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linux/scripts/mod/modpost.c
Masahiro Yamada 5b8a9a8fd1 modpost: fix module versioning when a symbol lacks valid CRC 
Since commit 7b4537199a ("kbuild: link symbol CRCs at final link,
removing CONFIG_MODULE_REL_CRCS"), module versioning is broken on
some architectures. Loading a module fails with "disagrees about
version of symbol module_layout".

On such architectures (e.g. ARCH=sparc build with sparc64_defconfig),
modpost shows a warning, like follows:

  WARNING: modpost: EXPORT symbol "_mcount" [vmlinux] version generation failed, symbol will not be versioned.
  Is "_mcount" prototyped in <asm/asm-prototypes.h>?

Previously, it was a harmless warning (CRC check was just skipped),
but now wrong CRCs are used for comparison because invalid CRCs are
just skipped.

  $ sparc64-linux-gnu-nm -n vmlinux
    [snip]
  0000000000c2cea0 r __ksymtab__kstrtol
  0000000000c2ceb8 r __ksymtab__kstrtoul
  0000000000c2ced0 r __ksymtab__local_bh_enable
  0000000000c2cee8 r __ksymtab__mcount
  0000000000c2cf00 r __ksymtab__printk
  0000000000c2cf18 r __ksymtab__raw_read_lock
  0000000000c2cf30 r __ksymtab__raw_read_lock_bh
    [snip]
  0000000000c53b34 D __crc__kstrtol
  0000000000c53b38 D __crc__kstrtoul
  0000000000c53b3c D __crc__local_bh_enable
  0000000000c53b40 D __crc__printk
  0000000000c53b44 D __crc__raw_read_lock
  0000000000c53b48 D __crc__raw_read_lock_bh

Please notice __crc__mcount is missing here.

When the module subsystem looks up a CRC that comes after, it results
in reading out a wrong address. For example, when __crc__printk is
needed, the module subsystem reads 0xc53b44 instead of 0xc53b40.

All CRC entries must be output for correct index accessing. Invalid
CRCs will be unused, but are needed to keep the one-to-one mapping
between __ksymtab_* and __crc_*.

The best is to fix all modpost warnings, but several warnings are still
remaining on less popular architectures.

Fixes: 7b4537199a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS")
Reported-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: matoro <matoro_mailinglist_kernel@matoro.tk>
2022-08-21 02:47:36 +09:00

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/* Postprocess module symbol versions
*
* Copyright 2003 Kai Germaschewski
* Copyright 2002-2004 Rusty Russell, IBM Corporation
* Copyright 2006-2008 Sam Ravnborg
* Based in part on module-init-tools/depmod.c,file2alias
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
*
* Usage: modpost vmlinux module1.o module2.o ...
*/
#define _GNU_SOURCE
#include <elf.h>
#include <fnmatch.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <limits.h>
#include <stdbool.h>
#include <errno.h>
#include "modpost.h"
#include "../../include/linux/license.h"
/* Are we using CONFIG_MODVERSIONS? */
static bool modversions;
/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
static bool all_versions;
/* If we are modposting external module set to 1 */
static bool external_module;
/* Only warn about unresolved symbols */
static bool warn_unresolved;
static int sec_mismatch_count;
static bool sec_mismatch_warn_only = true;
/* ignore missing files */
static bool ignore_missing_files;
/* If set to 1, only warn (instead of error) about missing ns imports */
static bool allow_missing_ns_imports;
static bool error_occurred;
/*
* Cut off the warnings when there are too many. This typically occurs when
* vmlinux is missing. ('make modules' without building vmlinux.)
*/
#define MAX_UNRESOLVED_REPORTS 10
static unsigned int nr_unresolved;
/* In kernel, this size is defined in linux/module.h;
* here we use Elf_Addr instead of long for covering cross-compile
*/
#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
void __attribute__((format(printf, 2, 3)))
modpost_log(enum loglevel loglevel, const char *fmt, ...)
{
va_list arglist;
switch (loglevel) {
case LOG_WARN:
fprintf(stderr, "WARNING: ");
break;
case LOG_ERROR:
fprintf(stderr, "ERROR: ");
break;
case LOG_FATAL:
fprintf(stderr, "FATAL: ");
break;
default: /* invalid loglevel, ignore */
break;
}
fprintf(stderr, "modpost: ");
va_start(arglist, fmt);
vfprintf(stderr, fmt, arglist);
va_end(arglist);
if (loglevel == LOG_FATAL)
exit(1);
if (loglevel == LOG_ERROR)
error_occurred = true;
}
static inline bool strends(const char *str, const char *postfix)
{
if (strlen(str) < strlen(postfix))
return false;
return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
}
void *do_nofail(void *ptr, const char *expr)
{
if (!ptr)
fatal("Memory allocation failure: %s.\n", expr);
return ptr;
}
char *read_text_file(const char *filename)
{
struct stat st;
size_t nbytes;
int fd;
char *buf;
fd = open(filename, O_RDONLY);
if (fd < 0) {
perror(filename);
exit(1);
}
if (fstat(fd, &st) < 0) {
perror(filename);
exit(1);
}
buf = NOFAIL(malloc(st.st_size + 1));
nbytes = st.st_size;
while (nbytes) {
ssize_t bytes_read;
bytes_read = read(fd, buf, nbytes);
if (bytes_read < 0) {
perror(filename);
exit(1);
}
nbytes -= bytes_read;
}
buf[st.st_size] = '\0';
close(fd);
return buf;
}
char *get_line(char **stringp)
{
char *orig = *stringp, *next;
/* do not return the unwanted extra line at EOF */
if (!orig || *orig == '\0')
return NULL;
/* don't use strsep here, it is not available everywhere */
next = strchr(orig, '\n');
if (next)
*next++ = '\0';
*stringp = next;
return orig;
}
/* A list of all modules we processed */
LIST_HEAD(modules);
static struct module *find_module(const char *modname)
{
struct module *mod;
list_for_each_entry(mod, &modules, list) {
if (strcmp(mod->name, modname) == 0)
return mod;
}
return NULL;
}
static struct module *new_module(const char *name, size_t namelen)
{
struct module *mod;
mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
memset(mod, 0, sizeof(*mod));
INIT_LIST_HEAD(&mod->exported_symbols);
INIT_LIST_HEAD(&mod->unresolved_symbols);
INIT_LIST_HEAD(&mod->missing_namespaces);
INIT_LIST_HEAD(&mod->imported_namespaces);
memcpy(mod->name, name, namelen);
mod->name[namelen] = '\0';
mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
/*
* Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
* is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
* modpost will exit wiht error anyway.
