+2012-06-27 Mark Wielaard <mjw@redhat.com>
+
+ * dwarf.h: Add DW_FORM_GNU_ref_alt and DW_FORM_GNU_strp_alt.
+ * dwarf_begin.c (dwarf_begin): Add INTDEF.
+ * dwarf_begin_elf.c (__check_build_id): New internal_function.
+ (try_debugaltlink): New function.
+ (open_debugaltlink): Likewise.
+ (check_section): Try open_debugaltlink for .gnu_debugaltlink.
+ * dwarf_end.c (dwarf_end): Free the alternative Dwarf descriptor if
+ necessary.
+ * dwarf_error.c (errmsgs): Add DWARF_E_NO_ALT_DEBUGLINK.
+ * dwarf_formref.c (__libdw_formref): Using DW_FORM_GNU_ref_alt
+ is an error here.
+ * dwarf_formref_die.c (dwarf_formref_die): Handle DW_FORM_GNU_ref_alt.
+ * dwarf_formstring.c (dwarf_formstring): Handle DW_FORM_GNU_strp_alt.
+ * dwarf_formudata.c (__libdw_formptr): Adjust __libdw_read_offset
+ calls.
+ * dwarf_getpubnames.c (get_offsets): Adjust __libdw_read_offset call.
+ * libdwP.h: Add DWARF_E_NO_ALT_DEBUGLINK.
+ (struct Dwarf): Add alt_dwarf and free_alt fields.
+ (__libdw_read_offset): Add dbg_ret argument, use to check with
+ __libdw_offset_in_section.
+ (__check_build_id): New function declaration.
+ (dwarf_begin): Define as INTDECL.
+ * libdw_form.c (__libdw_form_val_len): Handle DW_FORM_GNU_ref_alt
+ and DW_FORM_GNU_strp_alt.
+
2012-07-19 Mark Wielaard <mjw@redhat.com>
* dwarf.h: Add DW_OP_GNU_parameter_ref.
DW_FORM_sec_offset = 0x17,
DW_FORM_exprloc = 0x18,
DW_FORM_flag_present = 0x19,
- DW_FORM_ref_sig8 = 0x20
+ DW_FORM_ref_sig8 = 0x20,
+
+ DW_FORM_GNU_ref_alt = 0x1f20, /* offset in alternate .debuginfo. */
+ DW_FORM_GNU_strp_alt = 0x1f21 /* offset in alternate .debug_str. */
};
return result;
}
+INTDEF(dwarf_begin)
# include <config.h>
#endif
+#include <assert.h>
+#include <inttypes.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
+#include <stdio.h>
#include <string.h>
#include <unistd.h>
+#include <sys/types.h>
#include <sys/stat.h>
+#include <fcntl.h>
#include "libdwP.h"
};
#define ndwarf_scnnames (sizeof (dwarf_scnnames) / sizeof (dwarf_scnnames[0]))
+internal_function int
+__check_build_id (Dwarf *dw, const uint8_t *build_id, const size_t id_len)
+{
+ if (dw == NULL)
+ return -1;
+
+ Elf *elf = dw->elf;
+ Elf_Scn *scn = elf_nextscn (elf, NULL);
+ if (scn == NULL)
+ return -1;
+
+ do
+ {
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (likely (shdr != NULL) && shdr->sh_type == SHT_NOTE)
+ {
+ size_t pos = 0;
+ GElf_Nhdr nhdr;
+ size_t name_pos;
+ size_t desc_pos;
+ Elf_Data *data = elf_getdata (scn, NULL);
+ while ((pos = gelf_getnote (data, pos, &nhdr, &name_pos,
+ &desc_pos)) > 0)
+ if (nhdr.n_type == NT_GNU_BUILD_ID
+ && nhdr.n_namesz == sizeof "GNU"
+ && ! memcmp (data->d_buf + name_pos, "GNU", sizeof "GNU"))
+ return (nhdr.n_descsz == id_len
+ && ! memcmp (data->d_buf + desc_pos,
+ build_id, id_len)) ? 0 : 1;
+ }
+ }
+ while ((scn = elf_nextscn (elf, scn)) != NULL);
+
+ return -1;
+}
+
+/* Try to open an debug alt link by name, checking build_id.
