The #dest field used in the cris testsuite is a bit of hack to set the
argv[0] for the tests to read out later on. Now that the sim has an
option to set argv[0] explicitly, we don't need this custom field, so
let's drop it to harmonize the testsuites a little.
We default argv[0] to the program we run which is a standard *NIX
convention, but sometimes we want to be able to control the argv[0]
setting independently (especially for programs that inspect argv[0]
to change their behavior or output). Add an option to control it.
We use the program argv to both find the program to run (argv[0]) and
to hold the arguments to the program. Most of the time this is fine,
but if we want to let programs specify argv[0] independently (which is
possible in standard *NIX programs), this double duty doesn't work.
So let's split the path to the program to run out into a separate
field by itself. This simplifies the various sim_open funcs too.
By itself, this code is more of a logical cleanup than something that
is super useful. But it will open up customization of argv[0] in a
follow up commit. Split the changes to make it easier to review.
Set the mach to the right value all the time, and update xfail to
say the test fails on all targets. WIth multitarget testing, the
idea of target here doesn't make much sense.
R_PPC64_REL24_P9NOTOC is a variant of R_PPC64_REL24_NOTOC for use on
@notoc cals from non-power10 code in the rare case that using such a
construct is useful. R_PPC64_REL24_P9NOTOC will be emitted by gas
rather than R_PPC64_REL24_NOTOC when @notoc is used in a branch
instruction if power10 instructions are not enabled at that point.
The new relocation tells the linker to not use power10 instructions on
any stub emitted for that branch, unless overridden by
--power10-stubs=yes.
The current linker heuristic of only generating power10 instructions
for stubs if power10-only relocations are detected, continues to be
used.
include/
* elf/ppc64.h (R_PPC64_REL24_P9NOTOC): Define.
bfd/
* reloc.c (BFD_RELOC_PPC64_REL24_P9NOTOC): Define.
* elf64-ppc.c (ppc64_elf_howto_raw): Add entry for new reloc.
(ppc64_elf_reloc_type_lookup): Handle it.
(enum ppc_stub_type): Delete.
(enum ppc_stub_main_type, ppc_stub_sub_type): New.
(struct ppc_stub_type): New.
(struct ppc_stub_hash_entry): Use the above new type.
(struct ppc_link_hash_table): Update stub_count.
(is_branch_reloc, ppc64_elf_check_relocs),
(toc_adjusting_stub_needed): Handle new reloc.
(stub_hash_newfunc, select_alt_stub, ppc_merge_stub),
(ppc_type_of_stub, plt_stub_size, build_plt_stub),
(build_tls_get_addr_head, build_tls_get_addr_tail),
(ppc_build_one_stub, ppc_size_one_stub, ppc64_elf_size_stubs),
(ppc64_elf_build_stubs, ppc64_elf_relocate_section): Handle new
reloc. Modify stub handling to suit new scheme.
* bfd-in2.h: Regenerate.
* libbfd.h: Regenerate.
gas/
* config/tc-ppc.c (ppc_elf_suffix): When power10 is not enabled
return BFD_RELOC_PPC64_REL24_P9NOTOC for @notoc.
(fixup_size, ppc_force_relocation, ppc_fix_adjustable): Handle
BFD_RELOC_PPC64_REL24_P9NOTOC.
ld/
* testsuite/ld-powerpc/callstub-2.s: Add .machine power10.
A couple of files changed on my latest --enable-maintainer-mode
build. ld/Makefile.in had a missing dependency but better sorting of
the loongson entries.
intl/
* configure: Regenerate.
ld/
* Makefile.am: Sort loongson entries.
* Makefile.in: Regenerate.
Compiling GDB with current GCC (1b4a63593b) runs into this:
src/gdb/location.c: In function 'int event_location_empty_p(const event_location*)':
src/gdb/location.c:963:38: error: the address of 'event_location::<unnamed union>::explicit_loc' will never be NULL [-Werror=address]
963 | return (EL_EXPLICIT (location) == NULL
| ^
src/gdb/location.c:57:30: note: 'event_location::<unnamed union>::explicit_loc' declared here
57 | struct explicit_location explicit_loc;
| ^~~~~~~~~~~~
GCC is right, EL_EXPLICIT is defined as returning the address of an
union field:
/* An explicit location. */
struct explicit_location explicit_loc;
#define EL_EXPLICIT(P) (&((P)->u.explicit_loc))
and thus must always be non-NULL.
