When configuring gdb using --with-mpfr=no and running test-case
gdb.base/float128.exp, we run into:
...
FAIL: gdb.base/float128.exp: print large128 (GDB may be missing MPFR support!)
...
Fix this by detecting that gdb was build without mpfr using the show
configuration command, and changing the FAIL into UNSUPPORTED.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-12-11 Tom de Vries <tdevries@suse.de>
PR testsuite/26954
* gdb.base/float128.exp: Detect and handle no mpfr support.
That test fails intermittently for me. The problem is a race condition
between the exec syscall and GDB resuming threads.
The initial situation is that we have two threads, let's call them
"leader" and "other". Leader is the one who is going to do the exec.
We stop at the breakpoint on the all_started function, so both threads
are stopped. When resuming, GDB resumes leader first and other second.
However, between resuming the two threads, leader has time to run and do
its exec, making other disappear. When GDB tries to resume other, it is
ino longer there. We get some "Couldn't get registers: No such
process." messages, and the state is a bit messed up.
The issue can be triggered consistently by adding a small delay after
the resume syscall:
diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
index d5a062163c7..9540339a9da 100644
--- a/gdb/inf-ptrace.c
+++ b/gdb/inf-ptrace.c
@@ -308,6 +308,8 @@ inf_ptrace_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
gdb_ptrace (request, ptid, (PTRACE_TYPE_ARG3)1, gdb_signal_to_host (signal));
if (errno != 0)
perror_with_name (("ptrace"));
+ for (int i = 0 ; i < 100; i++)
+ usleep (10000);
}
/* Wait for the child specified by PTID to do something. Return the
This patch is about fixing the test to avoid this, since the test is not
about testing this particular corner case. Handling of multi-threaded
program doing execs should be improved too, but that's not the goal of
this patch.
Fix it by adding a synchronization point in the test to make sure both
threads were resumed by GDB before doing the exec. I added two
pthread_barrier_wait calls in each thread (for a total of three). I
think adding one call in each thread would not be enough, because this
could happen:
- both threads reach the first barrier
- the "other" thread is scheduled so has time to run and hit the second
barrier
- the "leader" thread hits the all_started function breakpoint, causing
both threads to be stopped by GDB
- GDB resumes the "leader" thread
- Since the "other" thread has already reached the second barrier, the
"leader" thread is free to run past its second barrier and do the
exec, while GDB still hasn't resumed the second one
By adding two barrier calls in each thread, I think we are good. The test
passes consistently for me, even with the artificial delay added.
gdb/testsuite/ChangeLog:
PR gdb/24694
* gdb.multi/multi-arch-exec.c (thread_start, main): Add barrier
calls.
Change-Id: I25c8ea9724010b6bf20b42691c716235537d0e27
In commit 4d91ddd342 "[gdb/testsuite] Fix unbalanced braces in
gdb.tui/new-layout.exp", I tried to fix a problem with test-case
gdb.tui/new-layout.exp when running with tcl 8.5.
However, at that point I only had access to the log containing the failure,
and unfortunately my patch turned out not to be effective.
So, finally fix this problem by guarding the problematic code with:
...
if { [tcl_version_at_least 8 6] } { ... }
...
Tested on x86_64-linux, specifically SLE-11 where I ran into the failure.
gdb/testsuite/ChangeLog:
2020-12-10 Tom de Vries <tdevries@suse.de>
PR testsuite/26947
* gdb.tui/new-layout.exp: Don't execute tests with unbalanced curly
braces for tcl 8.5 and earlier.
I noticed a spurious newline on infrun debugging output. The following patch
fixes that. I'll push as obvious.
gdb/ChangeLog:
2020-12-10 Luis Machado <luis.machado@linaro.org>
* breakpoint.c (should_be_inserted): Don't output newline.
The FPSIMD dump in signal frames and ptrace FPSIMD dump in the SVE context
structure follows the target endianness, whereas the SVE dumps are
endianness-independent (LE).
Therefore, when the system is in BE mode, we need to reverse the bytes
for the FPSIMD data.
Given the V registers are larger than 64-bit, I've added a way for value
bytes to be set, as opposed to passing a 64-bit fixed quantity. This fits
nicely with the unwinding *_got_bytes function and makes the trad-frame
more flexible and capable of saving larger registers.
The memory for the bytes is allocated via the frame obstack, so it gets freed
after we're done inspecting the frame.
gdb/ChangeLog:
2020-12-10 Luis Machado <luis.machado@linaro.org>
* aarch64-linux-tdep.c (aarch64_linux_restore_vreg) New function.
(aarch64_linux_sigframe_init): Call aarch64_linux_restore_vreg.
* aarch64-tdep.h (V_REGISTER_SIZE): Move to ...
* arch/aarch64.h: ... here.
* nat/aarch64-sve-linux-ptrace.c: Include endian.h.
(aarch64_maybe_swab128): New function.
(aarch64_sve_regs_copy_to_reg_buf)
(aarch64_sve_regs_copy_from_reg_buf): Adjust FPSIMD entries.
* trad-frame.c (trad_frame_reset_saved_regs): Initialize
the data field.
(TF_REG_VALUE_BYTES): New enum value.
(trad_frame_value_bytes_p): New function.
(trad_frame_set_value_bytes): New function.
