/*
SPDX-License-Identifier: GPL-2.0-only
Copyright (C) 2019 Arnaldo Carvalho de Melo <acme@redhat.com>
*/
#include <fcntl.h>
#include <gelf.h>
#include <limits.h>
#include <malloc.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <zlib.h>
#include "libctf.h"
#include "ctf.h"
#include "dutil.h"
#include "gobuffer.h"
#include "pahole_strings.h"
bool ctf__ignore_symtab_function(const GElf_Sym *sym, const char *sym_name)
{
return (!elf_sym__is_local_function(sym) ||
elf_sym__visibility(sym) != STV_DEFAULT ||
sym->st_size == 0 ||
memcmp(sym_name, "__libc_csu_",
sizeof("__libc_csu_") - 1) == 0);
}
bool ctf__ignore_symtab_object(const GElf_Sym *sym, const char *sym_name)
{
return (!elf_sym__is_local_object(sym) || sym->st_size == 0 ||
elf_sym__visibility(sym) != STV_DEFAULT ||
strchr(sym_name, '.') != NULL);
}
uint16_t ctf__get16(struct ctf *ctf, uint16_t *p)
{
uint16_t val = *p;
if (ctf->swapped)
val = ((val >> 8) | (val << 8));
return val;
}
uint32_t ctf__get32(struct ctf *ctf, uint32_t *p)
{
uint32_t val = *p;
if (ctf->swapped)
val = ((val >> 24) |
((val >> 8) & 0x0000ff00) |
((val << 8) & 0x00ff0000) |
(val << 24));
return val;
}
void ctf__put16(struct ctf *ctf, uint16_t *p, uint16_t val)
{
if (ctf->swapped)
val = ((val >> 8) | (val << 8));
*p = val;
}
void ctf__put32(struct ctf *ctf, uint32_t *p, uint32_t val)
{
if (ctf->swapped)
val = ((val >> 24) |
((val >> 8) & 0x0000ff00) |
((val << 8) & 0x00ff0000) |
(val << 24));
*p = val;
}
static int ctf__decompress(struct ctf *ctf, void *orig_buf, size_t orig_size)
{
struct ctf_header *hp = orig_buf;
const char *err_str;
z_stream state;
size_t len;
void *new;
len = (ctf__get32(ctf, &hp->ctf_str_off) +
ctf__get32(ctf, &hp->ctf_str_len));
new = malloc(len + sizeof(*hp));
if (!new) {
fprintf(stderr, "CTF decompression allocation failure.\n");
return -ENOMEM;
}
memcpy(new, hp, sizeof(*hp));
memset(&state, 0, sizeof(state));
state.next_in = (Bytef *) (hp + 1);
state.avail_in = orig_size - sizeof(*hp);
state.next_out = new + sizeof(*hp);
state.avail_out = len;
if (inflateInit(&state) != Z_OK) {
err_str = "struct ctf decompression inflateInit failure.";
goto err;
}
if (inflate(&state, Z_FINISH) != Z_STREAM_END) {
err_str = "struct ctf decompression inflate failure.";
goto err;
}
if (inflateEnd(&state) != Z_OK) {
err_str = "struct ctf decompression inflateEnd failure.";
goto err;
}
if (state.total_out != len) {
err_str = "struct ctf decompression truncation error.";
goto err;
}
ctf->buf = new;
ctf->size = len + sizeof(*hp);
return 0;
err:
fputs(err_str, stderr);
free(new);
return -EINVAL;
}
int ctf__load(struct ctf *ctf)
{
int err = -ENOTSUP;
GElf_Shdr shdr;
Elf_Scn *sec = elf_section_by_name(ctf->elf, &ctf->ehdr,
&shdr, ".SUNW_ctf", NULL);
if (sec == NULL)
return -ESRCH;
Elf_Data *data = elf_getdata(sec, NULL);
if (data == NULL) {
fprintf(stderr, "%s: cannot get data of CTF section.\n",
__func__);
return -1;
}
