svn commit: r366977 - in head: contrib/elftoolchain/libelf lib/libelf
Ed Maste
emaste at FreeBSD.org
Fri Oct 23 16:35:25 UTC 2020
Author: emaste
Date: Fri Oct 23 16:35:23 2020
New Revision: 366977
URL: https://svnweb.freebsd.org/changeset/base/366977
Log:
libelf: add compression header support
GNU and Oracle libelf implementations added support for section
compression, intended to reduce the size of DWARF debug info (which
might be an order of magnitude larger than the code).
There are two compressed ELF section formats:
1. Old GNU - sections are renmaed to start with 'z'. Section contains
a magic number, uncompressed size, and compressed data.
2. Oracle and New GNU - compressed sections use the SHF_COMPRESSED flag.
The compression header contains the compression type, uncompressed
size, and uncompressed alignment.
The second style is preferred and this change implements only that one.
Submitted by: Tiger Gao <tig at FreeBSDFoundation.org>
Reviewed by: markj
MFC after: 2 weeks
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D24566
Added:
head/contrib/elftoolchain/libelf/gelf_chdr.c (contents, props changed)
head/contrib/elftoolchain/libelf/gelf_getchdr.3 (contents, props changed)
head/contrib/elftoolchain/libelf/libelf_chdr.c (contents, props changed)
Modified:
head/contrib/elftoolchain/libelf/Version.map
head/contrib/elftoolchain/libelf/_libelf.h
head/contrib/elftoolchain/libelf/gelf.3
head/contrib/elftoolchain/libelf/gelf.h
head/contrib/elftoolchain/libelf/libelf.h
head/lib/libelf/Makefile
Modified: head/contrib/elftoolchain/libelf/Version.map
==============================================================================
--- head/contrib/elftoolchain/libelf/Version.map Fri Oct 23 15:56:22 2020 (r366976)
+++ head/contrib/elftoolchain/libelf/Version.map Fri Oct 23 16:35:23 2020 (r366977)
@@ -91,6 +91,13 @@ global:
gelf_update_symshndx;
gelf_xlatetof;
gelf_xlatetom;
+};
+
+R1.1 {
+global:
+ elf32_getchdr;
+ elf64_getchdr;
+ gelf_getchdr;
local:
*;
-};
+} R1.0;
Modified: head/contrib/elftoolchain/libelf/_libelf.h
==============================================================================
--- head/contrib/elftoolchain/libelf/_libelf.h Fri Oct 23 15:56:22 2020 (r366976)
+++ head/contrib/elftoolchain/libelf/_libelf.h Fri Oct 23 16:35:23 2020 (r366977)
@@ -220,6 +220,7 @@ size_t _libelf_fsize(Elf_Type _t, int _elfclass, unsig
size_t count);
_libelf_translator_function *_libelf_get_translator(Elf_Type _t,
int _direction, int _elfclass, int _elfmachine);
+void *_libelf_getchdr(Elf_Scn *_e, int _elfclass);
void *_libelf_getphdr(Elf *_e, int _elfclass);
void *_libelf_getshdr(Elf_Scn *_scn, int _elfclass);
void _libelf_init_elf(Elf *_e, Elf_Kind _kind);
Modified: head/contrib/elftoolchain/libelf/gelf.3
==============================================================================
--- head/contrib/elftoolchain/libelf/gelf.3 Fri Oct 23 15:56:22 2020 (r366976)
+++ head/contrib/elftoolchain/libelf/gelf.3 Fri Oct 23 16:35:23 2020 (r366977)
@@ -23,7 +23,7 @@
.\"
.\" $Id: gelf.3 3743 2019-06-12 19:36:30Z jkoshy $
.\"
-.Dd June 12, 2019
+.Dd October 23, 2020
.Dt GELF 3
.Os
.Sh NAME
@@ -45,6 +45,8 @@ The GElf API defines the following class-independent d
.Bl -tag -width GElf_Sxword
.It Vt GElf_Addr
A representation of ELF addresses.
+.It Vt GElf_Chdr
+A class-independent representation of an ELF Compression Header.
.It Vt GElf_Dyn
A class-independent representation of ELF
.Sy .dynamic
@@ -144,6 +146,8 @@ native representation.
