* [PATCH] readelf: Handle .debug_str_offsets.
@ 2018-05-28 15:03 Mark Wielaard
2018-05-30 10:16 ` Mark Wielaard
0 siblings, 1 reply; 2+ messages in thread
From: Mark Wielaard @ 2018-05-28 15:03 UTC (permalink / raw)
To: elfutils-devel; +Cc: Mark Wielaard
The .debug_str_offsets tables are indirect string offsets into the
.debug_str section. For DWARF5 they can be in both the main, skeleton
and split dwarf (.dwo) files.
For DWARF4 with the GNU DebugFission extension the tables will not have
an header and they will only be in the split DWARF (.dwo) file, never in
the main (skeleton) file.
For DWARF5 the (non-split) unit DIE will have a DW_AT_str_offsets_base
attribute pointing at the actual index (after the header). The split
unit will never have this attribute (and use the table at offset zero).
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
src/ChangeLog | 9 ++
src/readelf.c | 213 ++++++++++++++++++++++++++++++++++++++++++++++-
tests/ChangeLog | 6 ++
tests/Makefile.am | 4 +-
tests/run-readelf-str.sh | 211 ++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 440 insertions(+), 3 deletions(-)
create mode 100755 tests/run-readelf-str.sh
diff --git a/src/ChangeLog b/src/ChangeLog
index 01ecc61..545fb50 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,12 @@
+2018-04-29 Mark Wielaard <mark@klomp.org>
+
+ * readelf.c (parse_opt): Request implicit section_info for "str".
+ (known_stroffbases): New static variable.
+ (attr_callbackattr_callback): Handle DW_AT_str_offets_base.
+ (print_debug_str_offsets_section): New function.
+ (print_debug): Handle .debug_str_offsets as section_str. Reset
+ known_stroffbases.
+
2018-04-27 Mark Wielaard <mark@klomp.org>
* readelf.c (options): Add addr.
diff --git a/src/readelf.c b/src/readelf.c
index de38ac6..89960b3 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -484,7 +484,11 @@ parse_opt (int key, char *arg,
else if (strcmp (arg, "pubnames") == 0)
print_debug_sections |= section_pubnames;
else if (strcmp (arg, "str") == 0)
- print_debug_sections |= section_str;
+ {
+ print_debug_sections |= section_str;
+ /* For mapping string offset tables to CUs. */
+ implicit_debug_sections |= section_info;
+ }
else if (strcmp (arg, "macinfo") == 0)
print_debug_sections |= section_macinfo;
else if (strcmp (arg, "macro") == 0)
@@ -4824,6 +4828,7 @@ static struct listptr_table known_loclistsptr;
static struct listptr_table known_rangelistptr;
static struct listptr_table known_rnglistptr;
static struct listptr_table known_addrbases;
+static struct listptr_table known_stroffbases;
static void
reset_listptr (struct listptr_table *table)
@@ -7192,6 +7197,21 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
}
return DWARF_CB_OK;
+ case DW_AT_str_offsets_base:
+ {
+ bool stroffbase = notice_listptr (section_str, &known_stroffbases,
+ cbargs->addrsize,
+ cbargs->offset_size,
+ cbargs->cu, num, attr);
+ if (!cbargs->silent)
+ printf (" %*s%-20s (%s) str offsets base [%6"
+ PRIxMAX "]%s\n",
+ (int) (level * 2), "", dwarf_attr_name (attr),
+ dwarf_form_name (form), (uintmax_t) num,
+ stroffbase ? "" : " <WARNING offset too big>");
+ }
+ return DWARF_CB_OK;
+
case DW_AT_language:
valuestr = dwarf_lang_name (num);
break;
@@ -9936,6 +9956,193 @@ print_debug_str_section (Dwfl_Module *dwflmod __attribute__ ((unused)),
}
}
+static void
+print_debug_str_offsets_section (Dwfl_Module *dwflmod __attribute__ ((unused)),
+ Ebl *ebl, GElf_Ehdr *ehdr,
+ Elf_Scn *scn, GElf_Shdr *shdr, Dwarf *dbg)
+{
+ printf (gettext ("\
+\nDWARF section [%2zu] '%s' at offset %#" PRIx64 ":\n"),
+ elf_ndxscn (scn), section_name (ebl, ehdr, shdr),
+ (uint64_t) shdr->sh_offset);
+
