While working on the previous commit to fix PR cli/28665, I noticed
that the 'edit' command would suffer from the same problem. That is,
something like:
(gdb) edit task 123
would cause GDB to break. For a full explanation of what's going on
here, see the commit message for the previous commit.
As with the previous commit, this issue can be prevented by detecting,
and throwing, a junk at the end of the line error earlier, before
calling decode_line_1.
So, that's what this commit does. I've also added some tests for this
issue.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28665
In PR cli/28665, it was reported that GDB would crash when given a
command like:
(gdb) list task 123
The problem here is that in cli/cli-cmd.c:list_command, the string
'task 123' is passed to string_to_event_location in find a location
specification. However, this location parsing understands about
breakpoint conditions, and so, will stop parsing when it sees
something that looks like a condition, in this case, the 'task 123'
looks like a breakpoint condition.
As a result, the location we get back from string_to_event_location
has no actual location specification attached to it. The actual call
path is:
list_command
string_to_event_location
string_to_event_location_basic
new_linespec_location
In new_linespec_location we call linespec_lex_to_end, which looks at
'task 123' and decides that there's nothing there that describes a
location. As such, in new_linespec_location, the spec_string field of
the location is left as nullptr.
Back in list_command we then call decode_line_1, which calls
event_location_to_sals, which calls parse_linespec, which takes the
spec_string we found earlier, and tries to converts this into a list
of sals.
However, parse_linespec is not intended to be passed a nullptr, for
example, calling is_ada_operator will try to access through the
nullptr, causing undefined behaviour. But there are other cases
within parse_linespec which don't expect to see a nullptr.
When looking at how to fix this issue, I first considered having
linespec_lex_to_end detect the problem. That function understands
when the first thing in the linespec is a condition keyword, and so,
could throw an error saying something like: "no linespec before
condition keyword", however, this is not going to work, at least, not
without additional changes to GDB, it is valid to place a breakpoint
like:
(gdb) break task 123
This will place a breakpoint at the current location with the
condition 'task 123', and changing linespec_lex_to_end breaks this
behaviour.
So, next, I considered what would happen if I added a condition to an
otherwise valid list command, this is what I see:
(gdb) list file.c:1 task 123
Junk at end of line specification.
(gdb)
So, then I wondered, could we just pull the "Junk" detection forward,
so that we throw the error earlier, before we call decode_line_1?
It turns out that yes we can. Well, sort of.
It is simpler, I think, to add a separate check into the list_command
function, after calling string_to_event_location, but before calling
decode_line_1. We know when we call string_to_event_location that the
string in question is not empty, so, after calling
string_to_event_location, if non of the string has been consumed, then
the content of the string must be junk - it clearly doesn't look like
a location specification.
I've reused the same "Junk at end of line specification." error for
consistency, and added a few tests to cover this issue.
While the first version of this patch was on the mailing list, a
second bug PR gdb/28797 was raised. This was for a very similar
issue, but this time the problem command was:
(gdb) list ,,
Here the list command understands about the first comma, list can have
two arguments separated by a comma, and the first argument can be
missing. So we end up trying to parse the second command "," as a
linespec.
However, in linespec_lex_to_end, we will stop parsing a linespec at a
comma, so, in the above case we end up with an empty linespec (between
the two commas), and, like above, this results in the spec_string
being nullptr.
As with the previous case, I've resolved this issue by adding an extra
check for junk at the end of the line - after parsing (or failing to
parse) the nothing between the two commas, we still have the "," left
at the end of the list command line - when we see this we can throw
the same "junk at the end of the line" error, and all is good.
I've added tests for this case too.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28665
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28797
The gdb.base/linespecs.exp test should really live in the gdb.linespec
directory, so lets move it there.
As we already have gdb.linespec/linespec.exp, I've renamed the test to
gdb.linespec/errors.exp, as this better reflects what the test is
actually checking.
Finally, the test script doesn't have its own source file, it was
reusing a random other source file, gdb.base/memattr.c. Now the tests
script is in gdb.linespec/, I've updated the test to use a different
source file from that directory.
If parse_linespec (linespec.c) is passed ARG as an empty string then
we end up calling `strchr (linespec_quote_characters, '\0')`, which
will return a pointer to the '\0' at the end of
linespec_quote_characters. This then results in GDB calling
skip_quote_char with `ARG + 1`, which is undefined behaviour (as ARG
only contained a single character, the '\0').