.El
.It "Retrieving ELF Data"
.Bl -tag -compact -width indent
+.It Fn gelf_getchdr
+Retrieve an ELF Compression Header from the underlying ELF descriptor.
.It Fn gelf_getdyn
Retrieve an ELF
.Sy .dynamic
Modified: head/contrib/elftoolchain/libelf/gelf.h
==============================================================================
--- head/contrib/elftoolchain/libelf/gelf.h Fri Oct 23 15:56:22 2020 (r366976)
+++ head/contrib/elftoolchain/libelf/gelf.h Fri Oct 23 16:35:23 2020 (r366977)
@@ -39,6 +39,7 @@ typedef Elf64_Sxword GElf_Sxword; /* Signed long words
typedef Elf64_Word GElf_Word; /* Unsigned words (32 bit) */
typedef Elf64_Xword GElf_Xword; /* Unsigned long words (64 bit) */
+typedef Elf64_Chdr GElf_Chdr; /* Compressed section header */
typedef Elf64_Dyn GElf_Dyn; /* ".dynamic" section entries */
typedef Elf64_Ehdr GElf_Ehdr; /* ELF header */
typedef Elf64_Phdr GElf_Phdr; /* Program header */
@@ -73,6 +74,7 @@ extern "C" {
long gelf_checksum(Elf *_elf);
size_t gelf_fsize(Elf *_elf, Elf_Type _type, size_t _count,
unsigned int _version);
+GElf_Chdr *gelf_getchdr(Elf_Scn *_scn, GElf_Chdr *_dst);
int gelf_getclass(Elf *_elf);
GElf_Dyn *gelf_getdyn(Elf_Data *_data, int _index, GElf_Dyn *_dst);
GElf_Ehdr *gelf_getehdr(Elf *_elf, GElf_Ehdr *_dst);
Added: head/contrib/elftoolchain/libelf/gelf_chdr.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/contrib/elftoolchain/libelf/gelf_chdr.c Fri Oct 23 16:35:23 2020 (r366977)
@@ -0,0 +1,82 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 The FreeBSD Foundation
+ *
+ * This software was developed by Tiger Gao under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <gelf.h>
+#include <libelf.h>
+#include <limits.h>
+#include <stdint.h>
+
+#include "_libelf.h"
+
+Elf32_Chdr *
+elf32_getchdr(Elf_Scn *s)
+{
+ return (_libelf_getchdr(s, ELFCLASS32));
+}
+
+Elf64_Chdr *
+elf64_getchdr(Elf_Scn *s)
+{
+ return (_libelf_getchdr(s, ELFCLASS64));
+}
+
+GElf_Chdr *
+gelf_getchdr(Elf_Scn *s, GElf_Chdr *d)
+{
+ int ec;
+ void *ch;
+ Elf32_Chdr *ch32;
+ Elf64_Chdr *ch64;
+
+ if (d == NULL) {
+ LIBELF_SET_ERROR(ARGUMENT, 0);
+ return (NULL);
+ }
+
+ if ((ch = _libelf_getchdr(s, ELFCLASSNONE)) == NULL)
+ return (NULL);
+
+ ec = s->s_elf->e_class;
+ assert(ec == ELFCLASS32 || ec == ELFCLASS64);
+
+ if (ec == ELFCLASS32) {
+ ch32 = (Elf32_Chdr *)ch;
+
+ d->ch_type = (Elf64_Word)ch32->ch_type;
+ d->ch_size = (Elf64_Xword)ch32->ch_size;
+ d->ch_addralign = (Elf64_Xword)ch32->ch_addralign;
+ } else {
+ ch64 = (Elf64_Chdr *)ch;
+ *d = *ch64;
+ }
+
+ return (d);
+}
Added: head/contrib/elftoolchain/libelf/gelf_getchdr.3
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/contrib/elftoolchain/libelf/gelf_getchdr.3 Fri Oct 23 16:35:23 2020 (r366977)
@@ -0,0 +1,117 @@
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
+.\" Copyright (c) 2020 The FreeBSD Foundation
+.\"
+.\" This document was written by Tiger Gao under sponsorship from
+.\" the FreeBSD Foundation.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions are
+.\" met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in
+.\" the documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $Id: gelf_getchdr.3 3639 2020-10-20 16:07:02Z tig $
+.\"
+.Dd October 23, 2020
+.Dt GELF_GETCHDR 3
+.Os
+.Sh NAME
+.Nm elf32_getchdr ,
+.Nm elf64_getchdr ,
+.Nm gelf_getchdr
+.Nd retrieve the compression header of a section
+.Sh LIBRARY
+.Lb libelf
+.Sh SYNOPSIS
+.In libelf.h
+.Ft "Elf32_Chdr *"
+.Fn elf32_getchdr "Elf_Scn *s"
+.Ft "Elf64_Chdr *"
+.Fn elf64_getchdr "Elf_Scn *s"
+.In gelf.h
+.Ft "GElf_Chdr *"
+.Fn gelf_getchdr "Elf_Scn *scn" "GElf_Chdr *chdr"
+.Sh DESCRIPTION
+These functions return a pointer to the ELF Compression Header data
+structure associated with section descriptor
+.Ar scn .
