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/elf32_getshdr.c b/libelf/elf32_getshdr.c
new file mode 100644
index 0000000..237d912
--- /dev/null
+++ b/libelf/elf32_getshdr.c
@@ -0,0 +1,299 @@
+/* Return section header.
+ Copyright (C) 1998-2002, 2005, 2007, 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 <errno.h>
+#include <stdbool.h>
+#include <unistd.h>
+
+#include <system.h>
+#include "libelfP.h"
+#include "common.h"
+
+#ifndef LIBELFBITS
+# define LIBELFBITS 32
+#endif
+
+
+static ElfW2(LIBELFBITS,Shdr) *
+load_shdr_wrlock (Elf_Scn *scn)
+{
+ ElfW2(LIBELFBITS,Shdr) *result;
+
+ /* Read the section header table. */
+ Elf *elf = scn->elf;
+ ElfW2(LIBELFBITS,Ehdr) *ehdr = elf->state.ELFW(elf,LIBELFBITS).ehdr;
+
+ /* Try again, maybe the data is there now. */
+ result = scn->shdr.ELFW(e,LIBELFBITS);
+ if (result != NULL)
+ goto out;
+
+ size_t shnum;
+ if (__elf_getshdrnum_rdlock (elf, &shnum) != 0
+ || shnum > SIZE_MAX / sizeof (ElfW2(LIBELFBITS,Shdr)))
+ goto out;
+ size_t size = shnum * sizeof (ElfW2(LIBELFBITS,Shdr));
+
+ /* Allocate memory for the section headers. We know the number
+ of entries from the ELF header. */
+ ElfW2(LIBELFBITS,Shdr) *shdr = elf->state.ELFW(elf,LIBELFBITS).shdr =
+ (ElfW2(LIBELFBITS,Shdr) *) malloc (size);
+ if (elf->state.ELFW(elf,LIBELFBITS).shdr == NULL)
+ {
+ __libelf_seterrno (ELF_E_NOMEM);
+ goto out;
+ }
+ elf->state.ELFW(elf,LIBELFBITS).shdr_malloced = 1;
+
+ if (elf->map_address != NULL)
+ {
+ /* First see whether the information in the ELF header is
+ valid and it does not ask for too much. */
+ if (unlikely (ehdr->e_shoff >= elf->maximum_size)
+ || unlikely (elf->maximum_size - ehdr->e_shoff < size))
+ {
+ /* Something is wrong. */
+ __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER);
+ goto free_and_out;
+ }
+
+ ElfW2(LIBELFBITS,Shdr) *notcvt;
+
+ /* All the data is already mapped. If we could use it
+ directly this would already have happened. Unless
+ we allocated the memory ourselves and the ELF_F_MALLOCED
+ flag is set. */
+ void *file_shdr = ((char *) elf->map_address
+ + elf->start_offset + ehdr->e_shoff);
+
+ assert ((elf->flags & ELF_F_MALLOCED)
+ || ehdr->e_ident[EI_DATA] != MY_ELFDATA
+ || elf->cmd == ELF_C_READ_MMAP
+ || (! ALLOW_UNALIGNED
+ && ((uintptr_t) file_shdr
+ & (__alignof__ (ElfW2(LIBELFBITS,Shdr)) - 1)) != 0));
+
+ /* Now copy the data and at the same time convert the byte order. */
+ if (ehdr->e_ident[EI_DATA] == MY_ELFDATA)
+ {
+ assert ((elf->flags & ELF_F_MALLOCED)
+ || elf->cmd == ELF_C_READ_MMAP
+ || ! ALLOW_UNALIGNED);
+ memcpy (shdr, file_shdr, size);
+ }
+ else
+ {
+ bool copy = ! (ALLOW_UNALIGNED
+ || ((uintptr_t) file_shdr
+ & (__alignof__ (ElfW2(LIBELFBITS,Shdr)) - 1))
+ == 0);
+ if (! copy)
+ notcvt = (ElfW2(LIBELFBITS,Shdr) *)
+ ((char *) elf->map_address
+ + elf->start_offset + ehdr->e_shoff);
+ else
+ {
+ notcvt = (ElfW2(LIBELFBITS,Shdr) *) malloc (size);
+ if (unlikely (notcvt == NULL))
+ {
+ __libelf_seterrno (ELF_E_NOMEM);
+ goto out;
+ }
+ memcpy (notcvt, ((char *) elf->map_address
+ + elf->start_offset + ehdr->e_shoff),
+ size);
+ }
+
+ for (size_t cnt = 0; cnt < shnum; ++cnt)
+ {
+ CONVERT_TO (shdr[cnt].sh_name, notcvt[cnt].sh_name);
+ CONVERT_TO (shdr[cnt].sh_type, notcvt[cnt].sh_type);
+ CONVERT_TO (shdr[cnt].sh_flags, notcvt[cnt].sh_flags);
+ CONVERT_TO (shdr[cnt].sh_addr, notcvt[cnt].sh_addr);
+ CONVERT_TO (shdr[cnt].sh_offset, notcvt[cnt].sh_offset);
+ CONVERT_TO (shdr[cnt].sh_size, notcvt[cnt].sh_size);
+ CONVERT_TO (shdr[cnt].sh_link, notcvt[cnt].sh_link);