Fix this by checking for the first character of ARG being '\0' before
the call to strchr.
I have additionally added an assertion that ARG can't itself be
nullptr, as calling is_ada_operator with nullptr can end up calling
'startswith' on the nullptr, which is undefined behaviour.
Finally, I moved the declaration of TOKEN into the body of
parse_linespec, to where TOKEN is defined.
This patch came about while I was working on fixes for PR cli/28665
and PR gdb/28797. The actual fixes for these two issues will be in a
later commit in this series, but, with this patch in place, both of
the above bugs would hit the new assertion rather than accessing
invalid memory and crashing. The '\0' check is not currently ever
hit, but just makes the code a little safer.
Because this patch only changes the nature of the failure for the
above two bugs, there's no tests here. A later commit will fix the
above two issues, at which point I'll add some tests.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28665
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28797
The comment on string_to_event_location is (I believe) out of date.
This commit fixes the two issues I see:
1. This function can't return NULL any more. The implementation
calls string_to_explicit_location which can return NULL, but if this
is the case we then call string_to_event_location_basic, which I
don't believe can ever return NULL.
2. I've removed the mention that the returned string is malloc'd,
though this is true, now that we return a managed pointer, I believe
the source of the memory allocation is irrelevant, and so, shouldn't
be discussed in the header comment.
There should be no user visible changes after this commit.
Previously when fixing PR 21464 we masked out upper bits of the
relocation value in order to avoid overflow complaints when acceptable.
It turns out this does not work when the relocation value ends up being
signed.
To fix this this patch introduces a special howto with
complain_on_overflow set to complain_overflow_dont. This is used in
place of the normal R_OR1K_GOT16 howto when we detect R_OR1K_GOT_AHI16
relocations.
bfd/ChangeLog:
PR 28735
* elf32-or1k.c (or1k_elf_got16_no_overflow_howto): Define.
(or1k_elf_relocate_section): Use new howto instead of trying to
mask out relocation bits.
Currently, if flex fails, it will leave the resulting .c file in the
tree. This will cause a cascade of errors, and requires the manual
deletion of the .c file in order to recreate the problem.
It's better for the rule to fail such that the .c file is not updated.
This way, 'make' will fail the same way every time -- which is much
handier for debugging syntax errors.
This fix just updates the Makefile rule to follow the way that the
"yacc" rule already works.
When trying to use 'record btrace' on a system that does not support it,
the error message isn't as clear as it could be. See
https://sourceware.org/pipermail/gdb/2022-January/049870.html.
Improve the error message in a few cases.
Reported-by: Simon Sobisch <simonsobisch@gnu.org>
While experimenting with JIT reader API I realized that calling repr ()
on objfile created by JIT reader crashes GDB.
The problem was that objfpy_repr () called objfile_filename () which
returned NULL, causing PyString_FromFormat () to crash.
This commit fixes this problem by using objfile_name () instead of
objfile_filename (). This also makes consistent with the value of gdb.Objfile.filename variable.
The last updates of MIG introduced qualifying strings and arrays with
const as appropriate. We thus have to update the protypes in gdb too.
Change-Id: I3f72aac1dfa6e58d1394d5776b822d7c8f2409df
VER_FLG_WEAK doesn't indicate that all symbol references of the symbol
version have STB_WEAK. VER_FLG_WEAK indicates a weak symbol version
definition with no symbols associated with it. It is used to verify
the existence of a particular implementation without any symbol references
to the weak symbol version.
PR ld/24718
* testsuite/ld-elf/pr24718-1.d: New file.
* testsuite/ld-elf/pr24718-1.s: Likewise.
* testsuite/ld-elf/pr24718-1.t: Likewise.
Don't load debug sections if we aren't dumping any debug sections.
PR binutils/28843
* objdump.c (dump_any_debugging): New.
(load_debug_section): Return false if dump_any_debugging isn't
set.
(main): Set dump_any_debugging when dumping any debug sections.
* readelf (dump_any_debugging): New.
(parse_args): Set dump_any_debugging when dumping any debug
sections.
(load_debug_section): Return false if dump_any_debugging isn't
set.
I have warnings like these showing in my editor all the time, so I
thought I'd run clang-tidy with this diagnostic on all the files (that I
can compile) and fix them.
There is still one warning, in utils.c, but that's because some code
is mixed up with preprocessor macros (#ifdef TUI), so I think there no
good solution there.
