Trying to start a program with GDBserver on Windows yields
the following error:
$ gdbserver.exe --once :4444 simple_main.exe
Killing process(es): 5008
No program to debug
Exiting
The error itself comes from the following code shortly after
create_inferior gets called (in server.c::main):
/* Wait till we are at first instruction in program. */
create_inferior (program_path.get (), program_args);
[...]
if (last_status.kind == TARGET_WAITKIND_EXITED
|| last_status.kind == TARGET_WAITKIND_SIGNALLED)
was_running = 0;
else
was_running = 1;
if (!was_running && !multi_mode)
error ("No program to debug");
What happens is that the "last_status" global starts initialized
as zeroes, which means last_status.kind == TARGET_WAITKIND_EXITED,
and we expect create_inferior to be waiting for the inferior to
start until reaching the SIGTRAP, and to set the "last_status"
global to match that last event we received.
I suspect this is an unintended side-effect of the following change...
commit 2090129c36
Date: Thu Dec 22 21:11:11 2016 -0500
Subject: Share fork_inferior et al with gdbserver
... which removes some code in server.c that was responsible for
starting the inferior in a functin that was named start_inferior,
and looked like this:
signal_pid = create_inferior (new_argv[0], &new_argv[0]);
[...]
/* Wait till we are at 1st instruction in program, return new pid
(assuming success). */
last_ptid = mywait (pid_to_ptid (signal_pid), &last_status, 0, 0);
The code has been transitioned to using fork_inferior, but sadly,
only for the targets that support it. On Windows, the calls to wait
setting "last_status" simply disappeared.
This patch adds it back in the Windows-specific implementation of
create_inferior.
gdb/gdbserver/ChangeLog:
PR server/23158:
* win32-low.c (win32_create_inferior): Add call to my_wait
setting last_status global.
Trying to start GDBserver on Windows currently yields the following
error...
$ gdbserver.exe --once :4444 simple_main.exe
glob could not process pattern '(null)'.
Exiting
... after which GDB terminates with a nonzero status.
This is because create_process in win32-low.c calls gdb_tilde_expand
with the result of a call to get_inferior_cwd without verifying that
the returned directory is not NULL:
| static BOOL
| create_process (const char *program, char *args,
| DWORD flags, PROCESS_INFORMATION *pi)
| {
| const char *inferior_cwd = get_inferior_cwd ();
| std::string expanded_infcwd = gdb_tilde_expand (inferior_cwd);
This patch avoids this by only calling gdb_tilde_expand when
INFERIOR_CWD is not NULL, which is similar to what is done on
GNU/Linux for instance.
gdb/gdbserver/ChangeLog:
PR server/23158:
* win32-low.c (create_process): Only call gdb_tilde_expand if
inferior_cwd is not NULL.
This patch fixes tagged pointer support for AArch64 GDB. Linux kernel
debugging failure was reported after tagged pointer support was committed.
After a discussion around best path forward to manage tagged pointers
on GDB side we are going to disable tagged pointers support for
aarch64-none-elf-gdb because for non-linux applications we cant be
sure if tagged pointers will be used by MMU or not.
Also for aarch64-linux-gdb we are going to sign extend user-space
address after clearing tag bits. This will help debug both kernel
and user-space addresses based on information from linux kernel
documentation given below:
According to AArch64 memory map:
https://www.kernel.org/doc/Documentation/arm64/memory.txt
"User addresses have bits 63:48 set to 0 while the kernel addresses have
the same bits set to 1."
According to AArch64 tagged pointers document:
https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt
The kernel configures the translation tables so that translations made
via TTBR0 (i.e. userspace mappings) have the top byte (bits 63:56) of
the virtual address ignored by the translation hardware. This frees up
this byte for application use.
Running gdb testsuite after applying this patch introduces no regressions
and tagged pointer test cases still pass.
gdb/ChangeLog:
2018-05-10 Omair Javaid <omair.javaid@linaro.org>
PR gdb/23127
* aarch64-linux-tdep.c (aarch64_linux_init_abi): Add call to
set_gdbarch_significant_addr_bit.
* aarch64-tdep.c (aarch64_gdbarch_init): Remove call to
set_gdbarch_significant_addr_bit.
* utils.c (address_significant): Update to sign extend addr.