Change-Id: Ie74fee7834495a93affcefce03c06e4d83ad8191
The 'show user' command (which shows the definition of non-python/scheme
user defined commands) is currently missing a completer. This is
mentioned in PR 16238. Having one can improve the user experience.
In this commit I propose an implementation for such completer as well as
the associated tests.
Tested on x86_64 GNU/Linux.
All feedbacks are welcome.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=16238
In <=gcc-7 versions, -fstrict-overflow is enabled by default, and that
triggers warnings in this code that relies on integer overflows to test
for carries. Change the logic to test against the limit directly.
The test stops at <signal_handler called> which is the call to the handler
rather than in the handler as intended. This patch replaces the
gdb_test "$enter_cmd to handler" with a gdb_test_multiple test. The multiple
test looks for the stop at <signal_handler called>. If found, the command
is issued again. The test passes if gdb stops in the handler as expected.
(gdb) PASS: gdb.base/sigstep.exp: stepi to handler, nothing in handler, step
from handler: continue to signal
stepi
<signal handler called>
1: x/i $pc
=> 0x7ffff7f80440 <__kernel_start_sigtramp_rt64>: bctrl
(gdb) stepi
handler (sig=551) at sigstep.c:32
32 {
1: x/i $pc
=> 0x10000097c <handler>: addis r2,r12,2
(gdb) PASS: gdb.base/sigstep.exp: stepi to handler, nothing in handler,
step from handler: stepi to handler
Patch has been tested on x86_64-linux and ppc64le-linux with no test failures.
On OBS I ran into:
...
(gdb) PASS: gdb.base/foll-vfork.exp: exit: \
vfork relations in info inferiors: continue to child exit
info inferiors^M
Num Description Connection Executable ^M
1 <null> foll-vfork-exit ^M
* 2 <null> foll-vfork-exit ^M
(gdb) I'm the proud parent of child #5044!^M
FAIL: gdb.base/foll-vfork.exp: exit: vfork relations in info inferiors: \
vfork relation no longer appears in info inferiors (timeout)
...
Fix this by removing the '$' anchor in the corresponding '$gdb_prompt $'
regexps.
Tested on x86_64-linux.
Extract allowed styles from libiberty, so we don't have to worry about
our help messages getting out of date. The function probably belongs
in libiberty/cplus-dem.c but it can be here for a while to iron out
bugs.
PR 28581
* demanguse.c: New file.
* demanguse.h: New file.
* nm.c (usage): Break up output. Use display_demangler_styles.
* objdump.c (usage): Use display_demangler_styles.
* readelf.c (usage): Likewise.
* Makefile.am: Add demanguse.c and demanguse.h.
* Makefile.in: Regenerate.
* po/POTFILESin: Regenerate.
GDB hangs when doing this:
- launch inferior with multiple threads
- multiple threads hit some breakpoint(s)
- one breakpoint hit is presented as a stop, the rest are saved as
pending wait statuses
- "set scheduler-locking on"
- resume the currently selected thread (because of scheduler-locking,
it's the only one resumed), let it execute until exit
- GDB hangs, not showing the prompt, impossible to interrupt with ^C
When the resumed thread exits, we expect the target to return a
TARGET_WAITKIND_NO_RESUMED event, and that's what we see:
[infrun] fetch_inferior_event: enter
[infrun] scoped_disable_commit_resumed: reason=handling event
[infrun] random_pending_event_thread: None found.
[Thread 0x7ffff7d9c700 (LWP 309357) exited]
[infrun] print_target_wait_results: target_wait (-1.0.0 [process -1], status) =
[infrun] print_target_wait_results: -1.0.0 [process -1],
[infrun] print_target_wait_results: status->kind = no-resumed
[infrun] handle_inferior_event: status->kind = no-resumed
[infrun] handle_no_resumed: TARGET_WAITKIND_NO_RESUMED (ignoring: found resumed)
[infrun] prepare_to_wait: prepare_to_wait
[infrun] reset: reason=handling event
[infrun] maybe_set_commit_resumed_all_targets: not requesting commit-resumed for target native, no resumed threads
[infrun] fetch_inferior_event: exit
The problem is in handle_no_resumed: we check if some other thread is
actually resumed, to see if we should ignore that event (see comments in
that function for more info). If this condition is true:
(thread->executing () || thread->has_pending_waitstatus ())
... then we ignore the event. The problem is that there are some non-resumed
threads with a pending event, which makes us ignore the event. But these
threads are not resumed, so we end up waiting while nothing executes, hence
waiting for ever.