(trad_frame_set_reg_value_bytes): New function.
(trad_frame_get_prev_register): Handle register values saved as bytes.
* trad-frame.h (trad_frame_set_reg_value_bytes): New prototype.
(struct trad_frame_saved_reg) <data>: New field.
(trad_frame_set_value_bytes): New prototype.
(trad_frame_value_bytes_p): New prototype.
This function allows to create a BFD handle using an accessible memory
range in a target memory. It is currently contained in a JIT module but
this functionality may be of wider usefullness - for example, reading
ELF binaries contained within a core dump.
gdb/ChangeLog:
2020-12-07 Mihails Strasuns <mihails.strasuns@intel.com>
* jit.c (mem_bfd*, bfd_open_from_target_memory): Removed.
* gdb_bfd.h (gdb_bfd_open_from_target_memory): New function.
* gdb_bfd.c (mem_bfd*, gdb_bfd_open_from_target_memory): New functions.
https://github.com/riscv/riscv-asm-manual/pull/61
We aleady have sext.w, so just add sext.b, sext.h, zext.b, zext.h
and zext.w. In a certain sense, zext.b is not a pseudo - It is an
alias of andi. Similarly, sext.b and sext.h are aliases of other
rvb instructions, when we enable b extension; But they are pseudos
when we just enable rvi. However, this patch does not consider the
rvb cases. Besides, zext.w is only valid in rv64.
gas/
* config/tc-riscv.c (riscv_ext): New function. Use md_assemblef
to expand the zext and sext pseudos, to give them a chance to be
expanded into c-ext instructions.
(macro): Handle M_ZEXTH, M_ZEXTW, M_SEXTB and M_SEXTH.
* testsuite/gas/riscv/ext.s: New testcase.
* testsuite/gas/riscv/ext-32.d: Likewise.
* testsuite/gas/riscv/ext-64.d: Likewise.
include/
* opcode/riscv.h (M_ZEXTH, M_ZEXTW, M_SEXTB, M_SEXTH.): Added.
opcodes/
* riscv-opc.c (riscv_opcodes): Add sext.[bh] and zext.[bhw].
opcodes/
* disassemble.h (riscv_get_disassembler): Declare.
* disassemble.c (disassembler): Changed to riscv_get_disassembler.
* riscv-dis.c (riscv_get_disassembler): Check the elf privileged spec
attributes before calling print_insn_riscv.
(parse_riscv_dis_option): Same as the assembler, the priority of elf
attributes are higher than the options. If we find the privileged
attributes, but the -Mpriv-spec= is different, then output error/warning
and still use the elf attributes set.
bfd/
* elfxx-riscv.c (riscv_ext_dont_care_version): New function. Return
TRUE if we don't care the versions of the extensions. These extensions
are added to the subset list for special purposes, with the explicit
versions or the RISCV_UNKNOWN_VERSION versions.
(riscv_parse_add_subset): If we do care the versions of the extension,
and the versions are unknown, then report errors for the non-implicit
extensions, and return directly for the implicit one.
(riscv_arch_str1): Do not output i extension after e, and the extensions
which versions are unknown.
gas/
* config/tc-riscv.c (riscv_multi_subset_supports): Handle INSN_CLASS_ZICSR
and INSN_CLASS_ZIFENCEI.
* testsuite/gas/riscv/march-imply-i.s: New testcase.
* testsuite/gas/riscv/march-imply-i2p0-01.d: New testcase. The version
of i is less than 2.1, and zi* are supported in the chosen spec, so
enable the fence.i and csr instructions, also output the implicit zi* to
the arch string.
* testsuite/gas/riscv/march-imply-i2p0-02.d: Likewise, but the zi* are
not supported in the spec 2.2. Enable the related instructions since
i's version is less than 2.1, but do not output them.
* testsuite/gas/riscv/march-imply-i2p1-01.d: New testcase. The version
of i is 2.1, so don't add it's implicit zi*, and disable the related
instructions.
* testsuite/gas/riscv/march-imply-i2p1-01.l: Likewise.
* testsuite/gas/riscv/march-imply-i2p1-02.d: Likewise, and set the zi*
explicitly, so enable the related instructions.
* testsuite/gas/riscv/march-imply-i2p0.d: Removed.
* testsuite/gas/riscv/march-imply-i2p1.d: Removed.
include/
* opcode/riscv.h: Add INSN_CLASS_ZICSR and INSN_CLASS_ZIFENCEI.
opcodes/
* riscv-opc.c (riscv_opcodes): Control fence.i and csr instructions by
zifencei and zicsr.
Joel recently pointed out add_angle_brackets to me. This patch
changes one spot in ada-lang.c to use this function rather than doing
it on its own.
gdb/ChangeLog
2020-12-09 Tom Tromey <tromey@adacore.com>
* ada-lang.c (ada_lookup_encoded_symbol): Use add_angle_brackets.
In some cases, GNAT can emit 128-bit constants for fixed-point types.
This patch changes gdb to handle this scenario, by changing the
low-level rational-reading functions in dwarf2/read.c to work directly
with gdb_mpz values. (I'm not sure offhand if these 128-bit patches
have gone into upstream GCC yet -- but they will eventually, and
meanwhile I think it should be clear that this patch is otherwise
harmless.)
gdb/ChangeLog
2020-12-09 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (get_dwarf2_rational_constant): Change "numerator"
and "denominator" to gdb_mpz. Handle block forms.
