Comment puis-je diagnostiquer cette erreur de segmentation PHP?

Question

J'exécute un travail en ligne de commande PHP qui entraîne un défaut de segmentation. Ce travail fonctionne depuis longtemps, mais il traite quelque chose qui est envoyé par courrier électronique. Apparemment, il y a quelque chose dans ce courrier électronique c'est le casser, mais je ne sais pas quoi. Si je mets le fichier core dans gdb, ce n'est vraiment pas utile:

$ gdb /usr/local/bin/php core.20381 GNU gdb (GDB) 7.1-ubuntu Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-linux-gnu". For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>... Reading symbols from /usr/local/bin/php...done. [New Thread 20381] warning: Can't read pathname for load map: Input/output error. Reading symbols from /lib/libcrypt.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/libcrypt.so.1 Reading symbols from /lib/librt.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/librt.so.1 Reading symbols from /usr/lib/libmysqlclient_r.so.15...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libmysqlclient_r.so.15 Reading symbols from /lib/libpthread.so.0...(no debugging symbols found)...done. Loaded symbols for /lib/libpthread.so.0 Reading symbols from /lib/libz.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/libz.so.1 Reading symbols from /usr/lib/libmcrypt.so.4...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libmcrypt.so.4 Reading symbols from /usr/lib/libltdl.so.7...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libltdl.so.7 Reading symbols from /lib/libpng12.so.0...(no debugging symbols found)...done. Loaded symbols for /lib/libpng12.so.0 Reading symbols from /lib/libm.so.6...(no debugging symbols found)...done. Loaded symbols for /lib/libm.so.6 Reading symbols from /lib/libdl.so.2...(no debugging symbols found)...done. Loaded symbols for /lib/libdl.so.2 Reading symbols from /lib/libnsl.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/libnsl.so.1 Reading symbols from /usr/lib/libcurl-gnutls.so.4...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libcurl-gnutls.so.4 Reading symbols from /usr/lib/libxml2.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libxml2.so.2 Reading symbols from /lib/libc.so.6...(no debugging symbols found)...done. Loaded symbols for /lib/libc.so.6 Reading symbols from /lib/libresolv.so.2...(no debugging symbols found)...done. Loaded symbols for /lib/libresolv.so.2 Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols found)...done. Loaded symbols for /lib64/ld-linux-x86-64.so.2 Reading symbols from /usr/lib/libidn.so.11...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libidn.so.11 Reading symbols from /usr/lib/liblber-2.4.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/liblber-2.4.so.2 Reading symbols from /usr/lib/libldap_r-2.4.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libldap_r-2.4.so.2 Reading symbols from /usr/lib/libgssapi_krb5.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libgssapi_krb5.so.2 Reading symbols from /usr/lib/libgnutls.so.26...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libgnutls.so.26 Reading symbols from /lib/libgcrypt.so.11...(no debugging symbols found)...done. Loaded symbols for /lib/libgcrypt.so.11 Reading symbols from /usr/lib/libsasl2.so.2...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libsasl2.so.2 Reading symbols from /usr/lib/libkrb5.so.3...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libkrb5.so.3 Reading symbols from /usr/lib/libk5crypto.so.3...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libk5crypto.so.3 Reading symbols from /lib/libcom_err.so.2...(no debugging symbols found)...done. Loaded symbols for /lib/libcom_err.so.2 Reading symbols from /usr/lib/libkrb5support.so.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libkrb5support.so.0 Reading symbols from /lib/libkeyutils.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/libkeyutils.so.1 Reading symbols from /usr/lib/libtasn1.so.3...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libtasn1.so.3 Reading symbols from /lib/libgpg-error.so.0...(no debugging symbols found)...done. Loaded symbols for /lib/libgpg-error.so.0 Reading symbols from /lib/libgcc_s.so.1...(no debugging symbols found)...done. Loaded symbols for /lib/libgcc_s.so.1 Reading symbols from /lib/libnss_files.so.2...(no debugging symbols found)...done. Loaded symbols for /lib/libnss_files.so.2 Can't read symbols from system-supplied DSO at 0x7fffb4bfc000: File truncated Core was generated by `/usr/local/bin/php /src/prod/current/utils/cron.php --run=/utils/proces'. Program terminated with signal 11, Segmentation fault. #0 match ( eptr=0x1370a887 "/td>
						
					</tr>
					
				</table>
			</td>
		</tr>
		
		<tr>
			<td style=\"border-top:3px solid #efefef; padding:20px 10px;\">
				<table style=\"width:100%;\">
					<tr>
						
", '	' <repeats 12 times>, "
				"..., ecode=0x133dc3aa "N", mstart=0x13708600 "<html>
<head>
<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\" />
<meta name=\"viewport\" content=\"width=device-width, initial-scale=1, maximum-scale=1\">

</head>

<body style=\"padding"..., markptr=0x0, offset_top=4, md=0x7fffb4b1b620, ims=0, eptrb=0x0, flags=0, rdepth=17680) at /home/farmer/srcs/php-5.3.4/ext/pcre/pcrelib/pcre_exec.c:470 470 {