*/
mod->is_gpl_compatible = true;
list_add_tail(&mod->list, &modules);
return mod;
}
/* A hash of all exported symbols,
* struct symbol is also used for lists of unresolved symbols */
#define SYMBOL_HASH_SIZE 1024
struct symbol {
struct symbol *next;
struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */
struct module *module;
char *namespace;
unsigned int crc;
bool crc_valid;
bool weak;
bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */
char name[];
};
static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
/* This is based on the hash algorithm from gdbm, via tdb */
static inline unsigned int tdb_hash(const char *name)
{
unsigned value; /* Used to compute the hash value. */
unsigned i; /* Used to cycle through random values. */
/* Set the initial value from the key size. */
for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
return (1103515243 * value + 12345);
}
/**
* Allocate a new symbols for use in the hash of exported symbols or
* the list of unresolved symbols per module
**/
static struct symbol *alloc_symbol(const char *name)
{
struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
memset(s, 0, sizeof(*s));
strcpy(s->name, name);
return s;
}
/* For the hash of exported symbols */
static void hash_add_symbol(struct symbol *sym)
{
unsigned int hash;
hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE;
sym->next = symbolhash[hash];
symbolhash[hash] = sym;
}
static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
{
struct symbol *sym;
sym = alloc_symbol(name);
sym->weak = weak;
list_add_tail(&sym->list, &mod->unresolved_symbols);
}
static struct symbol *sym_find_with_module(const char *name, struct module *mod)
{
struct symbol *s;
/* For our purposes, .foo matches foo. PPC64 needs this. */
if (name[0] == '.')
name++;
for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
return s;
}
return NULL;
}
static struct symbol *find_symbol(const char *name)
{
return sym_find_with_module(name, NULL);
}
struct namespace_list {
struct list_head list;
char namespace[];
};
static bool contains_namespace(struct list_head *head, const char *namespace)
{
struct namespace_list *list;
list_for_each_entry(list, head, list) {
if (!strcmp(list->namespace, namespace))
return true;
}
return false;
}
static void add_namespace(struct list_head *head, const char *namespace)
{
struct namespace_list *ns_entry;
if (!contains_namespace(head, namespace)) {
ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
strlen(namespace) + 1));
strcpy(ns_entry->namespace, namespace);
list_add_tail(&ns_entry->list, head);
}
}
static void *sym_get_data_by_offset(const struct elf_info *info,
unsigned int secindex, unsigned long offset)
{
Elf_Shdr *sechdr = &info->sechdrs[secindex];
return (void *)info->hdr + sechdr->sh_offset + offset;
}
void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
{
return sym_get_data_by_offset(info, get_secindex(info, sym),
sym->st_value);
}
static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
{
return sym_get_data_by_offset(info, info->secindex_strings,
sechdr->sh_name);
}
static const char *sec_name(const struct elf_info *info, unsigned int secindex)
{
/*
* If sym->st_shndx is a special section index, there is no
* corresponding section header.
* Return "" if the index is out of range of info->sechdrs[] array.
*/
if (secindex >= info->num_sections)
return "";
return sech_name(info, &info->sechdrs[secindex]);
}
#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
static void sym_update_namespace(const char *symname, const char *namespace)
{
struct symbol *s = find_symbol(symname);
/*
* That symbol should have been created earlier and thus this is
* actually an assertion.
*/
if (!s) {
error("Could not update namespace(%s) for symbol %s\n",
namespace, symname);
return;
}
free(s->namespace);
s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
}
static struct symbol *sym_add_exported(const char *name, struct module *mod,
bool gpl_only)
{
struct symbol *s = find_symbol(name);
if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
error("%s: '%s' exported twice. Previous export was in %s%s\n",
mod->name, name, s->module->name,
s->module->is_vmlinux ? "" : ".ko");
}
s = alloc_symbol(name);
s->module = mod;
s->is_gpl_only = gpl_only;
list_add_tail(&s->list, &mod->exported_symbols);
hash_add_symbol(s);
return s;
}
static void sym_set_crc(struct symbol *sym, unsigned int crc)
{
sym->crc = crc;
sym->crc_valid = true;
}
static void *grab_file(const char *filename, size_t *size)
{
struct stat st;
void *map = MAP_FAILED;
int fd;
fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
if (fstat(fd, &st))
goto failed;
*size = st.st_size;
map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
failed:
close(fd);
if (map == MAP_FAILED)
return NULL;
return map;
}
static void release_file(void *file, size_t size)
{
munmap(file, size);
}
static int parse_elf(struct elf_info *info, const char *filename)
{
unsigned int i;
Elf_Ehdr *hdr;
Elf_Shdr *sechdrs;
Elf_Sym *sym;
const char *secstrings;
unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
hdr = grab_file(filename, &info->size);
if (!hdr) {
if (ignore_missing_files) {
fprintf(stderr, "%s: %s (ignored)\n", filename,
strerror(errno));
return 0;
}
perror(filename);
exit(1);
}
info->hdr = hdr;
if (info->size < sizeof(*hdr)) {
/* file too small, assume this is an empty .o file */
return 0;
}
/* Is this a valid ELF file? */
if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
(hdr->e_ident[EI_MAG1] != ELFMAG1) ||
(hdr->e_ident[EI_MAG2] != ELFMAG2) ||
(hdr->e_ident[EI_MAG3] != ELFMAG3)) {
/* Not an ELF file - silently ignore it */
return 0;
}
/* Fix endianness in ELF header */
hdr->e_type = TO_NATIVE(hdr->e_type);
hdr->e_machine = TO_NATIVE(hdr->e_machine);
hdr->e_version = TO_NATIVE(hdr->e_version);
hdr->e_entry = TO_NATIVE(hdr->e_entry);
hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
hdr->e_flags = TO_NATIVE(hdr->e_flags);
hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
sechdrs = (void *)hdr + hdr->e_shoff;
info->sechdrs = sechdrs;
/* modpost only works for relocatable objects */
if (hdr->e_type != ET_REL)
fatal("%s: not relocatable object.", filename);
/* Check if file offset is correct */
if (hdr->e_shoff > info->size) {
fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
(unsigned long)hdr->e_shoff, filename, info->size);
return 0;
}
if (hdr->e_shnum == SHN_UNDEF) {
/*
* There are more than 64k sections,
* read count from .sh_size.
