:::::: :::::: Manual check reason: "low confidence static check warning: lib/dynamic_debug.c:1070:44: warning: Subtracting pointers that point to different objects [comparePointers]" ::::::
CC: kbuild-...@lists.01.org BCC: l...@intel.com TO: Jim Cromie <jim.cro...@gmail.com> tree: https://github.com/jimc/linux.git ddn3j head: 717a666bd3fa45056435727f971badceaaebbed0 commit: 97c4bd16cf4cf6a091996f8e5b2d4af84697c7d4 [13/21] kernel/module: add __dyndbg_classes section :::::: branch date: 13 days ago :::::: commit date: 3 weeks ago compiler: s390-linux-gcc (GCC) 11.3.0 reproduce (cppcheck warning): # apt-get install cppcheck git checkout 97c4bd16cf4cf6a091996f8e5b2d4af84697c7d4 cppcheck --quiet --enable=style,performance,portability --template=gcc FILE If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <l...@intel.com> cppcheck possible warnings: (new ones prefixed by >>, may not real problems) >> lib/dynamic_debug.c:1070:44: warning: Subtracting pointers that point to >> different objects [comparePointers] int num_classes = __stop___dyndbg_classes - __start___dyndbg_classes; ^ lib/dynamic_debug.c:45:32: note: Variable declared here. extern struct ddebug_class_map __stop___dyndbg_classes[]; ^ lib/dynamic_debug.c:1070:20: note: Array decayed to pointer here. int num_classes = __stop___dyndbg_classes - __start___dyndbg_classes; ^ lib/dynamic_debug.c:44:32: note: Variable declared here. extern struct ddebug_class_map __start___dyndbg_classes[]; ^ lib/dynamic_debug.c:1070:46: note: Array decayed to pointer here. int num_classes = __stop___dyndbg_classes - __start___dyndbg_classes; ^ lib/dynamic_debug.c:1070:44: note: Subtracting pointers that point to different objects int num_classes = __stop___dyndbg_classes - __start___dyndbg_classes; ^ lib/dynamic_debug.c:1084:14: warning: Comparing pointers that point to different objects [comparePointers] for (; iter < __stop___dyndbg; iter++) { ^ lib/dynamic_debug.c:42:23: note: Variable declared here. extern struct _ddebug __start___dyndbg[]; ^ lib/dynamic_debug.c:1081:9: note: Array decayed to pointer here. iter = __start___dyndbg; ^ lib/dynamic_debug.c:43:23: note: Variable declared here. extern struct _ddebug __stop___dyndbg[]; ^ lib/dynamic_debug.c:1084:16: note: Array decayed to pointer here. for (; iter < __stop___dyndbg; iter++) { ^ lib/dynamic_debug.c:1084:14: note: Comparing pointers that point to different objects for (; iter < __stop___dyndbg; iter++) { ^ lib/dynamic_debug.c:821:60: warning: Parameter 'pos' can be declared with const [constParameter] static void *ddebug_proc_start(struct seq_file *m, loff_t *pos) ^ lib/dynamic_debug.c:844:57: warning: Parameter 'p' can be declared with const [constParameter] static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) ^ lib/dynamic_debug.c:172:23: warning: Uninitialized variable: dt->num_ddebugs [uninitvar] for (i = 0; i < dt->num_ddebugs; i++) { ^ lib/dynamic_debug.c:168:21: note: Assuming condition is false if (query->module && ^ lib/dynamic_debug.c:172:23: note: Uninitialized variable: dt->num_ddebugs for (i = 0; i < dt->num_ddebugs; i++) { ^ >> lib/dynamic_debug.c:1014:11: warning: Uninitialized variable: dt->mod_name >> [uninitvar] if (dt->mod_name == mod_name) { ^ >> lib/dynamic_debug.c:104:12: warning: Using argument fb that points at >> uninitialized variable flags [ctuuninitvar] char *p = fb->buf; ^ lib/dynamic_debug.c:878:27: note: Calling function ddebug_describe_flags, 2nd argument is uninitialized ddebug_describe_flags(dp->flags, &flags)); ^ lib/dynamic_debug.c:104:12: note: Using argument fb char *p = fb->buf; ^ vim +1070 lib/dynamic_debug.c e9d376f0fa66bd Jason Baron 2009-02-05 1002 e9d376f0fa66bd Jason Baron 2009-02-05 1003 /* e9d376f0fa66bd Jason Baron 2009-02-05 1004 * Called in response to a module being unloaded. Removes e9d376f0fa66bd Jason Baron 2009-02-05 1005 * any ddebug_table's which point at the module. e9d376f0fa66bd Jason Baron 2009-02-05 1006 */ ff49d74ad383f5 Yehuda Sadeh 2010-07-03 1007 int ddebug_remove_module(const char *mod_name) e9d376f0fa66bd Jason Baron 2009-02-05 1008 { e9d376f0fa66bd Jason Baron 2009-02-05 1009 struct ddebug_table *dt, *nextdt; e9d376f0fa66bd Jason Baron 2009-02-05 1010 int ret = -ENOENT; e9d376f0fa66bd Jason Baron 2009-02-05 1011 e9d376f0fa66bd Jason Baron 2009-02-05 1012 mutex_lock(&ddebug_lock); e9d376f0fa66bd Jason Baron 2009-02-05 1013 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { 4573fe15437c90 Rasmus Villemoes 2019-03-07 @1014 if (dt->mod_name == mod_name) { e9d376f0fa66bd Jason Baron 2009-02-05 1015 ddebug_table_free(dt); e9d376f0fa66bd Jason Baron 2009-02-05 1016 ret = 0; 4573fe15437c90 Rasmus Villemoes 2019-03-07 1017 break; e9d376f0fa66bd Jason Baron 2009-02-05 1018 } e9d376f0fa66bd Jason Baron 2009-02-05 1019 } e9d376f0fa66bd Jason Baron 2009-02-05 1020 mutex_unlock(&ddebug_lock); 7a5e202dfb8ab7 Jim Cromie 2021-10-13 1021 if (!ret) 7a5e202dfb8ab7 Jim Cromie 2021-10-13 1022 v2pr_info("removed module \"%s\"\n", mod_name); e9d376f0fa66bd Jason Baron 2009-02-05 1023 return ret; e9d376f0fa66bd Jason Baron 2009-02-05 1024 } e9d376f0fa66bd Jason Baron 2009-02-05 1025 e9d376f0fa66bd Jason Baron 2009-02-05 1026 static void ddebug_remove_all_tables(void) e9d376f0fa66bd Jason Baron 2009-02-05 1027 { e9d376f0fa66bd Jason Baron 2009-02-05 1028 mutex_lock(&ddebug_lock); e9d376f0fa66bd Jason Baron 2009-02-05 1029 while (!list_empty(&ddebug_tables)) { e9d376f0fa66bd Jason Baron 2009-02-05 1030 struct ddebug_table *dt = list_entry(ddebug_tables.next, e9d376f0fa66bd Jason Baron 2009-02-05 1031 struct ddebug_table, e9d376f0fa66bd Jason Baron 2009-02-05 1032 link); e9d376f0fa66bd Jason Baron 2009-02-05 1033 ddebug_table_free(dt); e9d376f0fa66bd Jason Baron 2009-02-05 1034 } e9d376f0fa66bd Jason Baron 2009-02-05 1035 mutex_unlock(&ddebug_lock); e9d376f0fa66bd Jason Baron 2009-02-05 1036 } e9d376f0fa66bd Jason Baron 2009-02-05 1037 6a5c083de2f5fb Thomas Renninger 2010-08-06 1038 static __initdata int ddebug_init_success; 6a5c083de2f5fb Thomas Renninger 2010-08-06 1039 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1040 static int __init dynamic_debug_init_control(void) e9d376f0fa66bd Jason Baron 2009-02-05 1041 { 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1042 struct proc_dir_entry *procfs_dir; 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1043 struct dentry *debugfs_dir; 6a5c083de2f5fb Thomas Renninger 2010-08-06 1044 6a5c083de2f5fb Thomas Renninger 2010-08-06 1045 if (!ddebug_init_success) 6a5c083de2f5fb