binutils-gdb/libctf/ctf-archive.c
Nick Alcock 3d16b64e28 bfd, include, ld, binutils, libctf: CTF should use the dynstr/sym
This is embarrassing.

The whole point of CTF is that it remains intact even after a binary is
stripped, providing a compact mapping from symbols to types for
everything in the externally-visible interface of an ELF object: it has
connections to the symbol table for that purpose, and to the string
table to avoid duplicating symbol names.  So it's a shame that the hooks
I implemented last year served to hook it up to the .symtab and .strtab,
which obviously disappear on strip, leaving any accompanying the CTF
dict containing references to strings (and, soon, symbols) which don't
exist any more because their containing strtab has been vaporized.  The
original Solaris design used .dynsym and .dynstr (well, actually,
.ldynsym, which has more symbols) which do not disappear. So should we.

Thankfully the work we did before serves as guide rails, and adjusting
things to use the .dynstr and .dynsym was fast and easy.  The only
annoyance is that the dynsym is assembled inside elflink.c in a fairly
piecemeal fashion, so that the easiest way to get the symbols out was to
hook in before every call to swap_symbol_out (we also leave in a hook in
front of symbol additions to the .symtab because it seems plausible that
we might want to hook them in future too: for now that hook is unused).
We adjust things so that rather than being offered a whole hash table of
symbols at once, libctf is now given symbols one at a time, with st_name
indexes already resolved and pointing at their final .dynstr offsets:
it's now up to libctf to resolve these to names as needed using the
strtab info we pass it separately.

Some bits might be contentious.  The ctf_new_dynstr callback takes an
elf_internal_sym, and this remains an elf_internal_sym right down
through the generic emulation layers into ldelfgen.  This is no worse
than the elf_sym_strtab we used to pass down, but in the future when we
gain non-ELF CTF symtab support we might want to lower the
elf_internal_sym to some other representation (perhaps a
ctf_link_symbol) in bfd or in ldlang_ctf_new_dynsym.  We rename the
'apply_strsym' hooks to 'acquire_strings' instead, becuse they no longer
have anything to do with symbols.

There are some API changes to pieces of API which are technically public
but actually totally unused by anything and/or unused by anything but ld
so they can change freely: the ctf_link_symbol gains new fields to allow
symbol names to be given as strtab offsets as well as strings, and a
symidx so that the symbol index can be passed in.  ctf_link_shuffle_syms
loses its callback parameter: the idea now is that linkers call the new
ctf_link_add_linker_symbol for every symbol in .dynsym, feed in all the
strtab entries with ctf_link_add_strtab, and then a call to
ctf_link_shuffle_syms will apply both and arrange to use them to reorder
the CTF symtab at CTF serialization time (which is coming in the next
commit).

Inside libctf we have a new preamble flag CTF_F_DYNSTR which is always
set in v3-format CTF dicts from this commit forwards: CTF dicts without
this flag are associated with .strtab like they used to be, so that old
dicts' external strings don't turn to garbage when loaded by new libctf.
Dicts with this flag are associated with .dynstr and .dynsym instead.
(The flag is not the next in sequence because this commit was written
quite late: the missing flags will be filled in by the next commit.)

Tests forthcoming in a later commit in this series.

bfd/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* elflink.c (elf_finalize_dynstr): Call examine_strtab after
	dynstr finalization.
	(elf_link_swap_symbols_out): Don't call it here.  Call
	ctf_new_symbol before swap_symbol_out.
	(elf_link_output_extsym): Call ctf_new_dynsym before
	swap_symbol_out.
	(bfd_elf_final_link): Likewise.
	* elf.c (swap_out_syms): Pass in bfd_link_info.  Call
	ctf_new_symbol before swap_symbol_out.
	(_bfd_elf_compute_section_file_positions): Adjust.

binutils/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* readelf.c (dump_section_as_ctf): Use .dynsym and .dynstr, not
	.symtab and .strtab.

include/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* bfdlink.h (struct elf_sym_strtab): Replace with...
	(struct elf_internal_sym): ... this.
	(struct bfd_link_callbacks) <examine_strtab>: Take only a
	symstrtab argument.
	<ctf_new_symbol>: New.
	<ctf_new_dynsym>: Likewise.
	* ctf-api.h (struct ctf_link_sym) <st_symidx>: New.
	<st_nameidx>: Likewise.
	<st_nameidx_set>: Likewise.
	(ctf_link_iter_symbol_f): Removed.
	(ctf_link_shuffle_syms): Remove most parameters, just takes a
	ctf_dict_t now.
	(ctf_link_add_linker_symbol): New, split from
	ctf_link_shuffle_syms.
