[ https://issues.apache.org/jira/browse/
STDCXX-625?page=com.atlassian.jira.plugin.system.issuetabpan
els:comment-tabpanel#action_12540297 ]
Travis Vitek commented on STDCXX-625:
-------------------------------------
Well, with that in mind, the rw_waitpid() function is
flawed. There is a potential missed signal window between
waitpid() and sleep(). If the child process is reaped after
waitpid() but before the sleep(), the signal is lost and we
wait the entire sleep interval. If we want this to work
reliably, we would need to avoid the sleep() if the child
has exited. The only way I see to do that is to use alarm()
and sigsuspend() to wait until I get a SIGALRM or SIGCHLD,
but then we have the problem that there is only one
SIGALRM.
I must be missing something because this doesn't seem like
it should be that difficult of a problem to solve.
> 0.process test fails with SEGV due to stack overflow
> ----------------------------------------------------
>
> Key: STDCXX-625
> URL: http
s://issues.apache.org/jira/browse/STDCXX-625
> Project: C++ Standard Library
> Issue Type: Bug
> Components: Tests
> Affects Versions: 4.2
> Environment: HP-UX or AIX platforms
> Reporter: Travis Vitek
> Assignee: Travis Vitek
> Priority: Minor
> Fix For: 4.2.1
>
> Attachments: stdcxx-625.patch, test.cpp
>
>
> It appears that when we re-register for the signal from
within the user signal handler the user signal handler is
immediately invoked again. This recursion causes a stack
overflow and a crash. Here is the stack on AIX....
> sig_handler(int)( = 20), line 528 in
"process.cpp"
> sigaction(??, ??, ??) at 0xd01fa358
> signal(??, ??) at 0xd02759a8
> sig_handler(int)( = 20), line 528 in
"process.cpp"
> sigaction(??, ??, ??) at 0xd01fa358
> signal(??, ??) at 0xd02759a8
> sig_handler(int)( = 20), line 528 in
"process.cpp"
> nsleep(??, ??) at 0xd01fa1d4
> sleep(??) at 0xd02051d4
> unnamed block $b656, line 553 in
"process.cpp"
> rw_waitpid(long,int*,int)(pid = 782442, result =
0x2ff226a0, timeout = 5), line 553 in
"process.cpp"
> join_test(long,bool)(pid = 782442, should_hang =
false), line 51 in "0.process.cpp"
> test_process_create1()(), line 109 in
"0.process.cpp"
> run_test(int,char**)(argc = 1, argv = 0x2ff22a60), line
276 in "0.process.cpp"
> rw_vtest(int,char**,const char*,const char*,const
char*,int(*)(int,char**),const char*,char*)(argc = 1, argv =
0x2ff22a60, file_name =
"/amd/devco/vitek/stdcxx-trunk/tests/self/0.process.cpp
", clause = "0.process", comment =
"", fun = 0x2000b85c, optstr = "|-child#0
|-timeout#", va = " "), line 1030 in
"driver.cpp"
> rw_test(int,char**,const char*,const char*,const
char*,int(*)(int,char**),const char*,...)(argc = 1, argv =
0x2ff22a60, fname =
"/amd/devco/vitek/stdcxx-trunk/tests/self/0.process.cpp
", clause = "0.process", comment =
"", testfun = 0x2000b85c, optstr = "|-child#0
|-timeout#", ... = 0x20009608), line 1128 in
"driver.cpp"
> main(argc = 1, argv = 0x2ff22a60), line 299 in