Change-Id: I345175fc7dd865318f0fbe61ac026c88c3b6a96b
Info symbol is expected to print the symbol table name of a symbol, since
symbol lookup happens via the minimal symbol table. This name
corresponds to the linkage name in the full symbol table.
For gfortran (and maybe others) these names currently have the form
XXXX.NUMBER where XXXX is the symbol name and NUMBER a compiler
generated appendix for mangling.
An example taken from the modified nested-funcs-2.exp would be
~~~~
$ objdump -t ./outputs/gdb.fortran/nested-funcs-2/nested-funcs-2 | grep \
increment
00000000000014ab l F .text 0000000000000095 increment.3883
000000000000141c l F .text 000000000000008f increment_program_global.3881
~~~~
This mangled name gets recognized by the Ada demangler/decoder and decoded as
Ada to XXXX (setting the symbol language to Ada). This leads to output
of XXXX over XXXX.NUMBER for info symbol on gfortran symbols.
For ifort and ifx the generated linkage names have the form
SCOPEA_SCOPEB_XXXX_ which are not recognized by the Ada decoder (or any
other demangler for that matter) and thus printed as is.
The respective objdump in the above case looks like
~~~~
$ objdump -t ./outputs/gdb.fortran/nested-funcs-2/nested-funcs-2 | grep \
increment
0000000000403a44 l F .text 0000000000000074 contains_keyword_IP_increment_
0000000000403ab8 l F .text 0000000000000070
contains_keyword_IP_increment_program_global_
~~~~
In the unmodified testcase this results in 'fails' when ran with the intel
compilers:
~~~~
>> make check RUNTESTFLAGS="gdb.fortran/nested-funcs-2.exp \
GDBFLAGS='$GDBFLAGS' CC_FOR_TARGET='icpc' F90_FOR_TARGET='ifort'"
...
=== gdb Summary ===
\# of expected passes 80
\# of unexpected failures 14
~~~~
Note that there is no Fortran mangling standard. We keep the gfortran
behavior as is and modify the test to reflect ifx and ifort mangled
names which fixes above fails.
Signed-off-by: Nils-Christian Kempke <nils-christian.kempke@intel.com>
PR 98886
PR 99935
* rust-demangle.c (struct rust_demangler): Add a recursion
counter.
(demangle_path): Increment/decrement the recursion counter upon
entry and exit. Fail if the counter exceeds a fixed limit.
(demangle_type): Likewise.
(rust_demangle_callback): Initialise the recursion counter,
disabling if requested by the option flags.
In trying to find a testcase for PR28827, I managed to hit a linker
error in bfd_set_section_contents with a .branch_lt input section
being too large for the output .branch_lt.
bfd/
PR 28827
* elf64-ppc.c (ppc64_elf_size_stubs): Set section size to
maxsize past STUB_SHRINK_ITER before laying out. Remove now
unnecessary conditional setting of maxsize at start of loop.
ld/
* testsuite/ld-powerpc/pr28827-2.d,
* testsuite/ld-powerpc/pr28827-2.lnk,
* testsuite/ld-powerpc/pr28827-2.s: New test.
* testsuite/ld-powerpc/powerpc.exp: Run it.
i386-fbsd-tdep.c and amd64-fbsd-tdep.c failed to build on my x86-64
Fedora 34 machine, using the system gcc, after a recent patch. These
two files now have unused variables, which provokes a warning in this
configuration.
I'm checking in this patch to remove the unused variables.
The previous patch wasn't quite correct. The size and padding depends
on offset used in the current iteration, and if we're fudging the
offset past STUB_SHRINK_ITER then we'd better use that offset. We
can't have plt_stub_pad using stub_sec->size as the offset.
PR 28827
* elf64-ppc.c (plt_stub_pad): Add stub_off param.
(ppc_size_one_stub): Set up stub_offset to value used in this
iteration before sizing the stub. Adjust plt_stub_pad calls.
From: Peilin Ye <peilin.ye@bytedance.com>
objcopy's --only-keep-debug option has been broken for ELF files since
commit 8c803a2dd7d3.
1. binutils/objcopy.c:setup_section() marks non-debug sections as
SHT_NOBITS, then calls bfd_copy_private_section_data();
2. If ISEC and OSEC share the same section flags,
bfd/elf.c:_bfd_elf_init_private_section_data() restores OSEC's
section type back to ISEC's section type, effectively undoing
"make_nobits".
* objcopy.c (setup_section): Act on make_nobits after calling
bfd_copy_private_section_data.