My first fix was to change the condition to:
(thread->executing ()
|| (thread->resumed () && thread->has_pending_waitstatus ()))
... but then it occured to me that we could simply check for:
(thread->resumed ())
Since "executing" implies "resumed", checking simply for "resumed"
covers threads that are resumed and executing, as well as threads that
are resumed with a pending status, which is what we want.
Change-Id: Ie796290f8ae7f34c026ca3a8fcef7397414f4780
When building with clang 13 (and -std=gnu++17 to work around an issue in
string_view-selftests.c), we run into a few Wimplicit-exception-spec-mismatch
warnings:
...
src/gdbsupport/new-op.cc:102:1: error: function previously declared with an \
explicit exception specification redeclared with an implicit exception \
specification [-Werror,-Wimplicit-exception-spec-mismatch]
operator delete (void *p)
^
/usr/include/c++/11/new:130:6: note: previous declaration is here
void operator delete(void*) _GLIBCXX_USE_NOEXCEPT
^
...
These are due to recent commit 5fff6115fe "Fix
LD_PRELOAD=/usr/lib64/libasan.so.6 gdb".
Fix this by adding the missing noexcept.
Build on x86_64-linux, using gcc 7.5.0 and clang 13.0.0.
When building with -std=c++11, we run into two Werror=missing-declarations:
...
new-op.cc: In function 'void operator delete(void*, std::size_t)':
new-op.cc:114:1: error: no previous declaration for \
'void operator delete(void*, std::size_t)' [-Werror=missing-declarations]
operator delete (void *p, std::size_t) noexcept
^~~~~~~~
new-op.cc: In function 'void operator delete [](void*, std::size_t)':
new-op.cc:132:1: error: no previous declaration for \
'void operator delete [](void*, std::size_t)' [-Werror=missing-declarations]
operator delete[] (void *p, std::size_t) noexcept
^~~~~~~~
...
These are due to recent commit 5fff6115fe "Fix
LD_PRELOAD=/usr/lib64/libasan.so.6 gdb".
The declarations are provided by <new> (which is included) for c++14 onwards,
but they are missing for c++11.
Fix this by adding the missing declarations.
Tested on x86_64-linux, with gcc 7.5.0, both without (implying -std=gnu++14) and
with -std=c++11.
Add a regression test-case for commit a50bdb99af "[gdb/tdep, rs6000] Don't
skip system call in skip_prologue":
- set a breakpoint on a local copy of glibc's _exit, and
- verify that it triggers.
The test-case uses an assembly file by default, but also has the possibility
to use a C source file instead.
Tested on ppc64le-linux. Verified that the test-case fails without
aforementioned commit, and passes with the commit. Both with assembly
and C source.
For now we should always generate the elf architecture attribute both for
elf and linux toolchains, so that we could dump the objects correctly
according to the generated architecture string. This patch resolves the
problem that we probably dump an object with c.nop instructions, but
in fact the c extension isn't allowed. Consider the following case,
nelson@LAPTOP-QFSGI1F2:~/test$ cat temp.s
.option norvc
.option norelax
.text
add a0, a0, a0
.byte 0x1
.balign 16
nelson@LAPTOP-QFSGI1F2:~/test$ ~/binutils-dev/build-elf32-upstream/build-install/bin/riscv32-unknown-elf-as temp.s -o temp.o
nelson@LAPTOP-QFSGI1F2:~/test$ ~/binutils-dev/build-elf32-upstream/build-install/bin/riscv32-unknown-elf-objdump -d temp.o
temp.o: file format elf32-littleriscv
Disassembly of section .text:
00000000 <.text>:
0: 00a50533 add a0,a0,a0
4: 01 .byte 0x01
5: 00 .byte 0x00
6: 0001 nop
8: 00000013 nop
c: 00000013 nop
nelson@LAPTOP-QFSGI1F2:~/test$ ~/binutils-dev/build-elf32-upstream/build-install/bin/riscv32-unknown-elf-readelf -A temp.o
Attribute Section: riscv
File Attributes
Tag_RISCV_arch: "rv32i2p0_m2p0_a2p0_f2p0_d2p0"
The c.nop at address 0x6 is generated for alignment, but since the rvc isn't
allowed for this object, dump it as a c.nop instruction looks wrong. After
applying this patch, I get the following result,
nelson@LAPTOP-QFSGI1F2:~/test$ ~/binutils-dev/build-elf32-upstream/build-install/bin/riscv32-unknown-elf-objdump -d temp.o
temp.o: file format elf32-littleriscv
Disassembly of section .text:
00000000 <.text>:
0: 00a50533 add a0,a0,a0
4: 01 .byte 0x01
5: 00 .byte 0x00
6: 0001 .2byte 0x1
8: 00000013 nop
c: 00000013 nop
For the current objdump, we dump data to .byte/.short/.word/.dword, and
dump the unknown or unsupported instructions to .2byte/.4byte/.8byte, which
respectively are 2, 4 and 8 bytes instructions. Therefore, we shouldn't
dump the 0x0001 as a c.nop instruction in the above case, we should dump
it to .2byte 0x1 as a unknown instruction, since the rvc is disabled.