(get_dwarf2_unsigned_rational_constant): Change "numerator" and
"denominator" to gdb_mpz.
(finish_fixed_point_type): Update.
(has_zero_over_zero_small_attribute): Update.
This removes ada-operator.def and fortran-operator.def, merging their
contents into std-operator.def.
Note that the comment for OP_EXTENDED0 is a bit wrong. IMO this
constant could be removed, as it is only used for a single assert that
does not provide much value. However, I haven't done so here.
gdb/ChangeLog
2020-12-09 Tom Tromey <tromey@adacore.com>
* expprint.c (op_name): Update.
* expression.h (enum exp_opcode): Update.
* std-operator.def: Add more opcodes.
* ada-operator.def, fortran-operator.def: Remove, moving contents
into std-operator.def.
I forgot to include fixes for review comments I got before pushing the
previous commits (or I pushed the wrong commits). This one fixes it.
- Return {} instead of false in get_discrete_low_bound and
get_discrete_high_bound.
- Compute high bound after confirming low bound is valid in
get_discrete_bounds.
gdb/ChangeLog:
* gdbtypes.c (get_discrete_low_bound, get_discrete_high_bound):
Return {} instead of false.
(get_discrete_bounds): Compute high bound only if low bound is
valid.
Change-Id: I5f9a66b3672adfac9441068c899ab113ab2c331a
Since commit 7c6f271296 ("gdb: make get_discrete_bounds check for
non-constant range bounds"), subscripting flexible array member fails:
struct no_size
{
int n;
int items[];
};
(gdb) p *ns
$1 = {n = 3, items = 0x5555555592a4}
(gdb) p ns->items[0]
Cannot access memory at address 0xfffe555b733a0164
(gdb) p *((int *) 0x5555555592a4)
$2 = 101 <--- we would expect that
(gdb) p &ns->items[0]
$3 = (int *) 0xfffe5559ee829a24 <--- wrong address
Since the flexible array member (items) has an unspecified size, the array type
created for it in the DWARF doesn't have dimensions (this is with gcc 9.3.0,
Ubuntu 20.04):
0x000000a4: DW_TAG_array_type
DW_AT_type [DW_FORM_ref4] (0x00000038 "int")
DW_AT_sibling [DW_FORM_ref4] (0x000000b3)
0x000000ad: DW_TAG_subrange_type
DW_AT_type [DW_FORM_ref4] (0x00000031 "long unsigned int")
This causes GDB to create a range type (TYPE_CODE_RANGE) with a defined
constant low bound (dynamic_prop with kind PROP_CONST) and an undefined
high bound (dynamic_prop with kind PROP_UNDEFINED).
value_subscript gets both bounds of that range using
get_discrete_bounds. Before commit 7c6f271296, get_discrete_bounds
didn't check the kind of the dynamic_props and would just blindly read
them as if they were PROP_CONST. It would return 0 for the high bound,
because we zero-initialize the range_bounds structure. And it didn't
really matter in this case, because the returned high bound wasn't used
in the end.
Commit 7c6f271296 changed get_discrete_bounds to return a failure if
either the low or high bound is not a constant, to make sure we don't
read a dynamic prop that isn't a PROP_CONST as a PROP_CONST. This
change made get_discrete_bounds start to return a failure for that
range, and as a result would not set *lowp and *highp. And since
value_subscript doesn't check get_discrete_bounds' return value, it just
carries on an uses an uninitialized value for the low bound. If
value_subscript did check the return value of get_discrete_bounds, we
would get an error message instead of a bogus value. But it would still
be a bug, as we wouldn't be able to print the flexible array member's
elements.
Looking at value_subscript, we see that the low bound is always needed,
but the high bound is only needed if !c_style. So, change
value_subscript to use get_discrete_low_bound and
get_discrete_high_bound separately. This fixes the case described
above, where the low bound is known but the high bound isn't (and is not
needed). This restores the original behavior without accessing a
dynamic_prop in a wrong way.
A test is added. In addition to the case described above, a case with
an array member of size 0 is added, which is a GNU C extension that
existed before flexible array members were introduced. That case
currently fails when compiled with gcc <= 8. gcc <= 8 produces DWARF
similar to the one shown above, while gcc 9 adds a DW_AT_count of 0 in
there, which makes the high bound known. A case where an array member
of size 0 is the only member of the struct is also added, as that was
how PR 28675 was originally reported, and it's an interesting corner
case that I think could trigger other funny bugs.
Question about the implementation: in value_subscript, I made it such
that if the low or high bound is unknown, we fall back to zero. That
effectively makes it the same as it was before 7c6f271296. But should
we instead error() out?
gdb/ChangeLog:
PR 26875, PR 26901
* gdbtypes.c (get_discrete_low_bound): Make non-static.
(get_discrete_high_bound): Make non-static.
* gdbtypes.h (get_discrete_low_bound): New declaration.
(get_discrete_high_bound): New declaration.
* valarith.c (value_subscript): Only fetch high bound if
necessary.
gdb/testsuite/ChangeLog:
PR 26875, PR 26901
* gdb.base/flexible-array-member.c: New test.
* gdb.base/flexible-array-member.exp: New test.
