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[2016-05-23 07:39 UTC] jccgls001 at 126 dot com
Description:
------------
hi,
I find that when using "get_defined_constants()" function with args "true", zend core will dump. the code like this :
var_dump(get_defined_constants(true));
---------------------------------------------------------
About debug detail:
I debug the code with gdb and find, this bug maybe caused by "zend_startup_builtin_functions()" in zend_builtin_functions.c(line 362), which the code :
zend_builtin_module.module_number = 0;
this place assign module index to 0, which will cause "get_defined_constants(true)" dump. Because in this function, the 0 index is reserved to "internal".
----------------------------------------------------------
About fix:
I think the code in zend_builtin_functions.c(line 362) can be modified to:
zend_builtin_module.module_number = zend_next_free_module();
this will lead index to 1, and can make "get_defined_constants(true)" run correctly.
Test script:
---------------
get_defined_constants(true);
Expected result:
----------------
two dimension array that contains all defined constants group by module's name
Actual result:
--------------
segmentation fault and core dump
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backtrace is here : ------------------------ Using host libthread_db library "/lib64/tls/libthread_db.so.1". Core was generated by `install/php/bin/php -r get_defined_constants(true);'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x000000302af6ff40 in strlen () from /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/install/php/bin/../../lib/gcc-3.4.5/libc.so.6 (gdb) bt #0 0x000000302af6ff40 in strlen () from /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/install/php/bin/../../lib/gcc-3.4.5/libc.so.6 #1 0x0000000000a652b6 in zif_get_defined_constants (execute_data=0x7f9e74c120a0, return_value=0x7f9e74c12090) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/Zend/zend_builtin_functions.c:2227 #2 0x0000000000ab1781 in ZEND_DO_ICALL_SPEC_HANDLER (execute_data=0x7f9e74c12030) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/Zend/zend_vm_execute.h:586 #3 0x0000000000ab04bc in execute_ex (ex=0x7f9e74c12030) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/Zend/zend_vm_execute.h:417 #4 0x0000000000ab0c66 in zend_execute (op_array=0x7f9e74c610e0, return_value=0x7ffffa23d620) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/Zend/zend_vm_execute.h:458 #5 0x0000000000a18f78 in zend_eval_stringl (str=0x17d4cd0 "get_defined_constants(true);", str_len=28, retval_ptr=0x0, string_name=0x1353fcc "Command line code") at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/Zend/zend_execute_API.c:1135 #6 0x0000000000a19135 in zend_eval_stringl_ex (str=0x17d4cd0 "get_defined_constants(true);", str_len=28, retval_ptr=0x0, string_name=0x1353fcc "Command line code", handle_exceptions=1) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/Zend/zend_execute_API.c:1176 #7 0x0000000000a191ad in zend_eval_string_ex (str=0x17d4cd0 "get_defined_constants(true);", retval_ptr=0x0, string_name=0x1353fcc "Command line code", handle_exceptions=1) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/Zend/zend_execute_API.c:1187 #8 0x0000000000b6a05c in do_cli (argc=3, argv=0x17d4c60) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/sapi/cli/php_cli.c:1005 #9 0x0000000000b6b0f5 in main (argc=3, argv=0x17d4c60) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/sapi/cli/php_cli.c:1344I find when i add USE_ZEND_ALLOC=0 the function run successful -------------------------------------------- these info are created by command without USE_ZEND_ALLOC=0: gdb --args ./php -n -r "var_dump(get_defined_constants(true));" (gdb) bt full #0 