A sufficiently mad compiler optimiser can take undefined behaviour
according to the C standard as an opportunity to remove code. Since
"data + size" might be seen to be past the end of an array,
calculating such an expression is UB.
_mul_overflow is infrastructure for later patches.
* bucomm.h (_mul_overflow): Define.
* dwarf.c (get_encoded_value): Avoid pointer UB.
An upstream Rust bug notes notes that the Python pretty-printing
feature is broken for values that appear as members of certain types
in Rust.
The bug here is that some of the Rust value-printing code calls
value_print_inner, a method on rust_language. This bypasses the
common code that calls into Python.
I'm checking this in.
gdb/ChangeLog
2021-05-14 Tom Tromey <tom@tromey.com>
* rust-lang.c (rust_language::val_print_struct)
(rust_language::print_enum): Use common_val_print, not
value_print_inner.
gdb/testsuite/ChangeLog
2021-05-14 Tom Tromey <tom@tromey.com>
* gdb.rust/pp.exp: New file.
* gdb.rust/pp.py: New file.
* gdb.rust/pp.rs: New file.
Rather than rely on off_t being the right size between the host &
target, have the interface always be 64-bit. We can figure out if
we need to truncate when actually outputting it to the right target.
PR sim/27705
Rather than rely on time_t being the right size between the host &
target, have the interface always be 64-bit. We can figure out if
we need to truncate when actually outputting it to the right target.
gold/
PR 27834
* options.h (General_options): Make -Bsymbolic and
-Bsymbolic-functions special and adjust the help messages. Add
enum Bsymbolic_kind and -Bno-symbolic.
* options.cc (General_options): Define parse_Bno_symbolic,
parse_Bsymbolic_functions, and parse_Bsymbolic.
After the gdb test-suite runs there are some files
left in /tmp/tmp*/*.gdb-index, remove those files
and the directory at the end of the test case.
gdb/testsuite:
2021-05-14 Bernd Edlinger <bernd.edlinger@hotmail.de>
* gdb.base/index-cache.exp: Cleanup $cache_dir/*.gdb-index and
remove the directory.
* gdb.dwarf2/per-bfd-sharing.exp: Likewise.
Define a 'connection_num' attribute for Inferior objects. The
read-only attribute is the ID of the connection of an inferior, as
printed by "info inferiors". In GDB's internal terminology, that's
the process stratum target of the inferior. If the inferior has no
target connection, the attribute is None.
gdb/ChangeLog:
2021-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* python/py-inferior.c (infpy_get_connection_num): New function.
(inferior_object_getset): Add a new element for 'connection_num'.
* NEWS: Mention the 'connection_num' attribute of Inferior objects.
gdb/doc/ChangeLog:
2021-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* python.texi (Inferiors In Python): Mention the 'connection_num'
attribute.
gdb/testsuite/ChangeLog:
2021-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb.python/py-inferior.exp: Add test cases for 'connection_num'.
Convert a couple of local variables from int to bool. There should be
no user visible changes after this commit.
gdb/ChangeLog:
* remote.c (check_pending_events_prevent_wildcard_vcont): Change
argument type, update and re-wrap, header comment.
(remote_target::commit_resumed): Convert any_process_wildcard and
may_global_wildcard_vcont from int to bool.
The %pcrel_lo addend may causes the overflow, and need more than one
%pcrel_hi values. But there may be only one auipc, shared by those
%pcrel_lo with addends. However, the existing check method in the
riscv_resolve_pcrel_lo_relocs, may not be able to work for some
special/corner cases.
Consider the testcases pcrel-lo-addend-2b. Before applying this patch,
I can compile it successfully. But in fact the addend cause the value
of %pcrel_hi to be different. This patch try to check the value of
%pcrel_hi directly, to make sure it won't be changed. Otherwise, linker
will report the following errors,
(.text+0xa): dangerous relocation: %pcrel_lo overflow with an addend,
the value of %pcrel_hi is 0x1000 without any addend, but may be 0x2000
after adding the %pcrel_lo addend
The toolchain regressions, rv64gc-linux/rv64gc-elf/rv32gc-linux/rv32i-elf,
pass expectedly and looks fine.
bfd/
* elfnn-riscv.c (riscv_resolve_pcrel_lo_relocs): Check the values
of %pcrel_hi, before and after adding the addend. Make sure the
value won't be changed, otherwise, report dangerous error.
ld/
* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Updated.