Change-Id: I832056f80e6c56f621f398b4780d55a3a1e299d7
get_discrete_bounds is not flexible for ranges (TYPE_CODE_RANGE), in the
sense that it returns true (success) only if both bounds are present and
constant values.
This is a problem for code that only needs to know the low bound and
fails unnecessarily if the high bound is unknown.
Split the function in two, get_discrete_low_bound and
get_discrete_high_bound, that both return an optional. Provide a new
implementation of get_discrete_bounds based on the two others, so the
callers don't have to be changed.
gdb/ChangeLog:
* gdbtypes.c (get_discrete_bounds): Implement with
get_discrete_low_bound and get_discrete_high_bound.
(get_discrete_low_bound): New.
(get_discrete_high_bound): New.
Change-Id: I986b5e9c0dd969800e3fb9546af9c827d52e80d0
get_discrete_bounds currently has three possible return values (see its
current doc for details). It appears that for all callers, it would be
sufficient to have a boolean "worked" / "didn't work" return value.
Change the return type of get_discrete_bounds to bool and adjust all
callers. Doing so simplifies the following patch.
gdb/ChangeLog:
* gdbtypes.h (get_discrete_bounds): Return bool, adjust all
callers.
* gdbtypes.c (get_discrete_bounds): Return bool.
Change-Id: Ie51feee23c75f0cd7939742604282d745db59172
Instead of returning a boolean status and returning the value through a
pointer, return an optional that does both jobs. This helps in the
following patches, and I think it is an improvement in general.
gdb/ChangeLog:
* ada-lang.c (ada_value_slice_from_ptr): Adjust.
(ada_value_slice): Adjust.
(pos_atr): Adjust.
* gdbtypes.c (get_discrete_bounds): Adjust.
(discrete_position): Return optional.
* gdbtypes.h (discrete_position): Return optional.
Change-Id: I758dbd8858b296ee472ed39ec35db1dbd624a5ae
For
.globl foo2
.section .data.foo,"aR"
.align 4
.type foo2, @object
.size foo2, 4
foo2:
.long 2
.globl foo1
.section .data.foo
.align 4
.type foo1, @object
.size foo1, 4
foo1:
.long 1
generate a new section if the SHF_GNU_RETAIN bit doesn't match.
* config/obj-elf.c (SEC_ASSEMBLER_SHF_MASK): New.
(get_section_by_match): Also check if SEC_ASSEMBLER_SHF_MASK of
sh_flags matches. Rename info to sh_info.
(obj_elf_change_section): Don't check previous SHF_GNU_RETAIN.
Rename info to sh_info.
(obj_elf_section): Rename info to sh_info. Set sh_flags for
SHF_GNU_RETAIN.
* config/obj-elf.h (elf_section_match): Rename info to sh_info.
Add sh_flags.
* testsuite/gas/elf/elf.exp: Run section27.
* testsuite/gas/elf/section24b.d: Updated.
* testsuite/gas/elf/section27.d: New file.
* testsuite/gas/elf/section27.s: Likewise.
Use the LOCALAPPDATA environment variable to determine the cache dir
when running on Windows with native command line, otherwise nasty
warning "Couldn't determine a path for index cached directory" appears.
Change-Id: I77903f9f0cb4743555866b8aea892cef55132589
Redo fix committed in commit 67748e0f66 "[gdb/testsuite] Make
gdb.arch/amd64-gs_base.exp unsupported for i386" using is_amd64_regs_target.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-12-08 Tom de Vries <tdevries@suse.de>
* gdb.arch/amd64-gs_base.exp: Undo commit 67748e0f66, reimplement
using is_amd64_regs_target.
When running test-case gdb.ada/mi_task_arg.exp with target board unix/-m32, I
run into:
...
(gdb) ^M
Expecting: ^(-stack-list-arguments 1[^M
]+)?(\^done,stack-args=\[ \
frame={level="0",args=\[\]}, \
frame={level="1",args=\[{name="<_task>",value="0x[0-9A-Fa-f]+"}\]}, \
frame={level="2",args=\[({name="self_id",value="0x[0-9A-Fa-f]+"})?\]},.*[^M
]+[(]gdb[)] ^M
[ ]*)
-stack-list-arguments 1^M
^done,stack-args=[ \
frame={level="0",args=[]}, \
frame={level="1",args=[{name="<_task>",value="0x808abf0"}]}, \
frame={level="2",args=[{name="self_id",value="<optimized out>"}]}, \
frame={level="3",args=[]},frame={level="4",args=[]}]^M
(gdb) ^M
FAIL: gdb.ada/mi_task_arg.exp: -stack-list-arguments 1 (unexpected output)
...
The problem is that we're expecting a $hex for the value of self_id, but
instead get <optimized out>.
Looking at the debug info for self_id:
...
<1><12a1f>: Abbrev Number: 84 (DW_TAG_subprogram)
<12a20> DW_AT_name : system__tasking__stages__task_wrapper
...
<2><12a35>: Abbrev Number: 61 (DW_TAG_formal_parameter)
<12a36> DW_AT_name : self_id
<12a40> DW_AT_location : 0x459e (location list)
...
it refers to location information here:
...