+.Pp
+Function
+.Fn elf32_getchdr
+retrieves a pointer to an
+.Vt Elf32_Chdr
+structure.
+Section descriptor
+.Ar scn
+must be associated with an ELF descriptor of class
+.Dv ELFCLASS32 .
+.Pp
+Function
+.Fn elf64_getchdr
+retrieves a pointer to an
+.Vt Elf64_Chdr
+structure.
+Section descriptor
+.Ar scn
+must be associated with an ELF descriptor of class
+.Dv ELFCLASS64 .
+.Pp
+Function
+.Fn gelf_getchdr
+copies the values in the compression header associated with argument
+.Ar scn
+to the structure pointed to be argument
+.Ar dst .
+The
+.Vt GElf_Chdr
+data structure is described in
+.Xr gelf 3 .
+.Sh RETURN VALUES
+Functions
+.Fn elf32_getchdr
+and
+.Fn elf64_getchdr
+return a valid pointer to the appropriate compression header on success
+or NULL if an error was encountered.
+.Pp
+Function
+.Fn gelf_getchdr
+returns argument
+.Ar dst
+if successful, or NULL if an error was encountered.
+.Sh ERRORS
+These functions may fail with the following errors:
+.Bl -tag -width "[ELF_E_RESOURCE]"
+.It Bq Er ELF_E_INVALID_SECTION_FLAGS
+Arguments
+.Ar scn
+has invalid flags.
+.It Bq Er ELF_E_INVALID_SECTION_TYPE
+Argument
+.Ar scn
+has invalid type.
+.It Bq Er ELF_E_NOT_COMPRESSED
+Argument
+.Ar scn
+is not compressed.
+.El
+.Sh SEE ALSO
+.Xr elf 3 ,
+.Xr elf_getscn 3 ,
+.Xr gelf 3 ,
Modified: head/contrib/elftoolchain/libelf/libelf.h
==============================================================================
--- head/contrib/elftoolchain/libelf/libelf.h Fri Oct 23 15:56:22 2020 (r366976)
+++ head/contrib/elftoolchain/libelf/libelf.h Fri Oct 23 16:35:23 2020 (r366977)
@@ -162,6 +162,9 @@ enum Elf_Error {
ELF_E_SEQUENCE, /* API calls out of sequence */
ELF_E_UNIMPL, /* Feature is unimplemented */
ELF_E_VERSION, /* Unknown API version */
+ ELF_E_INVALID_SECTION_FLAGS, /* Invalid ELF section header flags */
+ ELF_E_INVALID_SECTION_TYPE, /* Invalid ELF section header type */
+ ELF_E_NOT_COMPRESSED, /* Section is not compressed */
ELF_E_NUM /* Max error number */
};
@@ -227,6 +230,7 @@ unsigned int elf_version(unsigned int _version);
long elf32_checksum(Elf *_elf);
size_t elf32_fsize(Elf_Type _type, size_t _count,
unsigned int _version);
+Elf32_Chdr *elf32_getchdr(Elf_Scn *_scn);
Elf32_Ehdr *elf32_getehdr(Elf *_elf);
Elf32_Phdr *elf32_getphdr(Elf *_elf);
Elf32_Shdr *elf32_getshdr(Elf_Scn *_scn);
@@ -240,6 +244,7 @@ Elf_Data *elf32_xlatetom(Elf_Data *_dst, const Elf_Dat
long elf64_checksum(Elf *_elf);
size_t elf64_fsize(Elf_Type _type, size_t _count,
unsigned int _version);
+Elf64_Chdr *elf64_getchdr(Elf_Scn *_scn);