"0.process.cpp"
> Here is the stack on HP-UX
> #0 sig_handler (No.Identifier=18) at
/amd/devco/vitek/stdcxx-trunk/tests/src/process.cpp:529
> #1 <signal handler called>
> #2 0x7b0086c0 in _sigvector+0x10 () from
/usr/lib/libc.2
> #3 0x7b00f114 in signalvector+0xac () from
/usr/lib/libc.2
> #4 0x7b00f020 in signal+0xa0 () from /usr/lib/libc.2
> #5 0x187fc in sig_handler (No.Identifier=18) at
/amd/devco/vitek/stdcxx-trunk/tests/src/process.cpp:529
> #6 <signal handler called>
> #7 0x7b0086c0 in _sigvector+0x10 () from
/usr/lib/libc.2
> #8 0x7b00f114 in signalvector+0xac () from
/usr/lib/libc.2
> #9 0x7b00f020 in signal+0xa0 () from /usr/lib/libc.2
> #10 0x187fc in sig_handler (No.Identifier=18) at
/amd/devco/vitek/stdcxx-trunk/tests/src/process.cpp:529
> #11 <signal handler called>
> #12 0x7b0086c0 in _sigvector+0x10 () from
/usr/lib/libc.2
> #13 0x7b00f114 in signalvector+0xac () from
/usr/lib/libc.2
> #14 0x7b00f020 in signal+0xa0 () from /usr/lib/libc.2
> #15 0x187fc in sig_handler (No.Identifier=18) at
/amd/devco/vitek/stdcxx-trunk/tests/src/process.cpp:529
> #16 <signal handler called>
> #17 0x7b0086c0 in _sigvector+0x10 () from
/usr/lib/libc.2
> #18 0x7b00f114 in signalvector+0xac () from
/usr/lib/libc.2
> #19 0x7b00f020 in signal+0xa0 () from /usr/lib/libc.2
> #20 0x187fc in sig_handler (No.Identifier=18) at
/amd/devco/vitek/stdcxx-trunk/tests/src/process.cpp:529
> #21 <signal handler called>
> #22 0x7b00a160 in __sigtimedwait_sys+0x10 () from
/usr/lib/libc.2
> #23 0x7b013c84 in sigtimedwait+0x6c () from
/usr/lib/libc.2
> #24 0x7afa2a50 in sleep+0xe8 () from /usr/lib/libc.2
> #25 0x188f0 in rw_waitpid (pid=13825,
result=0x7f7f0db0, timeout=5)
> at
/amd/devco/vitek/stdcxx-trunk/tests/src/process.cpp:555
> #26 0x15250 in join_test (pid=13825, should_hang=false)
at
/amd/devco/vitek/stdcxx-trunk/tests/self/0.process.cpp:51
> #27 0x15424 in test_process_create1 () at
/amd/devco/vitek/stdcxx-trunk/tests/self/0.process.cpp:109
> #28 0x159b4 in run_test (argc=1, argv=0x7f7f08d4) at
/amd/devco/vitek/stdcxx-trunk/tests/self/0.process.cpp:276
> #29 0x16d1c in rw_vtest (argc=1, argv=0x7f7f08d4,
> file_name=0x8e090
"/amd/devco/vitek/stdcxx-trunk/tests/self/0.process.cpp
", clause=0x8e528 "0.process",
> comment=0x8e08f "", fun=0x4001ed52
<run_test(int, char **)>, optstr=0x8e534
"|-child#0 |-timeout#", va=0x7f7f0a34)
> at
/amd/devco/vitek/stdcxx-trunk/tests/src/driver.cpp:1030
> #30 0x171ec in rw_test (argc=1, argv=0x7f7f08d4,
fname=0x8e090
"/amd/devco/vitek/stdcxx-trunk/tests/self/0.process.cpp
",
> clause=0x8e528 "0.process",
comment=0x8e08f "", testfun=0x4001ed52
<run_test(int, char **)>,
> optstr=0x8e534 "|-child#0 |-timeout#") at
/amd/devco/vitek/stdcxx-trunk/tests/src/driver.cpp:1127
> #31 0x15ad4 in main (argc=1, argv=0x7f7f08d4) at
/amd/devco/vitek/stdcxx-trunk/tests/self/0.process.cpp:299
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue
online.
|