0000459e 08053060 080531ac (DW_OP_fbreg: 0)
000045aa 0805327c 080532a5 (DW_OP_fbreg: 0)
000045b6 08053320 08053324 (DW_OP_fbreg: 0)
...
while the pc used to retrieve the location information is 0x080531c5:
...
$ gdb -batch outputs/gdb.ada/mi_task_arg/task_switch \
-ex "break 57" -ex run -ex bt
...
#0 task_switch.break_me () at task_switch.adb:57
#1 0x0804aaae in task_switch.caller (<_task>=0x808abf0) \
at task_switch.adb:51
#2 0x080531c5 in system.tasking.stages.task_wrapper \
(self_id=<optimized out>) at s-tassta.adb:1295
...
which indeed falls outside of the ranges listed in the location info.
Fix this by accepting <optimized out> as valid value of self_id.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-12-08 Tom de Vries <tdevries@suse.de>
* gdb.ada/mi_task_arg.exp: Accept <optimized out> as valid value of
self_id.
smart_rename is capable of handling symlinks by copying and it also
tries to preserve ownership and permissions of files when they're
overwritten during the rename. This is useful in objcopy where the
file properties need to be preserved.
However because smart_rename does this using file names, it leaves a
race window between renames and permission fixes. This change removes
this race window by using file descriptors from the original BFDs that
were used to manipulate these files wherever possible.
The file that is to be renamed is also passed as a file descriptor so
that we use fchown/fchmod on the file descriptor, thus making sure
that we only modify the file we have opened to write. Further, in
case the file is to be overwritten (as is the case in ar or objcopy),
the permissions that need to be restored are taken from the file
descriptor that was opened for input so that integrity of the file
status is maintained all the way through to the rename.
binutils/
* rename.c
* ar.c
(write_archive) [!defined (_WIN32) || defined (__CYGWIN32__)]:
Initialize TARGET_STAT and OFD to pass to SMART_RENAME.
* arsup.c
(ar_save) [defined (_WIN32) || defined (__CYGWIN32__)]:
Likewise.
* bucomm.h (smart_rename): Add new arguments to declaration.
* objcopy.c
(strip_main)[defined (_WIN32) || defined (__CYGWIN32__)]:
Initialize COPYFD and pass to SMART_RENAME.
(copy_main) [defined (_WIN32) || defined (__CYGWIN32__)]:
Likewise.
* rename.c (try_preserve_permissions): New function.
(smart_rename): Use it and add new arguments.
Get file state from the descriptor opened by copy_file for the input
BFD. This ensures continuity in the view of the input file through
the descriptor. At the moment it is only to preserve timestamps
recorded at the point that we opened the file for input but in the
next patch this state will also be used to preserve ownership and
permissions wherever applicable.
binutils/
* objcopy.c (copy_file): New argument IN_STAT. Return stat of
ibfd through it.
(strip_main): Remove redundant stat calls. adjust copy_file
calls.
(copy_main): Likewise.
The purpose of creating a temporary file securely using mkstemp is
defeated if it is closed in make_tempname and reopened later for use;
it is as good as using mktemp. Get the file descriptor instead and
then use it to create the BFD object.
bfd/
* opncls.c (bfd_fdopenw): New function.
* bfd-in2.h: Regenerate.
binutils/
* bucomm.c (make_tempname): Add argument to return file
descriptor.
* bucomm.h (make_tempname): Likewise.
* ar.c: Include libbfd.h.
(write_archive): Adjust for change in make_tempname. Call
bfd_fdopenw instead of bfd_openw.
* objcopy.c: Include libbfd.h.
(copy_file): New argument OFD. Use bfd_fdopenw instead of
bfd_openw.
(strip_main): Adjust for change in make_tempname and
copy_file.
(copy_main): Likewise.
I happened to notice that expression completion did not work correctly
for "maint print type". This patch adds the appropriate completer
there.
gdb/ChangeLog
2020-12-07 Tom Tromey <tromey@adacore.com>
* maint.c (_initialize_maint_cmds): Use expression command
completer for "maint print type".
I'm unsure why this is deserving of a warning. Not writing the most
efficient code surely can't be a real problem, but that is what
https://gcc.gnu.org/bugzilla//show_bug.cgi?id=88059#c1 seems to say.
plugin.cc:528:10: error: 'char* strncpy(char*, const char*, size_t)' specified bound depends on the length of the source argument [-Werror=stringop-overflow=]
528 | strncpy(tempdir, dir_template, len);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
plugin.cc:526:22: note: length computed here
526 | size_t len = strlen(dir_template) + 1;
| ~~~~~~^~~~~~~~~~~~~~
* plugin.cc (Plugin_recorder::init): Replace strncpy with memcpy.
It looks like csky missed out on an edit for 706704c883. Not that it
matters very much. There doesn't appear to be any csky reloc howto
that sets the negate bit.
Similarly for ns32k and nds32.
* elf32-csky.c (csky_relocate_contents): Correct negate test.
* cpu-ns32k.c (_bfd_do_ns32k_reloc_contents): Likewise.
* elf32-nds32.c (nds32_relocate_contents): Likewise.
The commit
commit 733d554a46
Author: Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
Date: Tue Oct 27 10:56:03 2020 +0100
gdb/breakpoint: add flags to 'condition' and 'break' commands to force condition
introduced the '-force-condition' flag to the 'break' command. This
flag was defined as a keyword like 'thread', 'task', and 'if'.