However, consider that some people may use the new objdump to dump the old
objects, which don't have any elf attributes. We usually set the default
architecture string to rv64g by bfd/elfxx-riscv.c:riscv_set_default_arch.
But this will cause rvc instructions to be unrecognized. Therefore, we
set the default architecture string to rv64gc for disassembler, to keep
the previous behavior.
This patch pass the riscv-gnu-toolchain gcc/binutils regressions for
rv32emc-elf, rv32gc-linux, rv32i-elf, rv64gc-elf and rv64gc-linux
toolchains. Also, tested by --enable-targets=all and can build
riscv-gdb successfully.
bfd/
* elfnn-riscv.c (riscv_merge_arch_attr_info): Tidy the
codes for riscv_parse_subset_t setting.
* elfxx-riscv.c (riscv_get_default_ext_version): Updated.
(riscv_subset_supports): Moved from gas/config/tc-riscv.c.
(riscv_multi_subset_supports): Likewise.
* elfxx-riscv.h: Added extern for riscv_subset_supports and
riscv_multi_subset_supports.
gas/
* config/tc-riscv.c (riscv_subset_supports): Moved to
bfd/elfxx-riscv.c.
(riscv_multi_subset_supports): Likewise.
(riscv_rps_as): Defined for architectrue parser.
(riscv_set_arch): Updated.
(riscv_set_abi_by_arch): Likewise.
(riscv_csr_address): Likewise.
(reg_lookup_internal): Likewise.
(riscv_ip): Likewise.
(s_riscv_option): Updated.
* testsuite/gas/riscv/mapping-04b.d: Updated.
* testsuite/gas/riscv/mapping-norelax-03b.d: Likewise.
* testsuite/gas/riscv/mapping-norelax-04b.d: Likewise.
opcodes/
* riscv-dis.c: Include elfxx-riscv.h since we need the
architecture parser. Also removed the cpu-riscv.h, it
is already included in elfxx-riscv.h.
(default_isa_spec): Defined since the parser need this
to set the default architecture string.
(xlen): Moved out from riscv_disassemble_insn as a global
variable, it is more convenient to initialize riscv_rps_dis.
(riscv_subsets): Defined to recoed the supported
extensions.
(riscv_rps_dis): Defined for architectrue parser.
(riscv_disassemble_insn): Call riscv_multi_subset_supports
to make sure if the instructions are valid or not.
(print_insn_riscv): Initialize the riscv_subsets by parsing
the elf architectrue attribute. Otherwise, set the default
architectrue string to rv64gc.
Since gcc dropped support for a.out starting with 4.4.0 in 2009, it's
been impossible to verify this code actually still works. Since it
crashes in ld, and it uses a config option that no other tests uses
and we want to remove, drop the test to avoid all the trouble.
Outputting an extra space broke a cris test. Change the workaround
to use %s with an empty string to avoid the compiler warning but not
output an extra space.
There's no need to sync testutils.inc with remote hosts. The one
we have in the source tree is all we need and only thing we test.
Delete it to simplify.
Objcopy was used to create a binary file of just the executable code
since the environment requires code to based at address 0. We can
accomplish the same thing with the -Ttext=0 flag, so switch to that
to get rid of custom logic.
Simon pointed out that my recent patches to .debug_loclists caused
some regressions. After a brief discussion we realized it was because
his system compiler defaults to PIE.
