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android_kernel_motorola_sm6225/scripts/mod/modpost.c
Sam Ravnborg cb7e51d8b1 kbuild: fix modpost warnings for xtensa 
The Xtensa architecture places literal pools in sections separate
from the instructions. The corresponsing text sections, therefore,
reference the .literal section, and we have to suppress those
warnings.

The naming convention defines the name for a literal
section as .SECTION.literal, unless .SECTION is .text. In that case
the name is only .literal. Using strncmp() instead of strcmp()
to compare the from-section with .SECTION.init.refok in pattern 0
should not cause any regressions for other architectures.

We also need to suppress warnings for two informational
sections (.xt.lit and .xt.prop) used by the Xtensa architecture.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-07-25 22:24:52 +02:00

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/* Postprocess module symbol versions
*
* 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
* of the GNU General Public License, incorporated herein by reference.
*
* Usage: modpost vmlinux module1.o module2.o ...
*/
#include <ctype.h>
#include "modpost.h"
#include "../../include/linux/license.h"
/* Are we using CONFIG_MODVERSIONS? */
int modversions = 0;
/* Warn about undefined symbols? (do so if we have vmlinux) */
int have_vmlinux = 0;
/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
static int all_versions = 0;
/* If we are modposting external module set to 1 */
static int external_module = 0;
/* Warn about section mismatch in vmlinux if set to 1 */
static int vmlinux_section_warnings = 1;
/* Only warn about unresolved symbols */
static int warn_unresolved = 0;
/* How a symbol is exported */
enum export {
export_plain, export_unused, export_gpl,
export_unused_gpl, export_gpl_future, export_unknown
};
void fatal(const char *fmt, ...)
{
va_list arglist;
fprintf(stderr, "FATAL: ");
va_start(arglist, fmt);
vfprintf(stderr, fmt, arglist);
va_end(arglist);
exit(1);
}
void warn(const char *fmt, ...)
{
va_list arglist;
fprintf(stderr, "WARNING: ");
va_start(arglist, fmt);
vfprintf(stderr, fmt, arglist);
va_end(arglist);
}
void merror(const char *fmt, ...)
{
va_list arglist;
fprintf(stderr, "ERROR: ");
va_start(arglist, fmt);
vfprintf(stderr, fmt, arglist);
va_end(arglist);
}
static int is_vmlinux(const char *modname)
{
const char *myname;
if ((myname = strrchr(modname, '/')))
myname++;
else
myname = modname;
return (strcmp(myname, "vmlinux") == 0) ||
(strcmp(myname, "vmlinux.o") == 0);
}
void *do_nofail(void *ptr, const char *expr)
{
if (!ptr) {
fatal("modpost: Memory allocation failure: %s.\n", expr);
}
return ptr;
}
/* A list of all modules we processed */
static struct module *modules;
static struct module *find_module(char *modname)
{
struct module *mod;
for (mod = modules; mod; mod = mod->next)
if (strcmp(mod->name, modname) == 0)
break;
return mod;
}
static struct module *new_module(char *modname)
{
struct module *mod;
char *p, *s;
mod = NOFAIL(malloc(sizeof(*mod)));
memset(mod, 0, sizeof(*mod));
p = NOFAIL(strdup(modname));
/* strip trailing .o */
if ((s = strrchr(p, '.')) != NULL)
if (strcmp(s, ".o") == 0)
*s = '\0';
/* add to list */
mod->name = p;
mod->gpl_compatible = -1;
mod->next = modules;
modules = mod;
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 module *module;
unsigned int crc;
int crc_valid;
unsigned int weak:1;
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 */
enum export export; /* Type of export */
char name[0];
};
static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
/* This is based on the hash agorithm 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, unsigned int weak,
struct symbol *next)
{
struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
memset(s, 0, sizeof(*s));
strcpy(s->name, name);
s->weak = weak;
s->next = next;
return s;
}
/* For the hash of exported symbols */
static struct symbol *new_symbol(const char *name, struct module *module,
enum export export)
{
unsigned int hash;
struct symbol *new;
hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
new->module = module;
new->export = export;
return new;
}
static struct symbol *find_symbol(const char *name)
{
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)