* testsuite/ld-riscv-elf/pcrel-lo-addend-2a.d: Renamed from
pcrel-lo-addend-2.
* testsuite/ld-riscv-elf/pcrel-lo-addend-2a.s: Likewise.
* testsuite/ld-riscv-elf/pcrel-lo-addend-2b.d: New testcase.
* testsuite/ld-riscv-elf/pcrel-lo-addend-2b.s: Likewise.
The 'print max-depth' feature incorrectly causes GDB to skip printing
the string representation of pretty printed variables if the variable
is stored at a nested depth corresponding to the set max-depth value.
This change ensures that it is always printed before checking whether
the maximum print depth has been reached.
Regression tested with GCC 7.3.0 on x86_64, ppc64le, aarch64.
gdb/ChangeLog:
* cp-valprint.c (cp_print_value): Replaced duplicate code.
* guile/scm-pretty-print.c (ppscm_print_children): Check max_depth
just before printing child values.
(gdbscm_apply_val_pretty_printer): Don't check max_depth before
printing string representation.
* python/py-prettyprint.c (print_children): Check max_depth just
before printing child values.
(gdbpy_apply_val_pretty_printer): Don't check max_depth before
printing string representation.
gdb/testsuite/ChangeLog:
* gdb.python/py-format-string.c: Added a variable to test.
* gdb.python/py-format-string.exp: Check string representation is
printed at appropriate max_depth settings.
* gdb.python/py-nested-maps.exp: Likewise.
* gdb.guile/scm-pretty-print.exp: Add additional tests.
The gdb/callback.h & gdb/remote-sim.h headers have nothing to do with
gdb and are really definitions for the libsim API under the sim/ tree.
While gdb uses those headers as a client, it's not specific to it. So
create a new sim/ namespace and move the headers there.
I realized that with "follow-exec-mode == new", the process target
stayed pushed in the original inferior. This can cause a small
incoherence:
$ ./gdb -q -nx --data-directory=data-directory -ex "set follow-exec-mode new" --args execer args-for-execer
Reading symbols from execer...
(gdb) r
Starting program: /home/smarchi/build/binutils-gdb/gdb/execer args-for-execer
I am execer and my argv[1] is: args-for-execer
process 3562426 is executing new program: /home/smarchi/build/binutils-gdb/gdb/execee
[New inferior 2]
[New process 3562426]
I am execee and my argv[1] is: arg-for-execee
[Inferior 2 (process 3562426) exited normally]
(gdb) info inferiors
Num Description Connection Executable
1 <null> 1 (native) /home/smarchi/build/binutils-gdb/gdb/execer
* 2 <null> /home/smarchi/build/binutils-gdb/gdb/execee
(gdb) maintenance print target-stack
The current target stack is:
- exec (Local exec file)
- None (None)
(gdb) inferior 1
[Switching to inferior 1 [<null>] (/home/smarchi/build/binutils-gdb/gdb/execer)]
(gdb) maintenance print target-stack
The current target stack is:
- native (Native process)
- exec (Local exec file)
- None (None)
On exec, when execution continues into inferior 2, the native target
isn't unpushed from inferior 1. When inferior 2's execution finishes
normally, inf_child_target::mourn_inferior unpushes the native target,
because the native target has been implicitly opened.
I think that if the native target was implicitly opened, it should be
unpushed from inferior 1, just like it is unpushed from an inferior
whose execution terminate. This patch implements that.
gdb/ChangeLog:
* inf-child.h (inf_child_target) <follow_exec>: New.
* inf-child.c (inf_child_target::follow_exec): New.
Change-Id: I782cc08d73d93a990f4e53611107f68b2cb58af1
On "exec", some targets need to unpush themselves from the inferior,
and do some bookkeeping, like forgetting the data associated to the
exec'ing inferior.
One such example is the thread-db target. It does so in
a special case in thread_db_target::wait, just before returning the
TARGET_WAITKIND_EXECD event to its caller.
We have another such case in the context of rocm-gdb [1], where the
"rocm" target is pushed on top of the linux-nat target. When an exec
happens, we want to unpush the rocm target from the exec'ing inferior to
close some file descriptors that refer to the pre-exec address space and
forget about that inferior. We then want to push the target on the
inferior in which execution continues, to open the file descriptors for
the post-exec address space.
