Hi folks,
OS Env: OBSD4.3 running on a dual-PIII (ProLiant 380).
I've got a perl/CGI script doing a bunch of stuff (talking to PostgreSQL,
writing files, etc) which is dying with SIGSEGV, but only occasionally. I'm
unable to reproduce the death outside of the chrooted env manually. I did,
however, manage to get a ktrace of a good and a bad run. (see below). I
set up the chroot environment by copying all relevent files for perl to
/var/www. The SIGSEGV's started after I made some minor changes to the
script, and if I make yet other changes, such as adding debugging code, the
nasty behaviour stops. I doubt the script (and modules it uses) are
relevent, but someone thinks they might shed some light on the problem, I
can make them available. Naturally, I can make the complete ktrace/kdump
files available as well, if anybody wants to see them. Access to the
machine is also no problem.
Is there any hope of tracking down this kind of error?
thanks,
Rob Urban
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The bad looks like this:
<snip>
29904 perl CALL mprotect(0x29ef7000,0x1000,0x3)
29904 perl RET mprotect 0
29904 perl CALL mprotect(0x29ef7000,0x1000,0x1)
29904 perl RET mprotect 0
29904 perl CALL sigprocmask(0x3,0)
29904 perl RET sigprocmask -65793/0xfffefeff
29904 perl CALL stat(0x87e53280,0x27dcf680)
29904 perl NAMI
"/vhosts/urban/www.unix-beratung.de/html//absence/img/legend.png"
29904 perl RET stat 0
29904 perl CALL mmap(0,0x1000,0x3,0x1002,0xffffffff,0,0,0)
29904 perl RET mmap -1950830592/0x8bb8b000
29904 perl PSIG SIGSEGV SIG_DFL code 1 addr=0x82ddb000 trapno=1
29904 perl NAMI "perl.core"
<END-OF-KDUMP>
and the good like this:
<snip>
28237 perl CALL sigprocmask(0x1,0xffffffff)
28237 perl RET sigprocmask 0
28237 perl CALL mprotect(0x25720000,0x1000,0x3)
28237 perl RET mprotect 0
28237 perl CALL mprotect(0x25720000,0x1000,0x1)
28237 perl RET mprotect 0
28237 perl CALL sigprocmask(0x3,0)
28237 perl RET sigprocmask -65793/0xfffefeff
28237 perl CALL stat(0x82529200,0x2e854680)
28237 perl NAMI "/vhosts/urban/www.unix-beratung.de/html//absence/img/lege
nd.png"
28237 perl RET stat 0
28237 perl CALL mmap(0,0x1000,0x3,0x1002,0xffffffff,0,0,0)
28237 perl RET mmap -1953615872/0x8b8e3000
28237 perl CALL sigaction(0xd,0xcfbf2500,0xcfbf24f0)
28237 perl RET sigaction 0
28237 perl CALL sendto(0x11,0x8bfd5000,0x45,0,0,0)
28237 perl GIO fd 17 wrote 69 bytes
"Q\0\0\0D SELECT * FROM c_config WHERE name = 'type-modification-time';\
\0"
28237 perl RET sendto 69/0x45
28237 perl CALL sigaction(0xd,0xcfbf2500,0xcfbf24f0)
28237 perl RET sigaction 0
28237 perl CALL poll(0xcfbf2658,0x1,0xffffffff)
<snip>