+ if (shdr->sh_size == 0)
+ return;
+
+ /* We like to get the section from libdw to make sure they are relocated. */
+ Elf_Data *data = (dbg->sectiondata[IDX_debug_str_offsets]
+ ?: elf_rawdata (scn, NULL));
+ if (unlikely (data == NULL))
+ {
+ error (0, 0, gettext ("cannot get .debug_str_offsets section data: %s"),
+ elf_errmsg (-1));
+ return;
+ }
+
+ size_t idx = 0;
+ sort_listptr (&known_stroffbases, "str_offsets");
+
+ const unsigned char *start = (const unsigned char *) data->d_buf;
+ const unsigned char *readp = start;
+ const unsigned char *readendp = ((const unsigned char *) data->d_buf
+ + data->d_size);
+
+ while (readp < readendp)
+ {
+ /* Most string offset tables will have a header. For split
+ dwarf unit GNU DebugFission didn't add one. But they were
+ also only defined for split units (main or skeleton units
+ didn't have indirect strings). So if we don't have a
+ DW_AT_str_offsets_base at all and this is offset zero, then
+ just start printing offsets immediately, if this is a .dwo
+ section. */
+ Dwarf_Off off = (Dwarf_Off) (readp
+ - (const unsigned char *) data->d_buf);
+
+ printf ("Table at offset %" PRIx64 " ", off);
+
+ struct listptr *listptr = get_listptr (&known_stroffbases, idx++);
+ const unsigned char *next_unitp = readendp;
+ uint8_t offset_size;
+ bool has_header;
+ if (listptr == NULL)
+ {
+ /* This can happen for .dwo files. There is only an header
+ in the case this is a version 5 split DWARF file. */
+ Dwarf_CU *cu;
+ uint8_t unit_type;
+ if (dwarf_get_units (dbg, NULL, &cu, NULL, &unit_type,
+ NULL, NULL) != 0)
+ {
+ error (0, 0, "Warning: Cannot find any DWARF unit.");
+ /* Just guess some values. */
+ has_header = false;
+ offset_size = 4;
+ }
+ else if (off == 0
+ && (unit_type == DW_UT_split_type
+ || unit_type == DW_UT_split_compile))
+ {
+ has_header = cu->version > 4;
+ offset_size = cu->offset_size;
+ }
+ else
+ {
+ error (0, 0,
+ "Warning: No CU references .debug_str_offsets after %"
+ PRIx64, off);
+ has_header = cu->version > 4;
+ offset_size = cu->offset_size;
+ }
+ printf ("\n");
+ }
+ else
+ {
+ /* This must be DWARF5, since GNU DebugFission didn't define
+ DW_AT_str_offsets_base. */
+ has_header = true;
+
+ Dwarf_Die cudie;
+ if (dwarf_cu_die (listptr->cu, &cudie,
+ NULL, NULL, NULL, NULL,
+ NULL, NULL) == NULL)
+ printf ("Unknown CU (%s):\n", dwarf_errmsg (-1));
+ else
+ printf ("for CU [%6" PRIx64 "]:\n", dwarf_dieoffset (&cudie));
+ }
+
+ if (has_header)
+ {
+ uint64_t unit_length;
+ uint16_t version;
+ uint16_t padding;
+
+ unit_length = read_4ubyte_unaligned_inc (dbg, readp);
+ if (unlikely (unit_length == 0xffffffff))
+ {
+ if (unlikely (readp > readendp - 8))
+ {
+ invalid_data:
+ error (0, 0, "Invalid data");
+ return;
+ }
+ unit_length = read_8ubyte_unaligned_inc (dbg, readp);
+ offset_size = 8;
+ }
+ else
+ offset_size = 4;
+
+ printf ("\n");
+ printf (gettext (" Length: %8" PRIu64 "\n"),
+ unit_length);
+ printf (gettext (" Offset size: %8" PRIu8 "\n"),
+ offset_size);
+
+ /* We need at least 2-bytes (version) + 2-bytes (padding) =
+ 4 bytes to complete the header. And this unit cannot go
+ beyond the section data. */
+ if (readp > readendp - 4
+ || unit_length < 4
+ || unit_length > (uint64_t) (readendp - readp))
+ goto invalid_data;
+
+ next_unitp = readp + unit_length;
+
+ version = read_2ubyte_unaligned_inc (dbg, readp);
+ printf (gettext (" DWARF version: %8" PRIu16 "\n"), version);
+
+ if (version != 5)
+ {
+ error (0, 0, gettext ("Unknown version"));
+ goto next_unit;
+ }
+
+ padding = read_2ubyte_unaligned_inc (dbg, readp);
+ printf (gettext (" Padding: %8" PRIx16 "\n"), padding);
+
+ if (listptr != NULL