I think that a good way to address this cleanly is to do all this in the
target_ops::follow_exec implementations. Make the
process_stratum_target::follow_exec implementation have the default
behavior of pushing itself to the new inferior's target stack (if
execution continues in a new inferior) and add the initial thread.
remote_target::follow_exec is an example of process target that wants to
do a bit more than the default behavior. So it calls
process_stratum_target::follow_exec first and does the extra work
second.
linux-thread-db (a non-process target) implements follow_exec to do some
bookeeping (forget about that process' data), before handing down the
event down to the process target (which hits
process_stratum_target::follow_exec).
gdb/ChangeLog:
* target.h (struct target_ops) <follow_exec>: Add ptid_t
parameter.
(target_follow_exec): Likewise.
* target.c (target_follow_exec): Add ptid_t parameter.
* infrun.c (follow_exec): Adjust call to target_follow_exec,
don't push target nor create thread.
* linux-thread-db.c (class thread_db_target) <follow_exec>: New.
(thread_db_target::wait): Just return on TARGET_WAITKIND_EXECD.
(thread_db_target::follow_exec): New.
* remote.c (class remote_target) <follow_exec>: Add ptid_t parameter.
(remote_target::follow_exec): Call
process_stratum_target::follow_exec.
* target-delegates.c: Re-generate.
Change-Id: I3f96d0ba3ea0dde6540b7e1b4d5cdb01635088c8
target_follow_exec is currently only called in the "follow-exec-mode ==
new" branch of follow_exec, not the "follow-exec-mode == same" branch.
I think it would make sense to call it regardless of the mode to let
targets do some necessary handling.
This is needed in the context of rocm-gdb [1], where a target is pushed
on top of the linux-nat target. On exec, it needs to do some
bookkeeping, close some file descriptors / handles that were related to
the process pre-exec and open some new ones for the process post-exec.
However, by looking at the only in-tree implementation of
target_ops::follow_exec, remote_target::follow_exec, I found that it
would be useful for the extended-remote target too, to align its
behavior with native debugging (although I think that behavior is not
very user-friendly, see PR 27745 [2]).
Using two programs, one (let's call it "execer") that execs the other
(let's call it "execee"), with native:
$ ./gdb -q -nx --data-directory=data-directory ./execer
Reading symbols from ./execer...
(gdb) r
Starting program: /home/simark/build/binutils-gdb/gdb/execer
I am execer
process 1495622 is executing new program: /home/simark/build/binutils-gdb/gdb/execee
I am execee
[Inferior 1 (process 1495622) exited normally]
(gdb) r
Starting program: /home/simark/build/binutils-gdb/gdb/execee
I am execee
[Inferior 1 (process 1495626) exited normally]
And now with gdbserver (some irrelevant output lines removed for brevity):
$ ./gdbserver --once --multi :1234
...
$ ./gdb -q -nx --data-directory=data-directory ./execer -ex "set remote exec-file /home/simark/build/binutils-gdb/gdb/execer" -ex "tar ext :1234"
Reading symbols from ./execer...
Remote debugging using :1234
(gdb) r
Starting program: /home/simark/build/binutils-gdb/gdb/execer
process 1495724 is executing new program: /home/simark/build/binutils-gdb/gdb/execee
[Inferior 1 (process 1495724) exited normally]
(gdb) r
`target:/home/simark/build/binutils-gdb/gdb/execee' has disappeared; keeping its symbols.
Starting program: target:/home/simark/build/binutils-gdb/gdb/execee
warning: Build ID mismatch between current exec-file target:/home/simark/build/binutils-gdb/gdb/execee
and automatically determined exec-file target:/home/simark/build/binutils-gdb/gdb/execer
exec-file-mismatch handling is currently "ask"
Reading /home/simark/build/binutils-gdb/gdb/execer from remote target...
