[PATCH] libdw: Recognize zero terminator to end frame table in dwarf_next_cfi.
Mark Wielaard
mark@klomp.org
Thu Jun 28 22:26:00 GMT 2018
When the length is zero this is a the zero terminator that ends the
frame table. Return 1 (end of table) instead of -1 (error) in that case.
We cannot update next_off and don't want to caller to try again.
Add testcase for dwarf_next_cfi to show both .eh_frame and .debug_frame
tables and check consistency (FDEs should point to existing CIEs).
Also add a self check to make sure we can read the table from the just
build elfutils binaries.
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
libdw/ChangeLog | 4 ++
libdw/dwarf_next_cfi.c | 8 +++
tests/ChangeLog | 10 ++++
tests/Makefile.am | 8 +--
tests/next_cfi.c | 131 +++++++++++++++++++++++++++++++++++++++++++++
tests/run-next-cfi-self.sh | 21 ++++++++
tests/run-next-cfi.sh | 108 +++++++++++++++++++++++++++++++++++++
7 files changed, 287 insertions(+), 3 deletions(-)
create mode 100644 tests/next_cfi.c
create mode 100755 tests/run-next-cfi-self.sh
create mode 100755 tests/run-next-cfi.sh
diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 97f4f19..11b3c8a 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,7 @@
+2018-06-28 Mark Wielaard <mark@klomp.org>
+
+ * dwarf_next_cfi.c (dwarf_next_cfi): Check whether length is zero.
+
2018-06-27 Mark Wielaard <mark@klomp.org>
* dwarf_begin_elf.c (check_section): Allow a single .debug_frame
diff --git a/libdw/dwarf_next_cfi.c b/libdw/dwarf_next_cfi.c
index 53fc369..fa28d99 100644
--- a/libdw/dwarf_next_cfi.c
+++ b/libdw/dwarf_next_cfi.c
@@ -54,6 +54,7 @@ dwarf_next_cfi (const unsigned char e_ident[],
we don't know yet whether this is a 64-bit object or not. */
|| unlikely (off + 4 >= data->d_size))
{
+ done:
*next_off = (Dwarf_Off) -1l;
return 1;
}
@@ -79,6 +80,13 @@ dwarf_next_cfi (const unsigned char e_ident[],
}
length = read_8ubyte_unaligned_inc (&dw, bytes);
}
+
+ /* Not explicitly in the DWARF spec, but mentioned in the LSB exception
+ frames (.eh_frame) spec. If Length contains the value 0, then this
+ CIE shall be considered a terminator and processing shall end. */
+ if (length == 0)
+ goto done;
+
if (unlikely ((uint64_t) (limit - bytes) < length)
|| unlikely (length < offset_size + 1))
goto invalid;
diff --git a/tests/ChangeLog b/tests/ChangeLog
index 1e03f6b..4ce79f5 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,13 @@
+2018-06-28 Mark Wielaard <mark@klomp.org>
+
+ * next_cfi.c: New file.
+ * run-next-cfi.sh: New test.
+ * run-next-cfi-self.sh: Likewise.
+ * Makefile.am (check_PROGRAMS): Add next_cfi.
+ (TESTS): Add run-next-cfi.sh and run-next-cfi-self.sh.
+ (EXTRA_DIST): Likewise.
+ (next_cfi_LDADD): New variable.
+
2018-06-27 Mark Wielaard <mark@klomp.org>
* dwarf_cfi.c: New file.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 47e5555..ecc2d68 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -59,7 +59,7 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \
elfgetzdata elfputzdata zstrptr emptyfile vendorelf \
fillfile dwarf_default_lower_bound dwarf-die-addr-die \
get-units-invalid get-units-split attr-integrate-skel \
- all-dwarf-ranges unit-info
+ all-dwarf-ranges unit-info next_cfi
asm_TESTS = asm-tst1 asm-tst2 asm-tst3 asm-tst4 asm-tst5 \
asm-tst6 asm-tst7 asm-tst8 asm-tst9
@@ -151,7 +151,8 @@ TESTS = run-arextract.sh run-arsymtest.sh run-ar.sh newfile test-nlist \
run-get-units-invalid.sh run-get-units-split.sh \
run-attr-integrate-skel.sh \
run-all-dwarf-ranges.sh run-unit-info.sh \
- run-reloc-bpf.sh
+ run-reloc-bpf.sh \
+ run-next-cfi.sh run-next-cfi-self.sh
if !BIARCH
export ELFUTILS_DISABLE_BIARCH = 1
@@ -396,7 +397,7 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
run-attr-integrate-skel.sh \
run-all-dwarf-ranges.sh testfilesplitranges4.debug.bz2 \
testfile-ranges-hello.dwo.bz2 testfile-ranges-world.dwo.bz2 \
- run-unit-info.sh
+ run-unit-info.sh run-next-cfi.sh run-next-cfi-self.sh
if USE_VALGRIND
valgrind_cmd='valgrind -q --leak-check=full --error-exitcode=1'
@@ -563,6 +564,7 @@ get_units_split_LDADD = $(libdw)
attr_integrate_skel_LDADD = $(libdw)
all_dwarf_ranges_LDADD = $(libdw)
unit_info_LDADD = $(libdw)
+next_cfi_LDADD = $(libelf) $(libdw)
