Squashed 'third_party/elfutils/' content from commit 555e15e
Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libelf/elf_getarsym.c b/libelf/elf_getarsym.c
new file mode 100644
index 0000000..1f031fc
--- /dev/null
+++ b/libelf/elf_getarsym.c
@@ -0,0 +1,331 @@
+/* Return symbol table of archive.
+ Copyright (C) 1998-2000, 2002, 2005, 2009, 2012, 2014, 2015 Red Hat, Inc.
+ This file is part of elfutils.
+ Written by Ulrich Drepper <drepper@redhat.com>, 1998.
+
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of either
+
+ * the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at
+ your option) any later version
+
+ or
+
+ * the GNU General Public License as published by the Free
+ Software Foundation; either version 2 of the License, or (at
+ your option) any later version
+
+ or both in parallel, as here.
+
+ elfutils 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 copies of the GNU General Public License and
+ the GNU Lesser General Public License along with this program. If
+ not, see <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <byteswap.h>
+#include <endian.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <system.h>
+#include <dl-hash.h>
+#include "libelfP.h"
+
+
+static int
+read_number_entries (uint64_t *nump, Elf *elf, size_t *offp, bool index64_p)
+{
+ union u
+ {
+ uint64_t ret64;
+ uint32_t ret32;
+ } u;
+
+ size_t w = index64_p ? 8 : 4;
+ if (elf->map_address != NULL)
+ /* Use memcpy instead of pointer dereference so as not to assume the
+ field is naturally aligned within the file. */
+ memcpy (&u, elf->map_address + *offp, sizeof u);
+ else if ((size_t) pread_retry (elf->fildes, &u, w, *offp) != w)
+ return -1;
+
+ *offp += w;
+
+ if (__BYTE_ORDER == __LITTLE_ENDIAN)
+ *nump = index64_p ? bswap_64 (u.ret64) : bswap_32 (u.ret32);
+ else
+ *nump = index64_p ? u.ret64 : u.ret32;
+
+ return 0;
+}
+
+Elf_Arsym *
+elf_getarsym (Elf *elf, size_t *ptr)
+{
+ if (elf->kind != ELF_K_AR)
+ {
+ /* This is no archive. */
+ __libelf_seterrno (ELF_E_NO_ARCHIVE);
+ return NULL;
+ }
+
+ if (ptr != NULL)
+ /* In case of an error or when we know the value store the expected
+ value now. Doing this allows us easier exits in an error case. */
+ *ptr = elf->state.ar.ar_sym_num;
+
+ if (elf->state.ar.ar_sym == (Elf_Arsym *) -1l)
+ {
+ /* There is no index. */
+ __libelf_seterrno (ELF_E_NO_INDEX);
+ return NULL;
+ }
+
+ Elf_Arsym *result = elf->state.ar.ar_sym;
+ if (result == NULL)
+ {
+ /* We have not yet read the index. */
+ rwlock_wrlock (elf->lock);
+
+ /* In case we find no index remember this for the next call. */
+ elf->state.ar.ar_sym = (Elf_Arsym *) -1l;
+
+ /* We might have to allocate some temporary data for reading. */
+ void *temp_data = NULL;
+
+ struct ar_hdr *index_hdr;
+ if (elf->map_address == NULL)
+ {
+ /* We must read index from the file. */
+ assert (elf->fildes != -1);
+ if (pread_retry (elf->fildes, &elf->state.ar.ar_hdr,
+ sizeof (struct ar_hdr), elf->start_offset + SARMAG)
+ != sizeof (struct ar_hdr))
+ {
+ /* It is not possible to read the index. Maybe it does not
+ exist. */
+ __libelf_seterrno (ELF_E_READ_ERROR);
+ goto out;
+ }
+
+ index_hdr = &elf->state.ar.ar_hdr;
+ }
+ else
+ {
+ if (SARMAG + sizeof (struct ar_hdr) > elf->maximum_size)
+ {
+ /* There is no room for the full archive. */
+ __libelf_seterrno (ELF_E_NO_INDEX);
+ goto out;
+ }
+
+ index_hdr = (struct ar_hdr *) (elf->map_address
+ + elf->start_offset + SARMAG);
+ }
+
+ /* Now test whether this really is an archive. */
+ if (memcmp (index_hdr->ar_fmag, ARFMAG, 2) != 0)
+ {
+ /* Invalid magic bytes. */
+ __libelf_seterrno (ELF_E_ARCHIVE_FMAG);
+ goto out;
+ }
+
+ bool index64_p;
+ /* Now test whether this is the index. If the name is "/", this
+ is 32-bit index, if it's "/SYM64/", it's 64-bit index.
+
+ XXX This is not entirely true. There are some more forms.
+ Which of them shall we handle? */
+ if (memcmp (index_hdr->ar_name, "/ ", 16) == 0)
+ index64_p = false;
+ else if (memcmp (index_hdr->ar_name, "/SYM64/ ", 16) == 0)
+ index64_p = true;
+ else
+ {
+ /* If the index is not the first entry, there is no index.