	* ctf.h (CTF_F_DYNSTR): New.
	(CTF_F_MAX): Adjust.

ld/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* ldelfgen.c (struct ctf_strsym_iter_cb_arg): Rename to...
	(struct ctf_strtab_iter_cb_arg): ... this, changing fields:
	<syms>: Remove.
	<symcount>: Remove.
	<symstrtab>: Rename to...
	<strtab>: ... this.
	(ldelf_ctf_strtab_iter_cb): Adjust.
	(ldelf_ctf_symbols_iter_cb): Remove.
	(ldelf_new_dynsym_for_ctf): New, tell libctf about a single
	symbol.
	(ldelf_examine_strtab_for_ctf): Rename to...
	(ldelf_acquire_strings_for_ctf): ... this, only doing the strtab
	portion and not symbols.
	* ldelfgen.h: Adjust declarations accordingly.
	* ldemul.c (ldemul_examine_strtab_for_ctf): Rename to...
	(ldemul_acquire_strings_for_ctf): ... this.
	(ldemul_new_dynsym_for_ctf): New.
	* ldemul.h: Adjust declarations accordingly.
	* ldlang.c (ldlang_ctf_apply_strsym): Rename to...
	(ldlang_ctf_acquire_strings): ... this.
	(ldlang_ctf_new_dynsym): New.
	(lang_write_ctf): Call ldemul_new_dynsym_for_ctf with NULL to do
	the actual symbol shuffle.
	* ldlang.h (struct elf_strtab_hash): Adjust accordingly.
	* ldmain.c (bfd_link_callbacks): Wire up new/renamed callbacks.

libctf/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* ctf-link.c (ctf_link_shuffle_syms): Adjust.
	(ctf_link_add_linker_symbol): New, unimplemented stub.
	* libctf.ver: Add it.
	* ctf-create.c (ctf_serialize): Set CTF_F_DYNSTR on newly-serialized
	dicts.
	* ctf-open-bfd.c (ctf_bfdopen_ctfsect): Check for the flag: open the
	symtab/strtab if not present, dynsym/dynstr otherwise.
	* ctf-archive.c (ctf_arc_bufpreamble): New, get the preamble from
	some arbitrary member of a CTF archive.
	* ctf-impl.h (ctf_arc_bufpreamble): Declare it.
2020-11-20 13:34:07 +00:00

1004 lines
27 KiB
C

/* CTF archive files.
Copyright (C) 2019-2020 Free Software Foundation, Inc.
This file is part of libctf.
libctf is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not see
<http://www.gnu.org/licenses/>. */
#include <ctf-impl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <elf.h>
#include "ctf-endian.h"
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_MMAP
#include <sys/mman.h>
#endif
static off_t arc_write_one_ctf (ctf_dict_t * f, int fd, size_t threshold);
static ctf_dict_t *ctf_dict_open_by_offset (const struct ctf_archive *arc,
const ctf_sect_t *symsect,
const ctf_sect_t *strsect,
size_t offset, int *errp);
static int sort_modent_by_name (const void *one, const void *two, void *n);
static void *arc_mmap_header (int fd, size_t headersz);
static void *arc_mmap_file (int fd, size_t size);
static int arc_mmap_writeout (int fd, void *header, size_t headersz,
const char **errmsg);
static int arc_mmap_unmap (void *header, size_t headersz, const char **errmsg);
/* Write out a CTF archive to the start of the file referenced by the passed-in
fd. The entries in CTF_DICTS are referenced by name: the names are passed in
the names array, which must have CTF_DICTS entries.