Gold resolves GOT-relative relocs relative to the GOT base +
0x8000 when the GOT is larger than 0x8000. However, previously
the _GLOBAL_OFFSET_TABLE_ symbol was set to GOT base + 0x8000
when the .got.plt was larger than 0x8000. This patch makes both
checks use the size of the .got section so that they agree when
to add 0x8000.
Not all literals need to be moved in the presence of
--text-section-literals or --auto-litpools, but only those created by
.literal pseudo op or generated as a result of relaxation. Attempts to
move other literals may result in abnormal termination of the assembler
due to the following assertion failure:
Internal error in xg_find_litpool at gas/config/tc-xtensa.c:11209.
The same assertion may also be triggered by attempting to assign literal
pools to literals in .init and .fini sections; don't try to do that.
gas/
2018-05-09 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (xtensa_is_init_fini): New function.
(xtensa_move_literals): Only attempt to assign literal pool to
literals with tc_frag_data.is_literal mark and not in .init or
.fini sections.
Join nested 'if' conditions to simplify function structure.
(xtensa_switch_to_non_abs_literal_fragment): Use
xtensa_is_init_fini to test for .init/.fini sections.
* testsuite/gas/xtensa/all.exp (auto-litpools-3)
(auto-litpools-4, text-section-literals-1): New tests.
* testsuite/gas/xtensa/auto-litpools-3.d: New test results.
* testsuite/gas/xtensa/auto-litpools-3.s: New test source.
* testsuite/gas/xtensa/auto-litpools-4.d: New test results.
* testsuite/gas/xtensa/auto-litpools-4.s: New test source.
* testsuite/gas/xtensa/text-section-literals-1.d: New test results.
* testsuite/gas/xtensa/text-section-literals-1.s: New test source.
xtensa GDB may be used with both bare-metal and linux-based
applications. In case of bare-metal application gdbserver is able to
provide information about all CPU registers: both unprivileged and
privileged. In case of linux-based application only a small subset of
privileged state is available. Currently xtensa GDB only expects
unprivileged registers in 'g' packets and it fails to communicate with
server that sends both privileged and unprivileged registers.
Allow bare-metal xtensa GDB to deal with both privileged and
unprivileged registers by initializing tdep->num_regs with the total
number of target CPU registers. Keep linux-based xtensa GDB
functionality as is by copying tdep->num_nopriv_regs to tdep->num_regs.
gdb/
2018-05-09 Max Filippov <jcmvbkbc@gmail.com>
* xtensa-linux-tdep.c (xtensa-tdep.h): New include.
(xtensa_linux_init_abi): Limit tdep->num_regs by
tdep->num_nopriv_regs.
* xtensa-tdep.c (xtensa_derive_tdep): Calculate
tdep->num_nopriv_regs and only copy it to tdep->num_regs if it's
not initialized.
My original implementation for LDI32 pseudo does not conform to
the TI ABI. I wrongly documented my TI PRU ELF object files inspection,
which got propagated into my binutils implementation.
Issue was exposed when running the GCC ABI testsuite against TI toolchain.
According to TI ABI, LDI32 must use first LDI instruction to load
the MSB 16bits, and second LDI instruction for the LSB 16bits.
This patch will break binary compatibility with previously released
binutils versions for PRU. Still, I think it is better to fix
binutils to conform to the chip vendor ABI.
bfd * elf32-pru.c (pru_elf32_do_ldi32_relocate): Make LDI32 relocation
conformant to TI ABI.
(pru_elf32_relax_section): Likewise.
(pru_elf_relax_delete_bytes): Fix offsets for new LDI32 code.
* elf32-pru.c (pru_elf32_do_ldi32_relocate): Ignore addend.
(pru_elf32_pmem_relocate): Trap - should not get here.
(pru_elf32_relocate_section): Add support for REL relocations.
(elf_info_to_howto_rel): Enable REL.
(elf_backend_may_use_rel_p): Likewise.
(elf_backend_may_use_rela_p): Likewise.
(elf_backend_default_use_rela_p): Likewise.
gas * config/tc-pru.c (md_apply_fix): Make LDI32 relocation conformant
to TI ABI.
(pru_assemble_arg_i): Likewise.
(output_insn_ldi32): Likewise.
* testsuite/gas/pru/ldi.d: Update test for the now fixed LDI32.
* gas/config/tc-pru.c (pru_assemble_arg_b): Check imm8 operand range.
* gas/testsuite/gas/pru/illegal2.l: New test.
* gas/testsuite/gas/pru/illegal2.s: New test.