+ Marks free_alt on success, return NULL on failure. */
+static Dwarf *
+try_debugaltlink (Dwarf *result, const char *try_name,
+ const uint8_t *build_id, const size_t id_len)
+{
+ int fd = open (try_name, O_RDONLY);
+ if (fd > 0)
+ {
+ result->alt_dwarf = INTUSE (dwarf_begin) (fd, DWARF_C_READ);
+ if (result->alt_dwarf != NULL)
+ {
+ Elf *elf = result->alt_dwarf->elf;
+ if (__check_build_id (result->alt_dwarf, build_id, id_len) == 0
+ && elf_cntl (elf, ELF_C_FDREAD) == 0)
+ {
+ close (fd);
+ result->free_alt = 1;
+ return result;
+ }
+ INTUSE (dwarf_end) (result->alt_dwarf);
+ }
+ close (fd);
+ }
+ return NULL;
+}
+
+/* For dwz multifile support, ignore if it looks wrong. */
+static Dwarf *
+open_debugaltlink (Dwarf *result, const char *alt_name,
+ const uint8_t *build_id, const size_t id_len)
+{
+ /* First try the name itself, it is either an absolute path or
+ a relative one. Sadly we don't know relative from where at
+ this point. */
+ if (try_debugaltlink (result, alt_name, build_id, id_len) != NULL)
+ return result;
+
+ /* Lets try based on the build-id. This is somewhat distro specific,
+ we are following the Fedora implementation described at
+ https://fedoraproject.org/wiki/Releases/FeatureBuildId#Find_files_by_build_ID
+ */
+#define DEBUG_PREFIX "/usr/lib/debug/.build-id/"
+#define PREFIX_LEN sizeof (DEBUG_PREFIX)
+ char id_name[PREFIX_LEN + 1 + id_len * 2 + sizeof ".debug" - 1];
+ strcpy (id_name, DEBUG_PREFIX);
+ int n = snprintf (&id_name[PREFIX_LEN - 1],
+ 4, "%02" PRIx8 "/", (uint8_t) build_id[0]);
+ assert (n == 3);
+ for (size_t i = 1; i < id_len; ++i)
+ {
+ n = snprintf (&id_name[PREFIX_LEN - 1 + 3 + (i - 1) * 2],
+ 3, "%02" PRIx8, (uint8_t) build_id[i]);
+ assert (n == 2);
+ }
+ strcpy (&id_name[PREFIX_LEN - 1 + 3 + (id_len - 1) * 2],
+ ".debug");
+
+ if (try_debugaltlink (result, id_name, build_id, id_len))
+ return result;
+
+ /* Everything failed, mark this Dwarf as not having an alternate,
+ but don't fail the load. The user may want to set it by hand
+ before usage. */
+ result->alt_dwarf = NULL;
+ return result;
+}
static Dwarf *
check_section (Dwarf *result, GElf_Ehdr *ehdr, Elf_Scn *scn, bool inscngrp)
return NULL;
}
+ /* For dwz multifile support, ignore if it looks wrong. */
+ if (strcmp (scnname, ".gnu_debugaltlink") == 0)
+ {
+ Elf_Data *data = elf_getdata (scn, NULL);
+ if (data != NULL && data->d_size != 0)
+ {
+ const char *alt_name = data->d_buf;
+ const void *build_id = memchr (data->d_buf, '\0', data->d_size);
+ const int id_len = data->d_size - (build_id - data->d_buf + 1);