Returns 0 on success, or an errno, or an ECTF_* value. */
int
ctf_arc_write_fd (int fd, ctf_dict_t **ctf_dicts, size_t ctf_dict_cnt,
const char **names, size_t threshold)
{
const char *errmsg;
struct ctf_archive *archdr;
size_t i;
char dummy = 0;
size_t headersz;
ssize_t namesz;
size_t ctf_startoffs; /* Start of the section we are working over. */
char *nametbl = NULL; /* The name table. */
char *np;
off_t nameoffs;
struct ctf_archive_modent *modent;
ctf_dprintf ("Writing CTF archive with %lu files\n",
(unsigned long) ctf_dict_cnt);
/* Figure out the size of the mmap()ed header, including the
ctf_archive_modent array. We assume that all of this needs no
padding: a likely assumption, given that it's all made up of
uint64_t's. */
headersz = sizeof (struct ctf_archive)
+ (ctf_dict_cnt * sizeof (uint64_t) * 2);
ctf_dprintf ("headersz is %lu\n", (unsigned long) headersz);
/* From now on we work in two pieces: an mmap()ed region from zero up to the
headersz, and a region updated via write() starting after that, containing
all the tables. Platforms that do not support mmap() just use write(). */
ctf_startoffs = headersz;
if (lseek (fd, ctf_startoffs - 1, SEEK_SET) < 0)
{
errmsg = N_("ctf_arc_write(): cannot extend file while writing");
goto err;
}
if (write (fd, &dummy, 1) < 0)
{
errmsg = N_("ctf_arc_write(): cannot extend file while writing");
goto err;
}
if ((archdr = arc_mmap_header (fd, headersz)) == NULL)
{
errmsg = N_("ctf_arc_write(): cannot mmap");
goto err;
}
/* Fill in everything we can, which is everything other than the name
table offset. */
archdr->ctfa_magic = htole64 (CTFA_MAGIC);
archdr->ctfa_ndicts = htole64 (ctf_dict_cnt);
archdr->ctfa_ctfs = htole64 (ctf_startoffs);
/* We could validate that all CTF files have the same data model, but
since any reasonable construction process will be building things of
only one bitness anyway, this is pretty pointless, so just use the
model of the first CTF file for all of them. (It *is* valid to
create an empty archive: the value of ctfa_model is irrelevant in
this case, but we must be sure not to dereference uninitialized
memory.) */
if (ctf_dict_cnt > 0)
archdr->ctfa_model = htole64 (ctf_getmodel (ctf_dicts[0]));
/* Now write out the CTFs: ctf_archive_modent array via the mapping,
ctfs via write(). The names themselves have not been written yet: we
track them in a local strtab until the time is right, and sort the
modents array after construction.
The name table is not sorted. */
for (i = 0, namesz = 0; i < le64toh (archdr->ctfa_ndicts); i++)
namesz += strlen (names[i]) + 1;
nametbl = malloc (namesz);
if (nametbl == NULL)
{
errmsg = N_("ctf_arc_write(): error writing named CTF to archive");
goto err_unmap;
}
for (i = 0, namesz = 0,
modent = (ctf_archive_modent_t *) ((char *) archdr
+ sizeof (struct ctf_archive));
i < le64toh (archdr->ctfa_ndicts); i++)
{
off_t off;
strcpy (&nametbl[namesz], names[i]);
off = arc_write_one_ctf (ctf_dicts[i], fd, threshold);
if ((off < 0) && (off > -ECTF_BASE))
{
errmsg = N_("ctf_arc_write(): cannot determine file "
"position while writing to archive");
goto err_free;
}
if (off < 0)
{
errmsg = N_("ctf_arc_write(): cannot write CTF file to archive");
errno = off * -1;
goto err_free;
}
modent->name_offset = htole64 (namesz);
modent->ctf_offset = htole64 (off - ctf_startoffs);
namesz += strlen (names[i]) + 1;
modent++;
}
ctf_qsort_r ((ctf_archive_modent_t *) ((char *) archdr
+ sizeof (struct ctf_archive)),
le64toh (archdr->ctfa_ndicts),
sizeof (struct ctf_archive_modent), sort_modent_by_name,
nametbl);
/* Now the name table. */
if ((nameoffs = lseek (fd, 0, SEEK_CUR)) < 0)
{
errmsg = N_("ctf_arc_write(): cannot get current file position "
"in archive");
goto err_free;
}
archdr->ctfa_names = htole64 (nameoffs);
np = nametbl;
while (namesz > 0)
{
ssize_t len;
if ((len = write (fd, np, namesz)) < 0)
{
errmsg = N_("ctf_arc_write(): cannot write name table to archive");
goto err_free;
}
namesz -= len;
np += len;
}
free (nametbl);
if (arc_mmap_writeout (fd, archdr, headersz, &errmsg) < 0)
goto err_unmap;
if (arc_mmap_unmap (archdr, headersz, &errmsg) < 0)
goto err;
return 0;
err_free:
free (nametbl);
err_unmap:
arc_mmap_unmap (archdr, headersz, NULL);
err:
/* We report errors into the first file in the archive, if any: if this is a
zero-file archive, put it in the open-errors stream for lack of anywhere
else for it to go. */
ctf_err_warn (ctf_dict_cnt > 0 ? ctf_dicts[0] : NULL, 0, errno, "%s",
gettext (errmsg));
return errno;
}
/* Write out a CTF archive. The entries in CTF_DICTS are referenced by name:
the names are passed in the names array, which must have CTF_DICTS entries.
If the filename is NULL, create a temporary file and return a pointer to it.