This patch changes this code to unconditionally apply the text offset
here. It also changes loclist_describe_location to work more like
dwarf2_find_location_expression.
I tested this by running the gdb.dwarf2 tests both with and without
-pie.
This patch is adding support for Cortex-A710 CPU in Arm.
bfd/
* cpu-arm.c (processors): Add cortex-a710.
gas/
* NEWS: Update docs.
* config/tc-arm.c (arm_cpus): Add cortex-a710 to -mcpu.
* doc/c-arm.texi: Update docs.
* testsuite/gas/arm/cpu-cortex-a710.d: New test.
Commit e86fc4a5bc ("PR 28447: implement multiple parameters for .file
on XCOFF") changes the structure associated to the internal
representation of files in COFF formats. However, gdb directory update
has been forgotten, leading to compilation errors of this kind:
CXX coffread.o
/home/simark/src/binutils-gdb/gdb/coffread.c: In function 'const char* coff_getfilename(internal_auxent*)':
/home/simark/src/binutils-gdb/gdb/coffread.c:1343:29: error: 'union internal_auxent::<unnamed struct>::<unnamed>' has no member named 'x_zeroes'
1343 | if (aux_entry->x_file.x_n.x_zeroes == 0)
| ^~~~~~~~
Fix it by adjusting the COFF code in GDB.
Change-Id: I703fa134bc722d47515efbd72b88fa5650af6c3c
Add a test-case to excercise the problem scenario reported in PR28527 and
fixed in commit a50bdb99af "[gdb/tdep, rs6000] Don't skip system call in
skip_prologue":
- set a breakpoint on _exit, and
- verify that it triggers.
Note that this is not a regression test for that commit. Since the actual
code in _exit may vary across os instances, we cannot guarantee that the
problem will always trigger with this test-case.
Rather, this test-case is a version of the original test-case
(gdb.threads/process-dies-while-detaching.exp) that is minimal while still
reproducing the problem reported in PR28527, in that same setting.
The benefit of this test-case is that it exercise real-life code and may
expose similar problems in other settings. Also, it provides a much easier
test-case to investigate in case a similar problem occurs.
Tested on x86_64-linux and ppc64le-linux.
When I refactored this by scoping it to sim-frv-xxx in commit
e7954ef5e5 ("sim: frv: scope the
unique configure flag"), I changed the default from off to on.
While the feature is nice for developers, it breaks a bunch of
tests which aren't expecting this extra output. So flip it back
to off by default.
Since --unicode support (commit b3aa80b45c) both binutils/readelf.c
and binutils/strings.c use 'uint' in a few locations. It likely
should be 'unsigned int' since there isn't anything defining 'uint'
within binutils (besides zlib) and AFAIK it isn't a standard type.
* readelf.c (print_symbol): Replace uint with unsigned int.
* strings.c (string_min, display_utf8_char): Likewise.
(print_unicode_stream_body, print_unicode_stream): Likewise.
(print_strings): Likewise.
(get_unicode_byte): Wrap long line.
Previous flags were aimed to be run with XLC.
Nowadays, only GCC is being tested with GNU toolchain. Moreover,
recent XLC versions might also accept "-shared".
* testsuite/ld-shared/shared.exp: Adjust shared flags.
The purpose of this test is described in the comments in
dprintf-execution-x-script.exp.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28308
The name of this new test was based on that of an existing test,
bp-cmds-execution-x-script.exp. I started off by copying that test,
adding to it, and then rewriting almost all of it. It's different
enough that I decided that listing the copyright year as 2021
was sufficient.
This commit fixes Bug 28308, titled "Strange interactions with
dprintf and break/commands":
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28308
Since creating that bug report, I've found a somewhat simpler way of
reproducing the problem. I've encapsulated it into the GDB test case
which I've created along with this bug fix. The name of the new test
is gdb.base/dprintf-execution-x-script.exp, I'll demonstrate the
problem using this test case, though for brevity, I've placed all
relevant files in the same directory and have renamed the files to all
start with 'dp-bug' instead of 'dprintf-execution-x-script'.
The script file, named dp-bug.gdb, consists of the following commands:
dprintf increment, "dprintf in increment(), vi=%d\n", vi
break inc_vi
commands
continue
end
run
Note that the final command in this script is 'run'. When 'run' is
instead issued interactively, the bug does not occur. So, let's look
at the interactive case first in order to see the correct/expected
output:
$ gdb -q -x dp-bug.gdb dp-bug
... eliding buggy output which I'll discuss later ...