Load new symbol table from "target:/home/simark/build/binutils-gdb/gdb/execer"? (y or n)
When handling the exec, GDB updates the exec-file of the inferior to be
the execee. This means that a subsequent "run" will run the execee, not
the original executable (execer).
remote_target::follow_exec is meant to update the "remote exec-file",
which is the file on the remote system that will be executed if you
"run" the inferior, to the execee as well. However, this is not called
when follow-exec-mode is same, because target_follow_exec is not called
in this branch. As a result, GDB thinks the inferior is executing
execee but the remote side is really executing execer, hence the
mismatch message.
By calling target_follow_exec in the "same" branch of the follow_exec
function, we ensure that everybody agrees, and we get the same behavior
with the extended-remote target as we get with the native target, the
execee is executed on the second run:
$ ./gdbserver --once --multi :1234
...
$ ./gdb -q -nx --data-directory=data-directory ./execer -ex "set remote exec-file /home/simark/build/binutils-gdb/gdb/execer" -ex "tar ext :1234"
Reading symbols from ./execer...
Remote debugging using :1234
(gdb) r
Starting program: /home/simark/build/binutils-gdb/gdb/execer
process 1501445 is executing new program: /home/simark/build/binutils-gdb/gdb/execee
[Inferior 1 (process 1501445) exited normally]
(gdb) r
`target:/home/simark/build/binutils-gdb/gdb/execee' has disappeared; keeping its symbols.
Starting program: target:/home/simark/build/binutils-gdb/gdb/execee
[Inferior 1 (process 1501447) exited normally]
(gdb)
This scenario is tested in gdb.base/foll-exec-mode.exp, and in fact this
patch fixes the test for me when using
--target_board=native-extended-gdbserver.
gdb/ChangeLog:
* infrun.c (follow_exec): Call target_follow_fork when
follow-exec-mode is same.
* target.h (target_follow_fork): Improve doc.
[1] https://github.com/ROCm-Developer-Tools/ROCgdb
[2] https://sourceware.org/bugzilla/show_bug.cgi?id=27745
Change-Id: I4ee84a875e39bf3f8eaf3e6789a4bfe23a2a430e
The remaining duplicates are resolved by adding a with_test_prefix and
reindenting a proc. I also added a couple of additional test names to
some of the tests.
gdb/testsuite/ChangeLog:
* gdb.guile/scm-pretty-print.exp (run_lang_tests): Give some tests
unique names, also wrap proc body in with_test_prefix.
This commit resolves almost all of the remaining duplicate test names
in gdb.guile/*.exp. This is done by either:
- Making use of with_test_prefix,
- Giving tests a unique name,
- Extending the existing name to make it unique,
- Not printing PASS lines for simple setup commands (e.g. loading
support modules, or adjusting GDB internal settings not relating to
guile).
gdb/testsuite/ChangeLog:
* gdb.guile/scm-frame-args.exp: Add with_test_prefix to resolve
duplicate test names.
* gdb.guile/scm-parameter.exp: Provide test names to avoid
duplicate names based on the command being run.
* gdb.guile/scm-symbol.exp: Extend test name to make it unique.
* gdb.guile/scm-type.exp (restart_gdb): Don't print PASS line when
loading a support module.
(test_equality): Update test name to match the actual test, making
the name unique in the process.
* gdb.guile/scm-value.exp (test_value_in_inferior): Add test names
to resolve duplicate tests.
(test_inferior_function_call): Likewise.
(test_subscript_regression): Likewise.
The guile support library has some "tests" that are actually being
used to setup GDB ready for the real guile tests, e.g. we load some
support modules, and define some helper functions.
As this setup is done every time we call gdb_guile_runto_main, which
could be called multiple times in a single test script, this can lead
to duplicate PASS lines.
As this setup is all pretty basic, and isn't the actual focus of the
real tests, then in this commit I pass an empty test name through to
the gdb_test_no_output calls, the result of this is that the PASS
lines are no longer printed. This removes some duplicate tests from
the gdb.guile/*.exp set of tests.
gdb/testsuite/ChangeLog:
* lib/guile.exp (gdb_scm_load_file): Use empty test name to
silence PASS lines.
(gdb_install_guile_module): Likewise.
Well it didn't take long for the SAFE_BYTE_GET assert to trigger.
PR 27860
* dwarf.c (display_debug_frames): Sanity check cie_off before
attempting to read cie.
When we want to fetch tags from a memory range, the last address in that
range is not included.