return s;
}
return NULL;
}
static struct {
const char *str;
enum export export;
} export_list[] = {
{ .str = "EXPORT_SYMBOL", .export = export_plain },
{ .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
{ .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
{ .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
{ .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
{ .str = "(unknown)", .export = export_unknown },
};
static const char *export_str(enum export ex)
{
return export_list[ex].str;
}
static enum export export_no(const char * s)
{
int i;
if (!s)
return export_unknown;
for (i = 0; export_list[i].export != export_unknown; i++) {
if (strcmp(export_list[i].str, s) == 0)
return export_list[i].export;
}
return export_unknown;
}
static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
{
if (sec == elf->export_sec)
return export_plain;
else if (sec == elf->export_unused_sec)
return export_unused;
else if (sec == elf->export_gpl_sec)
return export_gpl;
else if (sec == elf->export_unused_gpl_sec)
return export_unused_gpl;
else if (sec == elf->export_gpl_future_sec)
return export_gpl_future;
else
return export_unknown;
}
/**
* Add an exported symbol - it may have already been added without a
* CRC, in this case just update the CRC
**/
static struct symbol *sym_add_exported(const char *name, struct module *mod,
enum export export)
{
struct symbol *s = find_symbol(name);
if (!s) {
s = new_symbol(name, mod, export);
} 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;
s->export = export;
return s;
}
static void sym_update_crc(const char *name, struct module *mod,
unsigned int crc, enum export export)
{
struct symbol *s = find_symbol(name);
if (!s)
s = new_symbol(name, mod, export);
s->crc = crc;
s->crc_valid = 1;
}
void *grab_file(const char *filename, unsigned long *size)
{
struct stat st;
void *map;
int fd;
fd = open(filename, O_RDONLY);
if (fd < 0 || fstat(fd, &st) != 0)
return NULL;
*size = st.st_size;
map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
close(fd);
if (map == MAP_FAILED)
return NULL;
return map;
}
/**
* Return a copy of the next line in a mmap'ed file.
* spaces in the beginning of the line is trimmed away.
* Return a pointer to a static buffer.
**/
char* get_next_line(unsigned long *pos, void *file, unsigned long size)
{
static char line[4096];
int skip = 1;
size_t len = 0;
signed char *p = (signed char *)file + *pos;
char *s = line;
for (; *pos < size ; (*pos)++)
{
if (skip && isspace(*p)) {
p++;
continue;
}
skip = 0;
if (*p != '\n' && (*pos < size)) {
len++;
*s++ = *p++;
if (len > 4095)
break; /* Too long, stop */
} else {
/* End of string */
*s = '\0';
return line;
}
}
/* End of buffer */
return NULL;
}
void release_file(void *file, unsigned long 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;
hdr = grab_file(filename, &info->size);
if (!hdr) {
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_shoff = TO_NATIVE(hdr->e_shoff);
hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
hdr->e_machine = TO_NATIVE(hdr->e_machine);
hdr->e_type = TO_NATIVE(hdr->e_type);
sechdrs = (void *)hdr + hdr->e_shoff;
info->sechdrs = sechdrs;
/* Fix endianness in section headers */
for (i = 0; i < hdr->e_shnum; i++) {
sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
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_name = TO_NATIVE(sechdrs[i].sh_name);
sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
}
/* Find symbol table. */
for (i = 1; i < hdr->e_shnum; i++) {
const char *secstrings
= (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
const char *secname;
if (sechdrs[i].sh_offset > info->size) {
fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr));
return 0;
}
secname = secstrings + sechdrs[i].sh_name;
if (strcmp(secname, ".modinfo") == 0) {
info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
info->modinfo_len = sechdrs[i].sh_size;
} else if (strcmp(secname, "__ksymtab") == 0)
info->export_sec = i;
else if (strcmp(secname, "__ksymtab_unused") == 0)
info->export_unused_sec = i;
else if (strcmp(secname, "__ksymtab_gpl") == 0)
info->export_gpl_sec = i;
else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
info->export_unused_gpl_sec = i;
else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
