-/**
- * Test if string s ends in string sub
- * return 0 if match
- **/
-static int strrcmp(const char *s, const char *sub)
-{
- int slen, sublen;
-
- if (!s || !sub)
- return 1;
-
- slen = strlen(s);
- sublen = strlen(sub);
-
- if ((slen == 0) || (sublen == 0))
- return 1;
-
- if (sublen > slen)
- return 1;
-
- return memcmp(s + slen - sublen, sub, sublen);
-}
-
-/**
- * Whitelist to allow certain references to pass with no warning.
- * Pattern 1:
- * If a module parameter is declared __initdata and permissions=0
- * then this is legal despite the warning generated.
- * We cannot see value of permissions here, so just ignore
- * this pattern.
- * The pattern is identified by:
- * tosec = .init.data
- * fromsec = .data*
- * atsym =__param*
- *
- * Pattern 2:
- * Many drivers utilise a *driver container with references to
- * add, remove, probe functions etc.
- * These functions may often be marked __init and we do not want to
- * warn here.
- * the pattern is identified by:
- * tosec = .init.text | .exit.text | .init.data
- * fromsec = .data
- * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one
- **/
-static int secref_whitelist(const char *tosec, const char *fromsec,
- const char *atsym)
-{
- int f1 = 1, f2 = 1;
- const char **s;
- const char *pat2sym[] = {
- "driver",
- "_template", /* scsi uses *_template a lot */
- "_sht", /* scsi also used *_sht to some extent */
- "_ops",
- "_probe",
- "_probe_one",
- NULL
- };
-
- /* Check for pattern 1 */
- if (strcmp(tosec, ".init.data") != 0)
- f1 = 0;
- if (strncmp(fromsec, ".data", strlen(".data")) != 0)
- f1 = 0;
- if (strncmp(atsym, "__param", strlen("__param")) != 0)
- f1 = 0;
-
- if (f1)
- return f1;
-
- /* Check for pattern 2 */
- if ((strcmp(tosec, ".init.text") != 0) &&
- (strcmp(tosec, ".exit.text") != 0) &&
- (strcmp(tosec, ".init.data") != 0))
- f2 = 0;
- if (strcmp(fromsec, ".data") != 0)
- f2 = 0;
-
- for (s = pat2sym; *s; s++)
- if (strrcmp(atsym, *s) == 0)
- f1 = 1;
-
- return f1 && f2;
-}
-
-/**
- * Find symbol based on relocation record info.
- * In some cases the symbol supplied is a valid symbol so
- * return refsym. If st_name != 0 we assume this is a valid symbol.
- * 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,
- Elf_Sym *relsym)
-{
- Elf_Sym *sym;
-
- if (relsym->st_name != 0)
- return relsym;
- for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
- if (sym->st_shndx != relsym->st_shndx)
- continue;
- if (sym->st_value == addr)
- return sym;
- }
- return NULL;
-}
-
-/*
- * Find symbols before or equal addr and after addr - in the section sec.
- * If we find two symbols with equal offset prefer one with a valid name.
- * 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)
-{
- 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;
-
- 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;
- if (strcmp(symsec, sec) != 0)
- 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) {
- /* equal offset, valid name? */
- const char *name = elf->strtab + sym->st_name;
- if (name && strlen(name))
- *before = sym;
- }
- }
- else
- {
- if ((sym->st_value - addr) < afterdiff) {
- afterdiff = sym->st_value - addr;
- *after = sym;
- }
- else if ((sym->st_value - addr) == afterdiff) {
- /* equal offset, valid name? */
- const char *name = elf->strtab + sym->st_name;
- if (name && strlen(name))
- *after = sym;
- }
- }
- }
-}
-
-/**
- * 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)
-{
- 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;
-
- 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;
-
- /* check whitelist - we may ignore it */
- if (before &&
- secref_whitelist(secname, fromsec, elf->strtab + before->st_name))
- return;
-
- if (before && after) {
- warn("%s - Section mismatch: reference to %s:%s from %s "
- "between '%s' (at offset 0x%llx) and '%s'\n",
- modname, secname, refsymname, fromsec,
- elf->strtab + before->st_name,
- (long long)r.r_offset,
- elf->strtab + after->st_name);
- } else if (before) {
- warn("%s - Section mismatch: reference to %s:%s from %s "
- "after '%s' (at offset 0x%llx)\n",
- modname, secname, refsymname, fromsec,
- elf->strtab + before->st_name,
- (long long)r.r_offset);
- } else if (after) {
- warn("%s - Section mismatch: reference to %s:%s from %s "
- "before '%s' (at offset -0x%llx)\n",
- modname, secname, refsymname, fromsec,
- elf->strtab + after->st_name,
- (long long)r.r_offset);
- } else {
- warn("%s - Section mismatch: reference to %s:%s from %s "
- "(offset 0x%llx)\n",
- modname, secname, fromsec, refsymname,
- (long long)r.r_offset);
- }
-}
-
-/**
- * A module includes a number of sections that are discarded
- * either when loaded or when used as built-in.
- * For loaded modules all functions marked __init and all data
- * marked __initdata will be discarded when the module has been intialized.
- * Likewise for modules used built-in the sections marked __exit
- * are discarded because __exit marked function are supposed to be called
- * only when a moduel is unloaded which never happes for built-in modules.
- * The check_sec_ref() function traverses all relocation records
- * to find all references to a section that reference a section that will
- * 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 *))
-{
- 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;
- /* 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) {
- r_sym = ELF64_MIPS_R_SYM(rela->r_info);
- r_sym = TO_NATIVE(r_sym);
- } 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) {
- r_sym = ELF64_MIPS_R_SYM(rel->r_info);
- r_sym = TO_NATIVE(r_sym);
- } 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;
- 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);
- }
- }
- }
-}
-
-/**
- * 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 int init_section(const char *name)
-{
- if (strcmp(name, ".init") == 0)
- return 1;
- if (strncmp(name, ".init.", strlen(".init.")) == 0)
- 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[] = {
- ".init",
- ".opd", /* see comment [OPD] at exit_section_ref_ok() */
- ".toc1", /* used by ppc64 */
- ".stab",
- ".rodata",
- ".text.lock",
- "__bug_table", /* used by powerpc for BUG() */
- ".pci_fixup_header",
- ".pci_fixup_final",
- ".pdr",
- "__param",
- NULL
- };
- /* Start of section names */
- const char *namelist2[] = {
- ".init.",
- ".altinstructions",
- ".eh_frame",
- ".debug",
- NULL
- };
- /* part of section name */
- const char *namelist3 [] = {
- ".unwind", /* sample: IA_64.unwind.init.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;
-}
-
-/*
- * 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)
-{
- if (strcmp(name, ".exit.text") == 0)
- return 1;
- if (strcmp(name, ".exit.data") == 0)
- return 1;
- return 0;
-
-}
-
-/*
- * Identify sections from which references to 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 exit_section_ref_ok(const char *name)
-{
- const char **s;
- /* Absolute section names */
- const char *namelist1[] = {
- ".exit.text",
- ".exit.data",
- ".init.text",
- ".rodata",
- ".opd", /* See comment [OPD] */
- ".toc1", /* used by ppc64 */
- ".altinstructions",
- ".pdr",
- "__bug_table", /* used by powerpc for BUG() */
- ".exitcall.exit",
- ".eh_frame",
- ".stab",
- NULL
- };
- /* Start of section names */
- const char *namelist2[] = {
- ".debug",
- 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;
-}
-
-static void read_symbols(char *modname)