My email address at IBM has changed from arnez@linux.vnet.ibm.com to
arnez@linux.ibm.com. Reflect that in the MAINTAINERS file.
gdb/ChangeLog:
* MAINTAINERS: Update my email address.
Despite PR19615, it doesn't make sense to use -Bsymbolic with PIEs.
Dynamic symbols in an executable won't be overridden anyway.
* ld.texi (-Bsymbolic, -Bsymbolic-functions): Don't mention PIEs.
* ld.h (symbolic_enum, dynamic_list_enum),
(args_type <symbolic, dynamic_list>): Move to..
* lexsup.c (parse_args): ..here, using auto vars opt_symbolic
and opt_dynamic_list rather than command_line fields. Only
act on -Bsymbolic and -Bsymbolic-functions for shared library
output. Free dynamic_list.
Removes a use of VEC from dwarf2read.{c,h} and replaces it with
std::vector. As far as possible this is a like for like replacement
with minimal refactoring.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* dwarf2read.c (struct type_unit_group) <tus>: Convert to
std::vector.
(build_type_psymtabs_reader): Update for std::vector.
(build_type_psymtab_dependencies): Likewise.
* dwarf2read.h: Remove use of DEF_VEC_P.
(typedef sig_type_ptr): Delete.
Replace a VEC with a std::vector in btrace.h, and update btrace.c to
match. It is worth noting that this code appears to be currently
untested by the GDB testsuite. I've tried to do a like for like
replacement when moving to std::vector, with minimal refactoring to
try and avoid introducing any bugs.
As the new vector is inside a union I've currently used a pointer to
vector, which makes the code slightly uglier than it might otherwise
be, but again, due to lack of testing I'm reluctant to start
refactoring the code in a big way.
gdb/ChangeLog:
* btrace.c (btrace_maint_clear): Update to handle change from VEC
to std::vector.
(btrace_maint_decode_pt): Likewise, and move allocation of the
vector outside of the loop.
(btrace_maint_update_packets): Update to handle change from VEC to
std::vector.
(btrace_maint_print_packets): Likewise.
(maint_info_btrace_cmd): Likewise.
* btrace.h: Remove use of DEF_VEC_O.
(typedef btrace_pt_packet_s): Delete.
(struct btrace_maint_info) <packets>: Change fromm VEC to
std::vector.
* gdbsupport/btrace-common.h: Remove 'vec.h' include.
Converts a VEC into a std::vector in gdbsupport/btrace-common.h. This
commit just performs a mechanical conversion and doesn't do any
refactoring. One consequence of this is that the std::vector must
actually be a pointer to std::vector as it is placed within a union.
It might be possible in future to refactor to a class hierarchy and
remove the need for a union, but I'd rather have that be a separate
change to make it easier to see the evolution of the code.
gdb/ChangeLog:
* btrace.c (btrace_compute_ftrace_bts): Update for std::vector,
make accesses into the vector constant references.
(btrace_add_pc): Update for std::vector.
(btrace_stitch_bts): Likewise.
(parse_xml_btrace_block): Likewise.
(btrace_maint_update_packets): Likewise.
(btrace_maint_print_packets): Likewise.
(maint_info_btrace_cmd): Likewise.
* gdbsupport/btrace-common.c (btrace_data::fini): Update for
std::vector.
(btrace_data::empty): Likewise.
(btrace_data_append): Likewise.
* gdbsupport/btrace-common.h: Remove use of DEF_VEC_O.
(typedef btrace_block_s): Delete.
(struct btrace_block): Add constructor.
(struct btrace_data_bts) <blocks>: Change to std::vector.
* nat/linux-btrace.c (perf_event_read_bts): Update for
std::vector.
(linux_read_bts): Likewise.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_low_read_btrace): Update for change to
std::vector.
PR 24942
* objcopy.c (copy_usage): Update description of
--set-section-alignment.
(copy_main): Interpret numeric argument of --set-section-alignment
as a byte alignment, not a power of two alignment.