info->export_gpl_future_sec = i;
if (sechdrs[i].sh_type != SHT_SYMTAB)
continue;
info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
+ sechdrs[i].sh_size;
info->strtab = (void *)hdr +
sechdrs[sechdrs[i].sh_link].sh_offset;
}
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);
}
return 1;
}
static void parse_elf_finish(struct elf_info *info)
{
release_file(info->hdr, info->size);
}
#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)
{
unsigned int crc;
enum export export = export_from_sec(info, sym->st_shndx);
switch (sym->st_shndx) {
case SHN_COMMON:
warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
break;
case SHN_ABS:
/* CRC'd symbol */
if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
crc = (unsigned int) sym->st_value;
sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
export);
}
break;
case SHN_UNDEF:
/* undefined symbol */
if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
ELF_ST_BIND(sym->st_info) != STB_WEAK)
break;
/* ignore global offset table */
if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
break;
/* ignore __this_module, it will be resolved shortly */
if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
break;
/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
/* add compatibility with older glibc */
#ifndef STT_SPARC_REGISTER
#define STT_SPARC_REGISTER STT_REGISTER
#endif
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 = 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 +
strlen(MODULE_SYMBOL_PREFIX),
ELF_ST_BIND(sym->st_info) == STB_WEAK,
mod->unres);
break;
default:
/* All exported symbols */
if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
export);
}
if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
mod->has_init = 1;
if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
mod->has_cleanup = 1;
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(void *modinfo, unsigned long modinfo_len,
const char *tag, char *info)
{
char *p;
unsigned int taglen = strlen(tag);
unsigned long size = modinfo_len;
if (info) {
size -= info - (char *)modinfo;
modinfo = next_string(info, &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(void *modinfo, unsigned long modinfo_len,
const char *tag)
{
return get_next_modinfo(modinfo, modinfo_len, tag, 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);
}
/*
* 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;
}
/*
* 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;
}
/*
* Data sections are named like this:
* .data | .data.rel | .data.rel.*
* Return 1 if the specified section is a data section
*/
static int data_section(const char *name)
{
if ((strcmp(name, ".data") == 0) ||
(strcmp(name, ".data.rel") == 0) ||
(strncmp(name, ".data.rel.", strlen(".data.rel.")) == 0))
return 1;
else
return 0;
}
/**
* Whitelist to allow certain references to pass with no warning.
*
* Pattern 0:
* Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
* The pattern is identified by:
* fromsec = .text.init.refok* | .data.init.refok*
*
* 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 or exit section
* fromsec = data section
* atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console, *_timer
*
* Pattern 3:
* Whitelist all refereces from .text.head to .init.data
* Whitelist all refereces from .text.head to .init.text
*
* 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:
* Xtensa uses literal sections for constants that are accessed PC-relative.
* Literal sections may safely reference their text sections.
* (Note that the name for the literal section omits any trailing '.text')
* tosec = <section>[.text]
* fromsec = <section>.literal
**/
static int secref_whitelist(const char *modname, const char *tosec,
const char *fromsec, const char *atsym,
const char *refsymname)
{
int len;
const char **s;
const char *pat2sym[] = {
"driver",
"_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",
NULL
};
const char *pat3refsym[] = {
"__init_begin",
"_sinittext",
"_einittext",
NULL
};
/* Check for pattern 0 */
if ((strncmp(fromsec, ".text.init.refok", strlen(".text.init.refok")) == 0) ||
(strncmp(fromsec, ".data.init.refok", strlen(".data.init.refok")) == 0))
return 1;
/* Check for pattern 1 */
if ((strcmp(tosec, ".init.data") == 0) &&