0x000000302af6ff40 in ?? () No symbol table info available. #1 0x0000000000a652b6 in zif_get_defined_constants (execute_data=0x7ffff7612120, return_value=0x7ffff7612090) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_builtin_functions.c:2227 _z = 0x1901690 _p = 0x1901690 _end = 0x190f2b0 val = 0x17ec910 modules = 0x7ffff7676000 const_val = {value = {lval = 2, dval = 9.8813129168249309e-324, counted = 0x2, str = 0x2, arr = 0x2, obj = 0x2, res = 0x2, ref = 0x2, ast = 0x2, zv = 0x2, ptr = 0x2, ce = 0x2, func = 0x2, ww = {w1 = 2, w2 = 0}}, u1 = {v = {type = 1 '\001', type_flags = 0 '\000', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 1}, u2 = {var_flags = 0, next = 0, cache_slot = 0, lineno = 0, num_args = 0, fe_pos = 0, fe_iter_idx = 0}} module = 0x17df330 i = 41 module_number = 1 module_names = 0x7ffff7679000 categorize = 1 '\001' #2 0x0000000000ab1781 in ZEND_DO_ICALL_SPEC_HANDLER (execute_data=0x7ffff7612030) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_vm_execute.h:586 opline = 0x7ffff7662220 call = 0x7ffff7612120 fbc = 0x17e9700 ret = 0x7ffff7612090 #3 0x0000000000ab04bc in execute_ex (ex=0x7ffff7612030) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_vm_execute.h:417 ret = 0 execute_data = 0x7ffff7612030 #4 0x0000000000ab0c66 in zend_execute (op_array=0x7ffff76620e0, return_value=0x7fffffffcdf0) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_vm_execute.h:458 execute_data = 0x7ffff7612030 #5 0x0000000000a18f78 in zend_eval_stringl (str=0x17d4d90 "var_dump(get_defined_constants(true));", str_len=38, retval_ptr=0x0, string_name=0x1353fcc "Command line code") at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_execute_API.c:1135 __orig_bailout = 0x7fffffffe050 __bailout = {{__jmpbuf = {0, 140737488342688, 14558992, 140737488348272, 0, 0, 140737488342256, 10587994}, __mask_was_saved = 0, __saved_mask = {__val = {140737488342432, 14558992, 10461214, 0, 26465744, 0, 140737488342608, 140737488342800, 11965133, 18446744073565204544, 1125281431552, 26465744, 26465744, 1129432048064, 26465696, 26465696}}}} local_retval = {value = {lval = 26465648, dval = 1.3075767471727095e-316, counted = 0x193d570, str = 0x193d570, arr = 0x193d570, obj = 0x193d570, res = 0x193d570, ref = 0x193d570, ast = 0x193d570, zv = 0x193d570, ptr = 0x193d570, ce = 0x193d570, func = 0x193d570, ww = {w1 = 26465648, w2 = 0}}, u1 = {v = {type = 0 '\000', type_flags = 0 '\000', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 0}, u2 = {var_flags = 0, next = 0, cache_slot = 0, lineno = 0, num_args = 0, fe_pos = 0, fe_iter_idx = 0}} pv = {value = {lval = 140737343656320, dval = 6.9533486587541203e-310, counted = 0x7ffff7601180, str = 0x7ffff7601180, arr = 0x7ffff7601180, obj = 0x7ffff7601180, res = 0x7ffff7601180, ref = 0x7ffff7601180, ast = 0x7ffff7601180, zv = 0x7ffff7601180, ptr = 0x7ffff7601180, ce = 0x7ffff7601180, func = 0x7ffff7601180, ww = {w1 = 4150268288, w2 = 32767}}, u1 = {v = {type = 6 '\006', type_flags = 20 '\024', const_flags = 0 '\000', reserved = 0 '\000'}, type_info = 5126}, u2 = {var_flags = 0, next = 0, cache_slot = 0, lineno = 0, num_args = 0, fe_pos = 0, fe_iter_idx = 0}} new_op_array = 0x7ffff76620e0 original_compiler_options = 2 retval = 26465744 #6 0x0000000000a19135 in zend_eval_stringl_ex (str=0x17d4d90 "var_dump(get_defined_constants(true));", str_len=38, retval_ptr=0x0, string_name=0x1353fcc "Command line code", handle_exceptions=1) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_execute_API.c:1176 result = 0 #7 0x0000000000a191ad in zend_eval_string_ex (str=0x17d4d90 "var_dump(get_defined_constants(true));", retval_ptr=0x0, string_name=0x1353fcc "Command line code", handle_exceptions=1) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_execute_API.c:1187 No locals. #8 