Go to file
Tom de Vries 6848938272 [gdb/symtab] Fix segfault on invalid debug info
While looking at PR symtab/31478 (a problem in the cooked indexer with invalid
dwarf) it occurred to me that I could trigger a similar problem using:
...
  Compilation Unit @ offset 0xb2:
   Length:        0x1f (32-bit)
   Version:       4
   Abbrev Offset: 0x6c
   Pointer Size:  8
 <0><bd>: Abbrev Number: 1 (DW_TAG_compile_unit)
    <be>   DW_AT_language    : 2	(non-ANSI C)
 <1><bf>: Abbrev Number: 2 (DW_TAG_subprogram)
    <c0>   DW_AT_low_pc      : 0x4004a7
    <c8>   DW_AT_high_pc     : 0x4004b2
    <d0>   DW_AT_specification: <0xd5>
 <1><d4>: Abbrev Number: 0
  Compilation Unit @ offset 0xd5:
   Length:        0x7 (32-bit)
   Version:       4
   Abbrev Offset: 0x7f
   Pointer Size:  8
...
and indeed I get:
...
$ gdb -q -batch outputs/gdb.dwarf2/dw2-inter-cu-error-2/dw2-inter-cu-error-2

Fatal signal: Segmentation fault
...

The problem is that we're calling prepare_one_comp_unit with cu == nullptr and
comp_unit_die == nullptr here in cooked_indexer::ensure_cu_exists:
...
      cutu_reader new_reader (per_cu, per_objfile, nullptr, nullptr, false,
                              m_index_storage->get_abbrev_cache ());

      prepare_one_comp_unit (new_reader.cu, new_reader.comp_unit_die,
                             language_minimal);
...

Fix this by bailing out for various types of dummy CUs:
...
      if (new_reader.dummy_p || new_reader.comp_unit_die == nullptr
	  || !new_reader.comp_unit_die->has_children)
	return nullptr;
...

Also make sure in scan_attributes that this triggers a dwarf error:
...
$ gdb -q -batch dw2-inter-cu-error-2
DWARF Error: cannot follow reference to DIE at 0xd5 \
  [in module dw2-inter-cu-error-2]
...

With target board readnow, the test-case triggers an assertion failure in
follow_die_offset, so fix this by throwing the same dwarf error.

While we're at it, make the other check for dummy CUs in
cooked_indexer::ensure_cu_exists more robust by adding an intermediate test
for comp_unit_die:
...
-  if (result->dummy_p || !result->comp_unit_die->has_children)
+  if (result->dummy_p || result->comp_unit_die == nullptr
+      || !result->comp_unit_die->has_children)
     return nullptr;
...

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>
2024-09-24 10:50:44 +02:00
bfd Automatic date update in version.in 2024-09-24 00:00:35 +00:00
binutils get_type_abbrev_from_form tidy 2024-08-29 21:05:57 +09:30
config
contrib Revert "contrib: Add autoregen.py" 2024-09-04 13:38:57 +00:00
cpu
elfcpp
etc
gas x86: Enable TLS relocation check only for ELF 2024-09-24 05:52:43 +08:00
gdb [gdb/symtab] Fix segfault on invalid debug info 2024-09-24 10:50:44 +02:00
gdbserver gdbserver: aarch64: Fix expedited registers list 2024-09-05 01:02:51 -03:00
gdbsupport gdbsupport/intrusive-list: add owning_intrusive_list 2024-09-13 07:38:56 -04:00
gnulib
gold gold: Always resolve non-default weak undefined to 0 2024-08-31 04:28:43 -07:00
gprof
gprofng Fix 32096 UBSAN issues in gprofng 2024-09-18 20:24:24 -07:00
include MIPS/opcodes: Rework documentation for instruction args 2024-09-15 13:27:33 +01:00
ld ld/pdb: Handle DEBUG_S_INLINEELINES data 2024-09-24 02:33:08 +01:00
libbacktrace
libctf PR32093, -Walloc-size warning in ctf-hash.c 2024-08-29 21:05:57 +09:30
libdecnumber
libiberty libiberty: sync with gcc 2024-09-04 15:35:42 +01:00
libsframe
opcodes x86/APX: Don't promote AVX/AVX2 instructions out of APX spec 2024-09-18 10:11:02 +08:00
readline
sim
texinfo
zlib
.cvsignore
.editorconfig
.gitattributes
.gitignore
.pre-commit-config.yaml
ar-lib
ChangeLog
compile
config-ml.in
config.guess
config.rpath
config.sub
configure Disable gprofng build for *musl* 2024-08-26 13:48:29 -07:00
configure.ac Disable gprofng build for *musl* 2024-08-26 13:48:29 -07:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4
lt~obsolete.m4
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS
Makefile.def
Makefile.in
Makefile.tpl
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
multilib.am
README
README-maintainer-mode
SECURITY.txt
setup.com
src-release.sh
symlink-tree
test-driver
ylwrap

		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.