However, it starts with '-'. This difference caused an uncovered case
when tab-completing a seemingly complete linespec.
Below, we see "-force-condition" in the completion list, where both
the options and the keywords are listed:
(gdb) break -function main <TAB>
-force-condition -function -label -line -qualified
-source if task thread
But tab-completing '-' lists only options:
(gdb) break -function main -<TAB>
-function -label -line -qualified -source
This patch fixes the problem by adding keywords to the completion
list, so that we see:
(gdb) break -function main -<TAB>
-force-condition -function -label -line -qualified -source
gdb/ChangeLog:
2020-12-07 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* completer.c (complete_explicit_location): Also add keywords
that start with '-' to the completion list.
gdb/testsuite/ChangeLog:
2020-12-07 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb.linespec/explicit.exp: Extend with a test to check completing
'-' after seemingly complete options.
The break command's "-force-condition" flag is currently required to
be followed by the "if" keyword. This prevents flexibility when using
other keywords, e.g. "thread":
(gdb) break main -force-condition thread 1 if foo
Function "main -force-condition" not defined.
Make breakpoint pending on future shared library load? (y or [n]) n
Remove the requirement that "-force-condition" is always followed by
an "if", so that more flexibility is obtained when positioning
keywords.
gdb/ChangeLog:
2020-12-07 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* linespec.c (linespec_lexer_lex_keyword): The "-force-condition"
keyword may be followed by any keyword.
* breakpoint.c (find_condition_and_thread): Advance 'tok' by
'toklen' in the case for "-force-condition".
gdb/testsuite/ChangeLog:
2020-12-07 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb.linespec/keywords.exp: Add tests to check positional
flexibility of "-force-condition".
Suppose we have the script file below:
break main
commands
print 123
end
run
If started with this script file, GDB executes the breakpoint command:
$ gdb -q -x myscript --args ./test
Reading symbols from ./test...
Breakpoint 1 at 0x114e: file test.c, line 2.
Breakpoint 1, main () at test.c:2
2 return 0;
$1 = 123
(gdb)
However, if we remove the "run" line from the script and pass it with
the '-ex' option instead, the command is not executed:
$ gdb -q -x myscript_no_run --args ./test
Reading symbols from ./test...
Breakpoint 1 at 0x114e: file test.c, line 2.
Starting program: /path/to/test
Breakpoint 1, main () at test.c:2
2 return 0;
(gdb)
If the user enters a command at this point, the breakpoint command
is executed, yielding weird output:
$ gdb -q -x myscript_no_run --args ./test
Reading symbols from ./test...
Breakpoint 1 at 0x114e: file test.c, line 2.
Starting program: /path/to/test
Breakpoint 1, main () at test.c:2
2 return 0;
(gdb) print "a"
$1 = "a"
$2 = 123
When consuming script files, GDB runs bp actions after executing a
command. See `command_handler` in event-top.c:
if (c[0] != '#')
{
execute_command (command, ui->instream == ui->stdin_stream);
/* Do any commands attached to breakpoint we stopped at. */
bpstat_do_actions ();
}
However, for '-ex' commands, `bpstat_do_actions` is not invoked.
Hence, the misaligned output explained above occurs. To fix the
problem, add a call to `bpstat_do_actions` after executing a command.
gdb/ChangeLog:
2020-12-07 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* main.c (catch_command_errors): Add a flag parameter; invoke
`bpstat_do_actions` if the flag is set.
(execute_cmdargs): Update a call to `catch_command_errors`.
gdb/testsuite/ChangeLog:
2020-12-07 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb.base/bp-cmds-run-with-ex.c: New file.
* gdb.base/bp-cmds-run-with-ex.exp: New file.
* gdb.base/bp-cmds-run-with-ex.gdb: New file.
* gdb.gdb/python-interrupts.exp: Update the call to
'catch_command_errors' with the new argument.
* gdb.gdb/python-selftest.exp: Ditto.
In replace_operator_with_call, we resize the elts array like this:
...
exp->nelts = exp->nelts + 7 - oplen;
exp->resize (exp->nelts);
...
Although all the current callers ensure that the new size is bigger, it could
also be smaller, in which case the following memmove possibly reads out of
bounds:
...
memmove (exp->elts + pc + 7, exp->elts + pc + oplen,
EXP_ELEM_TO_BYTES (save_nelts - pc - oplen));
...
Fix this by doing the resize after the memmove in case the new size is
smaller.
Tested on x86_64-linux.
gdb/ChangeLog:
2020-12-07 Tom de Vries <tdevries@suse.de>
* ada-lang.c (replace_operator_with_call): Handle shrink resize.
The patch to change struct expression to use new introduced a
regression -- there is a spot that reallocates expressions that I
failed to update.
This patch rewrites this code to follow the new approach. Now the
rewriting is done in place.
gdb/ChangeLog
2020-12-06 Tom Tromey <tom@tromey.com>
PR ada/26999
* ada-lang.c (replace_operator_with_call): Rewrite.
This fixes a long-lived bug in the s390 port.
When trying to step over a breakpoint set on a BC (branch on condition)
instruction with displaced stepping on IBM Z, gdb would incorrectly
adjust the pc regardless of whether or not the branch was taken. Since
the branch target is an absolute address, this would cause the inferior
to jump around wildly whenever the branch was taken, either crashing it
or causing it to behave unpredictably.
