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authorSam Ravnborg <sam@ravnborg.org>2008-01-24 15:12:37 -0500
committerSam Ravnborg <sam@ravnborg.org>2008-01-28 17:21:18 -0500
commit588ccd732ba2d32db8228802ef9283b583d3395f (patch)
tree435ad4432c165190d70b82f8392c37b375679b53 /scripts/mod/modpost.c
parentf5eaa323eb6819d2f737ead42464efccaf2b98b9 (diff)
kbuild: add verbose option to Section mismatch reporting in modpost
If the config option CONFIG_SECTION_MISMATCH is not set and we see a Section mismatch present the following to the user: modpost: Found 1 section mismatch(es). To see additional details select "Enable full Section mismatch analysis" in the Kernel Hacking menu (CONFIG_SECTION_MISMATCH). If the option CONFIG_SECTION_MISMATCH is selected then be verbose in the Section mismatch reporting from mdopost. Sample outputs: WARNING: o-x86_64/vmlinux.o(.text+0x7396): Section mismatch in reference from the function discover_ebda() to the variable .init.data:ebda_addr The function discover_ebda() references the variable __initdata ebda_addr. This is often because discover_ebda lacks a __initdata annotation or the annotation of ebda_addr is wrong. WARNING: o-x86_64/vmlinux.o(.data+0x74d58): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_plx9050_exit() The variable pci_serial_quirks references the function __devexit pci_plx9050_exit() If the reference is valid then annotate the variable with __exit* (see linux/init.h) or name the variable: *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console, WARNING: o-x86_64/vmlinux.o(__ksymtab+0x630): Section mismatch in reference from the variable __ksymtab_arch_register_cpu to the function .cpuinit.text:arch_register_cpu() The symbol arch_register_cpu is exported and annotated __cpuinit Fix this by removing the __cpuinit annotation of arch_register_cpu or drop the export. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Diffstat (limited to 'scripts/mod/modpost.c')
-rw-r--r--scripts/mod/modpost.c255
1 files changed, 226 insertions, 29 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index e75739ec9c03..3cf1ba8220d2 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -28,6 +28,9 @@ static int vmlinux_section_warnings = 1;
28/* Only warn about unresolved symbols */ 28/* Only warn about unresolved symbols */
29static int warn_unresolved = 0; 29static int warn_unresolved = 0;
30/* How a symbol is exported */ 30/* How a symbol is exported */
31static int sec_mismatch_count = 0;
32static int sec_mismatch_verbose = 1;
33
31enum export { 34enum export {
32 export_plain, export_unused, export_gpl, 35 export_plain, export_unused, export_gpl,
33 export_unused_gpl, export_gpl_future, export_unknown 36 export_unused_gpl, export_gpl_future, export_unknown
@@ -760,9 +763,23 @@ static const char *head_sections[] = { ".head.text*", NULL };
760static const char *linker_symbols[] = 763static const char *linker_symbols[] =
761 { "__init_begin", "_sinittext", "_einittext", NULL }; 764 { "__init_begin", "_sinittext", "_einittext", NULL };
762 765
766enum mismatch {
767 NO_MISMATCH,
768 TEXT_TO_INIT,
769 DATA_TO_INIT,
770 TEXT_TO_EXIT,
771 DATA_TO_EXIT,
772 XXXINIT_TO_INIT,
773 XXXEXIT_TO_EXIT,
774 INIT_TO_EXIT,
775 EXIT_TO_INIT,
776 EXPORT_TO_INIT_EXIT,
777};
778
763struct sectioncheck { 779struct sectioncheck {
764 const char *fromsec[20]; 780 const char *fromsec[20];
765 const char *tosec[20]; 781 const char *tosec[20];
782 enum mismatch mismatch;
766}; 783};
767 784
768const struct sectioncheck sectioncheck[] = { 785const struct sectioncheck sectioncheck[] = {
@@ -770,33 +787,54 @@ const struct sectioncheck sectioncheck[] = {
770 * normal code and data 787 * normal code and data
771 */ 788 */
772{ 789{
773 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, 790 .fromsec = { TEXT_SECTIONS, NULL },
774 .tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL } 791 .tosec = { ALL_INIT_SECTIONS, NULL },
792 .mismatch = TEXT_TO_INIT,
793},
794{
