Squashed 'third_party/elfutils/' content from commit 555e15e
Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libdwfl/open.c b/libdwfl/open.c
new file mode 100644
index 0000000..4e0461b
--- /dev/null
+++ b/libdwfl/open.c
@@ -0,0 +1,180 @@
+/* Decompression support for libdwfl: zlib (gzip), bzlib (bzip2) or lzma (xz).
+ Copyright (C) 2009, 2016 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 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 "../libelf/libelfP.h"
+#undef _
+#include "libdwflP.h"
+
+#include <unistd.h>
+
+#if !USE_BZLIB
+# define __libdw_bunzip2(...) DWFL_E_BADELF
+#endif
+
+#if !USE_LZMA
+# define __libdw_unlzma(...) DWFL_E_BADELF
+#endif
+
+/* Consumes and replaces *ELF only on success. */
+static Dwfl_Error
+decompress (int fd __attribute__ ((unused)), Elf **elf)
+{
+ Dwfl_Error error = DWFL_E_BADELF;
+ void *buffer = NULL;
+ size_t size = 0;
+
+ const off_t offset = (*elf)->start_offset;
+ void *const mapped = ((*elf)->map_address == NULL ? NULL
+ : (*elf)->map_address + offset);
+ const size_t mapped_size = (*elf)->maximum_size;
+ if (mapped_size == 0)
+ return error;
+
+ error = __libdw_gunzip (fd, offset, mapped, mapped_size, &buffer, &size);
+ if (error == DWFL_E_BADELF)
+ error = __libdw_bunzip2 (fd, offset, mapped, mapped_size, &buffer, &size);
+ if (error == DWFL_E_BADELF)
+ error = __libdw_unlzma (fd, offset, mapped, mapped_size, &buffer, &size);
+
+ if (error == DWFL_E_NOERROR)
+ {
+ if (unlikely (size == 0))
+ {
+ error = DWFL_E_BADELF;
+ free (buffer);
+ }
+ else
+ {
+ Elf *memelf = elf_memory (buffer, size);
+ if (memelf == NULL)
+ {
+ error = DWFL_E_LIBELF;
+ free (buffer);
+ }
+ else
+ {
+ memelf->flags |= ELF_F_MALLOCED;
+ elf_end (*elf);
+ *elf = memelf;
+ }
+ }
+ }
+ else
+ free (buffer);
+
+ return error;
+}
+
+static Dwfl_Error
+what_kind (int fd, Elf **elfp, Elf_Kind *kind, bool *close_fd)
+{
+ Dwfl_Error error = DWFL_E_NOERROR;
+ *kind = elf_kind (*elfp);
+ if (unlikely (*kind == ELF_K_NONE))
+ {
+ if (unlikely (*elfp == NULL))
+ error = DWFL_E_LIBELF;
+ else
+ {
+ error = decompress (fd, elfp);
+ if (error == DWFL_E_NOERROR)
+ {
+ *close_fd = true;
+ *kind = elf_kind (*elfp);
+ }
+ }
+ }
+ return error;
+}
+
+Dwfl_Error internal_function
+__libdw_open_file (int *fdp, Elf **elfp, bool close_on_fail, bool archive_ok)
+{
+ bool close_fd = false;
+
+ Elf *elf = elf_begin (*fdp, ELF_C_READ_MMAP_PRIVATE, NULL);
+
+ Elf_Kind kind;
+ Dwfl_Error error = what_kind (*fdp, &elf, &kind, &close_fd);
+ if (error == DWFL_E_BADELF)
+ {
+ /* It's not an ELF file or a compressed file.
+ See if it's an image with a header preceding the real file. */
+
+ off_t offset = elf->start_offset;
+ error = __libdw_image_header (*fdp, &offset,
+ (elf->map_address == NULL ? NULL
+ : elf->map_address + offset),
+ elf->maximum_size);
+ if (error == DWFL_E_NOERROR)
+ {
+ /* Pure evil. libelf needs some better interfaces. */
+ elf->kind = ELF_K_AR;
+ elf->state.ar.elf_ar_hdr.ar_name = "libdwfl is faking you out";
+ elf->state.ar.elf_ar_hdr.ar_size = elf->maximum_size - offset;
+ elf->state.ar.offset = offset - sizeof (struct ar_hdr);
+ Elf *subelf = elf_begin (-1, ELF_C_READ_MMAP_PRIVATE, elf);
+ elf->kind = ELF_K_NONE;
+ if (unlikely (subelf == NULL))
+ error = DWFL_E_LIBELF;
+ else
+ {
+ subelf->parent = NULL;
+ subelf->flags |= elf->flags & (ELF_F_MMAPPED | ELF_F_MALLOCED);
+ elf->flags &= ~(ELF_F_MMAPPED | ELF_F_MALLOCED);
+ elf_end (elf);
+ elf = subelf;
+ error = what_kind (*fdp, &elf, &kind, &close_fd);
+ }
+ }
+ }
+
+ if (error == DWFL_E_NOERROR
+ && kind != ELF_K_ELF
+ && !(archive_ok && kind == ELF_K_AR))
+ error = DWFL_E_BADELF;
+
+ if (error != DWFL_E_NOERROR)
+ {
+ elf_end (elf);
+ elf = NULL;
+ }
+
+ if (error == DWFL_E_NOERROR ? close_fd : close_on_fail)
+ {
+ close (*fdp);
+ *fdp = -1;
+ }
+
+ *elfp = elf;
+ return error;
+}