X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=scripts%2Fmod%2Fmodpost.c;h=110cf243fa4e56d3749781c7b4703bf4c62ae9b7;hb=0c81eed4b9d6273124c7ab5eb99760b4d3a3cb9e;hp=696d2a59e4b8f06e89206099c0849042d9aef87c;hpb=df578e7d831b4d280bf7c621eafb737e78cd26eb;p=safe%2Fjmp%2Flinux-2.6 diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 696d2a5..110cf24 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -11,6 +11,8 @@ * Usage: modpost vmlinux module1.o module2.o ... */ +#define _GNU_SOURCE +#include #include #include "modpost.h" #include "../../include/linux/license.h" @@ -28,6 +30,9 @@ static int vmlinux_section_warnings = 1; /* Only warn about unresolved symbols */ static int warn_unresolved = 0; /* How a symbol is exported */ +static int sec_mismatch_count = 0; +static int sec_mismatch_verbose = 1; + enum export { export_plain, export_unused, export_gpl, export_unused_gpl, export_gpl_future, export_unknown @@ -432,6 +437,8 @@ static int parse_elf(struct elf_info *info, const char *filename) info->export_unused_gpl_sec = i; else if (strcmp(secname, "__ksymtab_gpl_future") == 0) info->export_gpl_future_sec = i; + else if (strcmp(secname, "__markers_strings") == 0) + info->markers_strings_sec = i; if (sechdrs[i].sh_type != SHT_SYMTAB) continue; @@ -605,52 +612,286 @@ static int strrcmp(const char *s, const char *sub) return memcmp(s + slen - sublen, sub, sublen); } -/* - * Functions used only during module init is marked __init and is stored in - * a .init.text section. Likewise data is marked __initdata and stored in - * a .init.data section. - * If this section is one of these sections return 1 - * See include/linux/init.h for the details +static const char *sym_name(struct elf_info *elf, Elf_Sym *sym) +{ + if (sym) + return elf->strtab + sym->st_name; + else + return "(unknown)"; +} + +static const char *sec_name(struct elf_info *elf, int shndx) +{ + Elf_Shdr *sechdrs = elf->sechdrs; + return (void *)elf->hdr + + elf->sechdrs[elf->hdr->e_shstrndx].sh_offset + + sechdrs[shndx].sh_name; +} + +static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) +{ + return (void *)elf->hdr + + elf->sechdrs[elf->hdr->e_shstrndx].sh_offset + + sechdr->sh_name; +} + +/* if sym is empty or point to a string + * like ".[0-9]+" then return 1. + * This is the optional prefix added by ld to some sections */ -static int init_section(const char *name) +static int number_prefix(const char *sym) { - if (strcmp(name, ".init") == 0) - return 1; - if (strncmp(name, ".init.", strlen(".init.")) == 0) + if (*sym++ == '\0') return 1; + if (*sym != '.') + return 0; + do { + char c = *sym++; + if (c < '0' || c > '9') + return 0; + } while (*sym); + return 1; +} + +/* The pattern is an array of simple patterns. + * "foo" will match an exact string equal to "foo" + * "*foo" will match a string that ends with "foo" + * "foo*" will match a string that begins with "foo" + * "foo$" will match a string equal to "foo" or "foo.1" + * where the '1' can be any number including several digits. + * The $ syntax is for sections where ld append a dot number + * to make section name unique. + */ +int match(const char *sym, const char * const pat[]) +{ + const char *p; + while (*pat) { + p = *pat++; + const char *endp = p + strlen(p) - 1; + + /* "*foo" */ + if (*p == '*') { + if (strrcmp(sym, p + 1) == 0) + return 1; + } + /* "foo*" */ + else if (*endp == '*') { + if (strncmp(sym, p, strlen(p) - 1) == 0) + return 1; + } + /* "foo$" */ + else if (*endp == '$') { + if (strncmp(sym, p, strlen(p) - 1) == 0) { + if (number_prefix(sym + strlen(p) - 1)) + return 1; + } + } + /* no wildcards */ + else { + if (strcmp(p, sym) == 0) + return 1; + } + } + /* no match */ return 0; } +/* sections that we do not want to do full section mismatch check on */ +static const char *section_white_list[] = + { ".debug*", ".stab*", ".note*", ".got*", ".toc*", NULL }; + /* - * Functions used only during module exit is marked __exit and is stored in - * a .exit.text section. Likewise data is marked __exitdata and stored in - * a .exit.data section. - * If this section is one of these sections return 1 - * See include/linux/init.h for the details - **/ -static int exit_section(const char *name) + * Is this section one we do not want to check? + * This is often debug sections. + * If we are going to check this section then + * test if section name ends with a dot and a number. + * This is used to find sections where the linker have + * appended a dot-number to make the name unique. + * The cause of this is often a section specified in assembler + * without "ax" / "aw" and the same section used in .c + * code where gcc add these. + */ +static int check_section(const char *modname, const char *sec) { - if (strcmp(name, ".exit.text") == 0) - return 1; - if (strcmp(name, ".exit.data") == 0) + const char *e = sec + strlen(sec) - 1; + if (match(sec, section_white_list)) return 1; - return 0; + if (*e && isdigit(*e)) { + /* consume all digits */ + while (*e && e != sec && isdigit(*e)) + e--; + if (*e == '.') { + warn("%s (%s): unexpected section name.