*
* Copyright 2003 Kai Germaschewski
* Copyright 2002-2004 Rusty Russell, IBM Corporation
- *
+ * Copyright 2006 Sam Ravnborg
* Based in part on module-init-tools/depmod.c,file2alias
*
* This software may be used and distributed according to the terms
{
struct module *mod;
char *p, *s;
-
+
mod = NOFAIL(malloc(sizeof(*mod)));
memset(mod, 0, sizeof(*mod));
p = NOFAIL(strdup(modname));
unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
unsigned int kernel:1; /* 1 if symbol is from kernel
* (only for external modules) **/
+ unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
char name[0];
};
{
struct symbol *s = find_symbol(name);
- if (!s)
+ if (!s) {
s = new_symbol(name, mod);
-
+ } else {
+ if (!s->preloaded) {
+ warn("%s: '%s' exported twice. Previous export "
+ "was in %s%s\n", mod->name, name,
+ s->module->name,
+ is_vmlinux(s->module->name) ?"":".ko");
+ }
+ }
+ s->preloaded = 0;
s->vmlinux = is_vmlinux(mod->name);
s->kernel = 0;
return s;
continue;
info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
- info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
+ info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
+ sechdrs[i].sh_size;
- info->strtab = (void *)hdr +
+ info->strtab = (void *)hdr +
sechdrs[sechdrs[i].sh_link].sh_offset;
}
if (!info->symtab_start) {
release_file(info->hdr, info->size);
}
-#define CRC_PFX "__crc_"
-#define KSYMTAB_PFX "__ksymtab_"
+#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
+#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
static void handle_modversions(struct module *mod, struct elf_info *info,
Elf_Sym *sym, const char *symname)
/* Ignore register directives. */
if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
break;
- if (symname[0] == '.') {
- char *munged = strdup(symname);
- munged[0] = '_';
- munged[1] = toupper(munged[1]);
- symname = munged;
- }
+ if (symname[0] == '.') {
+ char *munged = strdup(symname);
+ munged[0] = '_';
+ munged[1] = toupper(munged[1]);
+ symname = munged;
+ }
}
#endif
-
+
if (memcmp(symname, MODULE_SYMBOL_PREFIX,
strlen(MODULE_SYMBOL_PREFIX)) == 0)
mod->unres = alloc_symbol(symname +
return NULL;
}
+/**
+ * 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
+ * fromsec = .data
+ * atsym = *_driver, *_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",
+ "_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))
+ 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++) {
+ Elf_Rela *rela;
+ Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
+ Elf_Rela *stop = (void*)start + sechdrs[i].sh_size;
+ const char *name = secstrings + sechdrs[i].sh_name +
+ strlen(".rela");
+ /* We want to process only relocation sections and not .init */
+ if (section_ref_ok(name) || (sechdrs[i].sh_type != SHT_RELA))
+ continue;
+
+ for (rela = start; rela < stop; rela++) {
+ Elf_Rela r;
+ const char *secname;
+ r.r_offset = TO_NATIVE(rela->r_offset);
+ r.r_info = TO_NATIVE(rela->r_info);
+ r.r_addend = TO_NATIVE(rela->r_addend);
+ sym = elf->symtab_start + ELF_R_SYM(r.r_info);
+ /* 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.
+ **/
+static int exit_section_ref_ok(const char *name)
+{
+ const char **s;
+ /* Absolute section names */
+ const char *namelist1[] = {
+ ".exit.text",
+ ".exit.data",
+ ".init.text",
+ ".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)
{
const char *symname;
handle_modversions(mod, &info, sym, symname);
handle_moddevtable(mod, &info, sym, symname);
}
+ check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
+ check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
version = get_modinfo(info.modinfo, info.modinfo_len, "version");
if (version)
char tmp[SZ];
int len;
va_list ap;
-
+
va_start(ap, fmt);
len = vsnprintf(tmp, SZ, fmt, ap);
- if (buf->size - buf->pos < len + 1) {
- buf->size += 128;
- buf->p = realloc(buf->p, buf->size);
- }
- strncpy(buf->p + buf->pos, tmp, len + 1);
- buf->pos += len;
+ buf_write(buf, tmp, len);
va_end(ap);
}
void buf_write(struct buffer *buf, const char *s, int len)
{
if (buf->size - buf->pos < len) {
- buf->size += len;
+ buf->size += len + SZ;
buf->p = realloc(buf->p, buf->size);
}
strncpy(buf->p + buf->pos, s, len);
mod->skip = 1;
}
s = sym_add_exported(symname, mod);
- s->kernel = kernel;
+ s->kernel = kernel;
+ s->preloaded = 1;
sym_update_crc(symname, mod, crc);
}
return;
return 0;
return 1;
}
-
+
static void write_dump(const char *fname)
{
struct buffer buf = { };
while (symbol) {
if (dump_sym(symbol))
buf_printf(&buf, "0x%08x\t%s\t%s\n",
- symbol->crc, symbol->name,
+ symbol->crc, symbol->name,
symbol->module->name);
symbol = symbol->next;
}
git.openpandora.org / pandora-kernel.git / blobdiff