The previous code triggered the following error on an i386 host:
/git/gdb/gdb/ppc-sysv-tdep.c:1764:34: error: non-constant-expression cannot be narrowed from type 'ULONGEST' (aka 'unsigned long long') to 'size_t' (aka 'unsigned int') in initializer list [-Wc++11-narrowing]
unscaled.read ({writebuf, TYPE_LENGTH (valtype)},
^~~~~~~~~~~~~~~~~~~~~
/git/gdb/gdb/gdbtypes.h:2043:31: note: expanded from macro 'TYPE_LENGTH'
^~~~~~~~~~~~~~~~~~
/git/gdb/gdb/ppc-sysv-tdep.c:1764:34: note: insert an explicit cast to silence this issue
unscaled.read ({writebuf, TYPE_LENGTH (valtype)},
^~~~~~~~~~~~~~~~~~~~~
static_cast<size_t>( )
/git/gdb/gdb/gdbtypes.h:2043:31: note: expanded from macro 'TYPE_LENGTH'
^~~~~~~~~~~~~~~~~~
1 error generated.
Fix this by using gdb::make_array_view.
Rather than using the x86-specific register offset tables, use
register maps to describe the layout of the general purpose registers
fetched via PT_GETREGS. The sole user-visible difference is that
FreeBSD/amd64 will now report additional segment registers ($ds, $es,
$fs, and $gs) for both 32-bit and 64-bit processes.
As part of these changes, the FreeBSD x86 native targets no longer use
amd64-bsd-nat.c or i386-bsd-nat.c. Remove FreeBSD-specific register
handling (for $fs_base, $gs_base, and XSAVE state) from these files.
Similarly, remove the global x86bsd_xsave_len from x86-bsd-nat.c. The
FreeBSD x86 native targets use a static xsave_len instead.
While here, rework the probing of PT_GETXMMREGS on FreeBSD/i386.
Probe the ptrace op once in the target read_description method and
cache the result for the future similar to the way the status of XSAVE
support is probed in the read_description method. In addition, return
the proper xcr0 mask (X87-only) for old kernels or systems without
either XSAVE or XMM support.
Use a register map to describe the registers in mcontext_t as part of
the signal frame as is done on several other FreeBSD arches. This
permits fetching the fsbase and gsbase register values from the signal
frame for both amd64 and i386 and permits fetching additional segment
registers stored as 16-bit values on amd64.
While signal frames on FreeBSD do contain floating point/XSAVE state,
these unwinders do not attempt to supply those registers. The
existing x86 signal frame uwinders do not support these registers, and
the only existing functions which handle FSAVE/FXSAVE/XSAVE state all
work with regcaches. In the future these unwinders could create a
tempory regcache, collect floating point registers, and then supply
values out of the regcache into the trad-frame.
In particular, this permits reporting the value of the $ds, $es, $fs,
and $gs segment registers from amd64 core dumps since they are stored
as 16-bit values rather than the 32-bit size assumed by i386_gregset.
When registers are supplied via regcache_supply_register from a
register block described by a register map, registers may be stored in
slots smaller than GDB's native register size (e.g. x86 segment
registers are 16 bits, but the GDB registers for those are 32-bits).
regcache_collect_regset is careful to zero-extend slots larger than a
register size, but regcache_supply_regset just used
regcache::raw_supply_part and did not initialize the upper bytes of a
register value.
trad_frame_set_reg_regmap assumes these semantics (zero-extending
short registers). Upcoming patches also require these semantics for
handling x86 segment register values stored in 16-bit slots on
FreeBSD. Note that architecturally x86 segment registers are 16 bits,
but the x86 gdb architectures treat these registers as 32 bits.
A few FreeBSD releases did not include the page holding the signal
code in core dumps. As a workaround, a sysctl was used to fetch the
default location of the signal code instead. The youngest affected
FreeBSD release is 10.1 released in November 2014 and EOLed in
December 2016. The fallback only works for native processes and would
require a separate unwinder once the FreeBSD arches are converted to
use tramp_frame for signal frames.
When building with clang, I run into an error:
...
tui/tui-disasm.c:138:25: error: moving a temporary object prevents copy
elision [-Werror,-Wpessimizing-move]
tal.addr_string = std::move (gdb_dis_out.release ());
^
tui/tui-disasm.c:138:25: note: remove std::move call here
tal.addr_string = std::move (gdb_dis_out.release ());
^~~~~~~~~~~ ~
...