+ && listptr->offset != (Dwarf_Off) (readp - start))
+ {
+ error (0, 0, "String offsets index doesn't start after header");
+ goto next_unit;
+ }
+
+ printf ("\n");
+ }
+
+ int digits = 1;
+ size_t offsets = (next_unitp - readp) / offset_size;
+ while (offsets >= 10)
+ {
+ ++digits;
+ offsets /= 10;
+ }
+
+ unsigned int index = 0;
+ size_t index_offset = readp - (const unsigned char *) data->d_buf;
+ printf (" Offsets start at 0x%zx:\n", index_offset);
+ while (readp <= next_unitp - offset_size)
+ {
+ Dwarf_Word offset;
+ if (offset_size == 4)
+ offset = read_4ubyte_unaligned_inc (dbg, readp);
+ else
+ offset = read_8ubyte_unaligned_inc (dbg, readp);
+ const char *str = dwarf_getstring (dbg, offset, NULL);
+ printf (" [%*u] [%*" PRIx64 "] \"%s\"\n",
+ digits, index++, (int) offset_size * 2, offset, str ?: "???");
+ }
+ printf ("\n");
+
+ if (readp != next_unitp)
+ error (0, 0, "extra %zd bytes at end of unit",
+ (size_t) (next_unitp - readp));
+
+ next_unit:
+ readp = next_unitp;
+ }
+}
+
/* Print the content of the call frame search table section
'.eh_frame_hdr'. */
@@ -10749,6 +10956,9 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr)
/* A DWARF5 specialised debug string section. */
{ ".debug_line_str", section_str,
print_debug_str_section },
+ /* DWARF5 string offsets table. */
+ { ".debug_str_offsets", section_str,
+ print_debug_str_offsets_section },
NEW_SECTION (macinfo),
NEW_SECTION (macro),
NEW_SECTION (ranges),
@@ -10804,6 +11014,7 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr)
reset_listptr (&known_rangelistptr);
reset_listptr (&known_rnglistptr);
reset_listptr (&known_addrbases);
+ reset_listptr (&known_stroffbases);
}
diff --git a/tests/ChangeLog b/tests/ChangeLog
index 6991551..7ac6bd3 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,9 @@
+2018-04-29 Mark Wielaard <mark@klomp.org>
+
+ * run-readelf-addr.sh: New test.
+ * Makefile.am (TESTS): Add run-readelf-addr.sh.
+ (EXTRA_DIST): Likewise.
+
2018-04-27 Mark Wielaard <mark@klomp.org>
* run-readelf-ranges.sh: Adjust expected output for address base.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index e15fe51..4cd0665 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -130,7 +130,7 @@ TESTS = run-arextract.sh run-arsymtest.sh run-ar.sh newfile test-nlist \
run-backtrace-core-aarch64.sh run-backtrace-core-sparc.sh \
run-backtrace-demangle.sh run-stack-d-test.sh run-stack-i-test.sh \
run-stack-demangled-test.sh run-readelf-zx.sh run-readelf-zp.sh \
- run-readelf-addr.sh \
+ run-readelf-addr.sh run-readelf-str.sh \
run-readelf-dwz-multi.sh run-allfcts-multi.sh run-deleted.sh \
run-linkmap-cut.sh run-aggregate-size.sh run-peel-type.sh \
vdsosyms run-readelf-A.sh \
@@ -246,7 +246,7 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
run-readelf-dwz-multi.sh libtestfile_multi_shared.so.bz2 \
testfile_multi.dwz.bz2 testfile_multi_main.bz2 \
testfile-dwzstr.bz2 testfile-dwzstr.multi.bz2 \
- run-readelf-addr.sh \
+ run-readelf-addr.sh run-readelf-str.sh \
run-allfcts-multi.sh \
test-offset-loop.bz2 test-offset-loop.alt.bz2 \
run-prelink-addr-test.sh \
diff --git a/tests/run-readelf-str.sh b/tests/run-readelf-str.sh
new file mode 100755
index 0000000..8b894e8
--- /dev/null
+++ b/tests/run-readelf-str.sh
@@ -0,0 +1,211 @@
+#! /bin/sh
+# Copyright (C) 2018 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
+
+# See tests/testfile-dwarf-45.source
+testfiles testfile-splitdwarf-4 testfile-splitdwarf-5
+testfiles testfile-hello4.dwo testfile-hello5.dwo
+testfiles testfile-world4.dwo testfile-world5.dwo
+
+# DWARF4 GNU DebugFission No real table header.
+# We don't really need the skeleton, but we don't want any Warnings.