struct ctf_header *hp = data->d_buf;
size_t orig_size = data->d_size;
if (hp->ctf_version != CTF_VERSION)
goto out;
err = -EINVAL;
if (hp->ctf_magic == CTF_MAGIC)
ctf->swapped = 0;
else if (hp->ctf_magic == CTF_MAGIC_SWAP)
ctf->swapped = 1;
else
goto out;
if (!(hp->ctf_flags & CTF_FLAGS_COMPR)) {
err = -ENOMEM;
ctf->buf = malloc(orig_size);
if (ctf->buf != NULL) {
memcpy(ctf->buf, hp, orig_size);
ctf->size = orig_size;
err = 0;
}
} else
err = ctf__decompress(ctf, hp, orig_size);
out:
return err;
}
bool ctf__verbose;
struct ctf *ctf__new(const char *filename, Elf *elf)
{
struct ctf *ctf = zalloc(sizeof(*ctf));
if (ctf != NULL) {
ctf->filename = strdup(filename);
if (ctf->filename == NULL)
goto out_delete;
if (elf != NULL) {
ctf->in_fd = -1;
ctf->elf = elf;
} else {
ctf->in_fd = open(filename, O_RDONLY);
if (ctf->in_fd < 0)
goto out_delete_filename;
if (elf_version(EV_CURRENT) == EV_NONE) {
fprintf(stderr, "%s: cannot set libelf version.\n",
__func__);
goto out_close;
}
ctf->elf = elf_begin(ctf->in_fd, ELF_C_READ_MMAP, NULL);
if (!ctf->elf) {
fprintf(stderr, "%s: cannot read %s ELF file.\n",
__func__, filename);
goto out_close;
}
}
if (gelf_getehdr(ctf->elf, &ctf->ehdr) == NULL) {
if (ctf__verbose)
fprintf(stderr, "%s: cannot get elf header.\n", __func__);
goto out_elf_end;
}
switch (ctf->ehdr.e_ident[EI_CLASS]) {
case ELFCLASS32: ctf->wordsize = 4; break;
case ELFCLASS64: ctf->wordsize = 8; break;
default: ctf->wordsize = 0; break;
}
}
return ctf;
out_elf_end:
if (elf == NULL)
elf_end(ctf->elf);
out_close:
if (elf == NULL)
close(ctf->in_fd);
out_delete_filename:
free(ctf->filename);
out_delete:
free(ctf);
return NULL;
}
void ctf__delete(struct ctf *ctf)
{
if (ctf != NULL) {
if (ctf->in_fd != -1) {
elf_end(ctf->elf);
close(ctf->in_fd);
}
__gobuffer__delete(&ctf->objects);
__gobuffer__delete(&ctf->types);
__gobuffer__delete(&ctf->funcs);
elf_symtab__delete(ctf->symtab);
free(ctf->filename);
free(ctf->buf);
free(ctf);
}
}
char *ctf__string(struct ctf *ctf, uint32_t ref)
{
struct ctf_header *hp = ctf->buf;
uint32_t off = CTF_REF_OFFSET(ref);
char *name;
if (CTF_REF_TBL_ID(ref) != CTF_STR_TBL_ID_0)
return "(external ref)";
if (off >= ctf__get32(ctf, &hp->ctf_str_len))
return "(ref out-of-bounds)";
if ((off + ctf__get32(ctf, &hp->ctf_str_off)) >= ctf->size)
return "(string table truncated)";
name = ((char *)(hp + 1) + ctf__get32(ctf, &hp->ctf_str_off) + off);
return name[0] == '\0' ? NULL : name;
}
void *ctf__get_buffer(struct ctf *ctf)
{
return ctf->buf;
}
size_t ctf__get_size(struct ctf *ctf)
{
return ctf->size;
}
int ctf__load_symtab(struct ctf *ctf)
{
ctf->symtab = elf_symtab__new(".symtab", ctf->elf, &ctf->ehdr);
return ctf->symtab == NULL ? -1 : 0;
}
void ctf__set_strings(struct ctf *ctf, struct strings *strings)
{
ctf->strings = strings;
}
uint32_t ctf__add_base_type(struct ctf *ctf, uint32_t name, uint16_t size)
{
struct ctf_full_type t;
t.base.ctf_name = name;