# We want to test the libelf header against the system elf.h header.
# Don't include any -I CPPFLAGS.
diff --git a/tests/next_cfi.c b/tests/next_cfi.c
new file mode 100644
index 0000000..b923744
--- /dev/null
+++ b/tests/next_cfi.c
@@ -0,0 +1,131 @@
+/* Test program for dwarf_next_cfi
+ 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/>. */
+
+#include <config.h>
+#include <assert.h>
+#include <inttypes.h>
+#include <error.h>
+#include ELFUTILS_HEADER(dw)
+#include <dwarf.h>
+#include <argp.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <locale.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+void
+handle_section (const unsigned char e_ident[],
+ Elf_Scn *scn, const bool is_eh)
+{
+ if (is_eh)
+ printf (".eh_frame\n");
+ else
+ printf (".debug_frame\n");
+
+ Elf_Data *data = elf_getdata (scn, NULL);
+ if (data == NULL || data->d_buf == NULL)
+ error (EXIT_FAILURE, 0, "no section data");
+
+ int res;
+ Dwarf_Off off;
+ Dwarf_Off next_off = 0;
+ Dwarf_CFI_Entry entry;
+ while ((res = dwarf_next_cfi (e_ident, data, is_eh, off = next_off,
+ &next_off, &entry)) == 0)
+ {
+ printf ("[%" PRId64 "] ", off);
+ if (dwarf_cfi_cie_p (&entry))
+ printf ("CIE augmentation=\"%s\"\n", entry.cie.augmentation);
+ else
+ {
+ printf ("FDE cie=[%" PRId64 "]\n", entry.fde.CIE_pointer);
+
+ Dwarf_Off cie_off = entry.fde.CIE_pointer;
+ Dwarf_Off cie_off_next;
+ Dwarf_CFI_Entry cie_entry;
+ if (dwarf_next_cfi (e_ident, data, is_eh, cie_off, &cie_off_next,
+ &cie_entry) != 0
+ || !dwarf_cfi_cie_p (&cie_entry))
+ error (EXIT_FAILURE, 0, "FDE doesn't point to CIE");
+ }
+ }
+
+ if (res < 0)
+ error (EXIT_FAILURE, 0, "dwarf_next_cfi failed: %s\n",
+ dwarf_errmsg (-1));
+}
+
+int
+main (int argc, char *argv[])
+{
+ if (argc != 2)
+ error (EXIT_FAILURE, 0, "need file name argument");
+
+ const char *file = argv[1];
+ printf ("%s\n", file);
+
+ int fd = open (file, O_RDONLY);
+ if (fd == -1)
+ error (EXIT_FAILURE, errno, "cannot open input file `%s'", file);
+
+ elf_version (EV_CURRENT);
+
+ Elf *elf = elf_begin (fd, ELF_C_READ, NULL);
+ if (elf == NULL)
+ error (EXIT_FAILURE, 0, "cannot create ELF descriptor: %s",
+ elf_errmsg (-1));
+
+ size_t esize;
+ const unsigned char *ident = (const unsigned char *) elf_getident (elf,
+ &esize);
+ if (ident == NULL || esize < EI_NIDENT)
+ error (EXIT_FAILURE, 0, "no, or too small, ELF ident");
+
+ GElf_Ehdr ehdr;
+ if (gelf_getehdr (elf, &ehdr) == NULL)
+ error (EXIT_FAILURE, 0, "cannot get the ELF header: %s\n",
+ elf_errmsg (-1));
+
+ size_t strndx = ehdr.e_shstrndx;
+
+ Elf_Scn *scn = NULL;
+ while ((scn = elf_nextscn (elf, scn)) != NULL)
+ {
+ GElf_Shdr shdr;
+ if (gelf_getshdr (scn, &shdr) != NULL)
+ {
+ char *name = elf_strptr (elf, strndx, (size_t) shdr.sh_name);