It turns out that the logic to handle BC instructions correctly was in
the code, but that the enum value representing its opcode has always
been incorrect.
This patch corrects the enum value to the actual opcode, fixing the
stepping problem. The enum value is also used in the prologue analysis
code, so this also fixes a minor bug where more of the prologue would
be read than was necessary.
gdb/ChangeLog:
PR breakpoints/27009
* s390-tdep.h (op_bc): Correct BC opcode value.
The gdb_mpz class currently provides a couple of methods which
essentially export an mpz_t value into either a buffer, or an integral
type. The export is based on using the mpz_export function which
we discovered can be a bit treacherous if used without caution.
In particular, the initial motivation for this patch was to catch
situations where the mpz_t value was so large that it would not fit
in the destination area. mpz_export does not know the size of
the buffer, and therefore can happily write past the end of our buffer.
While designing a solution to the above problem, I also discovered
that we also needed to be careful when exporting signed numbers.
In particular, numbers which are larger than the maximum value
for a given signed type size, but no so large as to fit in the
*unsigned* version with the same size, would end up being exported
incorrectly. This is related to the fact that mpz_export ignores
the sign of the value being exportd, and assumes an unsigned export.
Thus, for such large values, the appears as if mpz_export is able
to fit our value into our buffer, but in fact, it does not.
Also, I noticed that gdb_mpz::write wasn't taking its unsigned_p
parameter, which was a hole.
For all these reasons, a new low-level private method called
"safe_export" has been added to class gdb_mpz, whose goal is
to perform all necessary checks and manipulations for a safe
and correct export. As a bonus, this method allows us to factorize
the handling of negative value exports.
The gdb_mpz::as_integer and gdb_mpz::write methods are then simplified
to take advantage of this new safe_export method.
gdb/ChangeLog:
* gmp-utils.h (gdb_mpz::safe_export): New private method.
(gdb_mpz::as_integer): Reimplement using gdb_mpz::safe_export.
* gmp-utils.c (gdb_mpz::write): Rewrite using gdb_mpz::safe_export.
(gdb_mpz::safe_export): New method.
* unittests/gmp-utils-selftests .c (gdb_mpz_as_integer):
Update function description.
(check_as_integer_raises_out_of_range_error): New function.
(gdb_mpz_as_integer_out_of_range): New function.
(_initialize_gmp_utils_selftests): Register
gdb_mpz_as_integer_out_of_range as a selftest.
Match the condition used in `elf_vax_instantiate_got_entries' for the
creation of GOT entries in the processing of R_VAX_GOT32 relocations in
`elf_vax_check_relocs', removing incorrect warnings about a GOT addend
mismatch like:
./ld-new: tmpdir/got-local-ref-off-r.o: warning: GOT addend of 1 to `bar_hidden' does not match previous GOT addend of 0
./ld-new: tmpdir/got-local-ref-off-r.o: warning: GOT addend of 2 to `bar_hidden' does not match previous GOT addend of 0
and corresponding failures with the test cases newly added here:
FAIL: GOT test (executable hidden reference with offset)
FAIL: GOT test (executable visible reference with offset)
for symbols that are considered local for reasons other than having been
forced local with a version script, which is usually the ELF visibility.
Correct code is produced regardless, but the warning breaks `-Werror'
compilation and may upset people regardless.
Interestingly this shows with executable links only, because in shared
library links code from `elf_link_add_object_symbols' triggers:
/* If the symbol already has a dynamic index, but
visibility says it should not be visible, turn it into
a local symbol. */
switch (ELF_ST_VISIBILITY (h->other))
{
case STV_INTERNAL:
case STV_HIDDEN:
(*bed->elf_backend_hide_symbol) (info, h, TRUE);
dynsym = FALSE;
break;
}
that sets `h->forced_local' like with a version script.
Add suitable test cases including disassembly to verify correct code has
been produced where no warnings have been issued, and that warnings do
get issued where necessary. Do not verify (broken) code produced in the
latter case; we should probably make the warning an error, or preferably
actually start supporting GOT references with different addends as they
appear feasible with explicitly relocated GOT that we use.
bfd/
* elf32-vax.c (elf_vax_check_relocs) <R_VAX_GOT32>: Use
SYMBOL_REFERENCES_LOCAL rather than `h->forced_local' to check
whether the symbol referred is local or not.
ld/
* testsuite/ld-vax-elf/got-local-exe-off-hidden.dd: New test
dump.
* testsuite/ld-vax-elf/got-local-exe-off-visible.dd: New test
dump.
* testsuite/ld-vax-elf/got-local-lib-off-hidden.dd: New test
dump.
* testsuite/ld-vax-elf/got-local-lib-off-visible.ed: New test
dump.
* testsuite/ld-vax-elf/got-local-off-external.ed: New test dump.
* testsuite/ld-vax-elf/got-local-exe-off.xd: New test dump.
* testsuite/ld-vax-elf/got-local-lib-off.xd: New test dump.
* testsuite/ld-vax-elf/got-local.ld: New test linker script.
* testsuite/ld-vax-elf/got-local-aux-off.s: New test source.
* testsuite/ld-vax-elf/got-local-def-off.s: New test source.