Returns 0 on success, or an errno, or an ECTF_* value. */
int
ctf_arc_write (const char *file, ctf_dict_t **ctf_dicts, size_t ctf_dict_cnt,
const char **names, size_t threshold)
{
int err;
int fd;
if ((fd = open (file, O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0666)) < 0)
{
ctf_err_warn (ctf_dict_cnt > 0 ? ctf_dicts[0] : NULL, 0, errno,
_("ctf_arc_write(): cannot create %s"), file);
return errno;
}
err = ctf_arc_write_fd (fd, ctf_dicts, ctf_dict_cnt, names, threshold);
if (err)
goto err_close;
if ((err = close (fd)) < 0)
ctf_err_warn (ctf_dict_cnt > 0 ? ctf_dicts[0] : NULL, 0, errno,
_("ctf_arc_write(): cannot close after writing to archive"));
goto err;
err_close:
(void) close (fd);
err:
if (err < 0)
unlink (file);
return err;
}
/* Write one CTF file out. Return the file position of the written file (or
rather, of the file-size uint64_t that precedes it): negative return is a
negative errno or ctf_errno value. On error, the file position may no longer
be at the end of the file. */
static off_t
arc_write_one_ctf (ctf_dict_t * f, int fd, size_t threshold)
{
off_t off, end_off;
uint64_t ctfsz = 0;
char *ctfszp;
size_t ctfsz_len;
int (*writefn) (ctf_dict_t * fp, int fd);
if (ctf_serialize (f) < 0)
return f->ctf_errno * -1;
if ((off = lseek (fd, 0, SEEK_CUR)) < 0)
return errno * -1;
if (f->ctf_size > threshold)
writefn = ctf_compress_write;
else
writefn = ctf_write;
/* This zero-write turns into the size in a moment. */
ctfsz_len = sizeof (ctfsz);
ctfszp = (char *) &ctfsz;
while (ctfsz_len > 0)
{
ssize_t writelen = write (fd, ctfszp, ctfsz_len);
if (writelen < 0)
return errno * -1;
ctfsz_len -= writelen;
ctfszp += writelen;
}
if (writefn (f, fd) != 0)
return f->ctf_errno * -1;
if ((end_off = lseek (fd, 0, SEEK_CUR)) < 0)
return errno * -1;
ctfsz = htole64 (end_off - off);
if ((lseek (fd, off, SEEK_SET)) < 0)
return errno * -1;
/* ... here. */
ctfsz_len = sizeof (ctfsz);
ctfszp = (char *) &ctfsz;
while (ctfsz_len > 0)
{
ssize_t writelen = write (fd, ctfszp, ctfsz_len);
if (writelen < 0)
return errno * -1;
ctfsz_len -= writelen;
ctfszp += writelen;
}
end_off = LCTF_ALIGN_OFFS (end_off, 8);
if ((lseek (fd, end_off, SEEK_SET)) < 0)
return errno * -1;
return off;
}
/* qsort() function to sort the array of struct ctf_archive_modents into
ascending name order. */
static int
sort_modent_by_name (const void *one, const void *two, void *n)
{
const struct ctf_archive_modent *a = one;
const struct ctf_archive_modent *b = two;
char *nametbl = n;
return strcmp (&nametbl[le64toh (a->name_offset)],
&nametbl[le64toh (b->name_offset)]);
}
/* bsearch_r() function to search for a given name in the sorted array of struct
ctf_archive_modents. */
static int
search_modent_by_name (const void *key, const void *ent, void *arg)
{
const char *k = key;
const struct ctf_archive_modent *v = ent;
const char *search_nametbl = arg;
return strcmp (k, &search_nametbl[le64toh (v->name_offset)]);
}
/* Make a new struct ctf_archive_internal wrapper for a ctf_archive or a
ctf_dict. Closes ARC and/or FP on error. Arrange to free the SYMSECT or
STRSECT, as needed, on close. Possibly do not unmap on close. */
struct ctf_archive_internal *
ctf_new_archive_internal (int is_archive, int unmap_on_close,
struct ctf_archive *arc,
ctf_dict_t *fp, const ctf_sect_t *symsect,
const ctf_sect_t *strsect,
int *errp)
{
struct ctf_archive_internal *arci;
if ((arci = calloc (1, sizeof (struct ctf_archive_internal))) == NULL)
{
if (is_archive)
{
if (unmap_on_close)
ctf_arc_close_internal (arc);
}
else
ctf_dict_close (fp);
return (ctf_set_open_errno (errp, errno));
}
arci->ctfi_is_archive = is_archive;
if (is_archive)
arci->ctfi_archive = arc;
else
arci->ctfi_dict = fp;
if (symsect)
memcpy (&arci->ctfi_symsect, symsect, sizeof (struct ctf_sect));
if (strsect)
memcpy (&arci->ctfi_strsect, strsect, sizeof (struct ctf_sect));
arci->ctfi_free_symsect = 0;
arci->ctfi_free_strsect = 0;
arci->ctfi_unmap_on_close = unmap_on_close;
return arci;
}
/* Get the CTF preamble from data in a buffer, which may be either an archive or