+ if (name != NULL && shdr.sh_type == SHT_PROGBITS)
+ {
+ if (strcmp (name, ".eh_frame") == 0)
+ handle_section (ident, scn, true);
+ if (strcmp (name, ".debug_frame") == 0)
+ handle_section (ident, scn, false);
+ }
+ }
+ }
+
+ elf_end (elf);
+ close (fd);
+
+ return 0;
+}
diff --git a/tests/run-next-cfi-self.sh b/tests/run-next-cfi-self.sh
new file mode 100755
index 0000000..2c42ea3
--- /dev/null
+++ b/tests/run-next-cfi-self.sh
@@ -0,0 +1,21 @@
+#! /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
+
+# Sanity check toolchain/dwarf_next_cfi
+testrun_on_self ${abs_builddir}/next_cfi
diff --git a/tests/run-next-cfi.sh b/tests/run-next-cfi.sh
new file mode 100755
index 0000000..23c0d7d
--- /dev/null
+++ b/tests/run-next-cfi.sh
@@ -0,0 +1,108 @@
+#! /bin/sh
+# Test for dwarf_next_cfi.
+# 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
+
+# Test files come from run-addrcfi
+testfiles testfile11 testfile12
+testfiles testfilearm testfileaarch64
+testfiles testfileppc32 testfileppc64
+
+testrun_compare ${abs_builddir}/next_cfi testfile11 <<\EOF
+testfile11
+.eh_frame
+[0] CIE augmentation="zPL"
+[28] FDE cie=[0]
+[64] FDE cie=[0]
+[96] FDE cie=[0]
+[128] FDE cie=[0]
+.debug_frame
+[0] CIE augmentation=""
+[20] FDE cie=[0]
+[52] FDE cie=[0]
+[76] FDE cie=[0]
+[100] FDE cie=[0]
+[124] FDE cie=[0]
+[148] FDE cie=[0]
+[172] FDE cie=[0]
+[196] FDE cie=[0]
+EOF
+
+testrun_compare ${abs_builddir}/next_cfi testfile12 <<\EOF
+testfile12
+.eh_frame
+[0] CIE augmentation=""
+[16] CIE augmentation="zR"
+[40] FDE cie=[16]
+.debug_frame
+[0] CIE augmentation=""
+[24] FDE cie=[0]
+EOF
+
+testrun_compare ${abs_builddir}/next_cfi testfilearm <<\EOF
+testfilearm
+.eh_frame
+.debug_frame
+[0] CIE augmentation=""
+[16] FDE cie=[0]
+[32] CIE augmentation=""
+[48] FDE cie=[32]
+EOF
+
+testrun_compare ${abs_builddir}/next_cfi testfileaarch64 <<\EOF
+testfileaarch64
+.eh_frame
+[0] CIE augmentation="zR"
+[24] FDE cie=[0]
+[80] FDE cie=[0]
+.debug_frame
+[0] CIE augmentation=""
+[16] FDE cie=[0]
+[40] CIE augmentation=""
+[56] FDE cie=[40]
+EOF
+
+testrun_compare ${abs_builddir}/next_cfi testfileppc32 <<\EOF
+testfileppc32
+.eh_frame
+[0] CIE augmentation="zR"
+[20] FDE cie=[0]
+[40] FDE cie=[0]
+[96] FDE cie=[0]
+.debug_frame
+[0] CIE augmentation=""
+[16] FDE cie=[0]
+[32] CIE augmentation=""
+[48] FDE cie=[32]
+EOF
+
+testrun_compare ${abs_builddir}/next_cfi testfileppc64 <<\EOF
+testfileppc64
+.eh_frame
+[0] CIE augmentation="zR"
+[20] FDE cie=[0]
+[40] FDE cie=[0]
+[64] CIE augmentation="zR"
+[88] FDE cie=[64]
+[144] FDE cie=[64]
+.debug_frame
+[0] CIE augmentation=""
+[16] FDE cie=[0]
+[56] CIE augmentation=""
+[72] FDE cie=[56]
+EOF
--
1.8.3.1
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