+testrun_compare ${abs_top_builddir}/src/readelf --dwarf-skeleton testfile-splitdwarf-4 --debug-dump=str testfile-hello4.dwo testfile-world4.dwo<<\EOF
+
+testfile-hello4.dwo:
+
+
+DWARF section [ 5] '.debug_str_offsets.dwo' at offset 0x335:
+Table at offset 0
+ Offsets start at 0x0:
+ [ 0] [ 0] "long long int"
+ [ 1] [ e] "frob"
+ [ 2] [ 13] "long unsigned int"
+ [ 3] [ 25] "/home/mark/src/elfutils/tests"
+ [ 4] [ 43] "wchar_t"
+ [ 5] [ 4b] "main"
+ [ 6] [ 50] "long int"
+ [ 7] [ 59] "GNU C17 9.0.0 20180515 (experimental) -mtune=generic -march=x86-64 -gdwarf-4 -gsplit-dwarf -gno-as-loc-support -gno-variable-location-views -O2"
+ [ 8] [ e9] "long double"
+ [ 9] [ f5] "hello.c"
+
+
+DWARF section [ 6] '.debug_str.dwo' at offset 0x35d:
+ Offset String
+ [ 0] "long long int"
+ [ e] "frob"
+ [ 13] "long unsigned int"
+ [ 25] "/home/mark/src/elfutils/tests"
+ [ 43] "wchar_t"
+ [ 4b] "main"
+ [ 50] "long int"
+ [ 59] "GNU C17 9.0.0 20180515 (experimental) -mtune=generic -march=x86-64 -gdwarf-4 -gsplit-dwarf -gno-as-loc-support -gno-variable-location-views -O2"
+ [ e9] "long double"
+ [ f5] "hello.c"
+
+testfile-world4.dwo:
+
+
+DWARF section [ 5] '.debug_str_offsets.dwo' at offset 0x2e7:
+Table at offset 0
+ Offsets start at 0x0:
+ [ 0] [ 0] "long long unsigned int"
+ [ 1] [ 17] "/home/mark/src/elfutils/tests"
+ [ 2] [ 35] "long long int"
+ [ 3] [ 43] "signed char"
+ [ 4] [ 4f] "long int"
+ [ 5] [ 58] "world.c"
+ [ 6] [ 60] "unsigned int"
+ [ 7] [ 6d] "long unsigned int"
+ [ 8] [ 7f] "short unsigned int"
+ [ 9] [ 92] "frob"
+ [10] [ 97] "calc"
+ [11] [ 9c] "unsigned char"
+ [12] [ aa] "short int"
+ [13] [ b4] "exit"
+ [14] [ b9] "GNU C17 9.0.0 20180515 (experimental) -mtune=generic -march=x86-64 -gdwarf-4 -gsplit-dwarf -gno-as-loc-support -gno-variable-location-views -O2"
+ [15] [ 149] "char"
+ [16] [ 14e] "word"
+ [17] [ 153] "argv"
+ [18] [ 158] "argc"
+ [19] [ 15d] "main"
+
+
+DWARF section [ 6] '.debug_str.dwo' at offset 0x337:
+ Offset String
+ [ 0] "long long unsigned int"
+ [ 17] "/home/mark/src/elfutils/tests"
+ [ 35] "long long int"
+ [ 43] "signed char"
+ [ 4f] "long int"
+ [ 58] "world.c"
+ [ 60] "unsigned int"
+ [ 6d] "long unsigned int"
+ [ 7f] "short unsigned int"
+ [ 92] "frob"
+ [ 97] "calc"
+ [ 9c] "unsigned char"
+ [ aa] "short int"
+ [ b4] "exit"
+ [ b9] "GNU C17 9.0.0 20180515 (experimental) -mtune=generic -march=x86-64 -gdwarf-4 -gsplit-dwarf -gno-as-loc-support -gno-variable-location-views -O2"
+ [ 149] "char"
+ [ 14e] "word"
+ [ 153] "argv"
+ [ 158] "argc"
+ [ 15d] "main"
+EOF
+
+# DWARF5 Real table header.
+# We don't really need the skeleton, but we don't want any Warnings.