*/
info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
}
else {
info->num_sections = hdr->e_shnum;
}
if (hdr->e_shstrndx == SHN_XINDEX) {
info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
}
else {
info->secindex_strings = hdr->e_shstrndx;
}
/* Fix endianness in section headers */
for (i = 0; i < info->num_sections; i++) {
sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
}
/* Find symbol table. */
secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
for (i = 1; i < info->num_sections; i++) {
const char *secname;
int nobits = sechdrs[i].sh_type == SHT_NOBITS;
if (!nobits && sechdrs[i].sh_offset > info->size) {
fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
"sizeof(*hrd)=%zu\n", filename,
(unsigned long)sechdrs[i].sh_offset,
sizeof(*hdr));
return 0;
}
secname = secstrings + sechdrs[i].sh_name;
if (strcmp(secname, ".modinfo") == 0) {
if (nobits)
fatal("%s has NOBITS .modinfo\n", filename);
info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
info->modinfo_len = sechdrs[i].sh_size;
}
if (sechdrs[i].sh_type == SHT_SYMTAB) {
unsigned int sh_link_idx;
symtab_idx = i;
info->symtab_start = (void *)hdr +
sechdrs[i].sh_offset;
info->symtab_stop = (void *)hdr +
sechdrs[i].sh_offset + sechdrs[i].sh_size;
sh_link_idx = sechdrs[i].sh_link;
info->strtab = (void *)hdr +
sechdrs[sh_link_idx].sh_offset;
}
/* 32bit section no. table? ("more than 64k sections") */
if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
symtab_shndx_idx = i;
info->symtab_shndx_start = (void *)hdr +
sechdrs[i].sh_offset;
info->symtab_shndx_stop = (void *)hdr +
sechdrs[i].sh_offset + sechdrs[i].sh_size;
}
}
if (!info->symtab_start)
fatal("%s has no symtab?\n", filename);
/* Fix endianness in symbols */
for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
sym->st_shndx = TO_NATIVE(sym->st_shndx);
sym->st_name = TO_NATIVE(sym->st_name);
sym->st_value = TO_NATIVE(sym->st_value);
sym->st_size = TO_NATIVE(sym->st_size);
}
if (symtab_shndx_idx != ~0U) {
Elf32_Word *p;
if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
filename, sechdrs[symtab_shndx_idx].sh_link,
symtab_idx);
/* Fix endianness */
for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
p++)
*p = TO_NATIVE(*p);
}
return 1;
}
static void parse_elf_finish(struct elf_info *info)
{
release_file(info->hdr, info->size);
}
static int ignore_undef_symbol(struct elf_info *info, const char *symname)
{
/* ignore __this_module, it will be resolved shortly */
if (strcmp(symname, "__this_module") == 0)
return 1;
/* ignore global offset table */
if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
return 1;
if (info->hdr->e_machine == EM_PPC)
/* Special register function linked on all modules during final link of .ko */
if (strstarts(symname, "_restgpr_") ||
strstarts(symname, "_savegpr_") ||
strstarts(symname, "_rest32gpr_") ||
strstarts(symname, "_save32gpr_") ||
strstarts(symname, "_restvr_") ||
strstarts(symname, "_savevr_"))
return 1;
if (info->hdr->e_machine == EM_PPC64)
/* Special register function linked on all modules during final link of .ko */
if (strstarts(symname, "_restgpr0_") ||
strstarts(symname, "_savegpr0_") ||
strstarts(symname, "_restvr_") ||
strstarts(symname, "_savevr_") ||
strcmp(symname, ".TOC.") == 0)
return 1;
if (info->hdr->e_machine == EM_S390)
/* Expoline thunks are linked on all kernel modules during final link of .ko */
if (strstarts(symname, "__s390_indirect_jump_r"))
return 1;
/* Do not ignore this symbol */
return 0;
}
static void handle_symbol(struct module *mod, struct elf_info *info,
const Elf_Sym *sym, const char *symname)
{
switch (sym->st_shndx) {
case SHN_COMMON:
if (strstarts(symname, "__gnu_lto_")) {
/* Should warn here, but modpost runs before the linker */
} else
warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
break;
case SHN_UNDEF:
/* undefined symbol */
if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
ELF_ST_BIND(sym->st_info) != STB_WEAK)
break;
if (ignore_undef_symbol(info, symname))
break;
if (info->hdr->e_machine == EM_SPARC ||
info->hdr->e_machine == EM_SPARCV9) {
/* Ignore register directives. */
if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
break;
if (symname[0] == '.') {
char *munged = NOFAIL(strdup(symname));
munged[0] = '_';
munged[1] = toupper(munged[1]);
symname = munged;
}
}
sym_add_unresolved(symname, mod,
ELF_ST_BIND(sym->st_info) == STB_WEAK);
break;
default:
/* All exported symbols */
if (strstarts(symname, "__ksymtab_")) {
const char *name, *secname;
name = symname + strlen("__ksymtab_");
secname = sec_name(info, get_secindex(info, sym));
if (strstarts(secname, "___ksymtab_gpl+"))
sym_add_exported(name, mod, true);
else if (strstarts(secname, "___ksymtab+"))
sym_add_exported(name, mod, false);
}
if (strcmp(symname, "init_module") == 0)
mod->has_init = true;
if (strcmp(symname, "cleanup_module") == 0)
mod->has_cleanup = true;
break;
}
}
/**
* Parse tag=value strings from .modinfo section
**/
static char *next_string(char *string, unsigned long *secsize)
{
/* Skip non-zero chars */
while (string[0]) {
string++;
if ((*secsize)-- <= 1)
return NULL;
}
/* Skip any zero padding. */
while (!string[0]) {
string++;
if ((*secsize)-- <= 1)
return NULL;
}
return string;
}
static char *get_next_modinfo(struct elf_info *info, const char *tag,
char *prev)
{
char *p;
unsigned int taglen = strlen(tag);
char *modinfo = info->modinfo;
unsigned long size = info->modinfo_len;
if (prev) {
size -= prev - modinfo;
modinfo = next_string(prev, &size);
}
for (p = modinfo; p; p = next_string(p, &size)) {
if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
return p + taglen + 1;
}
return NULL;
}
static char *get_modinfo(struct elf_info *info, const char *tag)
{
return get_next_modinfo(info, tag, NULL);
}
static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
{
if (sym)
return elf->strtab + sym->st_name;
else
return "(unknown)";
}
/*
* Check whether the 'string' argument matches one of the 'patterns',
* an array of shell wildcard patterns (glob).
*
* Return true is there is a match.
*/
static bool match(const char *string, const char *const patterns[])
{
const char *pattern;
while ((pattern = *patterns++)) {
if (!fnmatch(pattern, string, 0))
return true;
}
return false;
}
/* useful to pass patterns to match() directly */
#define PATTERNS(...) \
({ \
static const char *const patterns[] = {__VA_ARGS__, NULL}; \
patterns; \
})
/* sections that we do not want to do full section mismatch check on */
static const char *const section_white_list[] =
{
".comment*",
".debug*",
".zdebug*", /* Compressed debug sections. */
".GCC.command.line", /* record-gcc-switches */
".mdebug*", /* alpha, score, mips etc. */
".pdr", /* alpha, score, mips etc. */
".stab*",
".note*",
".got*",
".toc*",
".xt.prop", /* xtensa */
".xt.lit", /* xtensa */
".arcextmap*", /* arc */
".gnu.linkonce.arcext*", /* arc : modules */
".cmem*", /* EZchip */
".fmt_slot*", /* EZchip */
".gnu.lto*",
".discard.*",
NULL
};
/*
* This is used to find sections missing the SHF_ALLOC flag.
* The cause of this is often a section specified in assembler
* without "ax" / "aw".
*/
static void check_section(const char *modname, struct elf_info *elf,
Elf_Shdr *sechdr)
{
const char *sec = sech_name(elf, sechdr);
if (sechdr->sh_type == SHT_PROGBITS &&
!(sechdr->sh_flags & SHF_ALLOC) &&
!match(sec, section_white_list)) {
warn("%s (%s): unexpected non-allocatable section.\n"
"Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
"Note that for example <linux/init.h> contains\n"
"section definitions for use in .S files.\n\n",
modname, sec);
}
}
#define ALL_INIT_DATA_SECTIONS \
".init.setup", ".init.rodata", ".meminit.rodata", \
".init.data", ".meminit.data"
#define ALL_EXIT_DATA_SECTIONS \
".exit.data", ".memexit.data"
#define ALL_INIT_TEXT_SECTIONS \
".init.text", ".meminit.text"
#define ALL_EXIT_TEXT_SECTIONS \
".exit.text", ".memexit.text"
#define ALL_PCI_INIT_SECTIONS \
".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
".pci_fixup_enable", ".pci_fixup_resume", \
".pci_fixup_resume_early", ".pci_fixup_suspend"
#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
#define DATA_SECTIONS ".data", ".data.rel"
#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
".kprobes.text", ".cpuidle.text", ".noinstr.text"
#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
".fixup", ".entry.text", ".exception.text", ".text.*", \
".coldtext", ".softirqentry.text"
#define INIT_SECTIONS ".init.*"
#define MEM_INIT_SECTIONS ".meminit.*"
#define EXIT_SECTIONS ".exit.*"
#define MEM_EXIT_SECTIONS ".memexit.*"
#define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
TEXT_SECTIONS, OTHER_TEXT_SECTIONS
/* init data sections */
static const char *const init_data_sections[] =
{ ALL_INIT_DATA_SECTIONS, NULL };
/* all init sections */
static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
/* all text sections */
static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
/* data section */
static const char *const data_sections[] = { DATA_SECTIONS, NULL };
static const char *const head_sections[] = { ".head.text*", NULL };
static const char *const linker_symbols[] =
{ "__init_begin", "_sinittext", "_einittext", NULL };
static const char *const optim_symbols[] = { "*.constprop.*", NULL };
enum mismatch {
TEXT_TO_ANY_INIT,
DATA_TO_ANY_INIT,
TEXT_TO_ANY_EXIT,
DATA_TO_ANY_EXIT,
XXXINIT_TO_SOME_INIT,
XXXEXIT_TO_SOME_EXIT,
ANY_INIT_TO_ANY_EXIT,
ANY_EXIT_TO_ANY_INIT,
EXPORT_TO_INIT_EXIT,
EXTABLE_TO_NON_TEXT,
};
/**
* Describe how to match sections on different criteria:
*
* @fromsec: Array of sections to be matched.
