return result;
}
+void
+internal_function
+__libelf_set_data_list_rdlock (Elf_Scn *scn, int wrlocked)
+{
+ if (scn->rawdata.d.d_buf != NULL && scn->rawdata.d.d_size > 0)
+ {
+ Elf *elf = scn->elf;
+
+ /* Upgrade the lock to a write lock if necessary and check
+ nobody else already did the work. */
+ if (!wrlocked)
+ {
+ rwlock_unlock (elf->lock);
+ rwlock_wrlock (elf->lock);
+ if (scn->data_list_rear != NULL)
+ return;
+ }
+
+ /* Convert according to the version and the type. */
+ convert_data (scn, __libelf_version, elf->class,
+ (elf->class == ELFCLASS32
+ || (offsetof (struct Elf, state.elf32.ehdr)
+ == offsetof (struct Elf, state.elf64.ehdr))
+ ? elf->state.elf32.ehdr->e_ident[EI_DATA]
+ : elf->state.elf64.ehdr->e_ident[EI_DATA]),
+ scn->rawdata.d.d_size, scn->rawdata.d.d_type);
+ }
+ else
+ {
+ /* This is an empty or NOBITS section. There is no buffer but
+ the size information etc is important. */
+ scn->data_list.data.d = scn->rawdata.d;
+ scn->data_list.data.s = scn;
+ }
+
+ scn->data_list_rear = &scn->data_list;
+}
+
Elf_Data *
internal_function
__elf_getdata_rdlock (scn, data)
empty in case the section has size zero (for whatever reason).
Now create the converted data in case this is necessary. */
if (scn->data_list_rear == NULL)
- {
- if (scn->rawdata.d.d_buf != NULL && scn->rawdata.d.d_size > 0)
- {
- if (!locked)
- {
- rwlock_unlock (elf->lock);
- rwlock_wrlock (elf->lock);
- if (scn->data_list_rear != NULL)
- goto pass;
- }
-
- /* Convert according to the version and the type. */
- convert_data (scn, __libelf_version, elf->class,
- (elf->class == ELFCLASS32
- || (offsetof (struct Elf, state.elf32.ehdr)
- == offsetof (struct Elf, state.elf64.ehdr))
- ? elf->state.elf32.ehdr->e_ident[EI_DATA]
- : elf->state.elf64.ehdr->e_ident[EI_DATA]),
- scn->rawdata.d.d_size, scn->rawdata.d.d_type);
- }
- else
- {
- /* This is an empty or NOBITS section. There is no buffer but
- the size information etc is important. */
- scn->data_list.data.d = scn->rawdata.d;
- scn->data_list.data.s = scn;
- }
-
- scn->data_list_rear = &scn->data_list;
- }
+ __libelf_set_data_list_rdlock (scn, locked);
- /* If no data is present we cannot return any. */
- if (scn->data_list_rear != NULL)
- pass:
- /* Return the first data element in the list. */
- result = &scn->data_list.data.d;
+ /* Return the first data element in the list. */
+ result = &scn->data_list.data.d;
out:
return result;
/* Create new, empty section data.
- Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
+ Copyright (C) 1998, 1999, 2000, 2001, 2002, 2015 Red Hat, Inc.
This file is part of elfutils.
Contributed by Ulrich Drepper <drepper@redhat.com>, 1998.
rwlock_wrlock (scn->elf->lock);
+ /* data_read is set when data has been read from the ELF image or
+ when a new section has been created by elf_newscn. If data has
+ been read from the ELF image, then rawdata_base will point to raw
+ data. If data_read has been set by elf_newscn, then rawdata_base
+ will be NULL. data_list_rear will be set by elf_getdata if the
+ data has been converted, or by this function, elf_newdata, when
+ new data has been added.
+
+ Currently elf_getdata and elf_update rely on the fact that when
+ data_list_read is not NULL all they have to do is walk the data
+ list. They will ignore any (unread) raw data in that case.
+
+ So we need to make sure the data list is setup if there is
+ already data available. */
+ if (scn->data_read
+ && scn->rawdata_base != NULL
+ && scn->data_list_rear == NULL)
+ __libelf_set_data_list_rdlock (scn, 1);
+
if (scn->data_read && scn->data_list_rear == NULL)
{
/* This means the section was created by the user and this is the
}
else
{
+ /* It would be more efficient to create new data without
+ reading/converting the data from the file. But then we
+ have to remember this. Currently elf_getdata and
+ elf_update rely on the fact that they don't have to
+ load/convert any data if data_list_rear is set. */
+ if (scn->data_read == 0)
+ {
+ if (__libelf_set_rawdata_wrlock (scn) != 0)
+ /* Something went wrong. The error value is already set. */
+ goto out;
+ __libelf_set_data_list_rdlock (scn, 1);
+ }
+
/* Create a new, empty data descriptor. */
result = (Elf_Data_List *) calloc (1, sizeof (Elf_Data_List));
if (result == NULL)
}
result->flags = ELF_F_DIRTY | ELF_F_MALLOCED;
-
- if (scn->data_list_rear == NULL)
- /* We create new data without reading/converting the data from the
- file. That is fine but we have to remember this. */
- scn->data_list_rear = &scn->data_list;
}
/* Set the predefined values. */
--- /dev/null
+/* Test program for elf_newdata function.