\n" + "The (.[number]+) following section name are " + "ld generated and not expected.\n" + "Did you forget to use \"ax\"/\"aw\" " + "in a .S file?\n" + "Note that for example contains\n" + "section definitions for use in .S files.\n\n", + modname, sec); + } + } + return 0; } -/* - * Data sections are named like this: - * .data | .data.rel | .data.rel.* - * Return 1 if the specified section is a data section + + +#define ALL_INIT_DATA_SECTIONS \ + ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$" +#define ALL_EXIT_DATA_SECTIONS \ + ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$" + +#define ALL_INIT_TEXT_SECTIONS \ + ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$" +#define ALL_EXIT_TEXT_SECTIONS \ + ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$" + +#define ALL_INIT_SECTIONS ALL_INIT_DATA_SECTIONS, ALL_INIT_TEXT_SECTIONS +#define ALL_EXIT_SECTIONS ALL_EXIT_DATA_SECTIONS, ALL_EXIT_TEXT_SECTIONS + +#define DATA_SECTIONS ".data$", ".data.rel$" +#define TEXT_SECTIONS ".text$" + +#define INIT_SECTIONS ".init.data$", ".init.text$" +#define DEV_INIT_SECTIONS ".devinit.data$", ".devinit.text$" +#define CPU_INIT_SECTIONS ".cpuinit.data$", ".cpuinit.text$" +#define MEM_INIT_SECTIONS ".meminit.data$", ".meminit.text$" + +#define EXIT_SECTIONS ".exit.data$", ".exit.text$" +#define DEV_EXIT_SECTIONS ".devexit.data$", ".devexit.text$" +#define CPU_EXIT_SECTIONS ".cpuexit.data$", ".cpuexit.text$" +#define MEM_EXIT_SECTIONS ".memexit.data$", ".memexit.text$" + +/* init data sections */ +static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL }; + +/* all init sections */ +static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL }; + +/* All init and exit sections (code + data) */ +static const char *init_exit_sections[] = + {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL }; + +/* data section */ +static const char *data_sections[] = { DATA_SECTIONS, NULL }; + +/* sections that may refer to an init/exit section with no warning */ +static const char *initref_sections[] = +{ + ".text.init.refok*", + ".exit.text.refok*", + ".data.init.refok*", + NULL +}; + + +/* symbols in .data that may refer to init/exit sections */ +static const char *symbol_white_list[] = +{ + "*driver", + "*_template", /* scsi uses *_template a lot */ + "*_timer", /* arm uses ops structures named _timer a lot */ + "*_sht", /* scsi also used *_sht to some extent */ + "*_ops", + "*_probe", + "*_probe_one", + "*_console", + NULL +}; + +static const char *head_sections[] = { ".head.text*", NULL }; +static const char *linker_symbols[] = + { "__init_begin", "_sinittext", "_einittext", NULL }; + +enum mismatch { + NO_MISMATCH, + TEXT_TO_INIT, + DATA_TO_INIT, + TEXT_TO_EXIT, + DATA_TO_EXIT, + XXXINIT_TO_INIT, + XXXEXIT_TO_EXIT, + INIT_TO_EXIT, + EXIT_TO_INIT, + EXPORT_TO_INIT_EXIT, +}; + +struct sectioncheck { + const char *fromsec[20]; + const char *tosec[20]; + enum mismatch mismatch; +}; + +const struct sectioncheck sectioncheck[] = { +/* Do not reference init/exit code/data from + * normal code and data */ -static int data_section(const char *name) { - if ((strcmp(name, ".data") == 0) || - (strcmp(name, ".data.rel") == 0) || - (strncmp(name, ".data.rel.", strlen(".data.rel.")) == 0)) - return 1; - else - return 0; + .fromsec = { TEXT_SECTIONS, NULL }, + .tosec = { ALL_INIT_SECTIONS, NULL }, + .mismatch = TEXT_TO_INIT, +}, +{ + .fromsec = { DATA_SECTIONS, NULL }, + .tosec = { ALL_INIT_SECTIONS, NULL }, + .mismatch = DATA_TO_INIT, +}, +{ + .fromsec = { TEXT_SECTIONS, NULL }, + .tosec = { ALL_EXIT_SECTIONS, NULL }, + .mismatch = TEXT_TO_EXIT, +}, +{ + .fromsec = { DATA_SECTIONS, NULL }, + .tosec = { ALL_EXIT_SECTIONS, NULL }, + .mismatch = DATA_TO_EXIT, +}, +/* Do not reference init code/data from devinit/cpuinit/meminit code/data */ +{ + .fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL }, + .tosec = { INIT_SECTIONS, NULL }, + .mismatch = XXXINIT_TO_INIT, +}, +/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */ +{ + .fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL }, + .tosec = { EXIT_SECTIONS, NULL }, + .mismatch = XXXEXIT_TO_EXIT, +}, +/* Do not use exit code/data from init code */ +{ + .fromsec = { ALL_INIT_SECTIONS, NULL }, + .tosec = { ALL_EXIT_SECTIONS, NULL }, + .mismatch = INIT_TO_EXIT, +}, +/* Do not use init code/data from exit code */ +{ + .fromsec = { ALL_EXIT_SECTIONS, NULL }, + .tosec = { ALL_INIT_SECTIONS, NULL }, + .mismatch = EXIT_TO_INIT, +}, +/* Do not export init/exit functions or data */ +{ + .fromsec = { "__ksymtab*", NULL }, + .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL }, + .mismatch = EXPORT_TO_INIT_EXIT +} +}; + +static int section_mismatch(const char *fromsec, const char *tosec) +{ + int i; + int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck); + const struct sectioncheck *check = §ioncheck[0]; + + for (i = 0; i < elems; i++) { + if (match(fromsec, check->fromsec) && + match(tosec, check->tosec)) + return check->mismatch; + check++; + } + return NO_MISMATCH; } /** @@ -695,78 +936,36 @@ static int data_section(const char *name) * This pattern is identified by * refsymname = __init_begin, _sinittext, _einittext * - * Pattern 5: - * Xtensa uses literal sections for constants that are accessed PC-relative. - * Literal sections may safely reference their text sections. - * (Note that the name for the literal section omits any trailing '.text') - * tosec =