0x0000000000b6a05c in do_cli (argc=4, argv=0x17d4cd0) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/sapi/cli/php_cli.c:1005 __orig_bailout = 0x7fffffffe270 __bailout = {{__jmpbuf = {0, 140737488347712, 14558992, 140737488348272, 0, 0, 140737488342816, 11965745}, __mask_was_saved = 0, __saved_mask = {__val = {16, 20146392, 20146440, 20146471, 20146480, 20146504, 20146517, 20146534, 20146555, 20146575, 20146592, 20146613, 20146623, 20146637, 20146659, 20146678}}}} c = -1 file_handle = {handle = {fd = 722660096, fp = 0x302b12eb00, stream = {handle = 0x302b12eb00, isatty = 10040959, mmap = { len = 10135242, pos = 10041794, map = 0x993470 <php_stream_open_for_zend>, buf = 0x99b7b9 <vspprintf> "UH\211\345H\203\354PH\211}\370H\211u\360H\211U\350H\211M\340H\215}\300", <incomplete sequence \374\272>, old_handle = 0x99b970 <vstrpprintf>, old_closer = 0x9a282f <sapi_getenv>}, reader = 0x993657 <php_resolve_path_for_zend>, fsizer = 0x302b130620, closer = 0x70}}, filename = 0x1353f76 "-", opened_path = 0x0, type = ZEND_HANDLE_FP, free_filename = 0 '\000'} behavior = 6 reflection_what = 0x0 request_started = 1 exit_status = 0 php_optarg = 0x17d4d90 "var_dump(get_defined_constants(true));" orig_optarg = 0x0 php_optind = 4 orig_optind = 1 exec_direct = 0x17d4d90 "var_dump(get_defined_constants(true));" exec_run = 0x0 exec_begin = 0x0 exec_end = 0x0 arg_free = 0x17d4d90 "var_dump(get_defined_constants(true));" arg_excp = 0x17d4ce8 script_file = 0x0 translated_path = 0x0 interactive = 0 param_error = 0x0 hide_argv = 0 #9 0x0000000000b6b0f5 in main (argc=4, argv=0x17d4cd0) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/sapi/cli/php_cli.c:1344 __orig_bailout = 0x0 __bailout = {{__jmpbuf = {0, 140737488348064, 14558992, 140737488348272, 0, 0, 140737488347728, 11972824}, __mask_was_saved = 0, __saved_mask = {__val = {23437640, 22686360, 140737488348272, 0, 0, 270766525504, 270765434426, 206158430209, 0, 140737346091280, 206878818672, 0, 270765434114, 0, 32, 0}}}} c = -1 exit_status = 0 module_started = 1 sapi_started = 1 php_optarg = 0x17d4d90 "var_dump(get_defined_constants(true));" php_optind = 4 use_extended_info = 0 ini_path_override = 0x0 ini_entries = 0x17d4fe0 "html_errors=0\nregister_argc_argv=1\nimplicit_flush=1\noutput_buffering=0\nmax_execution_time=0\nmax_input_time=-1\n" ini_entries_len = 110 ini_ignore = 1 sapi_module = 0x1672d60 <cli_sapi_module>by the way, f 1 locate code : #1 0x0000000000a652b6 in zif_get_defined_constants (execute_data=0x7ffff7612120, return_value=0x7ffff7612090) at /home/users/lvshun_iwm/php7_odp/trunk/php/.tmp/build/php-7.0.6/Zend/zend_builtin_functions.c:2227 2227 add_assoc_zval(return_value, module_names[module_number], &modules[module_number]); (gdb) list 2222 module_number = val->module_number; 2223 } 2224 2225 if (Z_TYPE(modules[module_number]) == IS_UNDEF) { 2226 array_init(&modules[module_number]); 2227 add_assoc_zval(return_value, module_names[module_number], &modules[module_number]); 2228 } 2229 2230 ZVAL_DUP(&const_val, &val->value); 2231 zend_hash_add_new(Z_ARRVAL(modules[module_number]), val->name, &const_val);I try my best to debug code with: gdb ./php -n -r "get_defined_constants(true);" and set breakpoint to see why module_names[1]=0x0 ----------------------------------------------------------- (gdb) b zend_builtin_functions.c :2198 Breakpoint 1, zif_get_defined_constants (execute_data=0x7ffff495a0b0, return_value=0x7ffff495a0a0) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_builtin_functions.c:2198 2198 int i = 1; (gdb) n 2203 module_names[0] = "internal"; <------ Important (gdb) p module_names[0] $1 = 0x134dc1e "internal" in this place, module_names[0] has assigned to "internal", and then: (gdb) n 0x0000000000a6511c in zif_get_defined_constants (execute_data=0x7ffff495a0b0, return_value=0x7ffff495a0a0) (gdb) n 2205 module_names[module->module_number] = (char *)module->name; (gdb) p module->name $2 = 0x134d795 "Core" (gdb) p module->module_number <------ Important, number is 0, but 0 is "internal" $3 = 0 I find "Core" module's number is 0, this means it will rewrite "internal", and then the next module "date": 2204 ZEND_HASH_FOREACH_PTR(&module_registry, module) { (gdb) 0x0000000000a6511c in zif_get_defined_constants (execute_data=0x7ffff495a0b0, return_value=0x7ffff495a0a0) (gdb) 2205 module_names[module->module_number] = (char *)module->name; (gdb) p module->name $5 = 0xde2964 "date" (gdb) p module->module_number $6 = 2 module "data" number is 2! This make me trouble, why "Core" is 0 but "data" is 2. To make this problem clearly, i continue debug code ... ------------------------------------------------ At last, I find the place to assign "Core" module_number. in zend_startup functions, zend engine will load builtin module "Core", these code are: Breakpoint 1, zend_startup_builtin_functions () at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_builtin_functions.c:362 362 zend_builtin_module.module_number = 0; (gdb) l 357 }; 358 /* }}} */ 359 360 int zend_startup_builtin_functions(void) /* {{{ */ 361 { 362 zend_builtin_module.module_number = 0; 363 zend_builtin_module.type = MODULE_PERSISTENT; 364 return (EG(current_module) = zend_register_module_ex(&zend_builtin_module)) == NULL ? FAILURE : SUCCESS; 365 } 366 /* }}} */ as we can see, "Core" module_number assign to 0. Then i debug other module load process and find: (gdb) b zend_API.c:2050 Breakpoint 2 at 0xa3c5ed: file /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_API.c, line 2050. (gdb) c Continuing. Breakpoint 2, zend_register_internal_module (module=0x165ac20 <date_module_entry>) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_API.c:2050 2050 module->module_number = zend_next_free_module(); (gdb) p module->name $1 = 0xde2964 "date" in these codes, other module get number by "zend_next_free_module()", and i step the code: (gdb) step zend_next_free_module () at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_API.c:2643 2643 return zend_hash_num_elements(&module_registry) + 1; (gdb) p module_registry.nNumOfElements $2 = 1 the result is, this will return 2 but not 1. Because module_registry contains "Core". I think the problem is come from here, which "Core" module_number don't use "zend_next_free_module()" but direct assign 0. This will lead other module_name calculate error. --------------------------------------------------------------------- Finally, "Core" module_number = 0, but "data" module_number = 2, so module_names[1]=0x0, this will lead core dump: #1 0x0000000000a652b6 in zif_get_defined_constants (execute_data=0x7ffff76120a0, return_value=0x7ffff7612090) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_builtin_functions.c:2227 2227 add_assoc_zval(return_value, module_names[module_number], &modules[module_number]); (gdb) p module_names[module_number] $1 = 0x0 (gdb) p module_number $2 = 1 add_assoc_zval expand to add_assoc_zval_ex(__arg, __key, strlen(__key), __value), which strlen(0x0) will make core dump. ----------------------------------------------------------------------- by the way, i add USE_ZEND_ALLOC=0 to see why it can run: Breakpoint 1, zif_get_defined_constants (execute_data=0x7ffff495a0b0, return_value=0x7ffff495a0a0) at /home/users/lvshun/php7/trunk/php/.tmp/build/php-7.0.6/Zend/zend_builtin_functions.c:2227 2227 add_assoc_zval(return_value, module_names[module_number], &modules[module_number]); (gdb) p module_number $2 = 1 (gdb) p module_names[module_number] $3 = 0x302b130b38 "(\v\023+0" <-------- may be USE_ZEND_ALLOC=0 make this value not 0x0