t.base.ctf_info = CTF_INFO_ENCODE(CTF_TYPE_KIND_INT, 0, 0);
t.base.ctf_size = size;
t.ctf_size_high = CTF_TYPE_INT_ENCODE(0, 0, size);
gobuffer__add(&ctf->types, &t, sizeof(t) - sizeof(uint32_t));
return ++ctf->type_index;
}
uint32_t ctf__add_short_type(struct ctf *ctf, uint16_t kind, uint16_t type, uint32_t name)
{
struct ctf_short_type t;
t.ctf_name = name;
t.ctf_info = CTF_INFO_ENCODE(kind, 0, 0);
t.ctf_type = type;
gobuffer__add(&ctf->types, &t, sizeof(t));
return ++ctf->type_index;
}
uint32_t ctf__add_fwd_decl(struct ctf *ctf, uint32_t name)
{
return ctf__add_short_type(ctf, CTF_TYPE_KIND_FWD, 0, name);
}
uint32_t ctf__add_array(struct ctf *ctf, uint16_t type, uint16_t index_type, uint32_t nelems)
{
struct {
struct ctf_short_type t;
struct ctf_array a;
} array;
array.t.ctf_name = 0;
array.t.ctf_info = CTF_INFO_ENCODE(CTF_TYPE_KIND_ARR, 0, 0);
array.t.ctf_size = 0;
array.a.ctf_array_type = type;
array.a.ctf_array_index_type = index_type;
array.a.ctf_array_nelems = nelems;
gobuffer__add(&ctf->types, &array, sizeof(array));
return ++ctf->type_index;
}
void ctf__add_short_member(struct ctf *ctf, uint32_t name, uint16_t type,
uint16_t offset, int64_t *position)
{
struct ctf_short_member m = {
.ctf_member_name = name,
.ctf_member_type = type,
.ctf_member_offset = offset,
};
memcpy(gobuffer__ptr(&ctf->types, *position), &m, sizeof(m));
*position += sizeof(m);
}
void ctf__add_full_member(struct ctf *ctf, uint32_t name, uint16_t type,
uint64_t offset, int64_t *position)
{
struct ctf_full_member m = {
.ctf_member_name = name,
.ctf_member_type = type,
.ctf_member_offset_high = offset >> 32,
.ctf_member_offset_low = offset & 0xffffffffl,
};
memcpy(gobuffer__ptr(&ctf->types, *position), &m, sizeof(m));
*position += sizeof(m);
}
uint32_t ctf__add_struct(struct ctf *ctf, uint16_t kind, uint32_t name,
uint64_t size, uint16_t nr_members, int64_t *position)
{
const bool is_short = size < CTF_SHORT_MEMBER_LIMIT;
uint32_t members_len = ((is_short ? sizeof(struct ctf_short_member) :
sizeof(struct ctf_full_member)) *
nr_members);
struct ctf_full_type t;
int len;
t.base.ctf_name = name;
t.base.ctf_info = CTF_INFO_ENCODE(kind, nr_members, 0);
if (size < 0xffff) {
len = sizeof(t.base);
t.base.ctf_size = size;
} else {
len = sizeof(t);
t.base.ctf_size = 0xffff;
t.ctf_size_high = size >> 32;
t.ctf_size_low = size & 0xffffffff;
}
gobuffer__add(&ctf->types, &t, len);
*position = gobuffer__allocate(&ctf->types, members_len);
return ++ctf->type_index;
}
void ctf__add_parameter(struct ctf *ctf, uint16_t type, int64_t *position)
{
uint16_t *parm = gobuffer__ptr(&ctf->types, *position);
*parm = type;
*position += sizeof(*parm);
}
uint32_t ctf__add_function_type(struct ctf *ctf, uint16_t type, uint16_t nr_parms,
bool varargs, int64_t *position)
{
struct ctf_short_type t;
int len = sizeof(uint16_t) * (nr_parms + !!varargs);
/*
* Round up to next multiple of 4 to maintain 32-bit alignment.