+ Copyright (C) 2015 Red Hat, Inc.
+ This file is part of elfutils.
+
+ This file 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 of the License, or
+ (at your option) any later version.
+
+ 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 a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include ELFUTILS_HEADER(elf)
+#include <gelf.h>
+
+// Random data string (16 bytes).
+static char *DATA = "123456789ABCDEF";
+static size_t DATA_LEN = 16;
+
+static void
+add_section_data (Elf *elf, char *buf, size_t len)
+{
+ printf ("Adding %zd bytes.\n", len);
+
+ Elf_Scn *scn = elf_getscn (elf, 1);
+ if (scn == NULL)
+ {
+ printf ("couldn't get data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ Elf_Data *data = elf_newdata (scn);
+ if (data == NULL)
+ {
+ printf ("cannot create newdata for section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ data->d_buf = buf;
+ data->d_type = ELF_T_BYTE;
+ data->d_size = len;
+ data->d_align = 1;
+ data->d_version = EV_CURRENT;
+
+ // Let the library compute the internal structure information.
+ if (elf_update (elf, ELF_C_NULL) < 0)
+ {
+ printf ("failure in elf_update(NULL): %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+}
+
+static Elf *
+create_elf (int fd, int class, int use_mmap)
+{
+ Elf *elf = elf_begin (fd, use_mmap ? ELF_C_WRITE_MMAP : ELF_C_WRITE, NULL);
+ if (elf == NULL)
+ {
+ printf ("cannot create ELF descriptor: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Create an ELF header.
+ if (gelf_newehdr (elf, class) == 0)
+ {
+ printf ("cannot create ELF header: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ GElf_Ehdr ehdr_mem;
+ GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
+ if (ehdr == NULL)
+ {
+ printf ("cannot get ELF header: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Initialize header.
+ ehdr->e_ident[EI_DATA] = class == ELFCLASS32 ? ELFDATA2LSB : ELFDATA2MSB;
+ ehdr->e_ident[EI_OSABI] = ELFOSABI_GNU;
+ ehdr->e_type = ET_NONE;
+ ehdr->e_machine = class == ELFCLASS32 ? EM_PPC : EM_X86_64;
+ ehdr->e_version = EV_CURRENT;
+
+ // Update the ELF header.
+ if (gelf_update_ehdr (elf, ehdr) == 0)
+ {
+ printf ("cannot update ELF header: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Create a section.
+ Elf_Scn *scn = elf_newscn (elf);
+ if (scn == NULL)
+ {
+ printf ("cannot create new section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ shdr->sh_type = SHT_PROGBITS;
+ shdr->sh_flags = 0;
+ shdr->sh_addr = 0;
+ shdr->sh_link = SHN_UNDEF;
+ shdr->sh_info = SHN_UNDEF;
+ shdr->sh_addralign = 1;
+ shdr->sh_entsize = 1;
+ shdr->sh_name = 0;
+
+ // Finish section, update the header.
+ if (gelf_update_shdr (scn, shdr) == 0)
+ {
+ printf ("cannot update header for DATA section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Add some data to the section.
+ add_section_data (elf, DATA, DATA_LEN);
+
+ // Write everything to disk.