* doc/binutils.texi: Update description of
--set-section-alignment.
* testsuite/binutils-all/set-section-alignment.d: New test.
* testsuite/binutils-all/objcopy.exp: Run the new test.
This changes "show logging filename" to style its output.
gdb/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* cli/cli-logging.c (show_logging_filename): Use styled_string.
gdb/testsuite/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* gdb.base/style.exp: Test "show logging filename".
This adds more uses of styled_string, changing gdb to style some
output that was previously left unstyled.
gdb/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* stack.c (print_frame, info_frame_command_core): Use
styled_string.
* linux-thread-db.c (try_thread_db_load_1)
(try_thread_db_load_from_pdir_1): Use styled_string.
* auto-load.c (file_is_auto_load_safe, execute_script_contents)
(auto_load_section_scripts, info_auto_load_local_gdbinit)
(maybe_print_unsupported_script_warning)
(maybe_print_script_not_found_warning): Use styled_string.
* ada-lang.c (user_select_syms): Use styled_string.
This introduces a new "metadata" style and changes many places in gdb
to use it. The idea here is to let the user distinguish gdb output
from output that (conceptually at least) comes directly from the
inferior. The newly-styled category includes text that gdb
traditionally surrounds in "<...>", like "<unavailable>".
I only added a single test for this. In many cases this output is
difficult to test. Also, while developing this errors in the
implementation of the new printf formats showed up as regressions.
gdb/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* p-lang.c (pascal_printstr): Use metadata style.
* value.c (show_convenience): Use metadata style.
* valprint.c (valprint_check_validity, val_print_optimized_out)
(val_print_not_saved, val_print_unavailable)
(val_print_invalid_address, generic_val_print, val_print)
(value_check_printable, val_print_array_elements): Use metadata
style.
* ui-out.h (class ui_out) <field_fmt>: New overload.
<do_field_fmt>: Add style parameter.
* ui-out.c (ui_out::field_fmt): New overload.
* typeprint.c (type_print_unknown_return_type)
(val_print_not_allocated, val_print_not_associated): Use metadata
style.
* tui/tui-out.h (class tui_ui_out) <do_field_fmt>: Add style
parameter.
* tui/tui-out.c (tui_ui_out::do_field_fmt): Update.
* tracepoint.c (tvariables_info_1): Use metadata style.
* stack.c (print_frame_arg, print_frame_info, print_frame)
(info_frame_command_core): Use metadata style.
* skip.c (info_skip_command): Use metadata style.
* rust-lang.c (rust_print_enum): Use metadata style.
* python/py-prettyprint.c (print_stack_unless_memory_error): Use
metadata style.
* python/py-framefilter.c (py_print_single_arg): Use metadata
style.
* printcmd.c (do_one_display, print_variable_and_value): Use
metadata style.
* p-valprint.c (pascal_val_print)
(pascal_object_print_value_fields): Use metadata style.
* p-typeprint.c (pascal_type_print_base): Use metadata style.
* mi/mi-out.h (class mi_ui_out) <do_field_fmt>: Add style
parameter.
* mi/mi-out.c (mi_ui_out::do_field_fmt): Update.
* m2-valprint.c (m2_print_long_set): Use metadata style.
* m2-typeprint.c (m2_print_type): Use metadata style.
* infcmd.c (print_return_value_1): Use metadata style.
* gnu-v3-abi.c (print_one_vtable): Use metadata style.
* f-valprint.c (info_common_command_for_block): Use metadata
style.
* f-typeprint.c (f_type_print_base): Use metadata style.
* expprint.c (print_subexp_standard): Use metadata style.
* cp-valprint.c (cp_print_value_fields): Use metadata style.
* cli/cli-style.h (class cli_style_option): Add constructor.
(metadata_style): Declare.
* cli/cli-style.c (metadata_style): New global.
(_initialize_cli_style): Register metadata style.
* cli-out.h (class cli_ui_out) <do_field_fmt>: Add style
parameter.
