souza@telesoft.UUCP (Steve Souza @eldest) (09/29/88)
Sun-Gods: We have a job spooler application here that has suddenly broken under SunOS 4.0. The setup is analogous to the remote shell software in that commands are remotely executed by a root daemon on behalf of users. The main difference is that the root daemon executes the job by doing a popen() on ". scriptfile" (as opposed to a fork/exec, as it will someday), where "scriptfile" contains a list of Bourne shell style variable initializations followed by the command to execute. The application compiles and runs without a hitch, but when "scriptfile" hits a 4.0 executable (i.e. the user command), it barfs with the message: crt0: /usr/lib/ld.so mapping failure If a 3.x program binary is copied to the remote (4.0) machine, the daemon has no problem executing it, so it appears to be a problem with 4.0 dynamic linking in a shell environment that is somehow different. I've tried compiling both the daemon software and the target command with and without the -Bstatic switch, to no avail. Any thoughts, suggestions, or guesses? Thanks! Steve Souza ...ucsd!telesoft!souza, telesoft!souza@ucsd.edu TELESOFT Inc., San Diego, CA (619)457-2700 x277
souza@telesoft.UUCP (Steve Souza @eldest) (10/06/88)
The problem is solved! Many thanks to all who responded.
Turns out to have been a problem with the max allocable
process stack segment. There is a call to setrlimit in our
daemon just prior to the system(3) of the sub-process. This
call removed the limit on RLIMIT_STACK, and set it to
RLIM_INFINITY.
This seems to make the dynamic linker (DL) unhappy. One
person (Greg Onufer) who had this problem reported that
increasing the swap partition size on his system fixed the
problem. Seems the DL uses less physical memory, but more
virtual memory. These pieces all fit together somehow, but I
don't know how without source. I wonder if the DL doesn't
pre-allocate stack to the limit before invoking the command...
Anyways, You can duplicate these messages on your 4.0
system by playing with the C-shell "limit" command:
unlimit stack
ls
limit stack 2048
Here are some of the command error messages I got after creeping up
towards the system limit:
ld.so: swap space exhausted for mmap of /usr/lib/libc.so.0.10
ld.so: map heap error (22) for /dev/zero
crt0: /usr/lib/ld.so mapping failure
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Steve Souza ucsd!telesoft!souza, telesoft!souza@ucsd.edu
TELESOFT Inc., San Diego, CA (619)457-2700 x277cudcv@warwick.ac.uk (Rob McMahon) (10/07/88)
In article <314@telesoft.UUCP> souza@telesoft.UUCP (Steve Souza @eldest) writes: >We have a job spooler application here that has suddenly broken >under SunOS 4.0. >... >The application compiles and runs without a hitch, but when "scriptfile" >hits a 4.0 executable (i.e. the user command), it barfs with the >message: > crt0: /usr/lib/ld.so mapping failure This may be completely unrelated, but it's worth knowing anyway. I had a user the other day who got this message with every command he tried to run, pwd, ls, printenv, whatever. The culprit turned out to be an `unlimit' command in his .login. Apparently if you `unlimit stack' you are suddenly unable to execute any dynamically linked executables. `limit stack 2M' cured the problem. Rob -- UUCP: ...!mcvax!ukc!warwick!cudcv PHONE: +44 203 523037 JANET: cudcv@uk.ac.warwick ARPA: cudcv@warwick.ac.uk Rob McMahon, Computing Services, Warwick University, Coventry CV4 7AL, England