* gas/testsuite/gas/pru/pru.exp: Register new illegal2 test.
ld * scripttempl/pru.sc: Add LD sections to allow linking TI
toolchain object files.
* scripttempl/pru.sc: Switch to init_array.
* testsuite/ld-pru/ldi32.d: Update LDI32 test to conform to TI ABI.
* testsuite/ld-pru/norelax_ldi32-data.d: Likewise.
* testsuite/ld-pru/norelax_ldi32-dis.d: Likewise.
* testsuite/ld-pru/relax_ldi32-data.d: Likewise.
* testsuite/ld-pru/relax_ldi32-dis.d: Likewise.
When building with x86_64-w64-mingw32-g++ (to test cross-compiling for
Windows), I get this error:
unittests/string_view-selftests.o: In function `selftests::string_view::inserters_2::test05(unsigned long long)':
/home/emaisin/src/binutils-gdb/gdb/unittests/basic_string_view/inserters/char/2.cc:60: undefined reference to `std::basic_ofstream<char, std::char_traits<char> >::rpl_close()'
This is caused by gnulib redefining "close" as "rpl_close", and
therefore messing up the declaration of basic_ofstream in the libstdc++
header. The solution would be to use gnulib namespaces [1]. Until we
use them across GDB, we can use them locally in files that are
problematic, like this one.
gdb/ChangeLog:
* unittests/string_view-selftests.c: Define GNULIB_NAMESPACE.
For GNU/Linux on x86-64, if the target is using the xsave format for
passing the floating-point information from the inferior then there
currently exists a bug relating to the x87 control registers, and the
mxcsr register.
The xsave format allows different floating-point features to be lazily
enabled, a bit in the xsave format tells GDB which floating-point
features have been enabled, and which have not.
Currently in GDB, when reading the floating point state, we check the
xsave bit flags, if the feature is enabled then we read the feature
from the xsave buffer, and if the feature is not enabled, then we
supply the default value from within GDB.
Within GDB, when writing the floating point state, we first fetch the
xsave state from the target and then, for any feature that is not yet
enabled, we write the default values into the xsave buffer. Next we
compare the regcache value with the value in the xsave buffer, and, if
the value has changed we update the value in the xsave buffer, and
mark the feature enabled in the xsave bit flags.
The problem then, is that the x87 control registers were not following
this pattern. We assumed that these registers were always written out
by the kernel, and we always wrote them out to the xsave buffer (but
didn't enabled the feature). The result of this is that if the kernel
had not yet enabled the x87 feature then within GDB we would see
random values for the x87 floating point control registers, and if the
user tried to modify one of these register, that modification would be
lost.
Finally, the mxcsr register was also broken in the same way as the x87
control registers. The added complexity with this case is that the
mxcsr register is part of both the avx and sse floating point feature
set. When reading or writing this register we need to check that at
least one of these features is enabled.
This bug was present in native GDB, and within gdbserver. Both are
fixed with this commit.
gdb/ChangeLog:
* common/x86-xstate.h (I387_FCTRL_INIT_VAL): New constant.
(I387_MXCSR_INIT_VAL): New constant.
* amd64-tdep.c (amd64_supply_xsave): Only read state from xsave
buffer if it was supplied by the inferior.
* i387-tdep.c (i387_supply_fsave): Use I387_MXCSR_INIT_VAL.
(i387_xsave_get_clear_bv): New function.
(i387_supply_xsave): Only read x87 control registers from the
xsave buffer if the feature is enabled, and the state will have
been written, otherwise, provide a suitable default.
(i387_collect_xsave): Pre-clear all registers in xsave buffer,
including x87 control registers. Update control registers if they
have changed from the default value, and mark features as enabled
as required.
* i387-tdep.h (i387_xsave_get_clear_bv): Declare.
gdb/gdbserver/ChangeLog:
* i387-fp.c (i387_cache_to_xsave): Only write x87 control
registers to the cache if their values have changed.
(i387_xsave_to_cache): Provide default values for x87 control
registers when these features are available, but disabled.
* regcache.c (supply_register_by_name_zeroed): New function.
* regcache.h (supply_register_by_name_zeroed): Declare new
function.
gdb/testsuite/ChangeLog:
* gdb.arch/amd64-init-x87-values.S: New file.
* gdb.arch/amd64-init-x87-values.exp: New file.
Another fuzzing fix. I think it's reasonable to simply strip out any
group section that is too weird for objcopy to handle.