*/
if (len & 0x2)
len += 0x2;
t.ctf_name = 0;
t.ctf_info = CTF_INFO_ENCODE(CTF_TYPE_KIND_FUNC,
nr_parms + !!varargs, 0);
t.ctf_type = type;
gobuffer__add(&ctf->types, &t, sizeof(t));
*position = gobuffer__allocate(&ctf->types, len);
if (varargs) {
unsigned int pos = *position + (nr_parms * sizeof(uint16_t));
uint16_t *end_of_args = gobuffer__ptr(&ctf->types, pos);
*end_of_args = 0;
}
return ++ctf->type_index;
}
uint32_t ctf__add_enumeration_type(struct ctf *ctf, uint32_t name, uint16_t size,
uint16_t nr_entries, int64_t *position)
{
struct ctf_short_type e;
e.ctf_name = name;
e.ctf_info = CTF_INFO_ENCODE(CTF_TYPE_KIND_ENUM, nr_entries, 0);
e.ctf_size = size;
gobuffer__add(&ctf->types, &e, sizeof(e));
*position = gobuffer__allocate(&ctf->types,
nr_entries * sizeof(struct ctf_enum));
return ++ctf->type_index;
}
void ctf__add_enumerator(struct ctf *ctf, uint32_t name, uint32_t value,
int64_t *position)
{
struct ctf_enum m = {
.ctf_enum_name = name,
.ctf_enum_val = value,
};
memcpy(gobuffer__ptr(&ctf->types, *position), &m, sizeof(m));
*position += sizeof(m);
}
void ctf__add_function_parameter(struct ctf *ctf, uint16_t type,
int64_t *position)
{
uint16_t *parm = gobuffer__ptr(&ctf->funcs, *position);
*parm = type;
*position += sizeof(*parm);
}
int ctf__add_function(struct ctf *ctf, uint16_t type, uint16_t nr_parms,
bool varargs, int64_t *position)
{
struct ctf_short_type func;
int len = sizeof(uint16_t) * (nr_parms + !!varargs);
/*
* Round up to next multiple of 4 to maintain 32-bit alignment.
*/
if (len & 0x2)
len += 0x2;
func.ctf_info = CTF_INFO_ENCODE(CTF_TYPE_KIND_FUNC,
nr_parms + !!varargs, 0);
func.ctf_type = type;
/*
* We don't store the name for the function, it comes from the
* symtab.
*/
gobuffer__add(&ctf->funcs, &func.ctf_info,
sizeof(func) - sizeof(func.ctf_name));
*position = gobuffer__allocate(&ctf->funcs, len);
if (varargs) {
unsigned int pos = *position + (nr_parms * sizeof(uint16_t));
uint16_t *end_of_args = gobuffer__ptr(&ctf->funcs, pos);
*end_of_args = 0;
}
return 0;
}
int ctf__add_object(struct ctf *ctf, uint16_t type)
{
return gobuffer__add(&ctf->objects, &type,
sizeof(type)) >= 0 ? 0 : -ENOMEM;
}
static const void *ctf__compress(void *orig_buf, unsigned int *size)
{
z_stream z = {
.zalloc = Z_NULL,
.zfree = Z_NULL,
.opaque = Z_NULL,
.avail_in = *size,
.next_in = (Bytef *)orig_buf,
};
void *bf = NULL;
unsigned int bf_size = 0;
if (deflateInit(&z, Z_BEST_COMPRESSION) != Z_OK)
goto out;
#define _GOBUFFER__ZCHUNK 16384 * 1024
do {
const unsigned int new_bf_size = bf_size + _GOBUFFER__ZCHUNK;
void *nbf = realloc(bf, new_bf_size);
if (nbf == NULL)
goto out_close_and_free;
bf = nbf;
z.avail_out = _GOBUFFER__ZCHUNK;
z.next_out = (Bytef *)bf + bf_size;
bf_size = new_bf_size;
if (deflate(&z, Z_FULL_FLUSH) == Z_STREAM_ERROR)
goto out_close_and_free;
#if 0
fprintf(stderr,