(gdb) run
Starting program: /mesquite2/sourceware-git/f34-master/bld/gdb/tmp/dp-bug
vi=0
dprintf in increment(), vi=0
Breakpoint 2, inc_vi () at dprintf-execution-x-script.c:26
26 in dprintf-execution-x-script.c
vi=1
dprintf in increment(), vi=1
Breakpoint 2, inc_vi () at dprintf-execution-x-script.c:26
26 in dprintf-execution-x-script.c
vi=2
dprintf in increment(), vi=2
Breakpoint 2, inc_vi () at dprintf-execution-x-script.c:26
26 in dprintf-execution-x-script.c
vi=3
[Inferior 1 (process 1539210) exited normally]
In this run, in which 'run' was issued from the gdb prompt (instead
of at the end of the script), there are three dprintf messages along
with three 'Breakpoint 2' messages. This is the correct output.
Now let's look at the output that I snipped above; this is the output
when 'run' is issued from the script loaded via GDB's -x switch:
$ gdb -q -x dp-bug.gdb dp-bug
Reading symbols from dp-bug...
Dprintf 1 at 0x40116e: file dprintf-execution-x-script.c, line 38.
Breakpoint 2 at 0x40113a: file dprintf-execution-x-script.c, line 26.
vi=0
dprintf in increment(), vi=0
Breakpoint 2, inc_vi () at dprintf-execution-x-script.c:26
26 dprintf-execution-x-script.c: No such file or directory.
vi=1
Breakpoint 2, inc_vi () at dprintf-execution-x-script.c:26
26 in dprintf-execution-x-script.c
vi=2
Breakpoint 2, inc_vi () at dprintf-execution-x-script.c:26
26 in dprintf-execution-x-script.c
vi=3
[Inferior 1 (process 1539175) exited normally]
In the output shown above, only the first dprintf message is printed.
The 2nd and 3rd dprintf messages are missing! However, all three
'Breakpoint 2...' messages are still printed.
Why does this happen?
bpstat_do_actions_1() in gdb/breakpoint.c contains the following
comment and code near the start of the function:
/* Avoid endless recursion if a `source' command is contained
in bs->commands. */
if (executing_breakpoint_commands)
return 0;
scoped_restore save_executing
= make_scoped_restore (&executing_breakpoint_commands, 1);
Also, as described by this comment prior to the 'async' field
in 'struct ui' in top.h, the main UI starts off in sync mode
when processing command line arguments:
/* True if the UI is in async mode, false if in sync mode. If in
sync mode, a synchronous execution command (e.g, "next") does not
return until the command is finished. If in async mode, then
running a synchronous command returns right after resuming the
target. Waiting for the command's completion is later done on
the top event loop. For the main UI, this starts out disabled,
until all the explicit command line arguments (e.g., `gdb -ex
"start" -ex "next"') are processed. */
This combination of things, the state of the static global
'executing_breakpoint_commands' plus the state of the async
field in the main UI causes this behavior.
This is a backtrace after hitting the dprintf breakpoint for
the second time when doing 'run' from the script file, i.e.