[.text] - * fromsec =
.literal **/ -static int secref_whitelist(const char *modname, const char *tosec, - const char *fromsec, const char *atsym, - const char *refsymname) +static int secref_whitelist(const char *fromsec, const char *fromsym, + const char *tosec, const char *tosym) { - int len; - const char **s; - const char *pat2sym[] = { - "driver", - "_template", /* scsi uses *_template a lot */ - "_timer", /* arm uses ops structures named _timer a lot */ - "_sht", /* scsi also used *_sht to some extent */ - "_ops", - "_probe", - "_probe_one", - "_console", - NULL - }; - - const char *pat3refsym[] = { - "__init_begin", - "_sinittext", - "_einittext", - NULL - }; - /* Check for pattern 0 */ - if ((strncmp(fromsec, ".text.init.refok", strlen(".text.init.refok")) == 0) || - (strncmp(fromsec, ".exit.text.refok", strlen(".exit.text.refok")) == 0) || - (strncmp(fromsec, ".data.init.refok", strlen(".data.init.refok")) == 0)) - return 1; + if (match(fromsec, initref_sections)) + return 0; /* Check for pattern 1 */ - if ((strcmp(tosec, ".init.data") == 0) && - (strncmp(fromsec, ".data", strlen(".data")) == 0) && - (strncmp(atsym, "__param", strlen("__param")) == 0)) - return 1; + if (match(tosec, init_data_sections) && + match(fromsec, data_sections) && + (strncmp(fromsym, "__param", strlen("__param")) == 0)) + return 0; /* Check for pattern 2 */ - if ((init_section(tosec) || exit_section(tosec)) - && data_section(fromsec)) - for (s = pat2sym; *s; s++) - if (strrcmp(atsym, *s) == 0) - return 1; + if (match(tosec, init_exit_sections) && + match(fromsec, data_sections) && + match(fromsym, symbol_white_list)) + return 0; /* Check for pattern 3 */ - if ((strcmp(fromsec, ".text.head") == 0) && - ((strcmp(tosec, ".init.data") == 0) || - (strcmp(tosec, ".init.text") == 0))) - return 1; + if (match(fromsec, head_sections) && + match(tosec, init_sections)) + return 0; /* Check for pattern 4 */ - for (s = pat3refsym; *s; s++) - if (strcmp(refsymname, *s) == 0) - return 1; - - /* Check for pattern 5 */ - if (strrcmp(tosec, ".text") == 0) - len = strlen(tosec) - strlen(".text"); - else - len = strlen(tosec); - if ((strncmp(tosec, fromsec, len) == 0) && (strlen(fromsec) > len) && - (strcmp(fromsec + len, ".literal") == 0)) - return 1; + if (match(tosym, linker_symbols)) + return 0; - return 0; + return 1; } /** @@ -776,10 +975,13 @@ static int secref_whitelist(const char *modname, const char *tosec, * In other cases the symbol needs to be looked up in the symbol table * based on section and address. * **/ -static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, +static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, Elf_Sym *relsym) { Elf_Sym *sym; + Elf_Sym *near = NULL; + Elf64_Sword distance = 20; + Elf64_Sword d; if (relsym->st_name != 0) return relsym; @@ -790,8 +992,20 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, continue; if (sym->st_value == addr) return sym; + /* Find a symbol nearby - addr are maybe negative */ + d = sym->st_value - addr; + if (d < 0) + d = addr - sym->st_value; + if (d < distance) { + distance = d; + near = sym; + } } - return NULL; + /* We need a close match */ + if (distance < 20) + return near; + else + return NULL; } static inline int is_arm_mapping_symbol(const char *str) @@ -824,117 +1038,252 @@ static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) * The ELF format may have a better way to detect what type of symbol * it is, but this works for now. **/ -static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, - const char *sec, - Elf_Sym **before, Elf_Sym **after) +static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr, + const char *sec) { Elf_Sym *sym; - Elf_Ehdr *hdr = elf->hdr; - Elf_Addr beforediff = ~0; - Elf_Addr afterdiff = ~0; - const char *secstrings = (void *)hdr + - elf->sechdrs[hdr->e_shstrndx].sh_offset; - - *before = NULL; - *after = NULL; + Elf_Sym *near = NULL; + Elf_Addr distance = ~0; for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { const char *symsec; if (sym->st_shndx >= SHN_LORESERVE) continue; - symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; + symsec = sec_name(elf, sym->st_shndx); if (strcmp(symsec, sec) != 0) continue; if (!is_valid_name(elf, sym)) continue; if (sym->st_value <= addr) { - if ((addr - sym->st_value) < beforediff) { - beforediff = addr - sym->st_value; - *before = sym; - } else if ((addr - sym->st_value) == beforediff) { - *before = sym; + if ((addr - sym->st_value) < distance) { + distance = addr - sym->st_value; + near = sym; + } else if ((addr - sym->st_value) == distance) { + near = sym; } - } else { - if ((sym->st_value - addr) < afterdiff) { - afterdiff = sym->st_value - addr; - *after = sym; - } else