(strncmp(fromsec, ".data", strlen(".data")) == 0) &&
(strncmp(atsym, "__param", strlen("__param")) == 0))
return 1;
/* Check for pattern 2 */
if ((init_section(tosec) || exit_section(tosec)) && data_section(fromsec))
for (s = pat2sym; *s; s++)
if (strrcmp(atsym, *s) == 0)
return 1;
/* Check for pattern 3 */
if ((strcmp(fromsec, ".text.head") == 0) &&
((strcmp(tosec, ".init.data") == 0) ||
(strcmp(tosec, ".init.text") == 0)))
return 1;
/* Check for pattern 4 */
for (s = pat3refsym; *s; s++)
if (strcmp(refsymname, *s) == 0)
return 1;
/* Check for pattern 5 */
if (strrcmp(tosec, ".text") == 0)
len = strlen(tosec) - strlen(".text");
else
len = strlen(tosec);
if ((strncmp(tosec, fromsec, len) == 0) && (strlen(fromsec) > len) &&
(strcmp(fromsec + len, ".literal") == 0))
return 1;
return 0;
}
/**
* 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 (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
continue;
if (sym->st_value == addr)
return sym;
}
return NULL;
}
static inline int is_arm_mapping_symbol(const char *str)
{
return str[0] == '$' && strchr("atd", str[1])
&& (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 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 (!is_valid_name(elf, sym))
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) {
*before = sym;
}
}
else
{
if ((sym->st_value - addr) < afterdiff) {
afterdiff = sym->st_value - addr;
*after = sym;
}
else if ((sym->st_value - addr) == afterdiff) {
*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 (secref_whitelist(modname, secname, fromsec,
before ? elf->strtab + before->st_name : "",
refsymname))
return;
if (before && after) {
warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
"(between '%s' and '%s')\n",
modname, fromsec, (unsigned long long)r.r_offset,
secname, refsymname,
elf->strtab + before->st_name,
elf->strtab + after->st_name);
} else if (before) {
warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
"(after '%s')\n",
modname, fromsec, (unsigned long long)r.r_offset,
secname, refsymname,
elf->strtab + before->st_name);
} else if (after) {
warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
"before '%s' (at offset -0x%llx)\n",
modname, fromsec, (unsigned long long)r.r_offset,
secname, refsymname,
elf->strtab + after->st_name);
} else {
warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",
modname, fromsec, (unsigned long long)r.r_offset,
secname, refsymname);
}
}
static unsigned int *reloc_location(struct elf_info *elf,
int rsection, Elf_Rela *r)
{
Elf_Shdr *sechdrs = elf->sechdrs;
int section = sechdrs[rsection].sh_info;
return (void *)elf->hdr + sechdrs[section].sh_offset +
(r->r_offset - sechdrs[section].sh_addr);
}
static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
{
unsigned int r_typ = ELF_R_TYPE(r->r_info);
unsigned int *location = reloc_location(elf, rsection, 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;
/* For CONFIG_RELOCATABLE=y */
if (elf->hdr->e_type == ET_EXEC)
r->r_addend += r->r_offset;
break;
}
return 0;
}
static int addend_arm_rel(struct elf_info *elf, int rsection, 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:
/* From ARM ABI: ((S + A) | T) - P */
r->r_addend = (int)(long)(elf->hdr + elf->sechdrs[rsection].sh_offset +
(r->r_offset - elf->sechdrs[rsection].sh_addr));
break;
default:
return 1;
}
return 0;
}
static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
{
unsigned int r_typ = ELF_R_TYPE(r->r_info);
unsigned int *location = reloc_location(elf, rsection, 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;
}
/**
* 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) {
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);
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) {
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 (hdr->e_machine) {
case EM_386:
if (addend_386_rel(elf, i, &r))
continue;
break;
case EM_ARM:
if(addend_arm_rel(elf, i, &r))
continue;
break;
case EM_MIPS:
if (addend_mips_rel(elf, i, &r))
continue;
break;
}
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 either a
* .init or a .exit section is OK.
*
* [OPD] Keith Ownes <kaos@sgi.com> commented:
* For our future {in}sanity, add a comment that this is the ppc .opd
* section, not the ia64 .opd section.
* ia64 .opd should not point to discarded sections.
