Segmentation Fault Occur when Apache-Worker restart

[illef]

Segmentation Fault Occur in Apache-Worker restart

Repro Steps

• build Examples/FunctionNoParameters using GCC 5.2.1, and add it to php.ini
• apache-worker start : OK
• apache-worker restart : Segmentation Fault

apache error log

• seg fault or similar nasty error detected in the parent process

gdb

Program received signal SIGSEGV, Segmentation fault.
0x00007f778666535b in sapi_register_post_entry (post_entry=post_entry@entry=0x7f7786fd4b40 <php_post_entries>)
at /share/sources/php/php-7.0.14/main/SAPI.c:952
952 if (SG(sapi_started) && EG(current_execute_data)) {

backtrace

#0 0x00007f778666535b in sapi_register_post_entry (post_entry=post_entry@entry=0x7f7786fd4b40 <php_post_entries>)
at /share/sources/php/php-7.0.14/main/SAPI.c:952
#1 0x00007f7786665452 in sapi_register_post_entries (post_entries=post_entries@entry=0x7f7786fd4b40 <php_post_entries>)
at /share/sources/php/php-7.0.14/main/SAPI.c:941
#2 0x00007f7786668680 in php_setup_sapi_content_types () at /share/sources/php/php-7.0.14/main/php_content_types.c:64
#3 0x00007f7786656f6c in ts_allocate_id (rsrc_id=rsrc_id@entry=0x7f7786ff76c8 <sapi_globals_id>, size=size@entry=560,
ctor=ctor@entry=0x7f7786662ea0 <sapi_globals_ctor>, dtor=dtor@entry=0x7f7786662e80 <sapi_globals_dtor>)
at /share/sources/php/php-7.0.14/TSRM/TSRM.c:259
#4 0x00007f778666325c in sapi_startup (sf=sf@entry=0x7f7786fde4a0 <apache2_sapi_module>)
at /share/sources/php/php-7.0.14/main/SAPI.c:84
#5 0x00007f778676d3cc in php_apache_server_startup (pconf=0x18dd138, plog=, ptemp=,
s=) at /share/sources/php/php-7.0.14/sapi/apache2handler/sapi_apache2.c:463
#6 0x000000000044ccb3 in ap_run_post_config (pconf=pconf@entry=0x18dd138, plog=0x190a378, ptemp=0x1908348, s=0x190ec88)
at config.c:103
#7 0x000000000042ba05 in main (argc=3, argv=0x7ffd9875e6d8) at main.c:765

[stamster]

sapi_apache2.
Have you tried with different SAPI, i.e. PHP-FPM or even CGI?

[illef]

It is OK with PHP-FPM , CGI and apache2-prefork.
Crash is reported in apache2-worker(ZTS).

[stamster]

Apache2 SAPI is known to cause those kinds of issues with other low level projects as well.

I'm only using PHP-FPM SAPI, thus, have no issues of a kind.

[sjinks]

Seems to be a PHP bug:

#include <sapi/embed/php_embed.h>

int main(int argc, char** argv)
{
        PHP_EMBED_START_BLOCK(0, 0)
        PHP_EMBED_END_BLOCK();

        PHP_EMBED_START_BLOCK(0, 0)
        PHP_EMBED_END_BLOCK();

        return 0;
}

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff73d826b in sapi_register_post_entry (post_entry=post_entry@entry=0x7ffff7dae160 <php_post_entries>) at /tmp/php-build/source/7.1.12/main/SAPI.c:951
951             if (SG(sapi_started) && EG(current_execute_data)) {
(gdb) bt
#0  0x00007ffff73d826b in sapi_register_post_entry (post_entry=post_entry@entry=0x7ffff7dae160 <php_post_entries>) at /tmp/php-build/source/7.1.12/main/SAPI.c:951
#1  0x00007ffff73d8362 in sapi_register_post_entries (post_entries=post_entries@entry=0x7ffff7dae160 <php_post_entries>) at /tmp/php-build/source/7.1.12/main/SAPI.c:940
#2  0x00007ffff73db5d0 in php_setup_sapi_content_types () at /tmp/php-build/source/7.1.12/main/php_content_types.c:64
#3  0x00007ffff73ca23c in ts_allocate_id (rsrc_id=rsrc_id@entry=0x7ffff7dd67b8 <sapi_globals_id>, size=size@entry=560, ctor=ctor@entry=0x7ffff73d5db0 <sapi_globals_ctor>, dtor=dtor@entry=0x7ffff73d5d90 <sapi_globals_dtor>) at /tmp/php-build/source/7.1.12/TSRM/TSRM.c:259
#4  0x00007ffff73d616c in sapi_startup (sf=sf@entry=0x7ffff7db7e40 <php_embed_module>) at /tmp/php-build/source/7.1.12/main/SAPI.c:84
#5  0x00007ffff74f2f74 in php_embed_init (argc=0, argv=0x0) at /tmp/php-build/source/7.1.12/sapi/embed/php_embed.c:182
#6  0x0000555555554a2e in main () at test.c:8

I suspect that this sequence:

    php_request_shutdown((void *) 0);
    php_module_shutdown();
    sapi_shutdown();
    tsrm_shutdown();

does not clear everything properly and PHP dies on sapi_startup().