*
* @bad_tosec: Relocations applied to a section in @fromsec to a section in
* this array is forbidden (black-list). Can be empty.
*
* @good_tosec: Relocations applied to a section in @fromsec must be
* targeting sections in this array (white-list). Can be empty.
*
* @mismatch: Type of mismatch.
*
* @handler: Specific handler to call when a match is found. If NULL,
* default_mismatch_handler() will be called.
*
*/
struct sectioncheck {
const char *fromsec[20];
const char *bad_tosec[20];
const char *good_tosec[20];
enum mismatch mismatch;
void (*handler)(const char *modname, struct elf_info *elf,
const struct sectioncheck* const mismatch,
Elf_Rela *r, Elf_Sym *sym, const char *fromsec);
};
static void extable_mismatch_handler(const char *modname, struct elf_info *elf,
const struct sectioncheck* const mismatch,
Elf_Rela *r, Elf_Sym *sym,
const char *fromsec);
static const struct sectioncheck sectioncheck[] = {
/* Do not reference init/exit code/data from
* normal code and data
*/
{
.fromsec = { TEXT_SECTIONS, NULL },
.bad_tosec = { ALL_INIT_SECTIONS, NULL },
.mismatch = TEXT_TO_ANY_INIT,
},
{
.fromsec = { DATA_SECTIONS, NULL },
.bad_tosec = { ALL_XXXINIT_SECTIONS, NULL },
.mismatch = DATA_TO_ANY_INIT,
},
{
.fromsec = { DATA_SECTIONS, NULL },
.bad_tosec = { INIT_SECTIONS, NULL },
.mismatch = DATA_TO_ANY_INIT,
},
{
.fromsec = { TEXT_SECTIONS, NULL },
.bad_tosec = { ALL_EXIT_SECTIONS, NULL },
.mismatch = TEXT_TO_ANY_EXIT,
},
{
.fromsec = { DATA_SECTIONS, NULL },
.bad_tosec = { ALL_EXIT_SECTIONS, NULL },
.mismatch = DATA_TO_ANY_EXIT,
},
/* Do not reference init code/data from meminit code/data */
{
.fromsec = { ALL_XXXINIT_SECTIONS, NULL },
.bad_tosec = { INIT_SECTIONS, NULL },
.mismatch = XXXINIT_TO_SOME_INIT,
},
/* Do not reference exit code/data from memexit code/data */
{
.fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
.bad_tosec = { EXIT_SECTIONS, NULL },
.mismatch = XXXEXIT_TO_SOME_EXIT,
},
/* Do not use exit code/data from init code */
{
.fromsec = { ALL_INIT_SECTIONS, NULL },
.bad_tosec = { ALL_EXIT_SECTIONS, NULL },
.mismatch = ANY_INIT_TO_ANY_EXIT,
},
/* Do not use init code/data from exit code */
{
.fromsec = { ALL_EXIT_SECTIONS, NULL },
.bad_tosec = { ALL_INIT_SECTIONS, NULL },
.mismatch = ANY_EXIT_TO_ANY_INIT,
},
{
.fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
.bad_tosec = { INIT_SECTIONS, NULL },
.mismatch = ANY_INIT_TO_ANY_EXIT,
},
/* Do not export init/exit functions or data */
{
.fromsec = { "___ksymtab*", NULL },
.bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
.mismatch = EXPORT_TO_INIT_EXIT,
},
{
.fromsec = { "__ex_table", NULL },
/* If you're adding any new black-listed sections in here, consider
* adding a special 'printer' for them in scripts/check_extable.
*/
.bad_tosec = { ".altinstr_replacement", NULL },
.good_tosec = {ALL_TEXT_SECTIONS , NULL},
.mismatch = EXTABLE_TO_NON_TEXT,
.handler = extable_mismatch_handler,
}
};
static const struct sectioncheck *section_mismatch(
const char *fromsec, const char *tosec)
{
int i;
/*
* The target section could be the SHT_NUL section when we're
* handling relocations to un-resolved symbols, trying to match it
* doesn't make much sense and causes build failures on parisc
* architectures.
*/
if (*tosec == '\0')
return NULL;
for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
const struct sectioncheck *check = &sectioncheck[i];
if (match(fromsec, check->fromsec)) {
if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
return check;
if (check->good_tosec[0] && !match(tosec, check->good_tosec))
return check;
}
}
return NULL;
}
/**
* 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 1a:
* module_param_call() ops can refer to __init set function if permissions=0
* The pattern is identified by:
* tosec = .init.text
* fromsec = .data*
* atsym = __param_ops_*
*
* Pattern 3:
* Whitelist all references from .head.text to any init section
*
* Pattern 4:
* Some symbols belong to init section but still it is ok to reference
* these from non-init sections as these symbols don't have any memory
* allocated for them and symbol address and value are same. So even
* if init section is freed, its ok to reference those symbols.
* For ex. symbols marking the init section boundaries.
* This pattern is identified by
* refsymname = __init_begin, _sinittext, _einittext
*
* Pattern 5:
* GCC may optimize static inlines when fed constant arg(s) resulting
* in functions like cpumask_empty() -- generating an associated symbol
* cpumask_empty.constprop.3 that appears in the audit. If the const that
* is passed in comes from __init, like say nmi_ipi_mask, we get a
* meaningless section warning. May need to add isra symbols too...
* This pattern is identified by
* tosec = init section
* fromsec = text section
* refsymname = *.constprop.*
*
* Pattern 6:
* Hide section mismatch warnings for ELF local symbols. The goal
* is to eliminate false positive modpost warnings caused by
* compiler-generated ELF local symbol names such as ".LANCHOR1".
* Autogenerated symbol names bypass modpost's "Pattern 2"
* whitelisting, which relies on pattern-matching against symbol
* names to work. (One situation where gcc can autogenerate ELF
* local symbols is when "-fsection-anchors" is used.)