+
+ XXX Is this true? */
+ __libelf_seterrno (ELF_E_NO_INDEX);
+ goto out;
+ }
+ int w = index64_p ? 8 : 4;
+
+ /* We have an archive. The first word in there is the number of
+ entries in the table. */
+ uint64_t n = 0;
+ size_t off = elf->start_offset + SARMAG + sizeof (struct ar_hdr);
+ if (read_number_entries (&n, elf, &off, index64_p) < 0)
+ {
+ /* Cannot read the number of entries. */
+ __libelf_seterrno (ELF_E_NO_INDEX);
+ goto out;
+ }
+
+ /* Now we can perform some first tests on whether all the data
+ needed for the index is available. */
+ char tmpbuf[17];
+ memcpy (tmpbuf, index_hdr->ar_size, 10);
+ tmpbuf[10] = '\0';
+ size_t index_size = atol (tmpbuf);
+
+ if (index_size > elf->maximum_size
+ || elf->maximum_size - index_size < SARMAG + sizeof (struct ar_hdr)
+#if SIZE_MAX <= 4294967295U
+ || n >= SIZE_MAX / sizeof (Elf_Arsym)
+#endif
+ || n > index_size / w)
+ {
+ /* This index table cannot be right since it does not fit into
+ the file. */
+ __libelf_seterrno (ELF_E_NO_INDEX);
+ goto out;
+ }
+
+ /* Now we can allocate the arrays needed to store the index. */
+ size_t ar_sym_len = (n + 1) * sizeof (Elf_Arsym);
+ elf->state.ar.ar_sym = (Elf_Arsym *) malloc (ar_sym_len);
+ if (elf->state.ar.ar_sym != NULL)
+ {
+ void *file_data; /* unit32_t[n] or uint64_t[n] */
+ char *str_data;
+ size_t sz = n * w;
+
+ if (elf->map_address == NULL)
+ {
+ temp_data = malloc (sz);
+ if (unlikely (temp_data == NULL))
+ {
+ __libelf_seterrno (ELF_E_NOMEM);
+ goto out;
+ }
+ file_data = temp_data;
+
+ ar_sym_len += index_size - n * w;
+ Elf_Arsym *newp = (Elf_Arsym *) realloc (elf->state.ar.ar_sym,
+ ar_sym_len);
+ if (newp == NULL)
+ {
+ free (elf->state.ar.ar_sym);
+ elf->state.ar.ar_sym = NULL;
+ __libelf_seterrno (ELF_E_NOMEM);
+ goto out;
+ }
+ elf->state.ar.ar_sym = newp;
+
+ char *new_str = (char *) (elf->state.ar.ar_sym + n + 1);
+
+ /* Now read the data from the file. */
+ if ((size_t) pread_retry (elf->fildes, file_data, sz, off) != sz
+ || ((size_t) pread_retry (elf->fildes, new_str,
+ index_size - sz, off + sz)
+ != index_size - sz))
+ {
+ /* We were not able to read the data. */
+ free (elf->state.ar.ar_sym);
+ elf->state.ar.ar_sym = NULL;
+ __libelf_seterrno (ELF_E_NO_INDEX);
+ goto out;
+ }
+
+ str_data = (char *) new_str;
+ }
+ else
+ {
+ file_data = (void *) (elf->map_address + off);
+ if (!ALLOW_UNALIGNED
+ && ((uintptr_t) file_data & -(uintptr_t) n) != 0)
+ {
+ temp_data = malloc (sz);
+ if (unlikely (temp_data == NULL))
+ {
+ __libelf_seterrno (ELF_E_NOMEM);
+ goto out;
+ }
+ file_data = memcpy (temp_data, elf->map_address + off, sz);
+ }
+ str_data = (char *) (elf->map_address + off + sz);
+ }
+
+ /* Now we can build the data structure. */
+ Elf_Arsym *arsym = elf->state.ar.ar_sym;
+ uint64_t (*u64)[n] = file_data;
+ uint32_t (*u32)[n] = file_data;
+ for (size_t cnt = 0; cnt < n; ++cnt)
+ {
+ arsym[cnt].as_name = str_data;
+ if (index64_p)
+ {
+ uint64_t tmp = (*u64)[cnt];
+ if (__BYTE_ORDER == __LITTLE_ENDIAN)
+ tmp = bswap_64 (tmp);
+
+ arsym[cnt].as_off = tmp;
+
+ /* Check whether 64-bit offset fits into 32-bit
+ size_t. */
+ if (sizeof (arsym[cnt].as_off) < 8
+ && arsym[cnt].as_off != tmp)
+ {
+ if (elf->map_address == NULL)
+ {
+ free (elf->state.ar.ar_sym);
+ elf->state.ar.ar_sym = NULL;
+ }
+
+ __libelf_seterrno (ELF_E_RANGE);
+ goto out;
+ }
+ }
+ else if (__BYTE_ORDER == __LITTLE_ENDIAN)
+ arsym[cnt].as_off = bswap_32 ((*u32)[cnt]);
+ else
+ arsym[cnt].as_off = (*u32)[cnt];
+
+ arsym[cnt].as_hash = _dl_elf_hash (str_data);
+#if HAVE_DECL_RAWMEMCHR
+ str_data = rawmemchr (str_data, '\0') + 1;
+#else
+ char c;
+ do {
+ c = *str_data;
+ str_data++;
+ } while (c);
+#endif
+ }
+
+ /* At the end a special entry. */
+ arsym[n].as_name = NULL;
+ arsym[n].as_off = 0;
+ arsym[n].as_hash = ~0UL;
+
+ /* Tell the caller how many entries we have. */
+ elf->state.ar.ar_sym_num = n + 1;
+ }
+
+ result = elf->state.ar.ar_sym;
+
+ out:
+ free (temp_data);
+ rwlock_unlock (elf->lock);
+ }
+
+ if (ptr != NULL)
+ *ptr = elf->state.ar.ar_sym_num;
+
+ return result;
+}