795 .fromsec = { DATA_SECTIONS, NULL },
796 .tosec = { ALL_INIT_SECTIONS, NULL },
797 .mismatch = DATA_TO_INIT,
798},
799{
800 .fromsec = { TEXT_SECTIONS, NULL },
801 .tosec = { ALL_EXIT_SECTIONS, NULL },
802 .mismatch = TEXT_TO_EXIT,
803},
804{
805 .fromsec = { DATA_SECTIONS, NULL },
806 .tosec = { ALL_EXIT_SECTIONS, NULL },
807 .mismatch = DATA_TO_EXIT,
775}, 808},
776/* Do not reference init code/data from devinit/cpuinit/meminit code/data */ 809/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
777{ 810{
778 .fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL }, 811 .fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL },
779 .tosec = { INIT_SECTIONS, NULL } 812 .tosec = { INIT_SECTIONS, NULL },
813 .mismatch = XXXINIT_TO_INIT,
780}, 814},
781/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ 815/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
782{ 816{
783 .fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL }, 817 .fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL },
784 .tosec = { EXIT_SECTIONS, NULL } 818 .tosec = { EXIT_SECTIONS, NULL },
819 .mismatch = XXXEXIT_TO_EXIT,
785}, 820},
786/* Do not use exit code/data from init code */ 821/* Do not use exit code/data from init code */
787{ 822{
788 .fromsec = { ALL_INIT_SECTIONS, NULL }, 823 .fromsec = { ALL_INIT_SECTIONS, NULL },
789 .tosec = { ALL_EXIT_SECTIONS, NULL }, 824 .tosec = { ALL_EXIT_SECTIONS, NULL },
825 .mismatch = INIT_TO_EXIT,
790}, 826},
791/* Do not use init code/data from exit code */ 827/* Do not use init code/data from exit code */
792{ 828{
793 .fromsec = { ALL_EXIT_SECTIONS, NULL }, 829 .fromsec = { ALL_EXIT_SECTIONS, NULL },
794 .tosec = { ALL_INIT_SECTIONS, NULL } 830 .tosec = { ALL_INIT_SECTIONS, NULL },
831 .mismatch = EXIT_TO_INIT,
795}, 832},
796/* Do not export init/exit functions or data */ 833/* Do not export init/exit functions or data */
797{ 834{
798 .fromsec = { "__ksymtab*", NULL }, 835 .fromsec = { "__ksymtab*", NULL },
799 .tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL } 836 .tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
837 .mismatch = EXPORT_TO_INIT_EXIT
800} 838}
801}; 839};
802 840
@@ -809,10 +847,10 @@ static int section_mismatch(const char *fromsec, const char *tosec)
809 for (i = 0; i < elems; i++) { 847 for (i = 0; i < elems; i++) {
810 if (match(fromsec, check->fromsec) && 848 if (match(fromsec, check->fromsec) &&
811 match(tosec, check->tosec)) 849 match(tosec, check->tosec))
812 return 1; 850 return check->mismatch;
813 check++; 851 check++;
814 } 852 }
815 return 0; 853 return NO_MISMATCH;
816} 854}
817 855
818/** 856/**
@@ -989,47 +1027,197 @@ static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
989} 1027}
990 1028
991/* 1029/*
1030 * Convert a section name to the function/data attribute
1031 * .init.text => __init
1032 * .cpuinit.data => __cpudata
1033 * .memexitconst => __memconst
1034 * etc.
1035*/
1036static char *sec2annotation(const char *s)
1037{
1038 if (match(s, init_exit_sections)) {
1039 char *p = malloc(20);
1040 char *r = p;
1041
1042 *p++ = '_';
1043 *p++ = '_';
1044 if (*s == '.')
1045 s++;
1046 while (*s && *s != '.')
1047 *p++ = *s++;
1048 *p = '\0';
1049 if (*s == '.')
1050 s++;
1051 if (strstr(s, "rodata") != NULL)
1052 strcat(p, "const ");
1053 else if (strstr(s, "data") != NULL)
1054 strcat(p, "data ");
1055 else
1056 strcat(p, " ");
1057 return r; /* we leak her but we do not care */
1058 } else {
1059 return "";
1060 }
1061}
1062
1063static int is_function(Elf_Sym *sym)
1064{
1065 if (sym)
1066 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1067 else
1068 return 0;
1069}
1070
1071/*
992 * Print a warning about a section mismatch. 1072 * Print a warning about a section mismatch.
993 * Try to find symbols near it so user can find it. 1073 * Try to find symbols near it so user can find it.
994 * Check whitelist before warning - it may be a false positive. 1074 * Check whitelist before warning - it may be a false positive.