**/
static int secref_whitelist(const struct sectioncheck *mismatch,
const char *fromsec, const char *fromsym,
const char *tosec, const char *tosym)
{
/* Check for pattern 1 */
if (match(tosec, init_data_sections) &&
match(fromsec, data_sections) &&
strstarts(fromsym, "__param"))
return 0;
/* Check for pattern 1a */
if (strcmp(tosec, ".init.text") == 0 &&
match(fromsec, data_sections) &&
strstarts(fromsym, "__param_ops_"))
return 0;
/* symbols in data sections that may refer to any init/exit sections */
if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
match(fromsym, PATTERNS("*_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")))
return 0;
/* symbols in data sections that may refer to meminit/exit sections */
if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
match(fromsym, PATTERNS("*driver")))
return 0;
/* Check for pattern 3 */
if (match(fromsec, head_sections) &&
match(tosec, init_sections))
return 0;
/* Check for pattern 4 */
if (match(tosym, linker_symbols))
return 0;
/* Check for pattern 5 */
if (match(fromsec, text_sections) &&
match(tosec, init_sections) &&
match(fromsym, optim_symbols))
return 0;
/* Check for pattern 6 */
if (strstarts(fromsym, ".L"))
return 0;
return 1;
}
static inline int is_arm_mapping_symbol(const char *str)
{
return str[0] == '$' &&
(str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x')
&& (str[2] == '\0' || str[2] == '.');
}
/*
* If there's no name there, ignore it; likewise, ignore it if it's
* one of the magic symbols emitted used by current ARM tools.
*
* Otherwise if find_symbols_between() returns those symbols, they'll
* fail the whitelist tests and cause lots of false alarms ... fixable
* only by merging __exit and __init sections into __text, bloating
* the kernel (which is especially evil on embedded platforms).
*/
static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
{
const char *name = elf->strtab + sym->st_name;
if (!name || !strlen(name))
return 0;
return !is_arm_mapping_symbol(name);
}
/**
* 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, Elf64_Sword addr,
Elf_Sym *relsym)
{
Elf_Sym *sym;
Elf_Sym *near = NULL;
Elf64_Sword distance = 20;
Elf64_Sword d;
unsigned int relsym_secindex;
if (relsym->st_name != 0)
return relsym;
relsym_secindex = get_secindex(elf, relsym);
for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
if (get_secindex(elf, sym) != relsym_secindex)
continue;
if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
continue;
if (!is_valid_name(elf, sym))
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;
}
}
/* We need a close match */
if (distance < 20)
return near;
else
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 Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
const char *sec)
{
Elf_Sym *sym;
Elf_Sym *near = NULL;
Elf_Addr distance = ~0;
for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
const char *symsec;
if (is_shndx_special(sym->st_shndx))
continue;
symsec = sec_name(elf, get_secindex(elf, sym));
if (strcmp(symsec, sec) != 0)
continue;
if (!is_valid_name(elf, sym))
continue;
if (sym->st_value <= addr && addr - sym->st_value <= distance) {
distance = addr - sym->st_value;
near = sym;
}
}
return near;
}
static int is_function(Elf_Sym *sym)
{
if (sym)
return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
else
return -1;
}
static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
{
switch (is_func) {
case 0: *name = "variable"; *name_p = ""; break;
case 1: *name = "function"; *name_p = "()"; break;
default: *name = "(unknown reference)"; *name_p = ""; break;
}
}
/*
* 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 report_sec_mismatch(const char *modname,
const struct sectioncheck *mismatch,
const char *fromsec,
const char *fromsym,
const char *tosec, const char *tosym)
{
sec_mismatch_count++;
switch (mismatch->mismatch) {
case TEXT_TO_ANY_INIT:
case DATA_TO_ANY_INIT:
case TEXT_TO_ANY_EXIT:
case DATA_TO_ANY_EXIT:
case XXXINIT_TO_SOME_INIT:
case XXXEXIT_TO_SOME_EXIT:
case ANY_INIT_TO_ANY_EXIT:
case ANY_EXIT_TO_ANY_INIT:
warn("%s: section mismatch in reference: %s (section: %s) -> %s (section: %s)\n",
modname, fromsym, fromsec, tosym, tosec);
break;
case EXPORT_TO_INIT_EXIT:
warn("%s: EXPORT_SYMBOL used for init/exit symbol: %s (section: %s)\n",
modname, tosym, tosec);
break;
case EXTABLE_TO_NON_TEXT:
fatal("There's a special handler for this mismatch type, we should never get here.\n");
break;
}
}
static void default_mismatch_handler(const char *modname, struct elf_info *elf,
const struct sectioncheck* const mismatch,
Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
{
const char *tosec;
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);
tosec = sec_name(elf, get_secindex(elf, sym));
to = find_elf_symbol(elf, r->r_addend, sym);
tosym = sym_name(elf, to);
/* check whitelist - we may ignore it */
if (secref_whitelist(mismatch,
fromsec, fromsym, tosec, tosym)) {
report_sec_mismatch(modname, mismatch,
fromsec, fromsym, tosec, tosym);
}
}
static int is_executable_section(struct elf_info* elf, unsigned int section_index)
{
if (section_index > elf->num_sections)
fatal("section_index is outside elf->num_sections!\n");
return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
}
/*
* We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
* to know the sizeof(struct exception_table_entry) for the target architecture.
*/
static unsigned int extable_entry_size = 0;
static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
{
/*
* If we're currently checking the second relocation within __ex_table,
* that relocation offset tells us the offsetof(struct
* exception_table_entry, fixup) which is equal to sizeof(struct
* exception_table_entry) divided by two. We use that to our advantage
* since there's no portable way to get that size as every architecture
* seems to go with different sized types. Not pretty but better than
* hard-coding the size for every architecture..
*/
if (!extable_entry_size)
extable_entry_size = r->r_offset * 2;
}
static inline bool is_extable_fault_address(Elf_Rela *r)
{
/*
* extable_entry_size is only discovered after we've handled the
* _second_ relocation in __ex_table, so only abort when we're not
* handling the first reloc and extable_entry_size is zero.