a CTF dict. If multiple dicts are present in an archive, the preamble comes
from an arbitrary dict. The preamble is a pointer into the ctfsect passed
in. */
const ctf_preamble_t *
ctf_arc_bufpreamble (const ctf_sect_t *ctfsect)
{
if (ctfsect->cts_size > sizeof (uint64_t) &&
(le64toh ((*(uint64_t *) ctfsect->cts_data)) == CTFA_MAGIC))
{
struct ctf_archive *arc = (struct ctf_archive *) ctfsect->cts_data;
return (const ctf_preamble_t *) ((char *) arc + le64toh (arc->ctfa_ctfs)
+ sizeof (uint64_t));
}
else
return (const ctf_preamble_t *) ctfsect->cts_data;
}
/* Open a CTF archive or dictionary from data in a buffer (which the caller must
preserve until ctf_arc_close() time). Returns the archive, or NULL and an
error in *err (if not NULL). */
ctf_archive_t *
ctf_arc_bufopen (const ctf_sect_t *ctfsect, const ctf_sect_t *symsect,
const ctf_sect_t *strsect, int *errp)
{
struct ctf_archive *arc = NULL;
int is_archive;
ctf_dict_t *fp = NULL;
if (ctfsect->cts_size > sizeof (uint64_t) &&
(le64toh ((*(uint64_t *) ctfsect->cts_data)) == CTFA_MAGIC))
{
/* The archive is mmappable, so this operation is trivial.
This buffer is nonmodifiable, so the trick involving mmapping only part
of it and storing the length in the magic number is not applicable: so
record this fact in the archive-wrapper header. (We cannot record it
in the archive, because the archive may very well be a read-only
mapping.) */
is_archive = 1;
arc = (struct ctf_archive *) ctfsect->cts_data;
}
else
{
is_archive = 0;
if ((fp = ctf_bufopen (ctfsect, symsect, strsect, errp)) == NULL)
{
ctf_err_warn (NULL, 0, *errp, _("ctf_arc_bufopen(): cannot open CTF"));
return NULL;
}
}
return ctf_new_archive_internal (is_archive, 0, arc, fp, symsect, strsect,
errp);
}
/* Open a CTF archive. Returns the archive, or NULL and an error in *err (if
not NULL). */
struct ctf_archive *
ctf_arc_open_internal (const char *filename, int *errp)
{
const char *errmsg;
int fd;
struct stat s;
struct ctf_archive *arc; /* (Actually the whole file.) */
libctf_init_debug();
if ((fd = open (filename, O_RDONLY)) < 0)
{
errmsg = N_("ctf_arc_open(): cannot open %s");
goto err;
}
if (fstat (fd, &s) < 0)
{
errmsg = N_("ctf_arc_open(): cannot stat %s");
goto err_close;
}
if ((arc = arc_mmap_file (fd, s.st_size)) == NULL)
{
errmsg = N_("ctf_arc_open(): cannot read in %s");
goto err_close;
}
if (le64toh (arc->ctfa_magic) != CTFA_MAGIC)
{
errmsg = N_("ctf_arc_open(): %s: invalid magic number");
errno = ECTF_FMT;
goto err_unmap;
}
/* This horrible hack lets us know how much to unmap when the file is
closed. (We no longer need the magic number, and the mapping
is private.) */
arc->ctfa_magic = s.st_size;
close (fd);
return arc;
err_unmap:
arc_mmap_unmap (arc, s.st_size, NULL);
err_close:
close (fd);
err:
if (errp)
*errp = errno;
ctf_err_warn (NULL, 0, errno, gettext (errmsg), filename);
return NULL;
}
/* Close an archive. */
void
ctf_arc_close_internal (struct ctf_archive *arc)
{
if (arc == NULL)
return;
/* See the comment in ctf_arc_open(). */
arc_mmap_unmap (arc, arc->ctfa_magic, NULL);
}
/* Public entry point: close an archive, or CTF file. */
void
ctf_arc_close (ctf_archive_t *arc)
{
if (arc == NULL)
return;
if (arc->ctfi_is_archive)
{
if (arc->ctfi_unmap_on_close)
ctf_arc_close_internal (arc->ctfi_archive);
}
else
ctf_dict_close (arc->ctfi_dict);
if (arc->ctfi_free_symsect)
free ((void *) arc->ctfi_symsect.cts_data);
if (arc->ctfi_free_strsect)
free ((void *) arc->ctfi_strsect.cts_data);
free (arc->ctfi_data);
if (arc->ctfi_bfd_close)
arc->ctfi_bfd_close (arc);
free (arc);
}
/* Return the ctf_dict_t with the given name, or NULL if none, setting 'err' if
non-NULL. A name of NULL means to open the default file. */
static ctf_dict_t *
ctf_dict_open_internal (const struct ctf_archive *arc,
const ctf_sect_t *symsect,
const ctf_sect_t *strsect,
const char *name, int *errp)
{
struct ctf_archive_modent *modent;
const char *search_nametbl;
if (name == NULL)
name = _CTF_SECTION; /* The default name. */
ctf_dprintf ("ctf_dict_open_internal(%s): opening\n", name);
modent = (ctf_archive_modent_t *) ((char *) arc