995 */ 1075 */
996static void report_sec_mismatch(const char *modname, 1076static void report_sec_mismatch(const char *modname, enum mismatch mismatch,
997 const char *fromsec, 1077 const char *fromsec,
998 unsigned long long fromaddr, 1078 unsigned long long fromaddr,
999 const char *fromsym, 1079 const char *fromsym,
1000 const char *tosec, const char *tosym) 1080 int from_is_func,
1001{ 1081 const char *tosec, const char *tosym,
1002 if (strlen(tosym)) { 1082 int to_is_func)
1003 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " 1083{
1004 "in '%s'\n", 1084 const char *from, *from_p;
1005 modname, fromsec, fromaddr, 1085 const char *to, *to_p;
1006 tosec, tosym, fromsym); 1086 from = from_is_func ? "function" : "variable";
1007 } else { 1087 from_p = from_is_func ? "()" : "";
1008 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n", 1088 to = to_is_func ? "function" : "variable";
1009 modname, fromsec, fromaddr, 1089 to_p = to_is_func ? "()" : "";
1010 tosec, tosym); 1090
1091 fprintf(stderr, "WARNING: %s(%s+0x%llx): Section mismatch in"
1092 " reference from the %s %s%s to the %s %s:%s%s\n",
1093 modname, fromsec, fromaddr, from, fromsym, from_p,
1094 to, tosec, tosym, to_p);
1095
1096 sec_mismatch_count++;
1097 if (!sec_mismatch_verbose)
1098 return;
1099
1100 switch (mismatch) {
1101 case TEXT_TO_INIT:
1102 fprintf(stderr,
1103 "The function %s %s() references\n"
1104 "the %s %s%s%s.\n"
1105 "This is often because %s lacks a %s\n"
1106 "annotation or the annotation of %s is wrong.\n",
1107 sec2annotation(fromsec), fromsym,
1108 to, sec2annotation(tosec), tosym, to_p,
1109 fromsym, sec2annotation(tosec), tosym);
1110 break;
1111 case DATA_TO_INIT: {
1112 const char **s = symbol_white_list;
1113 fprintf(stderr,
1114 "The variable %s references\n"
1115 "the %s %s%s%s\n"
1116 "If the reference is valid then annotate the\n"
1117 "variable with __init* (see linux/init.h) "
1118 "or name the variable:\n",
1119 fromsym, to, sec2annotation(tosec), tosym, to_p);
1120 while (*s)
1121 fprintf(stderr, "%s, ", *s++);
1122 fprintf(stderr, "\n");
1123 break;
1011 } 1124 }
1125 case TEXT_TO_EXIT:
1126 fprintf(stderr,
1127 "The function %s() references a %s in an exit section.\n"
1128 "Often the %s %s%s has valid usage outside the exit section\n"
1129 "and the fix is to remove the %sannotation of %s.\n",
1130 fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
1131 break;
1132 case DATA_TO_EXIT: {
1133 const char **s = symbol_white_list;
1134 fprintf(stderr,
1135 "The variable %s references\n"
1136 "the %s %s%s%s\n"
1137 "If the reference is valid then annotate the\n"
1138 "variable with __exit* (see linux/init.h) or "
1139 "name the variable:\n",
1140 fromsym, to, sec2annotation(tosec), tosym, to_p);
1141 while (*s)
1142 fprintf(stderr, "%s, ", *s++);
1143 fprintf(stderr, "\n");
1144 break;
1145 }
1146 case XXXINIT_TO_INIT:
1147 case XXXEXIT_TO_EXIT:
1148 fprintf(stderr,
1149 "The %s %s%s%s references\n"
1150 "a %s %s%s%s.\n"
1151 "If %s is only used by %s then\n"
1152 "annotate %s with a matching annotation.\n",
1153 from, sec2annotation(fromsec), fromsym, from_p,
1154 to, sec2annotation(tosec), tosym, to_p,
1155 fromsym, tosym, fromsym);
1156 break;
1157 case INIT_TO_EXIT:
1158 fprintf(stderr,
1159 "The %s %s%s%s references\n"
1160 "a %s %s%s%s.\n"
1161 "This is often seen when error handling "
1162 "in the init function\n"
1163 "uses functionality in the exit path.\n"
1164 "The fix is often to remove the %sannotation of\n"
1165 "%s%s so it may be used outside an exit section.\n",
1166 from, sec2annotation(fromsec), fromsym, from_p,
1167 to, sec2annotation(tosec), tosym, to_p,
1168 sec2annotation(tosec), tosym, to_p);