+testrun_compare ${abs_top_builddir}/src/readelf --dwarf-skeleton testfile-splitdwarf-5 --debug-dump=str testfile-hello5.dwo testfile-world5.dwo<<\EOF
+
+testfile-hello5.dwo:
+
+
+DWARF section [ 5] '.debug_str_offsets.dwo' at offset 0x353:
+Table at offset 0
+
+ Length: 44
+ Offset size: 4
+ DWARF version: 5
+ Padding: 0
+
+ Offsets start at 0x8:
+ [ 0] [ 0] "long long int"
+ [ 1] [ e] "frob"
+ [ 2] [ 13] "long unsigned int"
+ [ 3] [ 25] "/home/mark/src/elfutils/tests"
+ [ 4] [ 43] "wchar_t"
+ [ 5] [ 4b] "main"
+ [ 6] [ 50] "long int"
+ [ 7] [ 59] "GNU C17 9.0.0 20180515 (experimental) -mtune=generic -march=x86-64 -gdwarf-5 -gsplit-dwarf -gno-as-loc-support -gno-variable-location-views -O2"
+ [ 8] [ e9] "long double"
+ [ 9] [ f5] "hello.c"
+
+
+DWARF section [ 6] '.debug_str.dwo' at offset 0x383:
+ Offset String
+ [ 0] "long long int"
+ [ e] "frob"
+ [ 13] "long unsigned int"
+ [ 25] "/home/mark/src/elfutils/tests"
+ [ 43] "wchar_t"
+ [ 4b] "main"
+ [ 50] "long int"
+ [ 59] "GNU C17 9.0.0 20180515 (experimental) -mtune=generic -march=x86-64 -gdwarf-5 -gsplit-dwarf -gno-as-loc-support -gno-variable-location-views -O2"
+ [ e9] "long double"
+ [ f5] "hello.c"
+
+testfile-world5.dwo:
+
+
+DWARF section [ 5] '.debug_str_offsets.dwo' at offset 0x313:
+Table at offset 0
+
+ Length: 84
+ Offset size: 4
+ DWARF version: 5
+ Padding: 0
+
+ Offsets start at 0x8:
+ [ 0] [ 0] "long long unsigned int"
+ [ 1] [ 17] "GNU C17 9.0.0 20180515 (experimental) -mtune=generic -march=x86-64 -gdwarf-5 -gsplit-dwarf -gno-as-loc-support -gno-variable-location-views -O2"
+ [ 2] [ a7] "/home/mark/src/elfutils/tests"
+ [ 3] [ c5] "long long int"
+ [ 4] [ d3] "signed char"
+ [ 5] [ df] "long int"
+ [ 6] [ e8] "world.c"
+ [ 7] [ f0] "unsigned int"
+ [ 8] [ fd] "long unsigned int"
+ [ 9] [ 10f] "short unsigned int"
+ [10] [ 122] "frob"
+ [11] [ 127] "calc"
+ [12] [ 12c] "unsigned char"
+ [13] [ 13a] "short int"
+ [14] [ 144] "exit"
+ [15] [ 149] "char"
+ [16] [ 14e] "word"
+ [17] [ 153] "argv"
+ [18] [ 158] "argc"
+ [19] [ 15d] "main"
+
+
+DWARF section [ 6] '.debug_str.dwo' at offset 0x36b:
+ Offset String
+ [ 0] "long long unsigned int"
+ [ 17] "GNU C17 9.0.0 20180515 (experimental) -mtune=generic -march=x86-64 -gdwarf-5 -gsplit-dwarf -gno-as-loc-support -gno-variable-location-views -O2"
+ [ a7] "/home/mark/src/elfutils/tests"
+ [ c5] "long long int"
+ [ d3] "signed char"
+ [ df] "long int"
+ [ e8] "world.c"
+ [ f0] "unsigned int"
+ [ fd] "long unsigned int"
+ [ 10f] "short unsigned int"
+ [ 122] "frob"
+ [ 127] "calc"
+ [ 12c] "unsigned char"
+ [ 13a] "short int"
+ [ 144] "exit"
+ [ 149] "char"
+ [ 14e] "word"
+ [ 153] "argv"
+ [ 158] "argc"
+ [ 15d] "main"
+EOF
+
+exit 0
--
1.8.3.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] readelf: Handle .debug_str_offsets.
2018-05-28 15:03 [PATCH] readelf: Handle .debug_str_offsets Mark Wielaard
@ 2018-05-30 10:16 ` Mark Wielaard
0 siblings, 0 replies; 2+ messages in thread
From: Mark Wielaard @ 2018-05-30 10:16 UTC (permalink / raw)
To: elfutils-devel
On Mon, 2018-05-28 at 17:03 +0200, Mark Wielaard wrote:
> The .debug_str_offsets tables are indirect string offsets into the
> .debug_str section. For DWARF5 they can be in both the main, skeleton
> and split dwarf (.dwo) files.
>
> For DWARF4 with the GNU DebugFission extension the tables will not have
> an header and they will only be in the split DWARF (.dwo) file, never in
> the main (skeleton) file.
>
> For DWARF5 the (non-split) unit DIE will have a DW_AT_str_offsets_base
> attribute pointing at the actual index (after the header). The split
> unit will never have this attribute (and use the table at offset zero).
Pushed to master.
^ permalink raw reply [flat|nested] 2+ messages in thread
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