+ if (alt_name && build_id && id_len > 0)
+ return open_debugaltlink (result, alt_name, build_id + 1, id_len);
+ }
+ }
+
/* Recognize the various sections. Most names start with .debug_. */
size_t cnt;
if (dwarf->free_elf)
elf_end (dwarf->elf);
+ /* Free the alternative Dwarf descriptor if necessary. */
+ if (dwarf->free_alt)
+ INTUSE (dwarf_end) (dwarf->alt_dwarf);
+
/* Free the context descriptor. */
free (dwarf);
}
[DWARF_E_INVALID_OFFSET] = N_("invalid offset"),
[DWARF_E_NO_DEBUG_RANGES] = N_(".debug_ranges section missing"),
[DWARF_E_INVALID_CFI] = N_("invalid CFI section"),
+ [DWARF_E_NO_ALT_DEBUGLINK] = N_("no alternative debug link found"),
};
#define nerrmsgs (sizeof (errmsgs) / sizeof (errmsgs[0]))
case DW_FORM_ref_addr:
case DW_FORM_ref_sig8:
+ case DW_FORM_GNU_ref_alt:
+ /* These aren't handled by dwarf_formref, only by dwarf_formref_die. */
__libdw_seterrno (DWARF_E_INVALID_REFERENCE);
return -1;
struct Dwarf_CU *cu = attr->cu;
Dwarf_Off offset;
- if (attr->form == DW_FORM_ref_addr)
+ if (attr->form == DW_FORM_ref_addr || attr->form == DW_FORM_GNU_ref_alt)
{
/* This has an absolute offset. */
? cu->address_size
: cu->offset_size);
- if (__libdw_read_offset (cu->dbg, IDX_debug_info, attr->valp,
+ Dwarf *dbg_ret = (attr->form == DW_FORM_GNU_ref_alt
+ ? cu->dbg->alt_dwarf : cu->dbg);
+
+ if (dbg_ret == NULL)
+ {
+ __libdw_seterrno (DWARF_E_NO_ALT_DEBUGLINK);
+ return NULL;
+ }
+
+ if (__libdw_read_offset (cu->dbg, dbg_ret, IDX_debug_info, attr->valp,
ref_size, &offset, IDX_debug_info, 0))
return NULL;
- return INTUSE(dwarf_offdie) (cu->dbg, offset, result);
+ return INTUSE(dwarf_offdie) (dbg_ret, offset, result);
}
Elf_Data *data;
return (const char *) attrp->valp;
Dwarf *dbg = attrp->cu->dbg;
+ Dwarf *dbg_ret = attrp->form == DW_FORM_GNU_strp_alt ? dbg->alt_dwarf : dbg;
- if (unlikely (attrp->form != DW_FORM_strp)
+ if (unlikely (dbg_ret == NULL))
+ {
+ __libdw_seterrno (DWARF_E_NO_ALT_DEBUGLINK);
+ return NULL;
+ }
+
+
+ if (unlikely (attrp->form != DW_FORM_strp
+ && attrp->form != DW_FORM_GNU_strp_alt)
|| dbg->sectiondata[IDX_debug_str] == NULL)
{
__libdw_seterrno (DWARF_E_NO_STRING);
}
uint64_t off;
- if (__libdw_read_offset (dbg, cu_sec_idx (attrp->cu), attrp->valp,
+ if (__libdw_read_offset (dbg, dbg_ret, cu_sec_idx (attrp->cu), attrp->valp,
attrp->cu->offset_size, &off, IDX_debug_str, 1))
return NULL;
- return (const char *) dbg->sectiondata[IDX_debug_str]->d_buf + off;
+ return (const char *) dbg_ret->sectiondata[IDX_debug_str]->d_buf + off;
}
INTDEF(dwarf_formstring)
Dwarf_Word offset;
if (attr->form == DW_FORM_sec_offset)