The error above is caused by the recent commit 5d10a2041eb8 ("gdb: add
string_file::release method").
Fix this by removing std::move.
Build on x86_64-linux with clang 13.0.0.
Add a .editorconfig [1] file. This helps configure editors
automatically with the right whitespace settings. It will help me,
since I need to juggle with different whitespace settings for different
projects. But I think it can also help newcomers get things right from
the start.
Some editors have native support for reading these files, while others
require a plug-in [2]. And if you don't want to use it, then this file
doesn't change anything to your life.
I added rules for the kinds of files I edit most often, but more can be
added later. I assumed that the rules were the same for GDB and the
other projects, but if that's not the case, we can always put
.editorconfig files in project subdirectories to override settings.
[1] https://editorconfig.org/
[2] https://editorconfig.org/#download
Change-Id: Ifda136d13877fafcf0d137fec8501f6a34e1367b
This is just a tidy, making the __ehdr_start symbol flag tweaks all in
one place.
* ldelf.c (ldelf_before_allocation): Don't set rel_from_abs
for __ehdr_start.
* ldlang.c (lang_symbol_tweaks): Set it here instead.
Using a symbol other than .TOC. with @tocbase is an extension to the
ABI. It is never valid to use a symbol without a definition in the
binary, and symbols on these expressions cannot be overridden. Make
this explicit by using ".hidden" in the testcase.
* testsuite/ld-powerpc/symtocbase-1.s: Align data. Make function
entry symbol hidden.
* testsuite/ld-powerpc/symtocbase-2.s: Likewise.
* testsuite/ld-powerpc/symtocbase.d: Adjust expected output.
The assertion is this one in ppc_build_one_stub
BFD_ASSERT (stub_entry->stub_offset >= stub_entry->group->stub_sec->size);
It is checking that a stub doesn't overwrite the tail of a previous
stub, so not something trivial.
Normally, stub sizing iterates until no stubs are added, detected by
no change in stub section size. Iteration also continues if no stubs
are added but one or more stubs increases in size, which also can be
detected by a change in stub section size. But there is a
pathological case where stub section sizing decreases one iteration
then increases the next. To handle that situation, stub sizing also
stops at more than STUB_SHRINK_ITER (20) iterations when calculated
stub section size is smaller. The previous larger size is kept for
the actual layout (so that building the stubs, which behaves like
another iteration of stub sizing, will see the stub section sizes
shrink). The problem with that stopping condition is that it assumes
that stub sizing is only affected by addresses external to the stub
sections, which isn't always true.
This patch fixes that by also keeping larger individual stub_offset
addresses past STUB_SHRINK_ITER. It also catches a further
pathological case where one stub shrinks and another expands in such a
way that no stub section size change is seen.
PR 28827
* elf64-ppc.c (struct ppc_link_hash_table): Add stub_changed.
(STUB_SHRINK_ITER): Move earlier in file.
(ppc_size_one_stub): Detect any change in stub_offset. Keep
larger one if past STUB_SHRINK_ITER.
(ppc64_elf_size_stubs): Iterate on stub_changed too.
g++ 11.1.0 has a bug where it will emit a negative
DW_AT_data_member_location in some cases:
$ cat test.cpp
#include <memory>
int
main()
{
std::unique_ptr<int> ptr;
}
$ g++ -g test.cpp
$ llvm-dwarfdump -F a.out
...
0x00000964: DW_TAG_member
DW_AT_name [DW_FORM_strp] ("_M_head_impl")
DW_AT_decl_file [DW_FORM_data1] ("/usr/include/c++/11.1.0/tuple")
DW_AT_decl_line [DW_FORM_data1] (125)
DW_AT_decl_column [DW_FORM_data1] (0x27)
DW_AT_type [DW_FORM_ref4] (0x0000067a "default_delete<int>")
DW_AT_data_member_location [DW_FORM_sdata] (-1)
...
