diff options
| -rw-r--r-- | scripts/mod/modpost.c | 305 |
1 files changed, 128 insertions, 177 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index e463013..6c206b9 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -605,6 +605,61 @@ static int strrcmp(const char *s, const char *sub) return memcmp(s + slen - sublen, sub, sublen); } +/* 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 number_prefix(const char *sym) +{ + 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 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 (*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; +} + /* * 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 @@ -653,6 +708,68 @@ static int data_section(const char *name) 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 }; + +#define INIT_DATA_SECTIONS ".init.data$" +#define EXIT_DATA_SECTIONS ".exit.data$" + +#define INIT_TEXT_SECTIONS ".init.text$" +#define EXIT_TEXT_SECTIONS ".exit.text$" + +#define INIT_SECTIONS INIT_DATA_SECTIONS, INIT_TEXT_SECTIONS +#define EXIT_SECTIONS EXIT_DATA_SECTIONS, EXIT_TEXT_SECTIONS + +#define DATA_SECTIONS ".data$" +#define TEXT_SECTIONS ".text$" + +struct sectioncheck { + const char *fromsec[20]; + const char *tosec[20]; +}; + +const struct sectioncheck sectioncheck[] = { +/* Do not reference init/exit code/data from + * normal code and data + */ +{ + .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL }, + .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL } +}, +/* Do not use exit code/data from init code */ +{ + .fromsec = { INIT_SECTIONS, NULL }, + .tosec = { EXIT_SECTIONS, NULL }, +}, +/* Do not use init code/data from exit code */ +{ + .fromsec = { EXIT_SECTIONS, NULL }, + .tosec = { INIT_SECTIONS, NULL } +}, +/* Do not export init/exit functions or data */ +{ + .fromsec = { "__ksymtab*", NULL }, + .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL } +} +}; + +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 1; + check++; + } + return 0; +} + + /** * Whitelist to allow certain references to pass with no warning. * @@ -695,18 +812,11 @@ 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 = <section>[.text] - * fromsec = <section>.literal **/ static int secref_whitelist(const char *modname, const char *tosec, const char *fromsec, const char *atsym, const char *refsymname) { - int len; const char **s; const char *pat2sym[] = { "driver", @@ -757,15 +867,6 @@ static int secref_whitelist(const char *modname, const char *tosec, 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; - return 0; } @@ -1011,8 +1112,7 @@ static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) } static void section_rela(const char *modname, struct elf_info *elf, - Elf_Shdr *sechdr, int section(const char *), - int section_ref_ok(const char *)) + Elf_Shdr *sechdr) { Elf_Sym *sym; Elf_Rela *rela; @@ -1031,7 +1131,7 @@ static void section_rela(const char *modname, struct elf_info *elf, fromsec = secstrings + sechdr->sh_name; fromsec += strlen(".rela"); /* if from section (name) is know good then skip it */ - if (section_ref_ok(fromsec)) + if (match(fromsec, section_white_list)) return; for (rela = start; rela < stop; rela++) { @@ -1059,14 +1159,13 @@ static void section_rela(const char *modname, struct elf_info *elf, tosec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; - if (section(tosec)) + if (section_mismatch(fromsec, tosec)) warn_sec_mismatch(modname, fromsec, elf, sym, r); } } static void section_rel(const char *modname, struct elf_info *elf, - Elf_Shdr *sechdr, int section(const char *), - int section_ref_ok(const char *)) + Elf_Shdr *sechdr) { Elf_Sym *sym; Elf_Rel *rel; @@ -1085,7 +1184,7 @@ static void section_rel(const char *modname, struct elf_info *elf, fromsec = secstrings + sechdr->sh_name; fromsec += strlen(".rel"); /* if from section (name) is know good then skip it */ - if (section_ref_ok(fromsec)) + if (match(fromsec, section_white_list)) return; for (rel = start; rel < stop; rel++) { @@ -1127,7 +1226,7 @@ static void section_rel(const char *modname, struct elf_info *elf, tosec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; - if (section(tosec)) + if (section_mismatch(fromsec, tosec)) warn_sec_mismatch(modname, fromsec, elf, sym, r); } } @@ -1145,9 +1244,7 @@ static void section_rel(const char *modname, struct elf_info *elf, * 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_Ehdr *hdr = elf->hdr; @@ -1157,156 +1254,12 @@ static void check_sec_ref(struct module *mod, const char *modname, for (i = 0; i < hdr->e_shnum; i++) { /* We want to process only relocation sections and not .init */ if (sechdrs[i].sh_type == SHT_RELA) - section_rela(modname, elf, &elf->sechdrs[i], - section, section_ref_ok); + section_rela(modname, elf, &elf->sechdrs[i]); else if (sechdrs[i].sh_type == SHT_REL) - section_rel(modname, elf, &elf->sechdrs[i], - section, section_ref_ok); + 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 <kaos@sgi.com> 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; - - 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 section name ends with ".init" we allow references - * as is the case with .initcallN.init, .early_param.init, - * .taglist.init etc - */ - if (strrcmp(name, ".init") == 0) - return 1; - return 0; -} - -/* - * 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; - - for (s = namelist1; *s; s++) - if (strcmp(*s, name) == 0) - return 1; - return 0; -} - static void read_symbols(char *modname) { const char *symname; @@ -1347,10 +1300,8 @@ static void read_symbols(char *modname) handle_moddevtable(mod, &info, sym, symname); } if (!is_vmlinux(modname) || - (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); - } + (is_vmlinux(modname) && vmlinux_section_warnings)) + check_sec_ref(mod, modname, &info); version = get_modinfo(info.modinfo, info.modinfo_len, "version"); if (version) |