Si je fais un "bt", j'obtiens encore et encore cette instruction "match". Voici les premiers:

#1 0x000000000046ef1e in match ( eptr=0x1370a887 "/td>
						
					</tr>
					
				</table>
			</td>
		</tr>
		
		<tr>
			<td style=\"border-top:3px solid #efefef; padding:20px 10px;\">
				<table style=\"width:100%;\">
					<tr>
						
", '	' <repeats 12 times>, "
				"..., ecode=0x133dc3a5 "_", mstart=<value optimized out>, markptr=<value optimized out>, offset_top=<value optimized out>, md=0x7fffb4b1b620, ims=0, eptrb=0x0, flags=0, rdepth=17679) at /home/farmer/srcs/php-5.3.4/ext/pcre/pcrelib/pcre_exec.c:803 #2 0x0000000000479789 in match ( eptr=0x1370a887 "/td>
						
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				</table>
			</td>
		</tr>
		
		<tr>
			<td style=\"border-top:3px solid #efefef; padding:20px 10px;\">
				<table style=\"width:100%;\">
					<tr>
						
", '	' <repeats 12 times>, "
				"..., ecode=0x133dc5ca "V\002%\033U\002.", mstart=<value optimized out>, markptr=<value optimized out>, offset_top=<value optimized out>, md=0x7fffb4b1b620, ims=0, eptrb=0x0, flags=0, rdepth=<value optimized out>) at /home/farmer/srcs/php-5.3.4/ext/pcre/pcrelib/pcre_exec.c:1623 #3 0x000000000046ef1e in match ( eptr=0x1370a886 "</td>
						
					</tr>
					
				</table>
			</td>
		</tr>
		
		<tr>
			<td style=\"border-top:3px solid #efefef; padding:20px 10px;\">
				<table style=\"width:100%;\">
					<tr>
						
", '	' <repeats 12 times>, "
			"..., ecode=0x133dc3a5 "_", mstart=<value optimized out>, markptr=<value optimized out>, offset_top=<value optimized out>, md=0x7fffb4b1b620, ims=0, eptrb=0x0, flags=0, rdepth=17677) at /home/farmer/srcs/php-5.3.4/ext/pcre/pcrelib/pcre_exec.c:803 #4 0x0000000000479789 in match ( eptr=0x1370a886 "</td>
						
					</tr>
					
				</table>
			</td>
		</tr>
		
		<tr>
			<td style=\"border-top:3px solid #efefef; padding:20px 10px;\">
				<table style=\"width:100%;\">
					<tr>
						
", '	' <repeats 12 times>, "
			"..., ecode=0x133dc5ca "V\002%\033U\002.", mstart=<value optimized out>, markptr=<value optimized out>, offset_top=<value optimized out>, md=0x7fffb4b1b620, ims=0, eptrb=0x0, flags=0, rdepth=<value optimized out>) at /home/farmer/srcs/php-5.3.4/ext/pcre/pcrelib/pcre_exec.c:1623 #5 0x000000000046ef1e in match ( eptr=0x1370a885 "	</td>
						
					</tr>
					
				</table>
			</td>
		</tr>
		
		<tr>
			<td style=\"border-top:3px solid #efefef; padding:20px 10px;\">
				<table style=\"width:100%;\">
					<tr>
						
", '	' <repeats 12 times>, "
		"..., ecode=0x133dc3a5 "_", mstart=<value optimized out>, markptr=<value optimized out>, offset_top=<value optimized out>, md=0x7fffb4b1b620, ims=0, eptrb=0x0, flags=0, rdepth=17675) at /home/farmer/srcs/php-5.3.4/ext/pcre/pcrelib/pcre_exec.c:803

Je suis vraiment perdu ici. J'ai essayé d'exécuter la commande dans strace, et il semble y avoir des erreurs de segmentation dans la bibliothèque PEAR Mail_Queue. Voici la fin de la strace (certaines informations d'identification ont été supprimées):