* [.rodata] like for .init.text we ignore .rodata references -same reason
*/
static int initexit_section_ref_ok(const char *name)
{
const char **s;
/* Absolute section names */
const char *namelist1[] = {
"__bug_table", /* used by powerpc for BUG() */
"__ex_table",
".altinstructions",
".cranges", /* used by sh64 */
".fixup",
".machvec", /* ia64 + powerpc uses these */
".machine.desc",
".opd", /* See comment [OPD] */
".parainstructions",
".pdr",
".plt", /* seen on ARCH=um build on x86_64. Harmless */
".smp_locks",
".stab",
".m68k_fixup",
".xt.prop", /* xtensa informational section */
".xt.lit", /* xtensa informational section */
NULL
};
/* Start of section names */
const char *namelist2[] = {
".debug",
".eh_frame",
".note", /* ignore ELF notes - may contain anything */
".got", /* powerpc - global offset table */
".toc", /* powerpc - table of contents */
NULL
};
/* part of section name */
const char *namelist3 [] = {
".unwind", /* Sample: IA_64.unwind.exit.text */
NULL
};
for (s = namelist1; *s; s++)
if (strcmp(*s, name) == 0)
return 1;
for (s = namelist2; *s; s++)
if (strncmp(*s, name, strlen(*s)) == 0)
return 1;
for (s = namelist3; *s; s++)
if (strstr(name, *s) != NULL)
return 1;
return 0;
}
/*
* Identify sections from which references to a .init section is OK.
*
* Unfortunately references to read only data that referenced .init
* sections had to be excluded. Almost all of these are false
* positives, they are created by gcc. The downside of excluding rodata
* is that there really are some user references from rodata to
* init code, e.g. drivers/video/vgacon.c:
*
* const struct consw vga_con = {
* con_startup: vgacon_startup,
*
* where vgacon_startup is __init. If you want to wade through the false
* positives, take out the check for rodata.
*/
static int init_section_ref_ok(const char *name)
{
const char **s;
/* Absolute section names */
const char *namelist1[] = {
"__dbe_table", /* MIPS generate these */
"__ftr_fixup", /* powerpc cpu feature fixup */
"__fw_ftr_fixup", /* powerpc firmware feature fixup */
"__param",
".data.rel.ro", /* used by parisc64 */
".init",
".text.lock",
NULL
};
/* Start of section names */
const char *namelist2[] = {
".init.",
".pci_fixup",
".rodata",
NULL
};
if (initexit_section_ref_ok(name))
return 1;
for (s = namelist1; *s; s++)
if (strcmp(*s, name) == 0)
return 1;
for (s = namelist2; *s; s++)
if (strncmp(*s, name, strlen(*s)) == 0)
return 1;
/* If section name ends with ".init" we allow references
* as is the case with .initcallN.init, .early_param.init, .taglist.init etc
*/
if (strrcmp(name, ".init") == 0)
return 1;
return 0;
}
/*
* Identify sections from which references to a .exit section is OK.
*/
static int exit_section_ref_ok(const char *name)
{
const char **s;
/* Absolute section names */
const char *namelist1[] = {
".exit.data",
".exit.text",
".exitcall.exit",
".rodata",
NULL
};
if (initexit_section_ref_ok(name))
return 1;
for (s = namelist1; *s; s++)
if (strcmp(*s, name) == 0)
return 1;
return 0;
}
static void read_symbols(char *modname)
{
const char *symname;
char *version;
char *license;
struct module *mod;
struct elf_info info = { };
Elf_Sym *sym;
if (!parse_elf(&info, modname))
return;
mod = new_module(modname);
/* When there's no vmlinux, don't print warnings about
* unresolved symbols (since there'll be too many ;) */
if (is_vmlinux(modname)) {
have_vmlinux = 1;
mod->skip = 1;
}
license = get_modinfo(info.modinfo, info.modinfo_len, "license");
while (license) {
if (license_is_gpl_compatible(license))
mod->gpl_compatible = 1;
else {
mod->gpl_compatible = 0;
break;
}
license = get_next_modinfo(info.modinfo, info.modinfo_len,
"license", license);
}
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
symname = info.strtab + sym->st_name;
handle_modversions(mod, &info, sym, symname);
handle_moddevtable(mod, &info, sym, symname);