This leads to a GDB crash (when built with ASan, otherwise probably
garbage results), since it tries to read just before (to the left, in
ASan speak) of the value's buffer:
==888645==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000c52af at pc 0x7f711b239f4b bp 0x7fff356bd470 sp 0x7fff356bcc18
READ of size 1 at 0x6020000c52af thread T0
#0 0x7f711b239f4a in __interceptor_memcpy /build/gcc/src/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827
#1 0x555c4977efa1 in value_contents_copy_raw /home/simark/src/binutils-gdb/gdb/value.c:1347
#2 0x555c497909cd in value_primitive_field(value*, long, int, type*) /home/simark/src/binutils-gdb/gdb/value.c:3126
#3 0x555c478f2eaa in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:333
#4 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
#5 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
#6 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
#7 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
#8 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
#9 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
#10 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
#11 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
#12 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
#13 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
#14 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
#15 0x555c478f2fcb in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:335
#16 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
#17 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
#18 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
#19 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
#20 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
#21 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
#22 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
#23 0x555c478f2fcb in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:335
#24 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
#25 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
#26 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
#27 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
#28 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
#29 0x555c4760f04c in c_value_print(value*, ui_file*, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:587
#30 0x555c483ff954 in language_defn::value_print(value*, ui_file*, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:614
#31 0x555c49759f61 in value_print(value*, ui_file*, value_print_options const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1189
#32 0x555c48950f70 in print_formatted /home/simark/src/binutils-gdb/gdb/printcmd.c:337
#33 0x555c48958eda in print_value(value*, value_print_options const&) /home/simark/src/binutils-gdb/gdb/printcmd.c:1258
#34 0x555c48959891 in print_command_1 /home/simark/src/binutils-gdb/gdb/printcmd.c:1367
#35 0x555c4895a3df in print_command /home/simark/src/binutils-gdb/gdb/printcmd.c:1458
#36 0x555c4767f974 in do_simple_func /home/simark/src/binutils-gdb/gdb/cli/cli-decode.c:97
#37 0x555c47692e25 in cmd_func(cmd_list_element*, char const*, int) /home/simark/src/binutils-gdb/gdb/cli/cli-decode.c:2475
#38 0x555c4936107e in execute_command(char const*, int) /home/simark/src/binutils-gdb/gdb/top.c:670
#39 0x555c485f1bff in catch_command_errors /home/simark/src/binutils-gdb/gdb/main.c:523
#40 0x555c485f249c in execute_cmdargs /home/simark/src/binutils-gdb/gdb/main.c:618
#41 0x555c485f6677 in captured_main_1 /home/simark/src/binutils-gdb/gdb/main.c:1317
#42 0x555c485f6c83 in captured_main /home/simark/src/binutils-gdb/gdb/main.c:1338
#43 0x555c485f6d65 in gdb_main(captured_main_args*) /home/simark/src/binutils-gdb/gdb/main.c:1363
#44 0x555c46e41ba8 in main /home/simark/src/binutils-gdb/gdb/gdb.c:32
#45 0x7f71198bcb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
#46 0x555c46e4197d in _start (/home/simark/build/binutils-gdb-one-target/gdb/gdb+0x77f197d)
0x6020000c52af is located 1 bytes to the left of 8-byte region [0x6020000c52b0,0x6020000c52b8)
allocated by thread T0 here:
#0 0x7f711b2b7459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x555c470acdc9 in xcalloc /home/simark/src/binutils-gdb/gdb/alloc.c:100
#2 0x555c49b775cd in xzalloc(unsigned long) /home/simark/src/binutils-gdb/gdbsupport/common-utils.cc:29
#3 0x555c4977bdeb in allocate_value_contents /home/simark/src/binutils-gdb/gdb/value.c:1029
#4 0x555c4977be25 in allocate_value(type*) /home/simark/src/binutils-gdb/gdb/value.c:1040
#5 0x555c4979030d in value_primitive_field(value*, long, int, type*) /home/simark/src/binutils-gdb/gdb/value.c:3092
#6 0x555c478f6280 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:501
#7 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
#8 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
#9 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
#10 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
#11 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
#12 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
#13 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
#14 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
#15 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
#16 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
#17 0x555c478f2fcb in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:335
#18 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
#19 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
#20 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
#21 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
#22 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
#23 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
#24 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
#25 0x555c478f2fcb in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:335
#26 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
#27 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
#28 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
#29 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
Since there are some binaries with this in the wild, I think it would be
useful for GDB to work around this. I did the obvious simple thing, if
the DW_AT_data_member_location's value is -1, replace it with 0. I
added a producer check to only apply this fixup for GCC 11. The idea is
that if some other compiler ever uses a DW_AT_data_member_location value
of -1 by mistake, we don't know (before analyzing the bug at least) if
they did mean 0 or some other value. So I wouldn't want to apply the
fixup in that case.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28063
Change-Id: Ieef3459b0b9bbce8bdad838ba83b4b64e7269d42
Fedora Rawhide is now using gcc-12.0. As part of updating to the
gcc-12.0 package set, Rawhide is also now using a version of libgcc_s
which lacks a .data section. This causes gdb to fail in the following
fashion while debugging a program (such as gdb) which uses libgcc_s:
(top-gdb) run
Starting program: rawhide-master/bld/gdb/gdb
...
objfiles.h:467: internal-error: sect_index_data not initialized
A problem internal to GDB has been detected,
further debugging may prove unreliable.