"%s: size=%d, bf_size=%d, total_out=%ld, total_in=%ld\n",
__func__, *size, bf_size, z.total_out, z.total_in);
#endif
} while (z.total_in != *size);
if (deflate(&z, Z_FINISH) == Z_STREAM_ERROR)
goto out_close_and_free;
deflateEnd(&z);
*size = z.total_out;
out:
return bf;
out_close_and_free:
deflateEnd(&z);
free(bf);
bf = NULL;
goto out;
}
int ctf__encode(struct ctf *ctf, uint8_t flags)
{
struct ctf_header *hdr;
unsigned int size;
void *bf = NULL;
int err = -1;
/* Empty file, nothing to do, so... done! */
if (gobuffer__size(&ctf->types) == 0)
return 0;
size = (gobuffer__size(&ctf->types) +
gobuffer__size(&ctf->objects) +
gobuffer__size(&ctf->funcs) +
strings__size(ctf->strings));
ctf->size = sizeof(*hdr) + size;
ctf->buf = malloc(ctf->size);
if (ctf->buf == NULL) {
fprintf(stderr, "%s: malloc failed!\n", __func__);
return -ENOMEM;
}
hdr = ctf->buf;
memset(hdr, 0, sizeof(*hdr));
hdr->ctf_magic = CTF_MAGIC;
hdr->ctf_version = 2;
hdr->ctf_flags = flags;
uint32_t offset = 0;
hdr->ctf_object_off = offset;
offset += gobuffer__size(&ctf->objects);
hdr->ctf_func_off = offset;
offset += gobuffer__size(&ctf->funcs);
hdr->ctf_type_off = offset;
offset += gobuffer__size(&ctf->types);
hdr->ctf_str_off = offset;
hdr->ctf_str_len = strings__size(ctf->strings);
void *payload = ctf->buf + sizeof(*hdr);
gobuffer__copy(&ctf->objects, payload + hdr->ctf_object_off);
gobuffer__copy(&ctf->funcs, payload + hdr->ctf_func_off);
gobuffer__copy(&ctf->types, payload + hdr->ctf_type_off);
strings__copy(ctf->strings, payload + hdr->ctf_str_off);
*(char *)(ctf->buf + sizeof(*hdr) + hdr->ctf_str_off) = '\0';
if (flags & CTF_FLAGS_COMPR) {
bf = (void *)ctf__compress(ctf->buf + sizeof(*hdr), &size);
if (bf == NULL) {
printf("%s: ctf__compress failed!\n", __func__);
return -ENOMEM;
}
void *new_bf = malloc(sizeof(*hdr) + size);
if (new_bf == NULL)
return -ENOMEM;
memcpy(new_bf, hdr, sizeof(*hdr));
memcpy(new_bf + sizeof(*hdr), bf, size);
free(bf);
bf = new_bf;
size += sizeof(*hdr);
} else {
bf = ctf->buf;
size = ctf->size;
}
#if 0
printf("\n\ntypes:\n entries: %d\n size: %u"
"\nstrings:\n size: %u\ncompressed size: %d\n",
ctf->type_index,
gobuffer__size(&ctf->types),
strings__size(ctf->strings), size);
#endif
int fd = open(ctf->filename, O_RDWR);
if (fd < 0) {
fprintf(stderr, "Cannot open %s\n", ctf->filename);
return -1;
}
if (elf_version(EV_CURRENT) == EV_NONE) {
fprintf(stderr, "Cannot set libelf version.\n");
goto out_close;
}
Elf *elf = elf_begin(fd, ELF_C_RDWR, NULL);
if (elf == NULL) {
fprintf(stderr, "Cannot update ELF file.\n");
goto out_close;
}
elf_flagelf(elf, ELF_C_SET, ELF_F_DIRTY);
GElf_Ehdr ehdr_mem;
GElf_Ehdr *ehdr = gelf_getehdr(elf, &ehdr_mem);
if (ehdr == NULL) {
fprintf(stderr, "%s: elf_getehdr failed.\n", __func__);
goto out_close;
}
/*
* First we look if there was already a .SUNW_ctf section to overwrite.
