*
* 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));
s = new_symbol(name, mod);
} else {
if (!s->preloaded) {
- warn("%s: duplicate symbol '%s' previous definition "
+ warn("%s: '%s' exported twice. Previous export "
"was in %s%s\n", mod->name, name,
s->module->name,
is_vmlinux(s->module->name) ?"":".ko");
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 | .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
}
/*
- * Find symbols before or equal addr and after addr - in the section sec
+ * 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_Addr afterdiff = ~0;
const char *secstrings = (void *)hdr +
elf->sechdrs[hdr->e_shstrndx].sh_offset;
-
+
*before = NULL;
*after = NULL;
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
{
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 *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",
} else if (before) {
warn("%s - Section mismatch: reference to %s:%s from %s "
"after '%s' (at offset 0x%llx)\n",
- modname, secname, refsymname, fromsec,
+ 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 + before->st_name,
+ 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 "
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");
+ 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 (section_ref_ok(name) || (sechdrs[i].sh_type != SHT_RELA))
- continue;
+ 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++) {
- 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)
+ 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;
- secname = secstrings + sechdrs[sym->st_shndx].sh_name;
- if (section(secname))
- warn_sec_mismatch(modname, name, elf, sym, r);
+ 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);
+ }
}
}
}
/**
* 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,
*
/* 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",
".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++)
+ 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;
}
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)
{
".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",
".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++)
+ 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;
}
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);
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;
}