if ((sym->st_value - addr) == afterdiff) - *after = sym; } } + return near; } -/** +/* + * Convert a section name to the function/data attribute + * .init.text => __init + * .cpuinit.data => __cpudata + * .memexitconst => __memconst + * etc. +*/ +static char *sec2annotation(const char *s) +{ + if (match(s, init_exit_sections)) { + char *p = malloc(20); + char *r = p; + + *p++ = '_'; + *p++ = '_'; + if (*s == '.') + s++; + while (*s && *s != '.') + *p++ = *s++; + *p = '\0'; + if (*s == '.') + s++; + if (strstr(s, "rodata") != NULL) + strcat(p, "const "); + else if (strstr(s, "data") != NULL) + strcat(p, "data "); + else + strcat(p, " "); + return r; /* we leak her but we do not care */ + } else { + return ""; + } +} + +static int is_function(Elf_Sym *sym) +{ + if (sym) + return ELF_ST_TYPE(sym->st_info) == STT_FUNC; + else + return -1; +} + +/* * Print a warning about a section mismatch. * Try to find symbols near it so user can find it. * Check whitelist before warning - it may be a false positive. - **/ -static void warn_sec_mismatch(const char *modname, const char *fromsec, - struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) + */ +static void report_sec_mismatch(const char *modname, enum mismatch mismatch, + const char *fromsec, + unsigned long long fromaddr, + const char *fromsym, + int from_is_func, + const char *tosec, const char *tosym, + int to_is_func) { - const char *refsymname = ""; - Elf_Sym *before, *after; - Elf_Sym *refsym; - Elf_Ehdr *hdr = elf->hdr; - Elf_Shdr *sechdrs = elf->sechdrs; - const char *secstrings = (void *)hdr + - sechdrs[hdr->e_shstrndx].sh_offset; - const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; + const char *from, *from_p; + const char *to, *to_p; - find_symbols_between(elf, r.r_offset, fromsec, &before, &after); - - refsym = find_elf_symbol(elf, r.r_addend, sym); - if (refsym && strlen(elf->strtab + refsym->st_name)) - refsymname = elf->strtab + refsym->st_name; + switch (from_is_func) { + case 0: from = "variable"; from_p = ""; break; + case 1: from = "function"; from_p = "()"; break; + default: from = "(unknown reference)"; from_p = ""; break; + } + switch (to_is_func) { + case 0: to = "variable"; to_p = ""; break; + case 1: to = "function"; to_p = "()"; break; + default: to = "(unknown reference)"; to_p = ""; break; + } - /* check whitelist - we may ignore it */ - if (secref_whitelist(modname, secname, fromsec, - before ? elf->strtab + before->st_name : "", - refsymname)) + sec_mismatch_count++; + if (!sec_mismatch_verbose) return; - if (before && after) { - warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " - "(between '%s' and '%s')\n", - modname, fromsec, (unsigned long long)r.r_offset, - secname, refsymname, - elf->strtab + before->st_name, - elf->strtab + after->st_name); - } else if (before) { - warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " - "(after '%s')\n", - modname, fromsec, (unsigned long long)r.r_offset, - secname, refsymname, - elf->strtab + before->st_name); - } else if (after) { - warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s " - "before '%s' (at offset -0x%llx)\n", - modname, fromsec, (unsigned long long)r.r_offset, - secname, refsymname, - elf->strtab + after->st_name, - (unsigned long long)r.r_offset); - } else { - warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n", - modname, fromsec, (unsigned long long)r.r_offset, - secname, refsymname); + warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s " + "to the %s %s:%s%s\n", + modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec, + tosym, to_p); + + switch (mismatch) { + case TEXT_TO_INIT: + fprintf(stderr, + "The function %s%s() references\n" + "the %s %s%s%s.\n" + "This is often because %s lacks a %s\n" + "annotation or the annotation of %s is wrong.\n", + sec2annotation(fromsec), fromsym, + to, sec2annotation(tosec), tosym, to_p, + fromsym, sec2annotation(tosec), tosym); + break; + case DATA_TO_INIT: { + const char **s = symbol_white_list; + fprintf(stderr, + "The variable %s references\n" + "the %s %s%s%s\n" + "If the reference is valid then annotate the\n" + "variable with __init* (see linux/init.h) " + "or name the variable:\n", + fromsym, to, sec2annotation(tosec), tosym, to_p); + while (*s) + fprintf(stderr, "%s, ", *s++); + fprintf(stderr, "\n"); + break; + } + case TEXT_TO_EXIT: + fprintf(stderr, + "The function %s() references a %s in an exit section.\n" + "Often the %s %s%s has valid usage outside the exit section\n" + "and the fix is to remove the %sannotation of %s.\n", + fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym); + break; + case DATA_TO_EXIT: { + const char **s = symbol_white_list; + fprintf(stderr, + "The variable %s references\n" + "the %s %s%s%s\n" + "If the reference is valid then annotate the\n" + "variable with __exit* (see linux/init.h) or " + "name the variable:\n", + fromsym, to, sec2annotation(tosec), tosym, to_p); + while (*s) + fprintf(stderr, "%s, ", *s++); + fprintf(stderr, "\n"); + break; + } + case XXXINIT_TO_INIT: + case XXXEXIT_TO_EXIT: + fprintf(stderr, + "The %s %s%s%s references\n" + "a %s %s%s%s.