*/
Elf_Data *data = NULL;
size_t strndx;
GElf_Shdr shdr_mem;
GElf_Shdr *shdr;
Elf_Scn *scn = NULL;
elf_getshdrstrndx(elf, &strndx);
while ((scn = elf_nextscn(elf, scn)) != NULL) {
shdr = gelf_getshdr(scn, &shdr_mem);
if (shdr == NULL)
continue;
char *secname = elf_strptr(elf, strndx, shdr->sh_name);
if (strcmp(secname, ".SUNW_ctf") == 0) {
data = elf_getdata(scn, data);
goto out_update;
}
}
/* FIXME
* OK, if we have the section, that is ok, we can just replace the
* data, if not, I made a mistake on the small amount of boilerplate
* below, probably .relA.ted to relocations...
*/
#if 0
/* Now we look if the ".SUNW_ctf" string is in the strings table */
scn = elf_getscn(elf, strndx);
shdr = gelf_getshdr(scn, &shdr_mem);
data = elf_getdata(scn, data);
fprintf(stderr, "Looking for the string\n");
size_t ctf_name_offset = 1; /* First byte is '\0' */
while (ctf_name_offset < data->d_size) {
const char *cur_str = data->d_buf + ctf_name_offset;
fprintf(stderr, "*-> %s\n", cur_str);
if (strcmp(cur_str, ".SUNW_ctf") == 0)
goto found_SUNW_ctf_str;
ctf_name_offset += strlen(cur_str) + 1;
}
/* Add the section name */
const size_t ctf_name_len = strlen(".SUNW_ctf") + 1;
char *new_strings_table = malloc(data->d_size + ctf_name_len);
if (new_strings_table == NULL)
goto out_close;
memcpy(new_strings_table, data->d_buf, data->d_size);
strcpy(new_strings_table + data->d_size, ".SUNW_ctf");
ctf_name_offset = data->d_size;
data->d_size += ctf_name_len;
data->d_buf = new_strings_table;
elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY);
elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
Elf_Scn *newscn;
found_SUNW_ctf_str:
newscn = elf_newscn(elf);
if (newscn == NULL)
goto out_close;
data = elf_newdata(newscn);
if (data == NULL)
goto out_close;
shdr = gelf_getshdr(newscn, &shdr_mem);
shdr->sh_name = ctf_name_offset;
shdr->sh_type = SHT_PROGBITS;
gelf_update_shdr(newscn, &shdr_mem);
elf_flagshdr(newscn, ELF_C_SET, ELF_F_DIRTY);
#else
char pathname[PATH_MAX];
snprintf(pathname, sizeof(pathname), "%s.SUNW_ctf", ctf->filename);
fd = creat(pathname, S_IRUSR | S_IWUSR);
if (fd == -1) {
fprintf(stderr, "%s: open(%s) failed!\n", __func__, pathname);
goto out_close;
}
if (write(fd, bf, size) != size)
goto out_close;
if (close(fd) < 0)
goto out_unlink;
char cmd[PATH_MAX * 2];
snprintf(cmd, sizeof(cmd), "objcopy --add-section .SUNW_ctf=%s %s",
pathname, ctf->filename);
if (system(cmd) == 0)
err = 0;
out_unlink:
unlink(pathname);
return err;
#endif
out_update:
data->d_buf = bf;
data->d_size = size;
elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY);
if (elf_update(elf, ELF_C_NULL) < 0)
goto out_close;
if (elf_update(elf, ELF_C_WRITE) < 0)
goto out_close;
elf_end(elf);
err = 0;
out_close:
if (bf != ctf->buf)
free(bf);
close(fd);
return err;
}