...
I snipped the backtrace from the above output. Instead, here's a
portion of a backtrace obtained using GDB's backtrace command.
(Obviously, in order to obtain it, I used a GDB which has been patched
with this commit.)
#0 internal_error (
file=0xc6a508 "gdb/objfiles.h", line=467,
fmt=0xc6a4e8 "sect_index_data not initialized")
at gdbsupport/errors.cc:51
#1 0x00000000005f9651 in objfile::data_section_offset (this=0x4fa48f0)
at gdb/objfiles.h:467
#2 0x000000000097c5f8 in relocate_address (address=0x17244, objfile=0x4fa48f0)
at gdb/stap-probe.c:1333
#3 0x000000000097c630 in stap_probe::get_relocated_address (this=0xa1a17a0,
objfile=0x4fa48f0)
at gdb/stap-probe.c:1341
#4 0x00000000004d7025 in create_exception_master_breakpoint_probe (
objfile=0x4fa48f0)
at gdb/breakpoint.c:3505
#5 0x00000000004d7426 in create_exception_master_breakpoint ()
at gdb/breakpoint.c:3575
#6 0x00000000004efcc1 in breakpoint_re_set ()
at gdb/breakpoint.c:13407
#7 0x0000000000956998 in solib_add (pattern=0x0, from_tty=0, readsyms=1)
at gdb/solib.c:1001
#8 0x00000000009576a8 in handle_solib_event ()
at gdb/solib.c:1269
...
The function 'relocate_address' in gdb/stap-probe.c attempts to do
its "relocation" by using objfile->data_section_offset(). That
method, data_section_offset() is defined as follows in objfiles.h:
CORE_ADDR data_section_offset () const
{
return section_offsets[SECT_OFF_DATA (this)];
}
The internal error occurs when the SECT_OFF_DATA macro finds that the
'sect_index_data' field is -1:
#define SECT_OFF_DATA(objfile) \
((objfile->sect_index_data == -1) \
? (internal_error (__FILE__, __LINE__, \
_("sect_index_data not initialized")), -1) \
: objfile->sect_index_data)
relocate_address() is obtaining the section offset in order to compute
a relocated address. For some ABIs, such as the System V ABI, the
section offsets will all be the same. So for those ABIs, it doesn't
matter which offset is used. However, other ABIs, such as the FDPIC
ABI, will have different offsets for the various sections. Thus, for
those ABIs, it is vital that this and other relocation code use the
correct offset.
In stap_probe::get_relocated_address, the address to which to add the
offset (thus forming the relocated address) is obtained via
this->get_address (); get_address is a getter for m_address in
probe.h. It's documented/defined as follows (also in probe.h):
/* The address where the probe is inserted, relative to
SECT_OFF_TEXT. */
CORE_ADDR m_address;
(Thanks to Tom Tromey for this observation.)
So, based on this, the current use of data_section_offset /
SECT_OFF_DATA is wrong. This relocation code should have been using
text_section_offset / SECT_OFF_TEXT all along. That being the
case, I've adjusted the stap-probe.c relocation code accordingly.
Searching the sources turned up one other use of data_section_offset,
in gdb/dtrace-probe.c, so I've updated that code as well. The same
reasoning presented above applies to this case too.
Summary:
* gdb/dtrace-probe.c (dtrace_probe::get_relocated_address):
Use method text_section_offset instead of data_section_offset.
* gdb/stap-probe.c (relocate_address): Likewise.
In remote_target::remote_btrace_maybe_reopen, we switch to the currently
iterated thread in order to set inferior_ptid for a subsequent xfer.
Move the switch_to_thread call directly before the target_read_stralloc
call to clarify why we need to switch threads.
The enable_btrace target method takes a ptid_t to identify the thread on
which tracing shall be enabled.
Change this to thread_info * to avoid translating back and forth between
the two. This will be used in a subsequent patch.