*/
if (r->r_offset && extable_entry_size == 0)
fatal("extable_entry size hasn't been discovered!\n");
return ((r->r_offset == 0) ||
(r->r_offset % extable_entry_size == 0));
}
#define is_second_extable_reloc(Start, Cur, Sec) \
(((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
static void report_extable_warnings(const char* modname, struct elf_info* elf,
const struct sectioncheck* const mismatch,
Elf_Rela* r, Elf_Sym* sym,
const char* fromsec, const char* tosec)
{
Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
const char* fromsym_name = sym_name(elf, fromsym);
Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
const char* tosym_name = sym_name(elf, tosym);
const char* from_pretty_name;
const char* from_pretty_name_p;
const char* to_pretty_name;
const char* to_pretty_name_p;
get_pretty_name(is_function(fromsym),
&from_pretty_name, &from_pretty_name_p);
get_pretty_name(is_function(tosym),
&to_pretty_name, &to_pretty_name_p);
warn("%s(%s+0x%lx): Section mismatch in reference"
" from the %s %s%s to the %s %s:%s%s\n",
modname, fromsec, (long)r->r_offset, from_pretty_name,
fromsym_name, from_pretty_name_p,
to_pretty_name, tosec, tosym_name, to_pretty_name_p);
if (!match(tosec, mismatch->bad_tosec) &&
is_executable_section(elf, get_secindex(elf, sym)))
fprintf(stderr,
"The relocation at %s+0x%lx references\n"
"section \"%s\" which is not in the list of\n"
"authorized sections. If you're adding a new section\n"
"and/or if this reference is valid, add \"%s\" to the\n"
"list of authorized sections to jump to on fault.\n"
"This can be achieved by adding \"%s\" to \n"
"OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
fromsec, (long)r->r_offset, tosec, tosec, tosec);
}
static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
const struct sectioncheck* const mismatch,
Elf_Rela* r, Elf_Sym* sym,
const char *fromsec)
{
const char* tosec = sec_name(elf, get_secindex(elf, sym));
sec_mismatch_count++;
report_extable_warnings(modname, elf, mismatch, r, sym, fromsec, tosec);
if (match(tosec, mismatch->bad_tosec))
fatal("The relocation at %s+0x%lx references\n"
"section \"%s\" which is black-listed.\n"
"Something is seriously wrong and should be fixed.\n"
"You might get more information about where this is\n"
"coming from by using scripts/check_extable.sh %s\n",
fromsec, (long)r->r_offset, tosec, modname);
else if (!is_executable_section(elf, get_secindex(elf, sym))) {
if (is_extable_fault_address(r))
fatal("The relocation at %s+0x%lx references\n"
"section \"%s\" which is not executable, IOW\n"
"it is not possible for the kernel to fault\n"
"at that address. Something is seriously wrong\n"
"and should be fixed.\n",
fromsec, (long)r->r_offset, tosec);
else
fatal("The relocation at %s+0x%lx references\n"
"section \"%s\" which is not executable, IOW\n"
"the kernel will fault if it ever tries to\n"
"jump to it. Something is seriously wrong\n"
"and should be fixed.\n",
fromsec, (long)r->r_offset, tosec);
}
}
static void check_section_mismatch(const char *modname, struct elf_info *elf,
Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
{
const char *tosec = sec_name(elf, get_secindex(elf, sym));
const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
if (mismatch) {
if (mismatch->handler)
mismatch->handler(modname, elf, mismatch,
r, sym, fromsec);
else
default_mismatch_handler(modname, elf, mismatch,
r, sym, fromsec);
}
}
static unsigned int *reloc_location(struct elf_info *elf,
Elf_Shdr *sechdr, Elf_Rela *r)
{
return sym_get_data_by_offset(elf, sechdr->sh_info, r->r_offset);
}
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, sechdr, r);
switch (r_typ) {
case R_386_32:
r->r_addend = TO_NATIVE(*location);
break;
case R_386_PC32:
r->r_addend = TO_NATIVE(*location) + 4;
break;
}
return 0;
}
#ifndef R_ARM_CALL
#define R_ARM_CALL 28
#endif
#ifndef R_ARM_JUMP24
#define R_ARM_JUMP24 29
#endif
#ifndef R_ARM_THM_CALL
#define R_ARM_THM_CALL 10
#endif
#ifndef R_ARM_THM_JUMP24
#define R_ARM_THM_JUMP24 30
#endif
#ifndef R_ARM_THM_JUMP19
#define R_ARM_THM_JUMP19 51
#endif
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);
switch (r_typ) {
case R_ARM_ABS32:
/* From ARM ABI: (S + A) | T */
r->r_addend = (int)(long)
(elf->symtab_start + ELF_R_SYM(r->r_info));
break;
case R_ARM_PC24:
case R_ARM_CALL:
case R_ARM_JUMP24:
case R_ARM_THM_CALL:
case R_ARM_THM_JUMP24:
case R_ARM_THM_JUMP19:
/* From ARM ABI: ((S + A) | T) - P */
r->r_addend = (int)(long)(elf->hdr +
sechdr->sh_offset +
(r->r_offset - sechdr->sh_addr));
break;
default:
return 1;
}
return 0;
}
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, sechdr, r);
unsigned int inst;
if (r_typ == R_MIPS_HI16)
return 1; /* skip this */
inst = TO_NATIVE(*location);
switch (r_typ) {
case R_MIPS_LO16:
r->r_addend = inst & 0xffff;
break;
case R_MIPS_26:
r->r_addend = (inst & 0x03ffffff) << 2;
break;
case R_MIPS_32:
r->r_addend = inst;
break;
}
return 0;
}
#ifndef EM_RISCV
#define EM_RISCV 243
#endif
#ifndef R_RISCV_SUB32
#define R_RISCV_SUB32 39
#endif
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 = sec_name(elf, sechdr->sh_info);
/* if from section (name) is know good then skip it */
if (match(fromsec, section_white_list))
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);
switch (elf->hdr->e_machine) {
case EM_RISCV:
if (!strcmp("__ex_table", fromsec) &&
ELF_R_TYPE(r.r_info) == R_RISCV_SUB32)
continue;
break;
}
sym = elf->symtab_start + r_sym;
/* Skip special sections */
if (is_shndx_special(sym->st_shndx))
continue;
if (is_second_extable_reloc(start, rela, fromsec))
find_extable_entry_size(fromsec, &r);
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 = sec_name(elf, sechdr->sh_info);
/* if from section (name) is know good then skip it */
if (match(fromsec, section_white_list))
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 (is_shndx_special(sym->st_shndx))
continue;
if (is_second_extable_reloc(start, rel, fromsec))
find_extable_entry_size(fromsec, &r);
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.
* For loaded modules all functions marked __init and all data
* marked __initdata will be discarded when the module has been initialized.
* Likewise for modules used built-in the sections marked __exit
* are discarded because __exit marked function are supposed to be called
* only when a module is unloaded which never happens 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(const char *modname, struct elf_info *elf)
{
int i;
Elf_Shdr *sechdrs = elf->sechdrs;
/* Walk through all sections */
for (i = 0; i < elf->num_sections; i++) {
check_section(modname, elf, &elf->sechdrs[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]);
else if (sechdrs[i].sh_type == SHT_REL)
section_rel(modname, elf, &elf->sechdrs[i]);
}
}
static char *remove_dot(char *s)
{
size_t n = strcspn(s, ".");
if (n && s[n]) {
size_t m = strspn(s + n + 1, "0123456789");
if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
s[n] = 0;
}
return s;
}
/*
* The CRCs are recorded in .*.cmd files in the form of:
* #SYMVER <name> <crc>
*/
static void extract_crcs_for_object(const char *object, struct module *mod)
{
char cmd_file[PATH_MAX];
char *buf, *p;
const char *base;
int dirlen, ret;
base = strrchr(object, '/');
if (base) {
base++;
dirlen = base - object;
} else {
dirlen = 0;
base = object;
}
ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
dirlen, object, base);
if (ret >= sizeof(cmd_file)) {
error("%s: too long path was truncated\n", cmd_file);
return;
}
buf = read_text_file(cmd_file);
p = buf;
while ((p = strstr(p, "\n#SYMVER "))) {
char *name;
size_t namelen;
unsigned int crc;
struct symbol *sym;
name = p + strlen("\n#SYMVER ");
p = strchr(name, ' ');
if (!p)
break;
namelen = p - name;
p++;
if (!isdigit(*p))
continue; /* skip this line */
crc = strtol(p, &p, 0);
if (*p != '\n')
continue; /* skip this line */
name[namelen] = '\0';
/*
* sym_find_with_module() may return NULL here.
* It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
* Since commit e1327a127703, genksyms calculates CRCs of all
* symbols, including trimmed ones. Ignore orphan CRCs.
*/
sym = sym_find_with_module(name, mod);
if (sym)
sym_set_crc(sym, crc);
}
free(buf);
}
/*
* The symbol versions (CRC) are recorded in the .*.cmd files.
* Parse them to retrieve CRCs for the current module.