lstat("/src/prod/releases/20121025202143/www/application/pear/MDB2/Driver/mysql.php", {st_mode=S_IFREG|0770, st_size=55723, ...}) = 0 lstat("/src/prod/releases/20121025202143/www/application/pear/MDB2/Driver", {st_mode=S_IFDIR|0770, st_size=4096, ...}) = 0 lstat("/src/prod/releases/20121025202143/www/application/pear/MDB2", {st_mode=S_IFDIR|0770, st_size=4096, ...}) = 0 lstat("/src/prod/releases/20121025202143/www/application/pear", {st_mode=S_IFDIR|0770, st_size=4096, ...}) = 0 open("/src/prod/releases/20121025202143/www/application/pear/MDB2/Driver/mysql.php", O_RDONLY) = 6 fstat(6, {st_mode=S_IFREG|0770, st_size=55723, ...}) = 0 fstat(6, {st_mode=S_IFREG|0770, st_size=55723, ...}) = 0 fstat(6, {st_mode=S_IFREG|0770, st_size=55723, ...}) = 0 mmap(NULL, 55723, PROT_READ, MAP_SHARED, 6, 0) = 0x2b49f7bb4000 brk(0x987b000) = 0x987b000 brk(0x98bb000) = 0x98bb000 munmap(0x2b49f7bb4000, 55723) = 0 close(6) = 0 socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 6 fcntl(6, F_SETFL, O_RDONLY) = 0 fcntl(6, F_GETFL) = 0x2 (flags O_RDWR) fcntl(6, F_GETFL) = 0x2 (flags O_RDWR) fcntl(6, F_SETFL, O_RDWR|O_NONBLOCK) = 0 connect(6, {sa_family=AF_INET, sin_port=htons(3306), sin_addr=inet_addr("IP ADDRESS TO DB SERVER REMOVED")}, 16) = -1 EINPROGRESS (Operation now in progress) fcntl(6, F_SETFL, O_RDWR) = 0 poll([{fd=6, events=POLLIN|POLLPRI}], 1, 60000) = 1 ([{fd=6, revents=POLLIN}]) setsockopt(6, SOL_SOCKET, SO_RCVTIMEO, "\2003\341\1\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 0 setsockopt(6, SOL_SOCKET, SO_SNDTIMEO, "\2003\341\1\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 0 setsockopt(6, SOL_IP, IP_TOS, [8], 4) = 0 setsockopt(6, SOL_TCP, TCP_NODELAY, [1], 4) = 0 setsockopt(6, SOL_SOCKET, SO_KEEPALIVE, [1], 4) = 0 poll([{fd=6, events=POLLIN}], 1, 60000) = 1 ([{fd=6, revents=POLLIN}]) read(6, "C\0\0\0
5.1.37-1ubuntu5.5-log\0Q\257\3\0009"..., 16384) = 71 write(6, "=\0\0\1\205\242\2\0\0\0\0@\10\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 65) = 65 read(6, "\7\0\0\2\0\0\0\2\0\0\0", 16384) = 11 poll([{fd=6, events=POLLIN|POLLPRI}], 1, 0) = 0 (Timeout) write(6, "\10\0\0\0\2xxxxx", 12) = 12 read(6, "\7\0\0\1\0\0\0\2\0\0\0", 16384) = 11 lstat("/src/prod/current/www/application/pear/Mail/mime.php", {st_mode=S_IFREG|0770, st_size=50252, ...}) = 0 lstat("/src/prod/current/www/application/pear/Mail", {st_mode=S_IFDIR|0770, st_size=4096, ...}) = 0 lstat("/src/prod/current/www/application/pear", {st_mode=S_IFDIR|0770, st_size=4096, ...}) = 0 lstat("/src/prod/current/www/application", {st_mode=S_IFDIR|0776, st_size=4096, ...}) = 0 --- SIGSEGV (Segmentation fault) @ 0 (0) --- +++ killed by SIGSEGV +++ Segmentation fault

Si quelqu'un a des idées ou des indications sur des pistes d'enquête, je l'apprécierais vraiment. Je suis vraiment perplexe sur celui-ci.

Trendfischer · Answer

J'utilise généralement xdebug si je rencontre un défaut de segmentation. Je préfère utiliser la ligne suivante:

php -d xdebug.auto_trace=ON -d xdebug.trace_output_dir=mytracedir/ myscript.php

Avec la trace-sortie sous mytracedir /, vous pouvez facilement comprendre la ligne php approximative, qui casse le script. Réécrivez ensuite la ligne en une seule instruction par ligne et utilisez error_log() pour déboguer les variables. Si vous utilisez __destruct() ou __toString() cela pourrait devenir un peu plus compliqué.

Voir ici pour plus d'informations.

(Si l'extension n'est pas chargée, mais installée, essayez d'ajouter php -dzend_extension=xdebug.so [...])

hakre · Answer

Le débogueur vous indique déjà ce qui se passe:

... rdepth=17680) at /home/farmer/srcs/php-5.3.4/ext/pcre/pcrelib/pcre_exec.c:470

Voir pcre.recursion_limit setting :

pcre.recursion_limit - Limite de récursivité de PCRE. Veuillez noter que si vous définissez cette valeur sur un nombre élevé, vous pouvez consommer toute la pile de processus disponible et éventuellement planter PHP (en raison de l'atteinte de la limite de taille de pile imposée par le système d'exploitation).

Réduisez sa valeur afin qu'il ne se bloque plus pour la correction rapide. Vous verrez alors votre code HTML non entièrement traité par l'expression régulière.

Améliorez l'expression pour ne pas trop compter sur la récursivité. Vous voulez probablement simplement utiliser un analyseur HTML.

Pankaj Garg · Answer

Essayez de supprimer memcache.so et désactivez opcache depuis la ligne de commande php.ini, y compris les commentaires de la section opcache.

Publication qui exécute le script avec -c path/php.cli.ini et -d memory_limit -1 paramètre

Oktarin · Answer

J'ai eu ce problème. Il s'est avéré que les commandes que j'exécutais étaient pour PHP7.1, et sur le serveur c'était PHP7.3.

Une fois que je les ai exécutés comme /usr/bin/php71 ils ont été exécutés sans problème.

J'espère que cela aide quelqu'un :)