1169 break;
1170 case EXIT_TO_INIT:
1171 fprintf(stderr,
1172 "The %s %s%s%s references\n"
1173 "a %s %s%s%s.\n"
1174 "This is often seen when error handling "
1175 "in the exit function\n"
1176 "uses functionality in the init path.\n"
1177 "The fix is often to remove the %sannotation of\n"
1178 "%s%s so it may be used outside an init section.\n",
1179 from, sec2annotation(fromsec), fromsym, from_p,
1180 to, sec2annotation(tosec), tosym, to_p,
1181 sec2annotation(tosec), tosym, to_p);
1182 break;
1183 case EXPORT_TO_INIT_EXIT:
1184 fprintf(stderr,
1185 "The symbol %s is exported and annotated %s\n"
1186 "Fix this by removing the %sannotation of %s "
1187 "or drop the export.\n",
1188 tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
1189 case NO_MISMATCH:
1190 /* To get warnings on missing members */
1191 break;
1192 }
1193 fprintf(stderr, "\n");
1012} 1194}
1013 1195
1014static void check_section_mismatch(const char *modname, struct elf_info *elf, 1196static void check_section_mismatch(const char *modname, struct elf_info *elf,
1015 Elf_Rela *r, Elf_Sym *sym, const char *fromsec) 1197 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1016{ 1198{
1017 const char *tosec; 1199 const char *tosec;
1200 enum mismatch mismatch;
1018 1201
1019 tosec = sec_name(elf, sym->st_shndx); 1202 tosec = sec_name(elf, sym->st_shndx);
1020 if (section_mismatch(fromsec, tosec)) { 1203 mismatch = section_mismatch(fromsec, tosec);
1021 const char *fromsym; 1204 if (mismatch != NO_MISMATCH) {
1205 Elf_Sym *to;
1206 Elf_Sym *from;
1022 const char *tosym; 1207 const char *tosym;
1208 const char *fromsym;
1023 1209
1024 fromsym = sym_name(elf, 1210 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1025 find_elf_symbol2(elf, r->r_offset, fromsec)); 1211 fromsym = sym_name(elf, from);
1026 tosym = sym_name(elf, 1212 to = find_elf_symbol(elf, r->r_addend, sym);
1027 find_elf_symbol(elf, r->r_addend, sym)); 1213 tosym = sym_name(elf, to);
1028 1214
1029 /* check whitelist - we may ignore it */ 1215 /* check whitelist - we may ignore it */
1030 if (secref_whitelist(fromsec, fromsym, tosec, tosym)) { 1216 if (secref_whitelist(fromsec, fromsym, tosec, tosym)) {
1031 report_sec_mismatch(modname, fromsec, r->r_offset, 1217 report_sec_mismatch(modname, mismatch,
1032 fromsym, tosec, tosym); 1218 fromsec, r->r_offset, fromsym,
1219 is_function(from), tosec, tosym,
1220 is_function(to));
1033 } 1221 }
1034 } 1222 }
1035} 1223}
@@ -1643,7 +1831,7 @@ int main(int argc, char **argv)
1643 int opt; 1831 int opt;
1644 int err; 1832 int err;
1645 1833
1646 while ((opt = getopt(argc, argv, "i:I:mso:aw")) != -1) { 1834 while ((opt = getopt(argc, argv, "i:I:msSo:aw")) != -1) {
1647 switch (opt) { 1835 switch (opt) {
1648 case 'i': 1836 case 'i':
1649 kernel_read = optarg; 1837 kernel_read = optarg;
@@ -1664,6 +1852,9 @@ int main(int argc, char **argv)
1664 case 's': 1852 case 's':
1665 vmlinux_section_warnings = 0; 1853 vmlinux_section_warnings = 0;
1666 break; 1854 break;
1855 case 'S':
1856 sec_mismatch_verbose = 0;
1857 break;
1667 case 'w': 1858 case 'w':
1668 warn_unresolved = 1; 1859 warn_unresolved = 1;
1669 break; 1860 break;
@@ -1708,6 +1899,12 @@ int main(int argc, char **argv)
1708 1899
1709 if (dump_write) 1900 if (dump_write)
1710 write_dump(dump_write); 1901 write_dump(dump_write);
1902 if (sec_mismatch_count && !sec_mismatch_verbose)
1903 fprintf(stderr, "modpost: Found %d section mismatch(es).\n"
1904 "To see additional details select \"Enable full "
1905 "Section mismatch analysis\"\n"
1906 "in the Kernel Hacking menu "
1907 "(CONFIG_SECTION_MISMATCH).\n", sec_mismatch_count);
1711 1908
1712 return err; 1909 return err;
1713} 1910}