}
if (is_vmlinux(modname) && vmlinux_section_warnings) {
check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
}
version = get_modinfo(info.modinfo, info.modinfo_len, "version");
if (version)
maybe_frob_rcs_version(modname, version, info.modinfo,
version - (char *)info.hdr);
if (version || (all_versions && !is_vmlinux(modname)))
get_src_version(modname, mod->srcversion,
sizeof(mod->srcversion)-1);
parse_elf_finish(&info);
/* Our trick to get versioning for struct_module - 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 */
if (modversions)
mod->unres = alloc_symbol("struct_module", 0, mod->unres);
}
#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 = realloc(buf->p, buf->size);
}
strncpy(buf->p + buf->pos, s, len);
buf->pos += len;
}
static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
{
const char *e = is_vmlinux(m) ?"":".ko";
switch (exp) {
case export_gpl:
fatal("modpost: GPL-incompatible module %s%s "
"uses GPL-only symbol '%s'\n", m, e, s);
break;
case export_unused_gpl:
fatal("modpost: GPL-incompatible module %s%s "
"uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
break;
case export_gpl_future:
warn("modpost: GPL-incompatible module %s%s "
"uses future GPL-only symbol '%s'\n", m, e, s);
break;
case export_plain:
case export_unused:
case export_unknown:
/* ignore */
break;
}
}
static void check_for_unused(enum export exp, const char* m, const char* s)
{
const char *e = is_vmlinux(m) ?"":".ko";
switch (exp) {
case export_unused:
case export_unused_gpl:
warn("modpost: module %s%s "
"uses symbol '%s' marked UNUSED\n", m, e, s);
break;
default:
/* ignore */
break;
}
}
static void check_exports(struct module *mod)
{
struct symbol *s, *exp;
for (s = mod->unres; s; s = s->next) {
const char *basename;
exp = find_symbol(s->name);
if (!exp || exp->module == mod)
continue;
basename = strrchr(mod->name, '/');
if (basename)
basename++;
else
basename = mod->name;
if (!mod->gpl_compatible)
check_for_gpl_usage(exp->export, basename, exp->name);
check_for_unused(exp->export, basename, exp->name);
}
}
/**
* Header for the generated file
**/
static void add_header(struct buffer *b, struct module *mod)
{
buf_printf(b, "#include <linux/module.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, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
buf_printf(b, "\n");
buf_printf(b, "struct module __this_module\n");
buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
buf_printf(b, " .name = KBUILD_MODNAME,\n");
if (mod->has_init)
buf_printf(b, " .init = init_module,\n");
if (mod->has_cleanup)
buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
" .exit = cleanup_module,\n"
"#endif\n");
buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
buf_printf(b, "};\n");
}
/**
* Record CRCs for unresolved symbols
**/
static int add_versions(struct buffer *b, struct module *mod)
{
struct symbol *s, *exp;
int err = 0;
for (s = mod->unres; s; s = s->next) {
exp = find_symbol(s->name);
if (!exp || exp->module == mod) {
if (have_vmlinux && !s->weak) {
if (warn_unresolved) {
warn("\"%s\" [%s.ko] undefined!\n",
s->name, mod->name);
} else {
merror("\"%s\" [%s.ko] undefined!\n",
s->name, mod->name);
err = 1;
}
}
continue;
}
s->module = exp->module;
s->crc_valid = exp->crc_valid;
s->crc = exp->crc;
}
if (!modversions)
return err;
buf_printf(b, "\n");
buf_printf(b, "static const struct modversion_info ____versions[]\n");
buf_printf(b, "__attribute_used__\n");
buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
for (s = mod->unres; s; s = s->next) {
if (!s->module) {
continue;
}
if (!s->crc_valid) {
warn("\"%s\" [%s.ko] has no CRC!\n",
s->name, mod->name);
continue;
}
buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
}
buf_printf(b, "};\n");
return err;
}
static void add_depends(struct buffer *b, struct module *mod,
struct module *modules)
{