Thomas Renninger 2010-08-06 1046 return -ENODEV; e9d376f0fa66bd Jason Baron 2009-02-05 1047 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1048 /* Create the control file in debugfs if it is enabled */ 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1049 if (debugfs_initialized()) { 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1050 debugfs_dir = debugfs_create_dir("dynamic_debug", NULL); 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1051 debugfs_create_file("control", 0644, debugfs_dir, NULL, 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1052 &ddebug_proc_fops); 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1053 } 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1054 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1055 /* Also create the control file in procfs */ 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1056 procfs_dir = proc_mkdir("dynamic_debug", NULL); 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1057 if (procfs_dir) 239a5791ffd555 Greg Kroah-Hartman 2020-02-10 1058 proc_create("control", 0644, procfs_dir, &proc_fops); 9fd714cd7f4676 Greg Kroah-Hartman 2019-06-12 1059 6a5c083de2f5fb Thomas Renninger 2010-08-06 1060 return 0; 6a5c083de2f5fb Thomas Renninger 2010-08-06 1061 } 6a5c083de2f5fb Thomas Renninger 2010-08-06 1062 6a5c083de2f5fb Thomas Renninger 2010-08-06 1063 static int __init dynamic_debug_init(void) 6a5c083de2f5fb Thomas Renninger 2010-08-06 1064 { 6a5c083de2f5fb Thomas Renninger 2010-08-06 1065 struct _ddebug *iter, *iter_start; 6a5c083de2f5fb Thomas Renninger 2010-08-06 1066 const char *modname = NULL; b48420c1d3019c Jim Cromie 2012-04-27 1067 char *cmdline; 6a5c083de2f5fb Thomas Renninger 2010-08-06 1068 int ret = 0; 4107692760db81 Jim Cromie 2012-04-27 1069 int n = 0, entries = 0, modct = 0; 97c4bd16cf4cf6 Jim Cromie 2022-06-01 @1070 int num_classes = __stop___dyndbg_classes - __start___dyndbg_classes; 6a5c083de2f5fb Thomas Renninger 2010-08-06 1071 e5ebffe18e5add Jim Cromie 2020-07-19 1072 if (&__start___dyndbg == &__stop___dyndbg) { ceabef7dd71720 Orson Zhai 2020-06-07 1073 if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) { f657fd21e16e3a Joe Perches 2012-12-05 1074 pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n"); b5b78f83854af1 Jim Cromie 2011-12-19 1075 return 1; b5b78f83854af1 Jim Cromie 2011-12-19 1076 } ceabef7dd71720 Orson Zhai 2020-06-07 1077 pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n"); ceabef7dd71720 Orson Zhai 2020-06-07 1078 ddebug_init_success = 1; ceabef7dd71720 Orson Zhai 2020-06-07 1079 return 0; ceabef7dd71720 Orson Zhai 2020-06-07 1080 } e5ebffe18e5add Jim Cromie 2020-07-19 1081 iter = __start___dyndbg; e9d376f0fa66bd Jason Baron 2009-02-05 1082 modname = iter->modname; e9d376f0fa66bd Jason Baron 2009-02-05 1083 iter_start = iter; e5ebffe18e5add Jim Cromie 2020-07-19 1084 for (; iter < __stop___dyndbg; iter++) { 4107692760db81 Jim Cromie 2012-04-27 1085 entries++; e9d376f0fa66bd Jason Baron 2009-02-05 1086 if (strcmp(modname, iter->modname)) { 4107692760db81 Jim Cromie 2012-04-27 1087 modct++; 97c4bd16cf4cf6 Jim Cromie 2022-06-01 1088 ret = ddebug_add_module(iter_start, n, 97c4bd16cf4cf6 Jim Cromie 2022-06-01 1089 __start___dyndbg_classes, num_classes, 