There is a off-by-one error in aarch64_mte_get_tag_granules, which this
patch fixes.
gdb/ChangeLog:
2021-05-13 Luis Machado <luis.machado@linaro.org>
* arch/aarch64-mte-linux.c (aarch64_mte_get_tag_granules): Don't
include the last address in the range.
Add a new table, riscv_implicit_subsets, to record all implicit information.
So that we add all implicit subsets according to the table, to avoid too
many repeated codes in the riscv_parse_add_implicit_subsets. Besides, the
check_func is used to check whether we should add this implicit subset.
For example, check_implicit_for_i checks the version of i, and we only add
zicsr and zifencei implicitly only when the version less than 2.1.
bfd/
* elfxx-riscv.c (check_implicit_always): The check_func, always add
the implicit subset without checking.
(check_implicit_for_i): The check_func for i, only add zicsr and
zifencei when the version of i less than 2.1.
(struct riscv_implicit_subset): Record the subsets and their
corresponding implicit subsets.
(riscv_implicit_subsets): Table records all implicit informations.
(riscv_parse_add_implicit_subsets): Updated and add implicit subsets
according to riscv_implicit_subsets. Remove the redundant codes.
This avoids some manual memory management.
cmdpy_init correctly transfers ownership of the name to the
cmd_list_element, as it sets the name_allocated flag. However,
cmdpy_init (and add_setshow_generic) doesn't, it looks like the name is
just leaked. This is a bit tricky, because it actually creates two
commands (one set and one show), it would take a bit of refactoring of
the command code to give each their own allocated copy. For now, just
keep doing what the current code does but in a more explicit fashion,
with an explicit release.
gdb/ChangeLog:
* python/python-internal.h (gdbpy_parse_command_name): Return
gdb::unique_xmalloc_ptr.
* python/py-cmd.c (gdbpy_parse_command_name): Likewise.
(cmdpy_init): Adjust.
* python/py-param.c (parmpy_init): Adjust.
(add_setshow_generic): Take gdb::unique_xmalloc_ptr, release it
when done.
Change-Id: Iae5bc21fe2b22f12d5f954057b0aca7ca4cd3f0d
* dwarf.c (process_extended_line_op): Don't bump data pointer past
end when strnlen doesn't find string terminator.
(decode_location_expression): Remove dead code.
(skip_attr_bytes): Remove const from end param. Ensure data
pointer doesn't pass end.
(get_type_signedness): Remove const from end param.
(read_and_display_attr_value): Ensure data pointer doesn't pass end.
(display_debug_lines_raw, display_debug_lines_decoded): Likewise.
(display_debug_pubnames_worker): Likewise.
(display_debug_pubnames_worker): Use SAFE_BYTE_GET_AND INC rather
than blindly incrementing data pointer.
(display_debug_addr, display_debug_str_offsets): Likewise. Don't
compare pointers, compare lengths.
This rearranges SAFE_BYTE_GET* macros, eliminating some duplication,
and making sure that the _INC variants never increment their PTR arg
past END. I've added an assertion that should show us places where we
use them improperly with user derived PTR args, which I'm sure the
fuzzers will find for us.
* dwarf.c (SAFE_BYTE_GET_INTERNAL): Define.
(SAFE_BYTE_GET, SAFE_BYTE_GET_AND_INC): Define using the above.
(SAFE_SIGNED_BYTE_GET, SAFE_SIGNED_BYTE_GET_AND_INC): Likewise.
(display_discr_list): Use SAFE_BYTE_GET_AND_INC rather than
SAFE_BYTE_GET followed by increment.
(process_debug_info): Likewise, and test bytes remaining before
incrementing section_begin rather than using pointer comparison.
(display_debug_names): Pass lvalue as SAFE_BYTE_GET PTR.
(process_cu_tu_index): Likewise for SAFE_BYTE_GET_AND_INC.
The Guile API doesn't currently have an equivalent to the Python API's
gdb.Value.const_value(). This commit adds a procedure with equivalent
semantics to the Guile API.
gdb/ChangeLog:
* NEWS (Guile API): Note the addition of the new procedure.
* guile/scm-value.c (gdbscm_value_const_value): Add
implementation of value-const-value procedure.
(value_functions): Add value-const-value procedure.
gdb/doc/ChangeLog:
* guile.texi (Values From Inferior In Guile): Add documentation
for value-const-value.
gdb/testsuite/ChangeLog:
* gdb.guile/scm-value.exp (test_value_in_inferior): Add test for
value-const-value.