struct symbol *s;
struct module *m;
int first = 1;
for (m = modules; m; m = m->next) {
m->seen = is_vmlinux(m->name);
}
buf_printf(b, "\n");
buf_printf(b, "static const char __module_depends[]\n");
buf_printf(b, "__attribute_used__\n");
buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
buf_printf(b, "\"depends=");
for (s = mod->unres; s; s = s->next) {
const char *p;
if (!s->module)
continue;
if (s->module->seen)
continue;
s->module->seen = 1;
if ((p = strrchr(s->module->name, '/')) != NULL)
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_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:
file = fopen(fname, "w");
if (!file) {
perror(fname);
exit(1);
}
if (fwrite(b->p, 1, b->pos, file) != b->pos) {
perror(fname);
exit(1);
}
fclose(file);
}
/* parse Module.symvers file. line format:
* 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
**/
static void read_dump(const char *fname, unsigned int kernel)
{
unsigned long size, pos = 0;
void *file = grab_file(fname, &size);
char *line;
if (!file)
/* No symbol versions, silently ignore */
return;
while ((line = get_next_line(&pos, file, size))) {
char *symname, *modname, *d, *export, *end;
unsigned int crc;
struct module *mod;
struct symbol *s;
if (!(symname = strchr(line, '\t')))
goto fail;
*symname++ = '\0';
if (!(modname = strchr(symname, '\t')))
goto fail;
*modname++ = '\0';
if ((export = strchr(modname, '\t')) != NULL)
*export++ = '\0';
if (export && ((end = strchr(export, '\t')) != NULL))
*end = '\0';
crc = strtoul(line, &d, 16);
if (*symname == '\0' || *modname == '\0' || *d != '\0')
goto fail;
if (!(mod = find_module(modname))) {
if (is_vmlinux(modname)) {
have_vmlinux = 1;
}
mod = new_module(NOFAIL(strdup(modname)));
mod->skip = 1;
}
s = sym_add_exported(symname, mod, export_no(export));
s->kernel = kernel;
s->preloaded = 1;
sym_update_crc(symname, mod, crc, export_no(export));
}
return;
fail:
fatal("parse error in symbol dump file\n");
}
/* For normal builds always dump all symbols.
* For external modules only dump symbols
* that are not read from kernel Module.symvers.
**/
static int dump_sym(struct symbol *sym)
{
if (!external_module)
return 1;
if (sym->vmlinux || sym->kernel)
return 0;
return 1;
}
static void write_dump(const char *fname)
{
struct buffer buf = { };
struct symbol *symbol;
int n;
for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
symbol = symbolhash[n];
while (symbol) {
if (dump_sym(symbol))
buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
symbol->crc, symbol->name,
symbol->module->name,
export_str(symbol->export));
symbol = symbol->next;
}
}
write_if_changed(&buf, fname);
}
int main(int argc, char **argv)
{
struct module *mod;
struct buffer buf = { };
char fname[SZ];
char *kernel_read = NULL, *module_read = NULL;
char *dump_write = NULL;
int opt;
int err;
while ((opt = getopt(argc, argv, "i:I:mso:aw")) != -1) {
switch(opt) {
case 'i':
kernel_read = optarg;
break;
case 'I':
module_read = optarg;
external_module = 1;
break;
case 'm':
modversions = 1;
break;
case 'o':
dump_write = optarg;
break;
case 'a':
all_versions = 1;
break;
case 's':
vmlinux_section_warnings = 0;
break;
case 'w':
warn_unresolved = 1;
break;
default:
exit(1);
}
}
if (kernel_read)
read_dump(kernel_read, 1);
if (module_read)
read_dump(module_read, 0);
while (optind < argc) {
read_symbols(argv[optind++]);
}
for (mod = modules; mod; mod = mod->next) {
if (mod->skip)
continue;
check_exports(mod);
}
err = 0;
for (mod = modules; mod; mod = mod->next) {
if (mod->skip)
continue;
buf.pos = 0;
add_header(&buf, mod);
err |= add_versions(&buf, mod);
add_depends(&buf, mod, modules);
add_moddevtable(&buf, mod);
add_srcversion(&buf, mod);
sprintf(fname, "%s.mod.c", mod->name);
write_if_changed(&buf, fname);
}
if (dump_write)
write_dump(dump_write);
return err;
}
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