PR 23141
* objcopy.c (is_strip_section): Strip groups without a valid
signature symbol.
Defining SPE2_OPCD_SEGS as 13 discounts the possibility that we'd
ever look up spe2_opcd_indices[14..16], which I think is possible.
Extend that array to size 16+1, using the macros we use to index the
array. Similarly use the index macros for PPC_OPCD_SEGS and
VLE_OPCD_SEGS.
* ppc-dis.c (PPC_OPCD_SEGS): Define using PPC_OP.
(VLE_OPCD_SEGS, SPE2_OPCD_SEGS): Similarly, using macros used to
partition opcode space for index lookup.
The formatting of the output of the "info spu event" command changed, causing
spurious test suite failures. Use phex instead of phex_nz to get back the
expected format, and fix emission of new line characters.
gdb/ChangeLog:
2018-05-08 Ulrich Weigand <uweigand@de.ibm.com>
* spu-tdep.c (info_spu_event_command): Fix output formatting.
PR 22809
* elf.c (bfd_elf_get_str_section): Check for an excessively large
string section.
* elf-attrs.c (_bfd_elf_parse_attributes): Issue an error if the
attribute section is larger than the size of the file.
This patch replaces AddrPrefixOp0 with AddrPrefixOpReg to indicate that
the size of register operand is controlled by the address size prefix.
This will be used by Intel MOVDIRI and MOVDIR64B instructions later.
gas/
* config/tc-i386.c (process_suffix): Check addrprefixopreg
instead of addrprefixop0.
opcodes/
* i386-gen.c (opcode_modifiers): Replace AddrPrefixOp0 with
AddrPrefixOpReg.
* i386-opc.h (AddrPrefixOp0): Renamed to ...
(AddrPrefixOpReg): This.
(i386_opcode_modifier): Rename addrprefixop0 to addrprefixopreg.
* i386-opc.tbl: Replace AddrPrefixOp0 with AddrPrefixOpReg.
This adds -Wduplicated-cond to warnings.m4. This caught one bug.
I tried adding -Wduplicated-branches as well, but it results in some
spurious failures from code like this in cgen.h:
#define CGEN_ATTR_TYPE(n) \
struct { unsigned int bool_; \
CGEN_ATTR_VALUE_TYPE nonbool[(n) ? (n) : 1]; }
This will trigger a warning if passed n==1, which seems like a
perfectly valid thing to do; and there were other issues like this as
well.
ChangeLog
2018-05-07 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* warning.m4 (AM_GDB_WARNINGS): Add -Wduplicated-cond.
gdbserver/ChangeLog
2018-05-07 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
-Wduplicated-cond pointed out that arm_record_vfp_data_proc_insn
checks "opc1 == 0x0b" twice. I filed this a while ago as
PR tdep/20362.
Based on the ARM instruction manual at
https://www.scss.tcd.ie/~waldroj/3d1/arm_arm.pdf, I think the
instruction decoding in this function has two bugs.
First, opc1 is computed as:
opc1 = bits (arm_insn_r->arm_insn, 20, 23);
[...]
opc1 = opc1 & 0x04;
This means that tests like:
else if (opc1 == 0x01)
can never be true.
In the ARM manual, "opc1" corresponds to these bits:
name bit
r 20
q 21
D 22
p 23
... where the D bit is not used for VFP instruction decoding.
So, I believe this code should use ~0x04 instead.
Second, VDIV is recognized by the bits "pqrs" being equal to "1000".
This tranlates to opc1 == 0x08 -- not 0x0b. Note that pqrs==1001 is
an undefined encoding, which is probably why opc2 is not checked here;
this code doesn't seem to really deal with undefined encodings in
general, so I've left that as is.
I don't have an ARM machine or any reasonable way to test this.
ChangeLog
2018-05-07 Tom Tromey <tom@tromey.com>
PR tdep/20362:
* arm-tdep.c (arm_record_vfp_data_proc_insn): Properly mask off D
bit. Use correct value for VDIV.
Avoids gcc pr85623 for these calls.
* cofflink.c (_bfd_coff_link_input_bfd): Use memcmp rather than
strncmp when checking for ".bf" special symbol.
* prXXigen.c (_bfd_XXi_swap_scnhdr_out): Make pe_required_section_flags
section name a char array, remove sentinal known_sections entry,
and adjust loop over known_sections to suit. Use memcmp rather
than strncmp.
