Hi.
On one of my servers, apache segfaults when php4 loads the imap.so module.
I have a few servers with similar versions, and only one of the servers
experiences the segfault.
I am unable to discover the cause of the segfault, and would really appreciate
some advice in how to locate it.
What I have done:
I have set "LogLevel debug" in "/etc/apache/httpd.conf"
When commenting out the line "extension=imap.so" from
"/etc/php4/apache/php.ini", apache starts and works very well.
# tail -2 /var/log/apache/error.log
[Mon Apr 21 00:31:46 2003] [info] mod_unique_id: using ip addr 127.0.0.1
[Mon Apr 21 00:31:47 2003] [info] created shared memory segment #4194305
When uncommenting the line "extension=imap.so", I use the following to do a
strace of apache "strace apache -X 2> /tmp/apache.strace"
# tail -1 /var/log/apache/error.log
[Mon Apr 21 00:42:34 2003] [info] mod_unique_id: using ip addr 127.0.0.1
# tail /tmp/apache.strace
open("/etc/protocols", O_RDONLY) = 5
fcntl64(5, F_GETFD) = 0
fcntl64(5, F_SETFD, FD_CLOEXEC) = 0
fstat64(5, {st_mode=S_IFREG|0644, st_size=1748, ...}) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x40233000
read(5, "# /etc/protocols:\n# $Id: protoco"..., 4096) = 1748
close(5) = 0
munmap(0x40233000, 4096) = 0
--- SIGSEGV (Segmentation fault) ---
+++ killed by SIGSEGV +++
On another server, that doesn't experience the segfault, the following is
straced instead of the segfault:
open("/etc/protocols", O_RDONLY) = 5
fcntl64(5, F_GETFD) = 0
fcntl64(5, F_SETFD, FD_CLOEXEC) = 0
fstat64(5, {st_mode=S_IFREG|0644, st_size=1748, ...}) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0
x40245000
read(5, "# /etc/protocols:\n# $Id: protoco"..., 4096) = 1748
close(5) = 0
munmap(0x40245000, 4096) = 0
brk(0) = 0x80dd000
brk(0x80de000) = 0x80de000
brk(0) = 0x80de000
brk(0x80df000) = 0x80df000
brk(0) = 0x80df000
...
The two servers where php4-imap behave differently run mainly stable, but with
apache and php4 from unstable. Both with 2.4 kernels.
On the machine with the segfault:
# cat /proc/version
Linux version 2.4.18-686-smp ([EMAIL PROTECTED]) (gcc version 2.95.4 20011002
(Debian prerelease)) #1 SMP Sun Apr 14 12:07:19 EST 2002
# dpkg -l "apache*" | grep "^ii"
ii apache 1.3.27-0.1 Versatile, high-performance HTTP server
ii apache-common 1.3.27-0.1 Support files for all Apache webservers
arjuna:/etc/php4/apache# dpkg -l "php4*" | grep "^ii"
ii php4 4.2.3-13 A server-side, HTML-embedded scripting langu
ii php4-imap 4.2.3-13 IMAP module for php4
ii php4-pear 4.2.3-13 PEAR - PHP Extension and Application Reposit
ii php4-pear-log 1.6.0-1 Log module for PEAR
ii php4-pgsql 4.2.3-1 PostgreSQL module for php4
On the machine without the segfault:
cat /proc/version
Linux version 2.4.20-586tsc ([EMAIL PROTECTED]) (gcc version 2.95.4 20011002
(Debian prerelease)) #1 Sat Jan 11 20:01:58 EST 2003
# dpkg -l "apache*" | grep "^ii"
ii apache 1.3.27-0.1 Versatile, high-performance HTTP server
ii apache-common 1.3.27-0.1 Support files for all Apache webservers
ii apache-doc 1.3.26-0woody3 Apache webserver docs
h2o:/etc/php4/apache# dpkg -l "php4*" | grep "^ii"
ii php4 4.2.3-13 A server-side, HTML-embedded scripting langu
ii php4-apc 1.1.0pl1-9 Caches PHP scripts to get them loaded much f
ii php4-cgi 4.2.3-13 A server-side, HTML-embedded scripting langu
ii php4-imap 4.2.3-13 IMAP module for php4
ii php4-ldap 4.2.3-13 LDAP module for php4
ii php4-pear 4.2.3-13 PEAR - PHP Extension and Application Reposit
ii php4-pear-log 1.6.0-1 Log module for PEAR
ii php4-pgsql 4.2.3-1 PostgreSQL module for php4
And finally a look at how this imap.so file is linked:
On the machine with the segfault:
# ldd /usr/lib/php4/20020429/imap.so
libcrypto.so.0.9.7 => /usr/lib/i686/cmov/libcrypto.so.0.9.7
(0x40016000)
libssl.so.0.9.7 => /usr/lib/i686/cmov/libssl.so.0.9.7 (0x40108000)
libc-client.so.2003debian => /usr/lib/libc-client.so.2003debian
(0x40137000)
libgssapi_krb5.so.2 => /usr/lib/libgssapi_krb5.so.2 (0x401ed000)
libkrb5.so.3 => /usr/lib/libkrb5.so.3 (0x401fe000)
libk5crypto.so.3 => /usr/lib/libk5crypto.so.3 (0x40253000)
libcom_err.so.2 => /lib/libcom_err.so.2 (0x40264000)
libc.so.6 => /lib/libc.so.6 (0x40267000)
libdl.so.2 => /lib/libdl.so.2 (0x40377000)
libpam.so.0 => /lib/libpam.so.0 (0x4037a000)
libresolv.so.2 => /lib/libresolv.so.2 (0x40382000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000)
On the machine without the segfault:
# ldd /usr/lib/php4/20020429/imap.so
libcrypto.so.0.9.7 => /usr/lib/i686/cmov/libcrypto.so.0.9.7
(0x4001c000)
libssl.so.0.9.7 => /usr/lib/i686/cmov/libssl.so.0.9.7 (0x4010e000)
libc-client.so.2003debian => /usr/lib/libc-client.so.2003debian
(0x4013d000)
libgssapi_krb5.so.2 => /usr/lib/libgssapi_krb5.so.2 (0x401f3000)
libkrb5.so.3 => /usr/lib/libkrb5.so.3 (0x40205000)
libk5crypto.so.3 => /usr/lib/libk5crypto.so.3 (0x4025a000)
libcom_err.so.2 => /lib/libcom_err.so.2 (0x4026a000)
libc.so.6 => /lib/libc.so.6 (0x4026d000)
libdl.so.2 => /lib/libdl.so.2 (0x4037d000)
libpam.so.0 => /lib/libpam.so.0 (0x40380000)
libresolv.so.2 => /lib/libresolv.so.2 (0x40388000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000)
*************
Can you please give me some advice as to how I can track this down?
Or maybe some of the above information should be elaborated or reveal some
hint I fail to see?
Sincerely
Jørgen H. Fjeld