+ sizeof (struct ctf_archive));
search_nametbl = (const char *) arc + le64toh (arc->ctfa_names);
modent = bsearch_r (name, modent, le64toh (arc->ctfa_ndicts),
sizeof (struct ctf_archive_modent),
search_modent_by_name, (void *) search_nametbl);
/* This is actually a common case and normal operation: no error
debug output. */
if (modent == NULL)
{
if (errp)
*errp = ECTF_ARNNAME;
return NULL;
}
return ctf_dict_open_by_offset (arc, symsect, strsect,
le64toh (modent->ctf_offset), errp);
}
/* Return the ctf_dict_t with the given name, or NULL if none, setting 'err' if
non-NULL. A name of NULL means to open the default file.
Use the specified string and symbol table sections.
Public entry point. */
ctf_dict_t *
ctf_dict_open_sections (const ctf_archive_t *arc,
const ctf_sect_t *symsect,
const ctf_sect_t *strsect,
const char *name,
int *errp)
{
if (arc->ctfi_is_archive)
{
ctf_dict_t *ret;
ret = ctf_dict_open_internal (arc->ctfi_archive, symsect, strsect,
name, errp);
if (ret)
ret->ctf_archive = (ctf_archive_t *) arc;
return ret;
}
if ((name != NULL) && (strcmp (name, _CTF_SECTION) != 0))
{
if (errp)
*errp = ECTF_ARNNAME;
return NULL;
}
arc->ctfi_dict->ctf_archive = (ctf_archive_t *) arc;
/* Bump the refcount so that the user can ctf_dict_close() it. */
arc->ctfi_dict->ctf_refcnt++;
return arc->ctfi_dict;
}
/* Return the ctf_dict_t with the given name, or NULL if none, setting 'err' if
non-NULL. A name of NULL means to open the default file.
Public entry point. */
ctf_dict_t *
ctf_dict_open (const ctf_archive_t *arc, const char *name, int *errp)
{
const ctf_sect_t *symsect = &arc->ctfi_symsect;
const ctf_sect_t *strsect = &arc->ctfi_strsect;
if (symsect->cts_name == NULL)
symsect = NULL;
if (strsect->cts_name == NULL)
strsect = NULL;
return ctf_dict_open_sections (arc, symsect, strsect, name, errp);
}
/* Return the ctf_dict_t at the given ctfa_ctfs-relative offset, or NULL if
none, setting 'err' if non-NULL. */
static ctf_dict_t *
ctf_dict_open_by_offset (const struct ctf_archive *arc,
const ctf_sect_t *symsect,
const ctf_sect_t *strsect, size_t offset,
int *errp)
{
ctf_sect_t ctfsect;
ctf_dict_t *fp;
ctf_dprintf ("ctf_dict_open_by_offset(%lu): opening\n", (unsigned long) offset);
memset (&ctfsect, 0, sizeof (ctf_sect_t));
offset += le64toh (arc->ctfa_ctfs);
ctfsect.cts_name = _CTF_SECTION;
ctfsect.cts_size = le64toh (*((uint64_t *) ((char *) arc + offset)));
ctfsect.cts_entsize = 1;
ctfsect.cts_data = (void *) ((char *) arc + offset + sizeof (uint64_t));
fp = ctf_bufopen (&ctfsect, symsect, strsect, errp);
if (fp)
ctf_setmodel (fp, le64toh (arc->ctfa_model));
return fp;
}
/* Backward compatibility. */
ctf_dict_t *
ctf_arc_open_by_name (const ctf_archive_t *arc, const char *name,
int *errp)
{
return ctf_dict_open (arc, name, errp);
}
ctf_dict_t *
ctf_arc_open_by_name_sections (const ctf_archive_t *arc,
const ctf_sect_t *symsect,
const ctf_sect_t *strsect,
const char *name,
int *errp)
{
return ctf_dict_open_sections (arc, symsect, strsect, name, errp);
}
/* Return the number of members in an archive. */
size_t
ctf_archive_count (const ctf_archive_t *wrapper)
{
if (!wrapper->ctfi_is_archive)
return 1;
return wrapper->ctfi_archive->ctfa_ndicts;
}
/* Raw iteration over all CTF files in an archive. We pass the raw data for all
CTF files in turn to the specified callback function. */
static int
ctf_archive_raw_iter_internal (const struct ctf_archive *arc,
ctf_archive_raw_member_f *func, void *data)
{
int rc;
size_t i;
struct ctf_archive_modent *modent;
const char *nametbl;
modent = (ctf_archive_modent_t *) ((char *) arc
+ sizeof (struct ctf_archive));
nametbl = (((const char *) arc) + le64toh (arc->ctfa_names));
for (i = 0; i < le64toh (arc->ctfa_ndicts); i++)
{
const char *name;
char *fp;
name = &nametbl[le64toh (modent[i].name_offset)];
fp = ((char *) arc + le64toh (arc->ctfa_ctfs)
+ le64toh (modent[i].ctf_offset));
if ((rc = func (name, (void *) (fp + sizeof (uint64_t)),
le64toh (*((uint64_t *) fp)), data)) != 0)
return rc;
}
return 0;
}
/* Raw iteration over all CTF files in an archive: public entry point.