{
- if (__libdw_read_offset (attr->cu->dbg, cu_sec_idx (attr->cu), attr->valp,
+ if (__libdw_read_offset (attr->cu->dbg, attr->cu->dbg,
+ cu_sec_idx (attr->cu), attr->valp,
attr->cu->offset_size, &offset, sec_index, 0))
return NULL;
}
{
case DW_FORM_data4:
case DW_FORM_data8:
- if (__libdw_read_offset (attr->cu->dbg, cu_sec_idx (attr->cu),
+ if (__libdw_read_offset (attr->cu->dbg, attr->cu->dbg,
+ cu_sec_idx (attr->cu),
attr->valp,
attr->form == DW_FORM_data4 ? 4 : 8,
&offset, sec_index, 0))
}
/* Get the CU offset. */
- if (__libdw_read_offset (dbg, IDX_debug_pubnames, readp + 2, len_bytes,
+ if (__libdw_read_offset (dbg, dbg, IDX_debug_pubnames,
+ readp + 2, len_bytes,
&mem[cnt].cu_offset, IDX_debug_info, 3))
/* Error has been already set in reader. */
goto err_return;
DWARF_E_INVALID_OFFSET,
DWARF_E_NO_DEBUG_RANGES,
DWARF_E_INVALID_CFI,
+ DWARF_E_NO_ALT_DEBUGLINK
};
/* The underlying ELF file. */
Elf *elf;
+ /* dwz alternate DWARF file. */
+ Dwarf *alt_dwarf;
+
/* The section data. */
Elf_Data *sectiondata[IDX_last];
/* If true, we allocated the ELF descriptor ourselves. */
bool free_elf;
+ /* If true, we allocated the Dwarf descriptor for alt_dwarf ourselves. */
+ bool free_alt;
+
/* Information for traversing the .debug_pubnames section. This is
an array and separately allocated with malloc. */
struct pubnames_s
}
static inline int
-__libdw_read_offset (Dwarf *dbg,
+__libdw_read_offset (Dwarf *dbg, Dwarf *dbg_ret,
int sec_index, const unsigned char *addr,
int width, Dwarf_Off *ret, int sec_ret,
size_t size)
{
READ_AND_RELOCATE (__libdw_relocate_offset, (*ret));
- return __libdw_offset_in_section (dbg, sec_ret, *ret, size);
+ return __libdw_offset_in_section (dbg_ret, sec_ret, *ret, size);
}
static inline size_t
Dwarf_Off *offsetp)
internal_function;
+/* Checks that the build_id of the underlying Elf matches the expected.
+ Returns zero on match, -1 on error or no build_id found or 1 when
+ build_id doesn't match. */
+int __check_build_id (Dwarf *dw, const uint8_t *build_id, const size_t id_len)
+ internal_function;
+
/* Aliases to avoid PLTs. */
INTDECL (dwarf_aggregate_size)
INTDECL (dwarf_attr)
INTDECL (dwarf_attr_integrate)
+INTDECL (dwarf_begin)
INTDECL (dwarf_begin_elf)
INTDECL (dwarf_child)
INTDECL (dwarf_dieoffset)
case DW_FORM_strp:
case DW_FORM_sec_offset:
+ case DW_FORM_GNU_ref_alt:
+ case DW_FORM_GNU_strp_alt:
result = cu->offset_size;
break;
+2012-06-27 Mark Wielaard <mjw@redhat.com>
+
+ * readelf.c (dwarf_form_string): Handle DW_FORM_GNU_ref_alt and
+ DW_FORM_GNU_strp_alt.
+ (attr_callback): Likewise.