*/
static void mod_set_crcs(struct module *mod)
{
char objlist[PATH_MAX];
char *buf, *p, *obj;
int ret;
if (mod->is_vmlinux) {
strcpy(objlist, ".vmlinux.objs");
} else {
/* objects for a module are listed in the *.mod file. */
ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
if (ret >= sizeof(objlist)) {
error("%s: too long path was truncated\n", objlist);
return;
}
}
buf = read_text_file(objlist);
p = buf;
while ((obj = strsep(&p, "\n")) && obj[0])
extract_crcs_for_object(obj, mod);
free(buf);
}
static void read_symbols(const char *modname)
{
const char *symname;
char *version;
char *license;
char *namespace;
struct module *mod;
struct elf_info info = { };
Elf_Sym *sym;
if (!parse_elf(&info, modname))
return;
if (!strends(modname, ".o")) {
error("%s: filename must be suffixed with .o\n", modname);
return;
}
/* strip trailing .o */
mod = new_module(modname, strlen(modname) - strlen(".o"));
if (!mod->is_vmlinux) {
license = get_modinfo(&info, "license");
if (!license)
error("missing MODULE_LICENSE() in %s\n", modname);
while (license) {
if (!license_is_gpl_compatible(license)) {
mod->is_gpl_compatible = false;
break;
}
license = get_next_modinfo(&info, "license", license);
}
namespace = get_modinfo(&info, "import_ns");
while (namespace) {
add_namespace(&mod->imported_namespaces, namespace);
namespace = get_next_modinfo(&info, "import_ns",
namespace);
}
}
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
symname = remove_dot(info.strtab + sym->st_name);
handle_symbol(mod, &info, sym, symname);
handle_moddevtable(mod, &info, sym, symname);
}
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
symname = remove_dot(info.strtab + sym->st_name);
/* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
if (strstarts(symname, "__kstrtabns_"))
sym_update_namespace(symname + strlen("__kstrtabns_"),
sym_get_data(&info, sym));
}
check_sec_ref(modname, &info);
if (!mod->is_vmlinux) {
version = get_modinfo(&info, "version");
if (version || all_versions)
get_src_version(mod->name, mod->srcversion,
sizeof(mod->srcversion) - 1);
}
parse_elf_finish(&info);
if (modversions) {
/*
* Our trick to get versioning for module struct etc. - it's
* never passed as an argument to an exported function, so
* the automatic versioning doesn't pick it up, but it's really
* important anyhow.
*/
sym_add_unresolved("module_layout", mod, false);
mod_set_crcs(mod);
}
}
static void read_symbols_from_files(const char *filename)
{
FILE *in = stdin;
char fname[PATH_MAX];
if (strcmp(filename, "-") != 0) {
in = fopen(filename, "r");
if (!in)
fatal("Can't open filenames file %s: %m", filename);
}
while (fgets(fname, PATH_MAX, in) != NULL) {
if (strends(fname, "\n"))
fname[strlen(fname)-1] = '\0';
read_symbols(fname);
}
if (in != stdin)
fclose(in);
}
#define SZ 500
/* We first write the generated file into memory using the
* following helper, then compare to the file on disk and
* only update the later if anything changed */
void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
const char *fmt, ...)
{
char tmp[SZ];
int len;
va_list ap;
va_start(ap, fmt);
len = vsnprintf(tmp, SZ, fmt, ap);
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 + SZ;
buf->p = NOFAIL(realloc(buf->p, buf->size));
}
strncpy(buf->p + buf->pos, s, len);
buf->pos += len;
}
static void check_exports(struct module *mod)
{
struct symbol *s, *exp;
list_for_each_entry(s, &mod->unresolved_symbols, list) {
const char *basename;
exp = find_symbol(s->name);
if (!exp) {
if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
"\"%s\" [%s.ko] undefined!\n",
s->name, mod->name);
continue;
}
if (exp->module == mod) {
error("\"%s\" [%s.ko] was exported without definition\n",
s->name, mod->name);
continue;
}
s->module = exp->module;
s->crc_valid = exp->crc_valid;
s->crc = exp->crc;
basename = strrchr(mod->name, '/');
if (basename)
basename++;
else
basename = mod->name;
if (exp->namespace &&
!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
"module %s uses symbol %s from namespace %s, but does not import it.\n",
basename, exp->name, exp->namespace);
add_namespace(&mod->missing_namespaces, exp->namespace);
}
if (!mod->is_gpl_compatible && exp->is_gpl_only)
error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
basename, exp->name);
}
}
static void check_modname_len(struct module *mod)
{
const char *mod_name;
mod_name = strrchr(mod->name, '/');
if (mod_name == NULL)
mod_name = mod->name;
else
mod_name++;
if (strlen(mod_name) >= MODULE_NAME_LEN)
error("module name is too long [%s.ko]\n", mod->name);
}
/**
* Header for the generated file
**/
static void add_header(struct buffer *b, struct module *mod)
{
buf_printf(b, "#include <linux/module.h>\n");
/*
* Include build-salt.h after module.h in order to
* inherit the definitions.
*/
buf_printf(b, "#define INCLUDE_VERMAGIC\n");
buf_printf(b, "#include <linux/build-salt.h>\n");
buf_printf(b, "#include <linux/elfnote-lto.h>\n");
buf_printf(b, "#include <linux/export-internal.h>\n");
buf_printf(b, "#include <linux/vermagic.h>\n");
buf_printf(b, "#include <linux/compiler.h>\n");
buf_printf(b, "\n");
buf_printf(b, "BUILD_SALT;\n");
buf_printf(b, "BUILD_LTO_INFO;\n");
buf_printf(b, "\n");
buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
buf_printf(b, "\n");
buf_printf(b, "__visible struct module __this_module\n");
buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
if (mod->has_init)
buf_printf(b, "\t.init = init_module,\n");
if (mod->has_cleanup)
buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
"\t.exit = cleanup_module,\n"
"#endif\n");
buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
buf_printf(b, "};\n");
if (!external_module)
buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
buf_printf(b,
"\n"
"#ifdef CONFIG_RETPOLINE\n"
"MODULE_INFO(retpoline, \"Y\");\n"
"#endif\n");
if (strstarts(mod->name, "drivers/staging"))
buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
if (strstarts(mod->name, "tools/testing"))
buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
}
static void add_exported_symbols(struct buffer *buf, struct module *mod)
{
struct symbol *sym;
if (!modversions)
return;
/* record CRCs for exported symbols */
buf_printf(buf, "\n");
list_for_each_entry(sym, &mod->exported_symbols, list) {
if (!sym->crc_valid)
warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
"Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
sym->name);
buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
}
}
/**
* Record CRCs for unresolved symbols
**/
static void add_versions(struct buffer *b, struct module *mod)
{
struct symbol *s;
if (!modversions)
return;
buf_printf(b, "\n");
buf_printf(b, "static const struct modversion_info ____versions[]\n");
buf_printf(b, "__used __section(\"__versions\") = {\n");
list_for_each_entry(s, &mod->unresolved_symbols, list) {