This adds -Wimplicit-fallthrough to the set of default warnings.
2018-05-04 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* warning.m4 (AM_GDB_WARNINGS): Add -Wimplicit-fallthrough.
gdbserver/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
This adds a "break" at the end of the RECORD_SYS_RECVFROM case in
record_linux_system_call. This seemed correct to me.
2018-05-04 Tom Tromey <tom@tromey.com>
* linux-record.c (record_linux_system_call) <case
RECORD_SYS_RECVFROM>: Add "break".
This adds a "break" to a couple of spots where it was erroneously
omitted. I think these are the two (potential) real bugs caught by
this series.
2018-05-04 Tom Tromey <tom@tromey.com>
* mi/mi-main.c (mi_cmd_trace_frame_collected) <REGISTERS_FORMAT>:
Add missing "break".
* mi/mi-cmd-stack.c (mi_cmd_stack_list_locals) <NO_FRAME_FILTERS>:
Add missing "break".
This adds two fall-through comments in rs6000-tdep.c. I looked at the
PPC instruction manual and convinced myself that this was correct.
And, this isn't a semantic change. However, close review would still
be good.
2018-05-04 Tom Tromey <tom@tromey.com>
* rs6000-tdep.c (ppc_process_record_op4)
(ppc_process_record_op63): Add fall-through comment.
This adds a fall-through comment in i386-tdep.c. I was not sure what
to do here, so I elected to preserve the status quo. In review, John
Baldwin pointed out that: "I believe this is correct based on the diff
that added the special cases for xgetbv and xsetbv as previously ldgt
and lidt were treated the same".
gdb/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* i386-tdep.c (i386_process_record): Add fall-through comment.
This adds a fall-through comment to stabsread.c. I skimmed the stabs
manual a bit and it seems that 'p' and 'P' are similar enough that
this makes sense. Also, stabs is mostly deprecated, and the code has
been this way for a long time, so it seemed safest to keep the status
quo.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* stabsread.c (define_symbol) <case 'p'>: Add fall-through
comment.
This patch fixes the subset of -Wimplicit-fallthrough warnings that I
considered obvious. In most cases it was obvious from context that
falling through was desired; here I added the appropriate comment. In
a couple of cases it seemed clear that a "break" was missing.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* riscv-tdep.c (riscv_isa_xlen): Add fall-through comment.
* utils.c (can_dump_core) <LIMIT_CUR>: Add fall-through comment.
* eval.c (fetch_subexp_value) <MEMORY_ERROR>: Add fall-through
comment.
* d-valprint.c (d_val_print) <TYPE_CODE_STRUCT>: Add fall-through
comment.
* coffread.c (coff_symtab_read) <C_LABEL>: Add fall-through
comment.
This patch adds a missing ATTRIBUTE_NORETURN. This lets
-Wimplicit-fallthrough recognize that a given case does not fall
through.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* dwarf2loc.c (unimplemented): Add ATTRIBUTE_NORETURN.
This changes the Python API so that breakpoint commands can be set by
writing to the "commands" attribute.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR python/22731:
* NEWS: Mention that breakpoint commands are writable.
* python/py-breakpoint.c (bppy_set_commands): New function.
(breakpoint_object_getset) <"commands">: Use it.
doc/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR python/22731:
* python.texi (Breakpoints In Python): Mention that "commands" is
writable.
testsuite/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR python/22731:
* gdb.python/py-breakpoint.exp: Test setting breakpoint commands.
This changes some functions in cli-script.c to use function_view
rather than a function pointer and closure argument. This simplifies
the code a bit and is useful in a subsequent patch.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* tracepoint.c (actions_command): Update.
* mi/mi-cmd-break.c (mi_command_line_array)
(mi_command_line_array_cnt, mi_command_line_array_ptr)
(mi_read_next_line): Remove.
(mi_cmd_break_commands): Update.
* cli/cli-script.h (read_command_lines, read_command_lines_1): Use
function_view.
* cli/cli-script.c (get_command_line): Update.
(process_next_line): Use function_view. Constify.
(recurse_read_control_structure, read_command_lines)
(read_command_lines_1): Change argument types to function_view.
(do_define_command, document_command): Update.
* breakpoint.h (check_tracepoint_command): Don't declare.
* breakpoint.c (check_tracepoint_command): Remove.
(commands_command_1, create_tracepoint_from_upload): Update.