non-interactively:
Thread 1 "gdb" hit Breakpoint 3, bpstat_do_actions_1 (bsp=0x7fffffffc2b8)
at /ironwood1/sourceware-git/f34-master/bld/../../worktree-master/gdb/breakpoint.c:4431
4431 if (executing_breakpoint_commands)
#0 bpstat_do_actions_1 (bsp=0x7fffffffc2b8)
at gdb/breakpoint.c:4431
#1 0x00000000004d8bc6 in dprintf_after_condition_true (bs=0x1538090)
at gdb/breakpoint.c:13048
#2 0x00000000004c5caa in bpstat_stop_status (aspace=0x116dbc0, bp_addr=0x40116e, thread=0x137f450, ws=0x7fffffffc718,
stop_chain=0x1538090) at gdb/breakpoint.c:5498
#3 0x0000000000768d98 in handle_signal_stop (ecs=0x7fffffffc6f0)
at gdb/infrun.c:6172
#4 0x00000000007678d3 in handle_inferior_event (ecs=0x7fffffffc6f0)
at gdb/infrun.c:5662
#5 0x0000000000763cd5 in fetch_inferior_event ()
at gdb/infrun.c:4060
#6 0x0000000000746d7d in inferior_event_handler (event_type=INF_REG_EVENT)
at gdb/inf-loop.c:41
#7 0x00000000007a702f in handle_target_event (error=0, client_data=0x0)
at gdb/linux-nat.c:4207
#8 0x0000000000b8cd6e in gdb_wait_for_event (block=block@entry=0)
at gdbsupport/event-loop.cc:701
#9 0x0000000000b8d032 in gdb_wait_for_event (block=0)
at gdbsupport/event-loop.cc:597
#10 gdb_do_one_event () at gdbsupport/event-loop.cc:212
#11 0x00000000009d19b6 in wait_sync_command_done ()
at gdb/top.c:528
#12 0x00000000009d1a3f in maybe_wait_sync_command_done (was_sync=0)
at gdb/top.c:545
#13 0x00000000009d2033 in execute_command (p=0x7fffffffcb18 "", from_tty=0)
at gdb/top.c:676
#14 0x0000000000560d5b in execute_control_command_1 (cmd=0x13b9bb0, from_tty=0)
at gdb/cli/cli-script.c:547
#15 0x000000000056134a in execute_control_command (cmd=0x13b9bb0, from_tty=0)
at gdb/cli/cli-script.c:717
#16 0x00000000004c3bbe in bpstat_do_actions_1 (bsp=0x137f530)
at gdb/breakpoint.c:4469
#17 0x00000000004c3d40 in bpstat_do_actions ()
at gdb/breakpoint.c:4533
#18 0x00000000006a473a in command_handler (command=0x1399ad0 "run")
at gdb/event-top.c:624
#19 0x00000000009d182e in read_command_file (stream=0x113e540)
at gdb/top.c:443
#20 0x0000000000563697 in script_from_file (stream=0x113e540, file=0x13bb0b0 "dp-bug.gdb")
at gdb/cli/cli-script.c:1642
#21 0x00000000006abd63 in source_gdb_script (extlang=0xc44e80 <extension_language_gdb>, stream=0x113e540,
file=0x13bb0b0 "dp-bug.gdb") at gdb/extension.c:188
#22 0x0000000000544400 in source_script_from_stream (stream=0x113e540, file=0x7fffffffd91a "dp-bug.gdb",
file_to_open=0x13bb0b0 "dp-bug.gdb")
at gdb/cli/cli-cmds.c:692
#23 0x0000000000544557 in source_script_with_search (file=0x7fffffffd91a "dp-bug.gdb", from_tty=1, search_path=0)
at gdb/cli/cli-cmds.c:750
#24 0x00000000005445cf in source_script (file=0x7fffffffd91a "dp-bug.gdb", from_tty=1)
at gdb/cli/cli-cmds.c:759
#25 0x00000000007cf6d9 in catch_command_errors (command=0x5445aa <source_script(char const*, int)>,
arg=0x7fffffffd91a "dp-bug.gdb", from_tty=1, do_bp_actions=false)
at gdb/main.c:523
#26 0x00000000007cf85d in execute_cmdargs (cmdarg_vec=0x7fffffffd1b0, file_type=CMDARG_FILE, cmd_type=CMDARG_COMMAND,
ret=0x7fffffffd18c) at gdb/main.c:615
#27 0x00000000007d0c8e in captured_main_1 (context=0x7fffffffd3f0)
at gdb/main.c:1322
#28 0x00000000007d0eba in captured_main (data=0x7fffffffd3f0)
at gdb/main.c:1343
#29 0x00000000007d0f25 in gdb_main (args=0x7fffffffd3f0)
at gdb/main.c:1368
#30 0x00000000004186dd in main (argc=5, argv=0x7fffffffd508)
at gdb/gdb.c:32
There are two frames for bpstat_do_actions_1(), one at frame #16 and
the other at frame #0. The one at frame #16 is processing the actions
for Breakpoint 2, which is a 'continue'. The one at frame #0 is attempting
to process the dprintf breakpoint action. However, at this point,
the value of 'executing_breakpoint_commands' is 1, forcing an early
return, i.e. prior to executing the command(s) associated with the dprintf
breakpoint.
For the sake of comparison, this is what the stack looks like when hitting
the dprintf breakpoint for the second time when issuing the 'run'
command from the GDB prompt.
