/buildd/findutils-4.4.2/find/parser.c:501")
> process("/usr/bin/find").function("parse_openparen@/build/buildd/findutils-4.4.2/find/parser.c:1712")
> process("/usr/bin/find").function("get_new_pred_chk_op@/build/buildd/findutils-4.4.2/find/tree.c:1452")
> process("/usr/bin/find").function("find_parser@/build/buildd/findutils-4.4.2/find/parser.c:562")
> process("/usr/bin/find").function("found_parser@/build/buildd/findutils-4.4.2/find/parser.c:501")
> process("/usr/bin/find").function("get_new_pred@/build/buildd/findutils-4.4.2/find/tree.c:1406")
> process("/usr/bin/find").function("xmalloc@/build/buildd/findutils-4.4.2/gnulib/lib/xmalloc.c:47")
> process("/usr/bin/find").function("init_pred_perf@/build/buildd/findutils-4.4.2/find/tree.c:1390")
> process("/usr/bin/find").function("parse_begin_user_args@/build/buildd/findutils-4.4.2/find/parser.c:473")
> process("/usr/bin/find").function("pred_sanity_check@/build/buildd/findutils-4.4.2/find/pred.c:2487")
> process("/usr/bin/find").function("parse_end_user_args@/build/buildd/findutils-4.4.2/find/parser.c:485")
> 
> 
> I am using latest systemtap from repository with kernel 2.6.37.
>