Elf64_Ehdr *elf64_getehdr(Elf *_elf);
Elf64_Phdr *elf64_getphdr(Elf *_elf);
Elf64_Shdr *elf64_getshdr(Elf_Scn *_scn);
Added: head/contrib/elftoolchain/libelf/libelf_chdr.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/contrib/elftoolchain/libelf/libelf_chdr.c Fri Oct 23 16:35:23 2020 (r366977)
@@ -0,0 +1,104 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 The FreeBSD Foundation
+ *
+ * This software was developed by Tiger Gao under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <gelf.h>
+#include <libelf.h>
+
+#include "_libelf.h"
+
+void *
+_libelf_getchdr(Elf_Scn *s, int ec)
+{
+ Elf *e;
+ void *sh;
+ Elf32_Shdr *sh32;
+ Elf64_Shdr *sh64;
+
+ sh32 = NULL;
+ sh64 = NULL;
+
+ if (s == NULL || (e = s->s_elf) == NULL || e->e_kind != ELF_K_ELF) {
+ LIBELF_SET_ERROR(ARGUMENT, 0);
+ return (NULL);
+ }
+
+ if (ec == ELFCLASSNONE) {
+ ec = e->e_class;
+ } else if (ec != e->e_class) {
+ LIBELF_SET_ERROR(CLASS, 0);
+ return (NULL);
+ }
+
+ if ((sh = _libelf_getshdr(s, ec)) == NULL) {
+ LIBELF_SET_ERROR(HEADER, 0);
+ return (NULL);
+ }
+
+ if (ec == ELFCLASS32) {
+ sh32 = (Elf32_Shdr *)sh;
+ if ((sh32->sh_flags & SHF_ALLOC) != 0) {
+ LIBELF_SET_ERROR(INVALID_SECTION_FLAGS, 0);
+ return (NULL);
+ }
+
+ if (sh32->sh_type == SHT_NULL || sh32->sh_type == SHT_NOBITS) {
+ LIBELF_SET_ERROR(INVALID_SECTION_TYPE, 0);
+ return (NULL);
+ }
+
+ if ((sh32->sh_flags & SHF_COMPRESSED) == 0) {
+ LIBELF_SET_ERROR(NOT_COMPRESSED, 0);
+ return (NULL);
+ }
+ } else {
+ sh64 = (Elf64_Shdr *)sh;
+ if ((sh64->sh_flags & SHF_ALLOC) != 0) {
+ LIBELF_SET_ERROR(INVALID_SECTION_FLAGS, 0);
+ return (NULL);
+ }
+
+ if (sh64->sh_type == SHT_NULL || sh64->sh_type == SHT_NOBITS) {
+ LIBELF_SET_ERROR(INVALID_SECTION_TYPE, 0);
+ return (NULL);
+ }
+
+ if ((sh64->sh_flags & SHF_COMPRESSED) == 0) {
+ LIBELF_SET_ERROR(NOT_COMPRESSED, 0);
+ return (NULL);
+ }
+ }
+
+ Elf_Data *d = elf_getdata(s, NULL);
+
+ if (!d)
+ return (NULL);
+
+ return ((void *)d->d_buf);
+}
Modified: head/lib/libelf/Makefile
==============================================================================
--- head/lib/libelf/Makefile Fri Oct 23 15:56:22 2020 (r366976)
+++ head/lib/libelf/Makefile Fri Oct 23 16:35:23 2020 (r366977)
@@ -38,6 +38,7 @@ SRCS= elf.c \
elf_update.c \
elf_version.c \
gelf_cap.c \
+ gelf_chdr.c \
gelf_checksum.c \
gelf_dyn.c \
gelf_ehdr.c \
@@ -57,6 +58,7 @@ SRCS= elf.c \
libelf_allocate.c \
libelf_ar.c \
libelf_ar_util.c \
+ libelf_chdr.c \
libelf_checksum.c \
libelf_data.c \
libelf_ehdr.c \
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