id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
268	Conditional jump or move depends on uninitialised value(s)	Tatsuhiko Kubo	Valentin V. Bartenev	"
Hi, the latest nginx(1.3.10) is tripped over the check of Valgrind.

{{{
# valgrind /usr/local/nginx/sbin/nginx -g 'daemon off;'                                  
==24183== Memcheck, a memory error detector
==24183== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==24183== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==24183== Command: /usr/local/nginx/sbin/nginx -g daemon\ off;
==24183== 
==24183== Conditional jump or move depends on uninitialised value(s)
==24183==    at 0x4323F7: ngx_http_log_set_log (ngx_http_log_module.c:1278)
==24183==    by 0x41280A: ngx_conf_parse (ngx_conf_file.c:387)
==24183==    by 0x4275FA: ngx_http_core_server (ngx_http_core_module.c:2944)
==24183==    by 0x41280A: ngx_conf_parse (ngx_conf_file.c:387)
==24183==    by 0x421F4D: ngx_http_block (ngx_http.c:239)
==24183==    by 0x41280A: ngx_conf_parse (ngx_conf_file.c:387)
==24183==    by 0x41030A: ngx_init_cycle (ngx_cycle.c:268)
==24183==    by 0x40401B: main (nginx.c:333)
==24183== 
==24183== Syscall param socketcall.sendmsg(msg.msg_iov[i]) points to uninitialised byte(s)
==24183==    at 0x4E41320: __sendmsg_nocancel (syscall-template.S:82)
==24183==    by 0x41C916: ngx_write_channel (ngx_channel.c:77)
==24183==    by 0x41E447: ngx_pass_open_channel (ngx_process_cycle.c:450)
==24183==    by 0x41E4F6: ngx_start_worker_processes (ngx_process_cycle.c:369)
==24183==    by 0x41F5C1: ngx_master_process_cycle (ngx_process_cycle.c:136)
==24183==    by 0x404237: main (nginx.c:412)
==24183==  Address 0x7ff0004cc is on thread 1's stack
==24183== 
}}}

'''configuration to reproduce this problem'''

{{{
worker_processes  4;

events {
    worker_connections  4096;
}

http {
    log_format  main  '$host$remote_addr - $remote_user [$time_local] ""$http_host"" ""$request"" '
                      '$status $body_bytes_sent ""$http_referer"" '
                      '""$http_user_agent"" ""$http_x_forwarded_for""';

    server {
        listen       8000;
        server_name  localhost;

        root html;

        access_log /tmp/8000.log main buffer=16k;
    }

}
}}}

'''patch for curbing this output'''

Valgrind outputs following two errors in checking nginx.

 1. Conditional jump or move depends on uninitialised value(s)
 1. Syscall param socketcall.sendmsg(msg.msg_iov[i]) points to uninitialised byte(s)

I have no idea about 2. But I checked that 1 is fixed by following patch.

{{{
diff -ur orig/nginx-1.3.10/src/core/ngx_conf_file.c nginx-1.3.10/src/core/ngx_conf_file.c
--- orig/nginx-1.3.10/src/core/ngx_conf_file.c  2012-12-24 00:36:52.000000000 +0900
+++ nginx-1.3.10/src/core/ngx_conf_file.c       2013-01-01 17:35:06.991854337 +0900
@@ -946,6 +946,7 @@
     }

     file->flush = NULL;
+    file->data  = NULL;

     return file;
 }
}}}

Thanks.
"	defect	closed	minor		nginx-core	1.3.x	fixed			Linux bokko-mint 3.2.0-35-generic #55-Ubuntu SMP Wed Dec 5 17:42:16 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux	"nginx version: nginx/1.3.10
built by gcc 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) 
configure arguments: --with-pcre"