Thread 1 "gdb" hit Breakpoint 3, bpstat_do_actions_1 (bsp=0x7fffffffccd8)
at /ironwood1/sourceware-git/f34-master/bld/../../worktree-master/gdb/breakpoint.c:4431
4431 if (executing_breakpoint_commands)
#0 bpstat_do_actions_1 (bsp=0x7fffffffccd8)
at gdb/breakpoint.c:4431
#1 0x00000000004d8bc6 in dprintf_after_condition_true (bs=0x16b0290)
at gdb/breakpoint.c:13048
#2 0x00000000004c5caa in bpstat_stop_status (aspace=0x116dbc0, bp_addr=0x40116e, thread=0x13f0e60, ws=0x7fffffffd138,
stop_chain=0x16b0290) at gdb/breakpoint.c:5498
#3 0x0000000000768d98 in handle_signal_stop (ecs=0x7fffffffd110)
at gdb/infrun.c:6172
#4 0x00000000007678d3 in handle_inferior_event (ecs=0x7fffffffd110)
at gdb/infrun.c:5662
#5 0x0000000000763cd5 in fetch_inferior_event ()
at gdb/infrun.c:4060
#6 0x0000000000746d7d in inferior_event_handler (event_type=INF_REG_EVENT)
at gdb/inf-loop.c:41
#7 0x00000000007a702f in handle_target_event (error=0, client_data=0x0)
at gdb/linux-nat.c:4207
#8 0x0000000000b8cd6e in gdb_wait_for_event (block=block@entry=0)
at gdbsupport/event-loop.cc:701
#9 0x0000000000b8d032 in gdb_wait_for_event (block=0)
at gdbsupport/event-loop.cc:597
#10 gdb_do_one_event () at gdbsupport/event-loop.cc:212
#11 0x00000000007cf512 in start_event_loop ()
at gdb/main.c:421
#12 0x00000000007cf631 in captured_command_loop ()
at gdb/main.c:481
#13 0x00000000007d0ebf in captured_main (data=0x7fffffffd3f0)
at gdb/main.c:1353
#14 0x00000000007d0f25 in gdb_main (args=0x7fffffffd3f0)
at gdb/main.c:1368
#15 0x00000000004186dd in main (argc=5, argv=0x7fffffffd508)
at gdb/gdb.c:32
This relatively short backtrace is due to the current UI's async field
being set to 1.
Yet another thing to be aware of regarding this problem is the
difference in the way that commands associated to dprintf breakpoints
versus regular breakpoints are handled. While they both use a command
list associated with the breakpoint, regular breakpoints will place
the commands to be run on the bpstat chain constructed in
bp_stop_status(). These commands are run later on. For dprintf
breakpoints, commands are run via the 'after_condition_true' function
pointer directly from bpstat_stop_status(). (The 'commands' field in
the bpstat is cleared in dprintf_after_condition_true(). This
prevents the dprintf commands from being run again later on when other
commands on the bpstat chain are processed.)
Another thing that I noticed is that dprintf breakpoints are the only
type of breakpoint which use 'after_condition_true'. This suggests
that one possible way of fixing this problem, that of making dprintf
breakpoints work more like regular breakpoints, probably won't work.
(I must admit, however, that my understanding of this code isn't
complete enough to say why. I'll trust that whoever implemented it
had a good reason for doing it this way.)
The comment referenced earlier regarding 'executing_breakpoint_commands'
states that the reason for checking this variable is to avoid
potential endless recursion when a 'source' command appears in
bs->commands. We know that a dprintf command is constrained to either
1) execution of a GDB printf command, 2) an inferior function call of
a printf-like function, or 3) execution of an agent-printf command.
Therefore, infinite recursion due to a 'source' command cannot happen
when executing commands upon hitting a dprintf breakpoint.
I chose to fix this problem by having dprintf_after_condition_true()
directly call execute_control_commands(). This means that it no
longer attempts to go through bpstat_do_actions_1() avoiding the
infinite recursion check for potential 'source' commands on the
command chain. I think it simplifies this code a little bit too, a
definite bonus.
Summary:
* breakpoint.c (dprintf_after_condition_true): Don't call
bpstat_do_actions_1(). Call execute_control_commands()
instead.
This little tweak terminates fuzzed binary readelf output a little
quicker.
PR 28543
* dwarf.c (read_and_display_attr_value): Consume a byte when
form is unrecognized.
PR 28542
* readelf.c (dump_relocations): Check that section headers have
been read before attempting to access section name.
(print_dynamic_symbol): Likewise.
(process_mips_specific): Delete dead code.