Returns -EINVAL if not supported for this sort of archive. */
int
ctf_archive_raw_iter (const ctf_archive_t *arc,
ctf_archive_raw_member_f * func, void *data)
{
if (arc->ctfi_is_archive)
return ctf_archive_raw_iter_internal (arc->ctfi_archive, func, data);
return -EINVAL; /* Not supported. */
}
/* Iterate over all CTF files in an archive. We pass all CTF files in turn to
the specified callback function. */
static int
ctf_archive_iter_internal (const ctf_archive_t *wrapper,
const struct ctf_archive *arc,
const ctf_sect_t *symsect,
const ctf_sect_t *strsect,
ctf_archive_member_f *func, void *data)
{
int rc;
size_t i;
ctf_dict_t *f;
struct ctf_archive_modent *modent;
const char *nametbl;
modent = (ctf_archive_modent_t *) ((char *) arc
+ sizeof (struct ctf_archive));
nametbl = (((const char *) arc) + le64toh (arc->ctfa_names));
for (i = 0; i < le64toh (arc->ctfa_ndicts); i++)
{
const char *name;
name = &nametbl[le64toh (modent[i].name_offset)];
if ((f = ctf_dict_open_internal (arc, symsect, strsect,
name, &rc)) == NULL)
return rc;
f->ctf_archive = (ctf_archive_t *) wrapper;
if ((rc = func (f, name, data)) != 0)
{
ctf_dict_close (f);
return rc;
}
ctf_dict_close (f);
}
return 0;
}
/* Iterate over all CTF files in an archive: public entry point. We pass all
CTF files in turn to the specified callback function. */
int
ctf_archive_iter (const ctf_archive_t *arc, ctf_archive_member_f *func,
void *data)
{
const ctf_sect_t *symsect = &arc->ctfi_symsect;
const ctf_sect_t *strsect = &arc->ctfi_strsect;
if (symsect->cts_name == NULL)
symsect = NULL;
if (strsect->cts_name == NULL)
strsect = NULL;
if (arc->ctfi_is_archive)
return ctf_archive_iter_internal (arc, arc->ctfi_archive, symsect, strsect,
func, data);
return func (arc->ctfi_dict, _CTF_SECTION, data);
}
/* Iterate over all CTF files in an archive, returning each dict in turn as a
ctf_dict_t, and NULL on error or end of iteration. It is the caller's
responsibility to close it. Parent dicts may be skipped. Regardless of
whether they are skipped or not, the caller must ctf_import the parent if
need be.
