Re: URGENT: Apache HTTP Migration from 1.3 to 2.4 UNIX Solaris

[singhal.ankit@xxxxxxx]

Hi William,

Thank you for the response.

I have compiled the code with -g option.

Please find the excerpts from the code
and httpd.conf file:

Code declaration:
static const command_rec example_cmds[]
=
{
    ("SCENARIO",CallScenarioName,NULL,RSRC_CONF,"Define
scenario name"),
    {NULL}
};
module  MODULE_VAR_EXPORT example_module
=
{
STANDARD20_MODULE_STUFF,
    create_example_dir_config,
 /* per-directory config creator */
    NULL,   /* dir config
merger */
    example_create_server_config,
      /* server config creator */
    NULL,      
 /* server config merger */
    example_cmds,    
          /* command table */
    register_hooks,  
        /* [7] list of handlers */
};

httpd.conf:
<IfModule example_module>
    SCENARIO WEBUI_DEFAULTOPEN
</IfModule>

<Location /COMSHTTPS>
        SetHandler
example-handler
</Location>

Could you please suggest whether need
to make more entries in the httpd.conf of command entries?

Thanks & Regards
Ankit Singhal
Tata Consultancy Services
Mailto: singhal.ankit@xxxxxxx
Website: http://www.tcs.com
____________________________________________
Experience certainty.        IT Services
                
       Business Solutions
                
       Consulting
____________________________________________




From:      
 "William A Rowe
Jr" <wrowe@xxxxxxxxxxxxx>
To:      
 users@xxxxxxxxxxxxxxxx
Date:      
 08-01-2019 14:57
Subject:    
   Re: 
URGENT: Apache HTTP Migration from 1.3 to 2.4 UNIX Solaris

---

"External email. Open with Caution"
On Tue, Jan 8, 2019 at 10:48 AM <singhal.ankit@xxxxxxx>
wrote:

I have migrated a user module mod_example from 1.3 to 2.4. But when I try
to start the apache it is giving a segmentation fault and creating a core.

Following is the stacktrace while debug: 
t@1 (l@1) signal SEGV (no mapping at the fault address) in strlen at 0xfefcceb8
0xfefcceb8: strlen+0x0018:      ldub     [%o2],
%o1 
Current function is apr_pstrdup 
   77       len = strlen(s) + 1;
(dbx) where 
current thread: t@1 
  [1] strlen(0x1, 0xed568, 0x1, 0xed558, 0x1, 0x0), at 0xfefcceb8
=>[2] apr_pstrdup(a = 0xb8190, s = 0x1 "<bad address 0x00000001>"),
line 77 in "apr_strings.c" 
  [3] ap_add_module_commands(m = 0xfebc80d8, p = <value unavailable>),
line 546 in "config.c" 
  [4] ap_add_module(m = 0xfebc80d8, p = 0xb8190, sym_name = <value
unavailable>), at 0x5db30 
  [5] ap_add_loaded_module(mod = 0xfebc80d8, p = 0xb8190, short_name
= 0xed510 "example_module"), line 713 in "config.c"
  [6] load_module(cmd = 0xffbfec90, dummy = <value unavailable>,
modname = 0xed510 "example_module", filename = <value unavailable>),
line 302 in "mod_so.c" 

This is happening while loading a user module that I created:
LoadModule example_module modules/mod_example.so 

Please provide your valuable insight into it so that I can go forward.


The info above is a bit limited in diagnosing the specifics
of source code
you didn't share, and we aren't that great at divining
the invisible, so two
thoughts for you; first build an httpd/apr/your module
with CFLAGS -g -O0.
Sometimes you can only reproduce a crash with an optimized
build, but 
the -g flag always remains useful in this regard (and
objcopy can strip 
those symbols for general distribution.) I'm guessing
the above was built 
with '-g' but with some '-O', optimizing out some of the
args that might 
have been helpful.

Since we can't see above which command in your command_rec
array
caused this segfault, we can see you had an invalid string
element. 

Line 546 of config.c tripped over your input. config.c:546
was trying to;
        dir = apr_pstrdup(tpool, cmd->name);

This suggests you added a command to the list without
an actual char*
string name value.

Compare your command_rec list with the templates of the
various 
AP_INIT_* macros to ensure you provided valid initializers...
only 
static const array values. Ensure you NULL terminate that
list.

=====-----=====-----=====
Notice: The information contained in this e-mail
message and/or attachments to it may contain
confidential or privileged information. If you are
not the intended recipient, any dissemination, use,
review, distribution, printing or copying of the
information contained in this e-mail message
and/or attachments to it are strictly prohibited. If
you have received this communication in error,
please notify us by reply e-mail or telephone and
immediately and permanently delete the message
and any attachments. Thank you