* testsuite/ld-vax-elf/got-local-ref-off-external.s: New test
source.
* testsuite/ld-vax-elf/got-local-ref-off-hidden.s: New test
source.
* testsuite/ld-vax-elf/got-local-ref-off-visible.s: New test
source.
* testsuite/ld-vax-elf/vax-elf.exp: Run the new tests.
In a couple of gdb_mpz methods, we are computing the number of
bits in a gdb::array_view of gdb_byte. Since gdb_byte is defined
using a host-side type (see common-types.h), the number of bits
in a gdb_byte should be HOST_CHAR_BIT, not TARGET_CHAR_BIT.
gdb/ChangeLog:
* gmp-utils.c (gdb_mpz::read): Use HOST_CHAR_BIT instead of
TARGET_CHAR_BIT.
(gdb_mpz::write): Likewise.
Since converting load to mov needs to rewrite the REX byte and we don't
know if there is a REX byte with GOTPCREL relocation, do it only for
GOTPCRELX relocations.
bfd/
PR ld/27016
* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Convert load
to mov only for GOTPCRELX relocations.
ld/
PR ld/27016
* testsuite/ld-x86-64/x86-64.exp: Run pr27016a and pr27016b.
* testsuite/ld-x86-64/pr27016a.d: New file.
* testsuite/ld-x86-64/pr27016a.s: Likewise.
* testsuite/ld-x86-64/pr27016b.d: Likewise.
* testsuite/ld-x86-64/pr27016b.s: Likewise.
As observed on a binary compiled on AMD64 Ubuntu 20.04, against glibc
2.31 (I think it's the libc that provides this startup code, right?),
there are enough bytes at the executable's entry point to hold more than
one displaced step buffer. gdbarch_max_insn_length is 16, and the
code at _start looks like:
0000000000001040 <_start>:
1040: f3 0f 1e fa endbr64
1044: 31 ed xor %ebp,%ebp
1046: 49 89 d1 mov %rdx,%r9
1049: 5e pop %rsi
104a: 48 89 e2 mov %rsp,%rdx
104d: 48 83 e4 f0 and $0xfffffffffffffff0,%rsp
1051: 50 push %rax
1052: 54 push %rsp
1053: 4c 8d 05 56 01 00 00 lea 0x156(%rip),%r8 # 11b0 <__libc_csu_fini>
105a: 48 8d 0d df 00 00 00 lea 0xdf(%rip),%rcx # 1140 <__libc_csu_init>
1061: 48 8d 3d c1 00 00 00 lea 0xc1(%rip),%rdi # 1129 <main>
1068: ff 15 72 2f 00 00 callq *0x2f72(%rip) # 3fe0 <__libc_start_main@GLIBC_2.2.5>
106e: f4 hlt
106f: 90 nop
The two buffers would occupy [0x1040, 0x1060).
I checked on Alpine, which uses the musl C library, the startup code
looks like:
0000000000001048 <_start>:
1048: 48 31 ed xor %rbp,%rbp
104b: 48 89 e7 mov %rsp,%rdi
104e: 48 8d 35 e3 2d 00 00 lea 0x2de3(%rip),%rsi # 3e38 <_DYNAMIC>
1055: 48 83 e4 f0 and $0xfffffffffffffff0,%rsp
1059: e8 00 00 00 00 callq 105e <_start_c>
000000000000105e <_start_c>:
105e: 48 8b 37 mov (%rdi),%rsi
1061: 48 8d 57 08 lea 0x8(%rdi),%rdx
1065: 45 31 c9 xor %r9d,%r9d
1068: 4c 8d 05 47 01 00 00 lea 0x147(%rip),%r8 # 11b6 <_fini>
106f: 48 8d 0d 8a ff ff ff lea -0x76(%rip),%rcx # 1000 <_init>
1076: 48 8d 3d 0c 01 00 00 lea 0x10c(%rip),%rdi # 1189 <main>
107d: e9 9e ff ff ff jmpq 1020 <__libc_start_main@plt>
Even though there's a _start_c symbol, it all appears to be code that
runs once at the very beginning of the program, so it looks fine if the
two buffers occupy [0x1048, 0x1068).
One important thing I discovered while doing this is that when debugging
a dynamically-linked executable, breakpoints in the shared library
loader are hit before executing the _start code, and these breakpoints
may be displaced-stepped. So it's very important that the buffer bytes
are restored properly after doing the displaced steps, otherwise the
_start code will be corrupted once we try to execute it.
Another thing that made me think about is that library constructors (as
in `__attribute__((constructor))`) run before _start. And they are free
to spawn threads. What if one of these threads executes a displaced
step, therefore changing the bytes at _start, while the main thread
executes _start? That doesn't sound good and I don't know how we could
prevent it. But this is a problem that predates the current patch.
Even when stress-testing the implementation, by making many threads do
displaced steps over and over, I didn't see a significant performance (I
confirmed that the two buffers were used by checking the "set debug
displaced" logs though). However, this patch mostly helps make the
feature testable by anybody with an AMD64/Linux machine, so I think it's
useful.
gdb/ChangeLog:
* amd64-linux-tdep.c (amd64_linux_init_abi): Pass 2 as the
number of displaced step buffers.
Change-Id: Ia0c96ea0fcda893f4726df6fdac7be5214620112