The Guile API doesn't currently have an equivalent to the Python API's
Value.reference_value() or Value.rvalue_reference_value(). This commit
adds a procedure with equivalent semantics to the Guile API.
gdb/ChangeLog:
* NEWS (Guile API): Note the addition of new procedures.
* guile/scm-value.c (gdbscm_reference_value): Add helper function
for reference value creation.
(gdbscm_value_reference_value): Add implementation of
value-reference-value procedure.
(gdbscm_value_rvalue_reference_value): Add implementation of
value-rvalue-reference-value procedure.
(value_functions): Add value-reference-value procedure. Add
value-rvalue-reference-value procedure.
gdb/doc/ChangeLog:
* guile.texi (Values From Inferior In Guile): Add documentation
for value-reference-value. Add documentation for
value-rvalue-reference-value.
gdb/testsuite/ChangeLog:
* gdb.guile/scm-value.exp (test_value_in_inferior): Add test for
value-reference-value. Add test for value-rvalue-reference-value.
Adds a couple of missing bits to the Guile API to make C++11 rvalue
reference values and types usable from Guile scripts.
gdb/ChangeLog:
* guile/scm-type.c (type_integer_constants): Add binding for
TYPE_CODE_RVALUE_REF.
* guile/scm-value.c (gdbscm_value_referenced_value): Handle
dereferencing of rvalue references.
* NEWS (Guile API): Note improvements in rvalue reference support.
gdb/doc/ChangeLog:
* guile.texi (Types In Guile): Add documentation for
TYPE_CODE_RVALUE_REF.
The recent change to correct the detection of thumb2 object files
resulted in a ld test for veneering starting to fail. The problem was
the test itself, which was incorrectly expecting thumb1 type far-call
veneers instead of the thumb2 flavour. We already have a dump file of
the expected form, so the fix is to change the expected output
accordingly.
ld/
* testsuite/ld-arm/arm-elf.exp (farcall test for v8-m.mainline):
Correct expected output.
Previously, the prefixname field of struct cmd_list_element was manually
set for prefix commands. This seems verbose and error prone as it
required every single call to functions adding prefix commands to
specify the prefix name while the same information can be easily
generated.
Historically, this was not possible as the prefix field was null for
many commands, but this was fixed in commit
3f4d92ebdf by Philippe Waroquiers, so
we can rely on the prefix field being set when generating the prefix
name.
This commit also fixes a use after free in this scenario:
* A command gets created via Python (using the gdb.Command class).
The prefix name member is dynamically allocated.
* An alias to the new command is created. The alias's prefixname is set
to point to the prefixname for the original command with a direct
assignment.
* A new command with the same name as the Python command is created.
* The object for the original Python command gets freed and its
prefixname gets freed as well.
* The alias is updated to point to the new command, but its prefixname
is not updated so it keeps pointing to the freed one.
gdb/ChangeLog:
* command.h (add_prefix_cmd): Remove the prefixname argument as
it can now be generated automatically. Update all callers.
(add_basic_prefix_cmd): Ditto.
(add_show_prefix_cmd): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_abbrev_prefix_cmd): Ditto.
* cli/cli-decode.c (add_prefix_cmd): Ditto.
(add_basic_prefix_cmd): Ditto.
(add_show_prefix_cmd): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_abbrev_prefix_cmd): Ditto.
* cli/cli-decode.h (struct cmd_list_element): Replace the
prefixname member variable with a method which generates the
prefix name at runtime. Update all code reading the prefix
name to use the method, and remove all code setting it.
* python/py-cmd.c (cmdpy_destroyer): Remove code to free the
prefixname member as it's now a method.
(cmdpy_function): Determine if the command is a prefix by
looking at prefixlist, not prefixname.
Not quite infinite but much longer than it need be. The problem is
triggered by read_and_display_attr_value incrementing "data" past
"end". read_and_display_attr_value shouldn't do that, but be
defensive.
PR 27853
* dwarf.c (display_formatted_table): Test for data >= end rather
than data == end.
(process_extended_line_op): Likewise.
(display_debug_lines_raw): Likewise.
(display_debug_lines_decoded): Likewise.