97c4bd16cf4cf6 Jim Cromie 2022-06-01 1090 modname); e9d376f0fa66bd Jason Baron 2009-02-05 1091 if (ret) af442399fcf378 Jim Cromie 2012-04-27 1092 goto out_err; e9d376f0fa66bd Jason Baron 2009-02-05 1093 n = 0; e9d376f0fa66bd Jason Baron 2009-02-05 1094 modname = iter->modname; e9d376f0fa66bd Jason Baron 2009-02-05 1095 iter_start = iter; e9d376f0fa66bd Jason Baron 2009-02-05 1096 } e9d376f0fa66bd Jason Baron 2009-02-05 1097 n++; e9d376f0fa66bd Jason Baron 2009-02-05 1098 } 97c4bd16cf4cf6 Jim Cromie 2022-06-01 1099 ret = ddebug_add_module(iter_start, n, 97c4bd16cf4cf6 Jim Cromie 2022-06-01 1100 __start___dyndbg_classes, num_classes, modname); b5b78f83854af1 Jim Cromie 2011-12-19 1101 if (ret) af442399fcf378 Jim Cromie 2012-04-27 1102 goto out_err; a648ec05bb950f Thomas Renninger 2010-08-06 1103 af442399fcf378 Jim Cromie 2012-04-27 1104 ddebug_init_success = 1; 7af5662826f7b1 Jim Cromie 2021-05-24 1105 vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n", 7af5662826f7b1 Jim Cromie 2021-05-24 1106 entries, modct, (int)((modct * sizeof(struct ddebug_table)) >> 10), 7af5662826f7b1 Jim Cromie 2021-05-24 1107 (int)((entries * sizeof(struct _ddebug)) >> 10)); af442399fcf378 Jim Cromie 2012-04-27 1108 97c4bd16cf4cf6 Jim Cromie 2022-06-01 1109 if (num_classes) 97c4bd16cf4cf6 Jim Cromie 2022-06-01 1110 v2pr_info(" %d builtin ddebug class-maps\n", num_classes); 97c4bd16cf4cf6 Jim Cromie 2022-06-01 1111 b48420c1d3019c Jim Cromie 2012-04-27 1112 /* now that ddebug tables are loaded, process all boot args b48420c1d3019c Jim Cromie 2012-04-27 1113 * again to find and activate queries given in dyndbg params. b48420c1d3019c Jim Cromie 2012-04-27 1114 * While this has already been done for known boot params, it b48420c1d3019c Jim Cromie 2012-04-27 1115 * ignored the unknown ones (dyndbg in particular). Reusing b48420c1d3019c Jim Cromie 2012-04-27 1116 * parse_args avoids ad-hoc parsing. This will also attempt b48420c1d3019c Jim Cromie 2012-04-27 1117 * to activate queries for not-yet-loaded modules, which is b48420c1d3019c Jim Cromie 2012-04-27 1118 * slightly noisy if verbose, but harmless. b48420c1d3019c Jim Cromie 2012-04-27 1119 */ b48420c1d3019c Jim Cromie 2012-04-27 1120 cmdline = kstrdup(saved_command_line, GFP_KERNEL); b48420c1d3019c Jim Cromie 2012-04-27 1121 parse_args("dyndbg params", cmdline, NULL, ecc8617053e0a9 Luis R. Rodriguez 2015-03-30 1122 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb); b48420c1d3019c Jim Cromie 2012-04-27 1123 kfree(cmdline); af442399fcf378 Jim Cromie 2012-04-27 1124 return 0; a648ec05bb950f Thomas Renninger 2010-08-06 1125 af442399fcf378 Jim Cromie 2012-04-27 1126 out_err: e9d376f0fa66bd Jason Baron 2009-02-05 1127 ddebug_remove_all_tables(); e9d376f0fa66bd Jason Baron 2009-02-05 1128 return 0; e9d376f0fa66bd Jason Baron 2009-02-05 1129 } 6a5c083de2f5fb Thomas Renninger 2010-08-06 1130 /* Allow early initialization for boot messages via boot param */ 3ec5652ab70f6e Jim Cromie 2012-04-27 1131 early_initcall(dynamic_debug_init); b48420c1d3019c Jim Cromie 2012-04-27 1132 -- 0-DAY CI Kernel Test Service https://01.org/lkp _______________________________________________ kbuild mailing list -- kbuild@lists.01.org To unsubscribe send an email to kbuild-le...@lists.01.org
