On 2012-06-21 22:22, oh...@cox.net wrote:
[root@apachemodule bin]# gdb httpd
GNU gdb Red Hat Linux (6.3.0.0-1.162.el4rh)
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This GDB was configured as "x86_64-redhat-linux-gnu"...Using host libthread_db library
"/lib64/tls/libthread_db.so.1".
(gdb) b header_post_config
Function "header_post_config" not defined.
Make breakpoint pending on future shared library load? (y or [n]) y
Breakpoint 1 (header_post_config) pending.
(gdb) run -X
Starting program: /apps/httpd2222/bin/httpd -X
[Thread debugging using libthread_db enabled]
[New Thread 182897612000 (LWP 8741)]
Breakpoint 2 at 0x2a97a69060: file mod_headers.c, line 1026.
Pending breakpoint "header_post_config" resolved
mod_headers-jl V0.09 - start calling OAM API
In register_hooks
In create_headers_dir_config
In create_headers_dir_config
In header_cmd
In header_inout_cmd
In parse_format_tag
In parse_misc_string
In create_headers_dir_config
In header_cmd
In header_inout_cmd
In parse_format_tag
In parse_misc_string
[Switching to Thread 182897612000 (LWP 8741)]
Breakpoint 2, header_post_config (pconf=0x573138, plog=0x5a52c8,
ptemp=0x5a72d8, s=0x59d3a8) at mod_headers.c:1026
1026 printf("In header_post_config\n");
(gdb) s
1025 {
(gdb) s
1026 printf("In header_post_config\n");
(gdb) n
In header_post_config
1027 header_ssl_lookup = APR_RETRIEVE_OPTIONAL_FN(ssl_var_lookup);
(gdb) n
1029 }
(gdb) n
0x00000000004360c7 in ap_run_post_config (pconf=0x573138, plog=0x5a52c8,
ptemp=0x5a72d8, s=0x59d3a8) at config.c:91
91 AP_IMPLEMENT_HOOK_RUN_ALL(int, post_config,
(gdb) n
Program received signal SIGSEGV, Segmentation fault.
0x0000003518d6c1e1 in BN_num_bits () from /lib64/libcrypto.so.4
(gdb)
I have no idea what the above means :(.... But it looks like something blew up
in libcrypto?
Jim
Navigate the help of gdb (help, help data, help running).
Check the "bt" (backtrace), "up", and "down" commands. From your
segfault point in libcrypto you can go "up" the stack until you reach in
one of your functions.
When you reached your code after several "ups", do a "print" of the
variables (especially pointers that you suspect they are null but
shouldn't be null) that could have triggered the error.
S