+ CONVERT_TO (shdr[cnt].sh_info, notcvt[cnt].sh_info);
+ CONVERT_TO (shdr[cnt].sh_addralign,
+ notcvt[cnt].sh_addralign);
+ CONVERT_TO (shdr[cnt].sh_entsize, notcvt[cnt].sh_entsize);
+
+ /* If this is a section with an extended index add a
+ reference in the section which uses the extended
+ index. */
+ if (shdr[cnt].sh_type == SHT_SYMTAB_SHNDX
+ && shdr[cnt].sh_link < shnum)
+ elf->state.ELFW(elf,LIBELFBITS).scns.data[shdr[cnt].sh_link].shndx_index
+ = cnt;
+
+ /* Set the own shndx_index field in case it has not yet
+ been set. */
+ if (elf->state.ELFW(elf,LIBELFBITS).scns.data[cnt].shndx_index == 0)
+ elf->state.ELFW(elf,LIBELFBITS).scns.data[cnt].shndx_index
+ = -1;
+ }
+
+ if (copy)
+ free (notcvt);
+ }
+ }
+ else if (likely (elf->fildes != -1))
+ {
+ /* Read the header. */
+ ssize_t n = pread_retry (elf->fildes,
+ elf->state.ELFW(elf,LIBELFBITS).shdr, size,
+ elf->start_offset + ehdr->e_shoff);
+ if (unlikely ((size_t) n != size))
+ {
+ /* Severe problems. We cannot read the data. */
+ __libelf_seterrno (ELF_E_READ_ERROR);
+ goto free_and_out;
+ }
+
+ /* If the byte order of the file is not the same as the one
+ of the host convert the data now. */
+ if (ehdr->e_ident[EI_DATA] != MY_ELFDATA)
+ for (size_t cnt = 0; cnt < shnum; ++cnt)
+ {
+ CONVERT (shdr[cnt].sh_name);
+ CONVERT (shdr[cnt].sh_type);
+ CONVERT (shdr[cnt].sh_flags);
+ CONVERT (shdr[cnt].sh_addr);
+ CONVERT (shdr[cnt].sh_offset);
+ CONVERT (shdr[cnt].sh_size);
+ CONVERT (shdr[cnt].sh_link);
+ CONVERT (shdr[cnt].sh_info);
+ CONVERT (shdr[cnt].sh_addralign);
+ CONVERT (shdr[cnt].sh_entsize);
+ }
+ }
+ else
+ {
+ /* The file descriptor was already enabled and not all data was
+ read. Undo the allocation. */
+ __libelf_seterrno (ELF_E_FD_DISABLED);
+
+ free_and_out:
+ free (shdr);
+ elf->state.ELFW(elf,LIBELFBITS).shdr = NULL;
+ elf->state.ELFW(elf,LIBELFBITS).shdr_malloced = 0;
+
+ goto out;
+ }
+
+ /* Set the pointers in the `scn's. */
+ for (size_t cnt = 0; cnt < shnum; ++cnt)
+ elf->state.ELFW(elf,LIBELFBITS).scns.data[cnt].shdr.ELFW(e,LIBELFBITS)
+ = &elf->state.ELFW(elf,LIBELFBITS).shdr[cnt];
+
+ result = scn->shdr.ELFW(e,LIBELFBITS);
+ assert (result != NULL);
+
+out:
+ return result;
+}
+
+static bool
+scn_valid (Elf_Scn *scn)
+{
+ if (scn == NULL)
+ return false;
+
+ if (unlikely (scn->elf->state.elf.ehdr == NULL))
+ {
+ __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
+ return false;
+ }
+
+ if (unlikely (scn->elf->class != ELFW(ELFCLASS,LIBELFBITS)))
+ {
+ __libelf_seterrno (ELF_E_INVALID_CLASS);
+ return false;
+ }
+
+ return true;
+}
+
+ElfW2(LIBELFBITS,Shdr) *
+internal_function
+__elfw2(LIBELFBITS,getshdr_rdlock) (Elf_Scn *scn)
+{
+ ElfW2(LIBELFBITS,Shdr) *result;
+
+ if (!scn_valid (scn))
+ return NULL;
+
+ result = scn->shdr.ELFW(e,LIBELFBITS);
+ if (result == NULL)
+ {
+ rwlock_unlock (scn->elf->lock);
+ rwlock_wrlock (scn->elf->lock);
+ result = scn->shdr.ELFW(e,LIBELFBITS);
+ if (result == NULL)
+ result = load_shdr_wrlock (scn);
+ }
+
+ return result;
+}
+
+ElfW2(LIBELFBITS,Shdr) *
+internal_function
+__elfw2(LIBELFBITS,getshdr_wrlock) (Elf_Scn *scn)
+{
+ ElfW2(LIBELFBITS,Shdr) *result;
+
+ if (!scn_valid (scn))
+ return NULL;
+
+ result = scn->shdr.ELFW(e,LIBELFBITS);
+ if (result == NULL)
+ result = load_shdr_wrlock (scn);
+
+ return result;
+}
+
+ElfW2(LIBELFBITS,Shdr) *
+elfw2(LIBELFBITS,getshdr) (Elf_Scn *scn)
+{
+ ElfW2(LIBELFBITS,Shdr) *result;
+
+ if (!scn_valid (scn))
+ return NULL;
+
+ rwlock_rdlock (scn->elf->lock);
+ result = __elfw2(LIBELFBITS,getshdr_rdlock) (scn);
+ rwlock_unlock (scn->elf->lock);
+
+ return result;
+}