\n" + "If %s is only used by %s then\n" + "annotate %s with a matching annotation.\n", + from, sec2annotation(fromsec), fromsym, from_p, + to, sec2annotation(tosec), tosym, to_p, + tosym, fromsym, tosym); + break; + case INIT_TO_EXIT: + fprintf(stderr, + "The %s %s%s%s references\n" + "a %s %s%s%s.\n" + "This is often seen when error handling " + "in the init function\n" + "uses functionality in the exit path.\n" + "The fix is often to remove the %sannotation of\n" + "%s%s so it may be used outside an exit section.\n", + from, sec2annotation(fromsec), fromsym, from_p, + to, sec2annotation(tosec), tosym, to_p, + sec2annotation(tosec), tosym, to_p); + break; + case EXIT_TO_INIT: + fprintf(stderr, + "The %s %s%s%s references\n" + "a %s %s%s%s.\n" + "This is often seen when error handling " + "in the exit function\n" + "uses functionality in the init path.\n" + "The fix is often to remove the %sannotation of\n" + "%s%s so it may be used outside an init section.\n", + from, sec2annotation(fromsec), fromsym, from_p, + to, sec2annotation(tosec), tosym, to_p, + sec2annotation(tosec), tosym, to_p); + break; + case EXPORT_TO_INIT_EXIT: + fprintf(stderr, + "The symbol %s is exported and annotated %s\n" + "Fix this by removing the %sannotation of %s " + "or drop the export.\n", + tosym, sec2annotation(tosec), sec2annotation(tosec), tosym); + case NO_MISMATCH: + /* To get warnings on missing members */ + break; + } + fprintf(stderr, "\n"); +} + +static void check_section_mismatch(const char *modname, struct elf_info *elf, + Elf_Rela *r, Elf_Sym *sym, const char *fromsec) +{ + const char *tosec; + enum mismatch mismatch; + + tosec = sec_name(elf, sym->st_shndx); + mismatch = section_mismatch(fromsec, tosec); + if (mismatch != NO_MISMATCH) { + Elf_Sym *to; + Elf_Sym *from; + const char *tosym; + const char *fromsym; + + from = find_elf_symbol2(elf, r->r_offset, fromsec); + fromsym = sym_name(elf, from); + to = find_elf_symbol(elf, r->r_addend, sym); + tosym = sym_name(elf, to); + + /* check whitelist - we may ignore it */ + if (secref_whitelist(fromsec, fromsym, tosec, tosym)) { + report_sec_mismatch(modname, mismatch, + fromsec, r->r_offset, fromsym, + is_function(from), tosec, tosym, + is_function(to)); + } } } static unsigned int *reloc_location(struct elf_info *elf, - int rsection, Elf_Rela *r) + Elf_Shdr *sechdr, Elf_Rela *r) { Elf_Shdr *sechdrs = elf->sechdrs; - int section = sechdrs[rsection].sh_info; + int section = sechdr->sh_info; return (void *)elf->hdr + sechdrs[section].sh_offset + (r->r_offset - sechdrs[section].sh_addr); } -static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r) +static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) { unsigned int r_typ = ELF_R_TYPE(r->r_info); - unsigned int *location = reloc_location(elf, rsection, r); + unsigned int *location = reloc_location(elf, sechdr, r); switch (r_typ) { case R_386_32: @@ -950,7 +1299,7 @@ static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r) return 0; } -static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r) +static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) { unsigned int r_typ = ELF_R_TYPE(r->r_info); @@ -963,8 +1312,8 @@ static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r) case R_ARM_PC24: /* From ARM ABI: ((S + A) | T) - P */ r->r_addend = (int)(long)(elf->hdr + - elf->sechdrs[rsection].sh_offset + - (r->r_offset - elf->sechdrs[rsection].sh_addr)); + sechdr->sh_offset + + (r->r_offset - sechdr->sh_addr)); break; default: return 1; @@ -972,10 +1321,10 @@ static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r) return 0; } -static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r) +static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) { unsigned int r_typ = ELF_R_TYPE(r->r_info); - unsigned int *location = reloc_location(elf, rsection, r); + unsigned int *location = reloc_location(elf, sechdr, r); unsigned int inst; if (r_typ == R_MIPS_HI16) @@ -995,6 +1344,108 @@ static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r) return 0; } +static void section_rela(const char *modname, struct elf_info *elf, + Elf_Shdr *sechdr) +{ + Elf_Sym *sym; + Elf_Rela *rela; + Elf_Rela r; + unsigned int r_sym; + const char *fromsec; + + Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset; + Elf_Rela *stop = (void *)start + sechdr->sh_size; + + fromsec = sech_name(elf, sechdr); + fromsec += strlen(".rela"); + /* if from section (name) is know good then skip it */ + if (check_section(modname, fromsec)) + return; + + for (rela = start; rela < stop; rela++) { + r.r_offset = TO_NATIVE(rela->r_offset); +#if KERNEL_ELFCLASS == ELFCLASS64 + if (elf->hdr->e_machine == EM_MIPS) { + unsigned int r_typ; + r_sym = ELF64_MIPS_R_SYM(rela->r_info); + r_sym = TO_NATIVE(r_sym); + r_typ = ELF64_MIPS_R_TYPE(rela->r_info); + r.r_info = ELF64_R_INFO(r_sym, r_typ); + } else { + r.r_info = TO_NATIVE(rela->r_info); + r_sym = ELF_R_SYM(r.r_info); + } +#else + r.r_info = TO_NATIVE(rela->r_info); + r_sym = ELF_R_SYM(r.r_info); +#endif + r.r_addend = TO_NATIVE(rela->r_addend); + sym = elf->symtab_start + r_sym; + /* Skip special sections */ + if (sym->st_shndx >= SHN_LORESERVE) + continue; + check_section_mismatch(modname, elf, &r, sym, fromsec); + } +} + +static void section_rel(const char *modname, struct elf_info *elf, + Elf_Shdr *sechdr) +{ + Elf_Sym *sym; + Elf_Rel *rel; + Elf_Rela r; + unsigned int r_sym; + const char *fromsec; + + Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset; + Elf_Rel *stop = (void *)start + sechdr->sh_size; + + fromsec = sech_name(elf, sechdr); + fromsec += strlen(".rel"); + /* if from section (name) is know good then skip it */ + if (check_section(modname, fromsec)) + return; + + for (rel = start; rel < stop; rel++) { + r.r_offset = TO_NATIVE(rel->r_offset); +#if KERNEL_ELFCLASS == ELFCLASS64 + if (elf->hdr->e_machine == EM_MIPS) { + unsigned int r_typ; + r_sym = ELF64_MIPS_R_SYM(rel->r_info); + r_sym = TO_NATIVE(r_sym); + r_typ = ELF64_MIPS_R_TYPE(rel->r_info); + r.r_info = ELF64_R_INFO(r_sym, r_typ); + } else { + r.r_info = TO_NATIVE(rel->r_info); + r_sym = ELF_R_SYM(r.r_info); + } +#else + r.r_info = TO_NATIVE(rel->r_info); + r_sym = ELF_R_SYM(r.r_info); +#endif + r.r_addend = 0; + switch (elf->hdr->e_machine) { + case EM_386: + if (addend_386_rel(elf, sechdr, &r)) + continue; + break; + case EM_ARM: + if (addend_arm_rel(elf, sechdr, &r)) + continue; + break; + case EM_MIPS: + if (addend_mips_rel(elf, sechdr, &r)) + continue; + break; + } + sym = elf->symtab_start + r_sym; + /* Skip special sections */ + if (sym->st_shndx >= SHN_LORESERVE) + continue; + check_section_mismatch(modname, elf, &r, sym, fromsec); + } +} + /** * A module includes a number of sections that are discarded * either when loaded or when used as built-in. @@ -1008,256 +1459,75 @@ static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r) * be discarded and warns about it. **/ static void check_sec_ref(struct module *mod, const char *modname, - struct elf_info *elf, - int section(const char *), - int section_ref_ok(const char *)) + struct elf_info *elf) { int i; - Elf_Sym *sym; - Elf_Ehdr *hdr = elf->hdr; Elf_Shdr *sechdrs = elf->sechdrs; - const char *secstrings = (void *)hdr + - sechdrs[hdr->e_shstrndx].sh_offset; /* Walk through all sections */ - for (i = 0; i < hdr->e_shnum; i++) { - const char *name = secstrings + sechdrs[i].sh_name; - const char *secname; - Elf_Rela r; - unsigned int r_sym; + for (i = 0; i < elf->hdr->e_shnum; i++) { /* We want to process only relocation sections and not .init */ - if (sechdrs[i].sh_type == SHT_RELA) { - Elf_Rela *rela; - Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; - Elf_Rela *stop = (void *)start + sechdrs[i].sh_size; - name += strlen(".rela"); - if (section_ref_ok(name)) - continue; - - for (rela = start; rela < stop; rela++) { - r.r_offset = TO_NATIVE(rela->r_offset); -#if KERNEL_ELFCLASS == ELFCLASS64 - if (hdr->e_machine == EM_MIPS) { - unsigned int r_typ; - r_sym = ELF64_MIPS_R_SYM(rela->r_info); - r_sym = TO_NATIVE(r_sym); - r_typ = ELF64_MIPS_R_TYPE(rela->r_info); - r.r_info = ELF64_R_INFO(r_sym, r_typ); - } else { - r.r_info = TO_NATIVE(rela->r_info); - r_sym = ELF_R_SYM(r.r_info); - } -#else - r.r_info = TO_NATIVE(rela->r_info); - r_sym = ELF_R_SYM(r.r_info); -#endif - r.r_addend = TO_NATIVE(rela->r_addend); - sym = elf->symtab_start + r_sym; - /* Skip special sections */ - if (sym->st_shndx >= SHN_LORESERVE) - continue; - - secname = secstrings + - sechdrs[sym->st_shndx].sh_name; - if (section(secname)) - warn_sec_mismatch(modname, name, - elf, sym, r); - } - } else if (sechdrs[i].sh_type == SHT_REL) { - Elf_Rel *rel; - Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; - Elf_Rel *stop = (void *)start + sechdrs[i].sh_size; - name += strlen(".rel"); - if (section_ref_ok(name)) - continue; - - for (rel = start; rel < stop; rel++) { - r.r_offset = TO_NATIVE(rel->r_offset); -#if KERNEL_ELFCLASS == ELFCLASS64 - if (hdr->e_machine == EM_MIPS) { - unsigned int r_typ; - r_sym = ELF64_MIPS_R_SYM(rel->r_info); - r_sym = TO_NATIVE(r_sym); - r_typ = ELF64_MIPS_R_TYPE(rel->r_info); - r.r_info = ELF64_R_INFO(r_sym, r_typ); - } else { - r.r_info = TO_NATIVE(rel->r_info); - r_sym = ELF_R_SYM(r.r_info); - } -#else - r.r_info = TO_NATIVE(rel->r_info); - r_sym = ELF_R_SYM(r.r_info); -#endif - r.r_addend = 0; - switch (hdr->e_machine) { - case EM_386: - if (addend_386_rel(elf, i, &r)) - continue; - break; - case EM_ARM: - if (addend_arm_rel(elf, i, &r)) - continue; - break; - case EM_MIPS: - if (addend_mips_rel(elf, i, &r)) - continue; - break; - } - sym = elf->symtab_start + r_sym; - /* Skip special sections */ - if (sym->st_shndx >= SHN_LORESERVE) - continue; - - secname = secstrings + - sechdrs[sym->st_shndx].sh_name; - if (section(secname)) - warn_sec_mismatch(modname, name, - elf, sym, r); - } - } + if (sechdrs[i].sh_type == SHT_RELA) + section_rela(modname, elf, &elf->sechdrs[i]); + else if (sechdrs[i].sh_type == SHT_REL) + section_rel(modname, elf, &elf->sechdrs[i]); } } -/* - * Identify sections from which references to either a - * .init or a .exit section is OK. - * - * [OPD] Keith Ownes commented: - * For our future {in}sanity, add a comment that this is the ppc .opd - * section, not the ia64 .opd section. - * ia64 .opd should not point to discarded sections. - * [.rodata] like for .init.text we ignore .rodata references -same reason - */ -static int initexit_section_ref_ok(const char *name) -{ - const char **s; - /* Absolute section names */ - const char *namelist1[] = { - "__bug_table", /* used by powerpc for BUG() */ - "__ex_table", - ".altinstructions", - ".cranges", /* used by sh64 */ - ".fixup", - ".machvec", /* ia64 + powerpc uses these */ - ".machine.desc", - ".opd", /* See comment [OPD] */ - "__dbe_table", - ".parainstructions", - ".pdr", - ".plt", /* seen on ARCH=um build on x86_64. Harmless */ - ".smp_locks", - ".stab", - ".m68k_fixup", - ".xt.prop", /* xtensa informational section */ - ".xt.lit", /* xtensa informational section */ - NULL - }; - /* Start of section names */ - const char *namelist2[] = { - ".debug", - ".eh_frame", - ".note", /* ignore ELF notes - may contain anything */ - ".got", /* powerpc - global offset table */ - ".toc", /* powerpc - table of contents */ - NULL - }; - /* part of section name */ - const char *namelist3 [] = { - ".unwind", /* Sample: IA_64.unwind.exit.text */ - NULL - }; - - for (s = namelist1; *s; s++) - if (strcmp(*s, name) == 0) - return 1; - for (s = namelist2; *s; s++) - if (strncmp(*s, name, strlen(*s)) == 0) - return 1; - for (s = namelist3; *s; s++) - if (strstr(name, *s) != NULL) - return 1; - return 0; -} - - -/* - * Identify sections from which references to a .init section is OK. - * - * Unfortunately references to read only data that referenced .init - * sections had to be excluded. Almost all of these are false - * positives, they are created by gcc. The downside of excluding rodata - * is that there really are some user references from rodata to - * init code, e.g. drivers/video/vgacon.c: - * - * const struct consw vga_con = { - * con_startup: vgacon_startup, - * - * where vgacon_startup is __init. If you want to wade through the false - * positives, take out the check for rodata. - */ -static int init_section_ref_ok(const char *name) -{ - const char **s; - /* Absolute section names */ - const char *namelist1[] = { - "__dbe_table", /* MIPS generate these */ - "__ftr_fixup", /* powerpc cpu feature fixup */ - "__fw_ftr_fixup", /* powerpc firmware feature fixup */ - "__param", - ".data.rel.ro", /* used by parisc64 */ - ".init", - ".text.lock", - NULL - }; - /* Start of section names */ - const char *namelist2[] = { - ".init.", - ".pci_fixup", - ".rodata", - NULL - }; - - if (initexit_section_ref_ok(name)) - return 1; +static void get_markers(struct elf_info *info, struct module *mod) +{ + const Elf_Shdr *sh = &info->sechdrs[info->markers_strings_sec]; + const char *strings = (const char *) info->hdr + sh->sh_offset; + const Elf_Sym *sym, *first_sym, *last_sym; + size_t n; - for (s = namelist1; *s; s++) - if (strcmp(*s, name) == 0) - return 1; - for (s = namelist2; *s; s++) - if (strncmp(*s, name, strlen(*s)) == 0) - return 1; + if (!info->markers_strings_sec) + return; - /* If section name ends with ".init" we allow references - * as is the case with .initcallN.init, .early_param.init, - * .taglist.init etc + /* + * First count the strings. We look for all the symbols defined + * in the __markers_strings section named __mstrtab_*. For + * these local names, the compiler puts a random .NNN suffix on, + * so the names don't correspond exactly. */ - if (strrcmp(name, ".init") == 0) - return 1; - return 0; -} + first_sym = last_sym = NULL; + n = 0; + for (sym = info->symtab_start; sym < info->symtab_stop; sym++) + if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT && + sym->st_shndx == info->markers_strings_sec && + !strncmp(info->strtab + sym->st_name, + "__mstrtab_", sizeof "__mstrtab_" - 1)) { + if (first_sym == NULL) + first_sym = sym; + last_sym = sym; + ++n; + } -/* - * Identify sections from which references to a .exit section is OK. - */ -static int exit_section_ref_ok(const char *name) -{ - const char **s; - /* Absolute section names */ - const char *namelist1[] = { - ".exit.data", - ".exit.text", - ".exitcall.exit", - ".rodata", - NULL - }; - - if (initexit_section_ref_ok(name)) - return 1; + if (n == 0) + return; - for (s = namelist1; *s; s++) - if (strcmp(*s, name) == 0) - return 1; - return 0; + /* + * Now collect each name and format into a line for the output. + * Lines look like: + * marker_name vmlinux marker %s format %d + * The format string after the second \t can use whitespace. + */ + mod->markers = NOFAIL(malloc(sizeof mod->markers[0] * n)); + mod->nmarkers = n; + + n = 0; + for (sym = first_sym; sym <= last_sym; sym++) + if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT && + sym->st_shndx == info->markers_strings_sec && + !strncmp(info->strtab + sym->st_name, + "__mstrtab_", sizeof "__mstrtab_" - 1)) { + const char *name = strings + sym->st_value; + const char *fmt = strchr(name, '\0') + 1; + char *line = NULL; + asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt); + NOFAIL(line); + mod->markers[n++] = line; + } } static void read_symbols(char *modname) @@ -1299,10 +1569,9 @@ static void read_symbols(char *modname) handle_modversions(mod, &info, sym, symname); handle_moddevtable(mod, &info, sym, symname); } - if (is_vmlinux(modname) && vmlinux_section_warnings) { - check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); - check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); - } + if (!is_vmlinux(modname) || + (is_vmlinux(modname) && vmlinux_section_warnings)) + check_sec_ref(mod, modname, &info); version = get_modinfo(info.modinfo, info.modinfo_len, "version"); if (version) @@ -1312,6 +1581,8 @@ static void read_symbols(char *modname) get_src_version(modname, mod->srcversion, sizeof(mod->srcversion)-1); + get_markers(&info, mod); + parse_elf_finish(&info); /* Our trick to get versioning for struct_module - it's @@ -1469,7 +1740,7 @@ static int add_versions(struct buffer *b, struct module *mod) buf_printf(b, "\n"); buf_printf(b, "static const struct modversion_info ____versions[]\n"); - buf_printf(b, "__attribute_used__\n"); + buf_printf(b, "__used\n"); buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); for (s = mod->unres; s; s = s->next) { @@ -1500,7 +1771,7 @@ static void add_depends(struct buffer *b, struct module *mod, buf_printf(b, "\n"); buf_printf(b, "static const char __module_depends[]\n"); - buf_printf(b, "__attribute_used__\n"); + buf_printf(b, "__used\n"); buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); buf_printf(b, "\"depends="); for (s = mod->unres; s; s = s->next) { @@ -1658,16 +1929,104 @@ static void write_dump(const char *fname) write_if_changed(&buf, fname); } +static void add_marker(struct module *mod, const char *name, const char *fmt) +{ + char *line = NULL; + asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt); + NOFAIL(line); + + mod->markers = NOFAIL(realloc(mod->markers, ((mod->nmarkers + 1) * + sizeof mod->markers[0]))); + mod->markers[mod->nmarkers++] = line; +} + +static void read_markers(const char *fname) +{ + unsigned long size, pos = 0; + void *file = grab_file(fname, &size); + char *line; + + if (!file) /* No old markers, silently ignore */ + return; + + while ((line = get_next_line(&pos, file, size))) { + char *marker, *modname, *fmt; + struct module *mod; + + marker = line; + modname = strchr(marker, '\t'); + if (!modname) + goto fail; + *modname++ = '\0'; + fmt = strchr(modname, '\t'); + if (!fmt) + goto fail; + *fmt++ = '\0'; + if (*marker == '\0' || *modname == '\0') + goto fail; + + mod = find_module(modname); + if (!mod) { + if (is_vmlinux(modname)) + have_vmlinux = 1; + mod = new_module(NOFAIL(strdup(modname))); + mod->skip = 1; + } + + add_marker(mod, marker, fmt); + } + return; +fail: + fatal("parse error in markers list file\n"); +} + +static int compare_strings(const void *a, const void *b) +{ + return strcmp(*(const char **) a, *(const char **) b); +} + +static void write_markers(const char *fname) +{ + struct buffer buf = { }; + struct module *mod; + size_t i; + + for (mod = modules; mod; mod = mod->next) + if ((!external_module || !mod->skip) && mod->markers != NULL) { + /* + * Sort the strings so we can skip duplicates when + * we write them out. + */ + qsort(mod->markers, mod->nmarkers, + sizeof mod->markers[0], &compare_strings); + for (i = 0; i < mod->nmarkers; ++i) { + char *line = mod->markers[i]; + buf_write(&buf, line, strlen(line)); + while (i + 1 < mod->nmarkers && + !strcmp(mod->markers[i], + mod->markers[i + 1])) + free(mod->markers[i++]); + free(mod->markers[i]); + } + free(mod->markers); + mod->markers = NULL; + } + + write_if_changed(&buf, fname); +} + int main(int argc, char **argv) { struct module *mod; struct buffer buf = { }; char *kernel_read = NULL, *module_read = NULL; char *dump_write = NULL; + char *markers_read = NULL; + char *markers_write = NULL; int opt; int err; - while ((opt = getopt(argc, argv, "i:I:mso:aw")) != -1) { + while ((opt = getopt(argc, argv, "i:I:cmsSo:awM:K:")) != -1) { switch (opt) { case 'i': kernel_read = optarg; @@ -1676,6 +2035,9 @@ int main(int argc, char **argv) module_read = optarg; external_module = 1; break; + case 'c': + cross_build = 1; + break; case 'm': modversions = 1; break; @@ -1688,9 +2050,18 @@ int main(int argc, char **argv) case 's': vmlinux_section_warnings = 0; break; + case 'S': + sec_mismatch_verbose = 0; + break; case 'w': warn_unresolved = 1; break; + case 'M': + markers_write = optarg; + break; + case 'K': + markers_read = optarg; + break; default: exit(1); } @@ -1732,6 +2103,17 @@ int main(int argc, char **argv) if (dump_write) write_dump(dump_write); + if (sec_mismatch_count && !sec_mismatch_verbose) + warn("modpost: Found %d section mismatch(es).\n" + "To see full details build your kernel with:\n" + "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n", + sec_mismatch_count); + + if (markers_read) + read_markers(markers_read); + + if (markers_write) + write_markers(markers_write); return err; }