+ if (elf_update (elf, ELF_C_WRITE) < 0)
+ {
+ printf ("failure in elf_update(WRITE): %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ return elf;
+}
+
+static Elf *
+read_elf (int fd, int use_mmap)
+{
+ printf ("Reading ELF file\n");
+ Elf *elf = elf_begin (fd, use_mmap ? ELF_C_RDWR_MMAP : ELF_C_RDWR, NULL);
+ if (elf == NULL)
+ {
+ printf ("cannot create ELF descriptor read-again: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ return elf;
+}
+
+static void
+check_section_size (Elf *elf, size_t size)
+{
+ Elf_Scn *scn = elf_getscn (elf, 1);
+ if (scn == NULL)
+ {
+ printf ("couldn't get data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for DATA section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ if (shdr->sh_size == size)
+ printf ("OK %zd bytes.\n", size);
+ else
+ {
+ printf ("BAD size, expected %zd, got %" PRIu64 "\n",
+ size, shdr->sh_size);
+ exit (-1);
+ }
+}
+
+static void
+check_section_data (Elf *elf, char *data, size_t len, size_t times)
+{
+ Elf_Scn *scn = elf_getscn (elf, 1);
+ if (scn == NULL)
+ {
+ printf ("couldn't get data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ Elf_Data *d = NULL;
+ for (size_t i = 0; i < times; i++)
+ {
+ if (d == NULL || i * len >= d->d_off + d->d_size)
+ {
+ d = elf_getdata (scn, d);
+ if (d == NULL)
+ {
+ printf ("cannot get data for section item %zd: %s\n",
+ i, elf_errmsg (-1));
+ exit (1);
+ }
+ else
+ printf ("OK, section data item %zd (d_off: %zd, d_size: %zd)\n",
+ i, d->d_off, d->d_size);
+ }
+ char *d_data = (char *) d->d_buf + (len * i) - d->d_off;
+ printf ("%zd data (d_off: %zd, len * i: %zd): (%p + %zd) %s\n",
+ i, d->d_off, len * i, d->d_buf, (len * i) - d->d_off, d_data);
+ if (memcmp (data, d_data, len) != 0)
+ {
+ printf ("Got bad data in section for item %zd.\n", i);
+ exit (1);
+ }
+ }
+}
+
+static void
+check_elf (int class, int use_mmap)
+{
+ static const char *fname;
+ if (class == ELFCLASS32)
+ fname = use_mmap ? "newdata.elf32.mmap" : "newdata.elf32";
+ else
+ fname = use_mmap ? "newdata.elf64.mmap" : "newdata.elf64";
+
+ printf ("\ncheck_elf: %s\n", fname);
+
+ int fd = open (fname, O_RDWR|O_CREAT|O_TRUNC, 00666);
+ if (fd == -1)
+ {
+ printf ("cannot create `%s': %s\n", fname, strerror (errno));
+ exit (1);
+ }
+
+ Elf *elf = create_elf (fd, class, use_mmap);
+ check_section_size (elf, DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 1);
+
+ // Add some more data (won't be written to disk).
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 2 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 2);
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("failure in elf_end: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ close (fd);
+
+ // Read the ELF from disk now. And add new data directly.
+ fd = open (fname, O_RDONLY);
+ if (fd == -1)
+ {
+ printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
+ exit (1);
+ }
+
+ elf = read_elf (fd, use_mmap);
+ check_section_size (elf, DATA_LEN);
+ // But don't check contents, that would read the data...
+
+ // Add some more data.
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 2 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 2);
+
+ // And some more.
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 3 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 3);
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("failure in elf_end: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ close (fd);
+
+ // Read the ELF from disk now. And add new data after raw reading.
+ fd = open (fname, O_RDONLY);
+ if (fd == -1)
+ {
+ printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
+ exit (1);
+ }
+
+ elf = read_elf (fd, use_mmap);
+ check_section_size (elf, DATA_LEN);
+ // But don't check contents, that would read the data...
+
+ // Get raw data before adding new data.
+ Elf_Scn *scn = elf_getscn (elf, 1);
+ if (scn == NULL)
+ {
+ printf ("couldn't get data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ printf ("elf_rawdata\n");
+ Elf_Data *data = elf_rawdata (scn, NULL);
+ if (data == NULL)
+ {
+ printf ("couldn't get raw data from section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ if (data->d_size != DATA_LEN)
+ {
+ printf ("Unexpected Elf_Data: %zd", data->d_size);
+ exit (1);
+ }
+
+ // Now add more data.
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 2 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 2);
+
+ // And some more.
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 3 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 3);
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("failure in elf_end: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ close (fd);
+
+ // Read the ELF from disk now. And add new data after data reading.
+ fd = open (fname, O_RDONLY);
+ if (fd == -1)
+ {
+ printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
+ exit (1);
+ }
+
+ elf = read_elf (fd, use_mmap);
+ check_section_size (elf, DATA_LEN);
+ // Get (converted) data before adding new data.
+ check_section_data (elf, DATA, DATA_LEN, 1);
+
+ printf ("elf_getdata\n");
+
+ // Now add more data.
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 2 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 2);
+
+ // And some more.
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 3 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 3);
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("failure in elf_end: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ close (fd);
+
+ unlink (fname);
+}
+
+int
+main (int argc __attribute__ ((unused)), char *argv[] __attribute__ ((unused)))
+{
+ // Initialize libelf.
+ elf_version (EV_CURRENT);
+
+ // Fill holes with something non-zero to more easily spot bad data.
+ elf_fill ('X');
+
+ check_elf (ELFCLASS32, 0);
+ check_elf (ELFCLASS32, 1);
+ check_elf (ELFCLASS64, 0);
+ check_elf (ELFCLASS64, 1);
+
+ return 0;
+}
projects / thirdparty / elfutils.git / commitdiff