We identify parents by name rather than by flag value: for now, with the
linker only emitting parents named _CTF_SECTION, this works well enough. */
ctf_dict_t *
ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name,
int skip_parent, int *errp)
{
ctf_dict_t *f;
ctf_next_t *i = *it;
struct ctf_archive *arc;
struct ctf_archive_modent *modent;
const char *nametbl;
const char *name_;
if (!i)
{
if ((i = ctf_next_create()) == NULL)
{
if (errp)
*errp = ENOMEM;
return NULL;
}
i->cu.ctn_arc = wrapper;
i->ctn_iter_fun = (void (*) (void)) ctf_archive_next;
*it = i;
}
if ((void (*) (void)) ctf_archive_next != i->ctn_iter_fun)
{
if (errp)
*errp = ECTF_NEXT_WRONGFUN;
return NULL;
}
if (wrapper != i->cu.ctn_arc)
{
if (errp)
*errp = ECTF_NEXT_WRONGFP;
return NULL;
}
/* Iteration is made a bit more complex by the need to handle ctf_dict_t's
transparently wrapped in a single-member archive. These are parents: if
skip_parent is on, they are skipped and the iterator terminates
immediately. */
if (!wrapper->ctfi_is_archive && i->ctn_n == 0)
{
i->ctn_n++;
if (!skip_parent)
{
wrapper->ctfi_dict->ctf_refcnt++;
return wrapper->ctfi_dict;
}
}
arc = wrapper->ctfi_archive;
/* The loop keeps going when skip_parent is on as long as the member we find
is the parent (i.e. at most two iterations, but possibly an early return if
*all* we have is a parent). */
const ctf_sect_t *symsect;
const ctf_sect_t *strsect;
do
{
if ((!wrapper->ctfi_is_archive) || (i->ctn_n >= le64toh (arc->ctfa_ndicts)))
{
ctf_next_destroy (i);
*it = NULL;
if (errp)
*errp = ECTF_NEXT_END;
return NULL;
}
symsect = &wrapper->ctfi_symsect;
strsect = &wrapper->ctfi_strsect;
if (symsect->cts_name == NULL)
symsect = NULL;
if (strsect->cts_name == NULL)
strsect = NULL;
modent = (ctf_archive_modent_t *) ((char *) arc
+ sizeof (struct ctf_archive));
nametbl = (((const char *) arc) + le64toh (arc->ctfa_names));
name_ = &nametbl[le64toh (modent[i->ctn_n].name_offset)];
i->ctn_n++;
} while (skip_parent && strcmp (name_, _CTF_SECTION) == 0);
if (name)
*name = name_;
f = ctf_dict_open_internal (arc, symsect, strsect, name_, errp);
f->ctf_archive = (ctf_archive_t *) wrapper;
return f;
}
#ifdef HAVE_MMAP
/* Map the header in. Only used on new, empty files. */
static void *arc_mmap_header (int fd, size_t headersz)
{
void *hdr;
if ((hdr = mmap (NULL, headersz, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
0)) == MAP_FAILED)
return NULL;
return hdr;
}
/* mmap() the whole file, for reading only. (Map it writably, but privately: we
need to modify the region, but don't need anyone else to see the
modifications.) */
static void *arc_mmap_file (int fd, size_t size)
{
void *arc;
if ((arc = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
fd, 0)) == MAP_FAILED)
return NULL;
return arc;
}
/* Persist the header to disk. */
static int arc_mmap_writeout (int fd _libctf_unused_, void *header,
size_t headersz, const char **errmsg)
{
if (msync (header, headersz, MS_ASYNC) < 0)
{
if (errmsg)
*errmsg = N_("arc_mmap_writeout(): cannot sync after writing "
"to %s: %s");
return -1;
}
return 0;
}
/* Unmap the region. */
static int arc_mmap_unmap (void *header, size_t headersz, const char **errmsg)
{
if (munmap (header, headersz) < 0)
{
if (errmsg)
*errmsg = N_("arc_mmap_munmap(): cannot unmap after writing "
"to %s: %s");
return -1;
}
return 0;
}
#else
/* Map the header in. Only used on new, empty files. */
static void *arc_mmap_header (int fd _libctf_unused_, size_t headersz)
{
void *hdr;
if ((hdr = malloc (headersz)) == NULL)
return NULL;
return hdr;
}
/* Pull in the whole file, for reading only. We assume the current file
position is at the start of the file. */
static void *arc_mmap_file (int fd, size_t size)
{
char *data;
if ((data = malloc (size)) == NULL)
return NULL;
if (ctf_pread (fd, data, size, 0) < 0)
{
free (data);
return NULL;
}
return data;
}
/* Persist the header to disk. */
static int arc_mmap_writeout (int fd, void *header, size_t headersz,
const char **errmsg)
{
ssize_t len;
size_t acc = 0;
char *data = (char *) header;
ssize_t count = headersz;
if ((lseek (fd, 0, SEEK_SET)) < 0)
{
if (errmsg)
*errmsg = N_("arc_mmap_writeout(): cannot seek while writing header to "
"%s: %s");
return -1;
}
while (headersz > 0)
{
if ((len = write (fd, data, count)) < 0)
{
if (errmsg)
*errmsg = N_("arc_mmap_writeout(): cannot write header to %s: %s");
return len;
}
if (len == EINTR)
continue;
acc += len;
if (len == 0) /* EOF. */
break;
count -= len;
data += len;
}
return 0;
}
/* Unmap the region. */
static int arc_mmap_unmap (void *header, size_t headersz _libctf_unused_,
const char **errmsg _libctf_unused_)
{
free (header);
return 0;
}
#endif