if (!s->module)
continue;
if (!s->crc_valid) {
warn("\"%s\" [%s.ko] has no CRC!\n",
s->name, mod->name);
continue;
}
if (strlen(s->name) >= MODULE_NAME_LEN) {
error("too long symbol \"%s\" [%s.ko]\n",
s->name, mod->name);
break;
}
buf_printf(b, "\t{ %#8x, \"%s\" },\n",
s->crc, s->name);
}
buf_printf(b, "};\n");
}
static void add_depends(struct buffer *b, struct module *mod)
{
struct symbol *s;
int first = 1;
/* Clear ->seen flag of modules that own symbols needed by this. */
list_for_each_entry(s, &mod->unresolved_symbols, list) {
if (s->module)
s->module->seen = s->module->is_vmlinux;
}
buf_printf(b, "\n");
buf_printf(b, "MODULE_INFO(depends, \"");
list_for_each_entry(s, &mod->unresolved_symbols, list) {
const char *p;
if (!s->module)
continue;
if (s->module->seen)
continue;
s->module->seen = true;
p = strrchr(s->module->name, '/');
if (p)
p++;
else
p = s->module->name;
buf_printf(b, "%s%s", first ? "" : ",", p);
first = 0;
}
buf_printf(b, "\");\n");
}
static void add_srcversion(struct buffer *b, struct module *mod)
{
if (mod->srcversion[0]) {
buf_printf(b, "\n");
buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
mod->srcversion);
}
}
static void write_buf(struct buffer *b, const char *fname)
{
FILE *file;
if (error_occurred)
return;
file = fopen(fname, "w");
if (!file) {
perror(fname);
exit(1);
}
if (fwrite(b->p, 1, b->pos, file) != b->pos) {
perror(fname);
exit(1);
}
if (fclose(file) != 0) {
perror(fname);
exit(1);
}
}
static void write_if_changed(struct buffer *b, const char *fname)
{
char *tmp;
FILE *file;
struct stat st;
file = fopen(fname, "r");
if (!file)
goto write;
if (fstat(fileno(file), &st) < 0)
goto close_write;
if (st.st_size != b->pos)
goto close_write;
tmp = NOFAIL(malloc(b->pos));
if (fread(tmp, 1, b->pos, file) != b->pos)
goto free_write;
if (memcmp(tmp, b->p, b->pos) != 0)
goto free_write;
free(tmp);
fclose(file);
return;
free_write:
free(tmp);
close_write:
fclose(file);
write:
write_buf(b, fname);
}
static void write_vmlinux_export_c_file(struct module *mod)
{
struct buffer buf = { };
buf_printf(&buf,
"#include <linux/export-internal.h>\n");
add_exported_symbols(&buf, mod);
write_if_changed(&buf, ".vmlinux.export.c");
free(buf.p);
}
/* do sanity checks, and generate *.mod.c file */
static void write_mod_c_file(struct module *mod)
{
struct buffer buf = { };
char fname[PATH_MAX];
int ret;
check_modname_len(mod);
check_exports(mod);
add_header(&buf, mod);
add_exported_symbols(&buf, mod);
add_versions(&buf, mod);
add_depends(&buf, mod);
add_moddevtable(&buf, mod);
add_srcversion(&buf, mod);
ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
if (ret >= sizeof(fname)) {
error("%s: too long path was truncated\n", fname);
goto free;
}
write_if_changed(&buf, fname);
free:
free(buf.p);
}
/* parse Module.symvers file. line format:
* 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
**/
static void read_dump(const char *fname)
{
char *buf, *pos, *line;
buf = read_text_file(fname);
if (!buf)
/* No symbol versions, silently ignore */
return;
pos = buf;
while ((line = get_line(&pos))) {
char *symname, *namespace, *modname, *d, *export;
unsigned int crc;
struct module *mod;
struct symbol *s;
bool gpl_only;
if (!(symname = strchr(line, '\t')))
goto fail;
*symname++ = '\0';
if (!(modname = strchr(symname, '\t')))
goto fail;
*modname++ = '\0';
if (!(export = strchr(modname, '\t')))
goto fail;
*export++ = '\0';
if (!(namespace = strchr(export, '\t')))
goto fail;
*namespace++ = '\0';
crc = strtoul(line, &d, 16);
if (*symname == '\0' || *modname == '\0' || *d != '\0')
goto fail;
if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
gpl_only = true;
} else if (!strcmp(export, "EXPORT_SYMBOL")) {
gpl_only = false;
} else {
error("%s: unknown license %s. skip", symname, export);
continue;
}
mod = find_module(modname);
if (!mod) {
mod = new_module(modname, strlen(modname));
mod->from_dump = true;
}
s = sym_add_exported(symname, mod, gpl_only);
sym_set_crc(s, crc);
sym_update_namespace(symname, namespace);
}
free(buf);
return;
fail:
free(buf);
fatal("parse error in symbol dump file\n");
}
static void write_dump(const char *fname)
{
struct buffer buf = { };
struct module *mod;
struct symbol *sym;
list_for_each_entry(mod, &modules, list) {
if (mod->from_dump)
continue;
list_for_each_entry(sym, &mod->exported_symbols, list) {
buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
sym->crc, sym->name, mod->name,
sym->is_gpl_only ? "_GPL" : "",
sym->namespace ?: "");
}
}
write_buf(&buf, fname);
free(buf.p);
}
static void write_namespace_deps_files(const char *fname)
{
struct module *mod;
struct namespace_list *ns;
struct buffer ns_deps_buf = {};
list_for_each_entry(mod, &modules, list) {
if (mod->from_dump || list_empty(&mod->missing_namespaces))
continue;
buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
list_for_each_entry(ns, &mod->missing_namespaces, list)
buf_printf(&ns_deps_buf, " %s", ns->namespace);
buf_printf(&ns_deps_buf, "\n");
}
write_if_changed(&ns_deps_buf, fname);
free(ns_deps_buf.p);
}
struct dump_list {
struct list_head list;
const char *file;
};
int main(int argc, char **argv)
{
struct module *mod;
char *missing_namespace_deps = NULL;
char *dump_write = NULL, *files_source = NULL;
int opt;
LIST_HEAD(dump_lists);
struct dump_list *dl, *dl2;
while ((opt = getopt(argc, argv, "ei:mnT:o:awENd:")) != -1) {
switch (opt) {
case 'e':
external_module = true;
break;
case 'i':
dl = NOFAIL(malloc(sizeof(*dl)));
dl->file = optarg;
list_add_tail(&dl->list, &dump_lists);
break;
case 'm':
modversions = true;
break;
case 'n':
ignore_missing_files = true;
break;
case 'o':
dump_write = optarg;
break;
case 'a':
all_versions = true;
break;
case 'T':
files_source = optarg;
break;
case 'w':
warn_unresolved = true;
break;
case 'E':
sec_mismatch_warn_only = false;
break;
case 'N':
allow_missing_ns_imports = true;
break;
case 'd':
missing_namespace_deps = optarg;
break;
default:
exit(1);
}
}
list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
read_dump(dl->file);
list_del(&dl->list);
free(dl);
}
while (optind < argc)
read_symbols(argv[optind++]);
if (files_source)
read_symbols_from_files(files_source);
list_for_each_entry(mod, &modules, list) {
if (mod->from_dump)
continue;
if (mod->is_vmlinux)
write_vmlinux_export_c_file(mod);
else
write_mod_c_file(mod);
}
if (missing_namespace_deps)
write_namespace_deps_files(missing_namespace_deps);
if (dump_write)
write_dump(dump_write);
if (sec_mismatch_count && !sec_mismatch_warn_only)
error("Section mismatches detected.\n"
"Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
warn("suppressed %u unresolved symbol warnings because there were too many)\n",
nr_unresolved - MAX_UNRESOLVED_REPORTS);
return error_occurred ? 1 : 0;
}
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