+
2012-07-30 Petr Machata <pmachata@redhat.com>
* nm.c (show_symbols_bsd): Reorder arguments in {S,}FMTSTRS (and
if (likely (form < nknown_forms))
result = known_forms[form];
+ else
+ {
+ /* GNU extensions use vendor numbers. */
+ switch (form)
+ {
+ case DW_FORM_GNU_ref_alt:
+ result = "GNU_ref_alt";
+ break;
+
+ case DW_FORM_GNU_strp_alt:
+ result = "GNU_strp_alt";
+ break;
+ }
+ }
if (unlikely (result == NULL))
{
case DW_FORM_indirect:
case DW_FORM_strp:
case DW_FORM_string:
+ case DW_FORM_GNU_strp_alt:
if (cbargs->silent)
break;
const char *str = dwarf_formstring (attrp);
case DW_FORM_ref8:
case DW_FORM_ref4:
case DW_FORM_ref2:
- case DW_FORM_ref1:;
+ case DW_FORM_ref1:
+ case DW_FORM_GNU_ref_alt:
if (cbargs->silent)
break;
Dwarf_Die ref;
+2012-06-27 Mark Wielaard <mjw@redhat.com>
+
+ * Makefile.am (TESTS): Add run-readelf-dwz-multi.sh.
+ (EXTRA_DIST): Add run-readelf-dwz-multi.sh,
+ libtestfile_multi_shared.so.bz2, testfile_multi.dwz.bz2 and
+ testfile_multi_main.bz2.
+ * run-readelf-dwz-multi.sh: New test.
+ * libtestfile_multi_shared.so.bz2: New testfile.
+ * testfile_multi.dwz.bz2: New testifle.
+ * testfile_multi_main.bz2: New testifle.
+
2012-08-01 Petr Machata <pmachata@redhat.com>
* run-test-archive64.sh: New test.
run-nm-self.sh run-readelf-self.sh \
run-readelf-test1.sh run-readelf-test2.sh run-readelf-test3.sh \
run-readelf-test4.sh run-readelf-twofiles.sh \
- run-readelf-macro.sh \
+ run-readelf-macro.sh run-readelf-dwz-multi.sh \
run-native-test.sh run-bug1-test.sh \
dwfl-bug-addr-overflow run-addrname-test.sh \
dwfl-bug-fd-leak dwfl-bug-report \
testfile46.bz2 testfile47.bz2 testfile48.bz2 testfile48.debug.bz2 \
testfile49.bz2 testfile50.bz2 testfile51.bz2 \
run-readelf-macro.sh testfilemacro.bz2 \
+ run-readelf-dwz-multi.sh libtestfile_multi_shared.so.bz2 \
+ testfile_multi.dwz.bz2 testfile_multi_main.bz2 \
run-prelink-addr-test.sh \
testfile52-32.so.bz2 testfile52-32.so.debug.bz2 \
testfile52-32.prelink.so.bz2 testfile52-32.noshdrs.so.bz2 \
--- /dev/null
+#! /bin/sh
+# Copyright (C) 2012 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/>.
+
+. $srcdir/test-subr.sh
+
+# common.h
+#
+# #include <stdio.h>
+#
+# struct foobar
+# {
+# int foo;
+# struct foobar *bar;
+# };
+#
+# extern int call_foo(struct foobar *foobar_struct_ptr);
+
+# main.c
+#
+# #include "common.h"
+#
+# int main(int argc, char ** argv)
+# {
+# struct foobar b;
+# b.foo = 42;
+# b.bar = &b;
+#
+# return call_foo(b.bar);
+# }
+
+# shared.c
+#
+# #include "common.h"
+#
+# int call_foo(struct foobar *fb)
+# {
+# return fb->bar->foo - 42;
+# }
+
+# gcc -fPIC -g -c -Wall shared.c
+# gcc -shared -o libtestfile_multi_shared.so shared.o
+# gcc -g -o testfile_multi_main -L. -ltestfile_multi_shared main.c -Wl,-rpath,.
+# dwz -m testfile_multi.dwz testfile_multi_main libtestfile_multi_shared.so
+
+testfiles libtestfile_multi_shared.so testfile_multi_main testfile_multi.dwz
+
+testrun_compare ../src/readelf --debug-dump=info testfile_multi_main <<\EOF
+
+DWARF section [28] '.debug_info' at offset 0x1078:
+ [Offset]
+ Compilation unit at offset 0:
+ Version: 4, Abbreviation section offset: 0, Address size: 8, Offset size: 4
+ [ b] compile_unit
+ producer (strp) "GNU C 4.7.0 20120507 (Red Hat 4.7.0-5) -mtune=generic -march=x86-64 -g"
+ language (data1) ISO C89 (1)
+ name (strp) "main.c"
+ comp_dir (GNU_strp_alt) "/home/mark/src/tests/dwz"
+ low_pc (addr) 0x00000000004006ac <main>
+ high_pc (udata) 44
+ stmt_list (sec_offset) 0
+ [ 26] imported_unit
+ import (GNU_ref_alt) [ b]
+ [ 2b] pointer_type
+ byte_size (data1) 8
+ type (GNU_ref_alt) [ 53]
+ [ 31] subprogram
+ external (flag_present)
+ name (strp) "main"
+ decl_file (data1) 1
+ decl_line (data1) 3
+ prototyped (flag_present)
+ type (GNU_ref_alt) [ 3e]
+ low_pc (addr) 0x00000000004006ac <main>
+ high_pc (udata) 44
+ frame_base (exprloc)
+ [ 0] call_frame_cfa
+ GNU_all_tail_call_sites (flag_present)
+ sibling (ref_udata) [ 6e]
+ [ 48] formal_parameter
+ name (strp) "argc"
+ decl_file (data1) 1
+ decl_line (data1) 3
+ type (GNU_ref_alt) [ 3e]
+ location (exprloc)
+ [ 0] fbreg -36
+ [ 56] formal_parameter
+ name (strp) "argv"
+ decl_file (data1) 1
+ decl_line (data1) 3
+ type (ref_udata) [ 6e]
+ location (exprloc)
+ [ 0] fbreg -48
+ [ 61] variable
+ name (string) "b"
+ decl_file (data1) 1
+ decl_line (data1) 5
+ type (GNU_ref_alt) [ 5a]
+ location (exprloc)
+ [ 0] fbreg -32
+ [ 6e] pointer_type
+ byte_size (data1) 8
+ type (ref_udata) [ 2b]
+EOF
+
+testrun_compare ../src/readelf --debug-dump=info libtestfile_multi_shared.so <<\EOF
+
+DWARF section [25] '.debug_info' at offset 0x106c:
+ [Offset]
+ Compilation unit at offset 0:
+ Version: 4, Abbreviation section offset: 0, Address size: 8, Offset size: 4
+ [ b] compile_unit
+ producer (strp) "GNU C 4.7.0 20120507 (Red Hat 4.7.0-5) -fpreprocessed -mtune=generic -march=x86-64 -g -fPIC"
+ language (data1) ISO C89 (1)
+ name (strp) "shared.c"
+ comp_dir (GNU_strp_alt) "/home/mark/src/tests/dwz"
+ low_pc (addr) +0x0000000000000670 <call_foo>
+ high_pc (udata) 23
+ stmt_list (sec_offset) 0
+ [ 26] imported_unit
+ import (GNU_ref_alt) [ b]
+ [ 2b] subprogram
+ external (flag_present)
+ name (strp) "call_foo"
+ decl_file (data1) 1
+ decl_line (data1) 3
+ prototyped (flag_present)
+ type (GNU_ref_alt) [ 3e]
+ low_pc (addr) +0x0000000000000670 <call_foo>
+ high_pc (udata) 23
+ frame_base (exprloc)
+ [ 0] call_frame_cfa
+ GNU_all_call_sites (flag_present)
+ [ 41] formal_parameter
+ name (string) "fb"
+ decl_file (data1) 1
+ decl_line (data1) 3
+ type (GNU_ref_alt) [ 76]
+ location (exprloc)
+ [ 0] fbreg -24
+EOF
+
+exit 0
projects / thirdparty / elfutils.git / commitdiff