* cli-out.c (cli_ui_out::do_field_fmt): Update.
* c-typeprint.c (c_type_print_base_struct_union)
(c_type_print_base_1): Use metadata style.
* breakpoint.c (watchpoint_value_print)
(print_one_breakpoint_location): Use metadata style.
* break-catch-syscall.c (print_one_catch_syscall): Use metadata
style.
* break-catch-sig.c (signal_catchpoint_print_one): Use metadata
style.
* ada-valprint.c (val_print_packed_array_elements, printstr)
(print_field_values, ada_val_print_ref, ada_val_print): Use
metadata style.
* ada-typeprint.c (print_array_type, ada_print_type): Use metadata
style.
* ada-tasks.c (print_ada_task_info, info_task): Use metadata
style.
* ada-lang.c (user_select_syms): Use metadata style.
gdb/testsuite/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* lib/gdb-utils.exp (style): Handle "metadata" argument.
* gdb.base/style.exp: Add metadata style test.
This changes the "pwd" command to style its output.
gdb/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* cli/cli-cmds.c (pwd_command): Style output.
gdb/testsuite/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* gdb.base/style.exp: Test "pwd".
This changes various spots in gdb to use the new %p format suffixes.
gdb/ChangeLog
2019-10-01 Pedro Alves <palves@redhat.com>
Tom Tromey <tom@tromey.com>
* symtab.c (print_symbol_info): Use %ps.
(print_msymbol_info): Use %ps.
* symfile.c (symbol_file_add_with_addrs): Use %ps.
* printcmd.c (print_variable_and_value): Use %ps.
* macrocmd.c (show_pp_source_pos): Use %ps.
* infrun.c (print_exited_reason): Use ui_out::message.
* breakpoint.c (watchpoint_check, print_one_breakpoint_location)
(describe_other_breakpoints): Use ui_out::message and new
formats.
(say_where): Use new formats.
(bkpt_print_it, tracepoint_print_one_detail): Use ui_out::message
and new formats.
This introduces a few gdb-specific %p format suffixes. This is useful
for emitting gdb-specific output in an ergonomic way. It also yields
code that is more i18n-friendly.
The comment before ui_out::message explains the details.
Note that the tests had to change a little. When using one of the gdb
printf functions with styling, there can be spurious style changes
emitted to the output. This did not seem worthwhile to fix, as the
low-level output functions are rather spaghetti-ish already, and I
didn't want to make them even worse.
This change also necessitated adding support for "*" as precision and
width in format_pieces. These are used in various spots in gdb, and
it seemed better to me to implement them than to remove the uses.
gdb/ChangeLog
2019-10-01 Pedro Alves <palves@redhat.com>
Tom Tromey <tom@tromey.com>
* unittests/format_pieces-selftests.c: Add gdb_format parameter.
(test_gdb_formats): New function.
(run_tests): Call it.
(test_format_specifier): Update.
* utils.h (fputs_filtered): Update comment.
(vfprintf_styled, vfprintf_styled_no_gdbfmt)
(fputs_styled_unfiltered): Declare.
* utils.c (fputs_styled_unfiltered): New function.
(vfprintf_maybe_filtered): Add gdbfmt parameter.
(vfprintf_filtered): Update.
(vfprintf_unfiltered, vprintf_filtered): Update.
(vfprintf_styled, vfprintf_styled_no_gdbfmt): New functions.
* ui-out.h (enum ui_out_flag) <unfiltered_output,
disallow_ui_out_field>: New constants.
(enum class field_kind): New.
(struct base_field_s, struct signed_field_s): New.
(signed_field): New function.
(struct string_field_s): New.
(string_field): New function.
(struct styled_string_s): New.
(styled_string): New function.
(class ui_out) <message>: Add comment.
<vmessage, call_do_message>: New methods.
<do_message>: Add style parameter.
* ui-out.c (ui_out::call_do_message, ui_out::vmessage): New
methods.
(ui_out::message): Rewrite.
* mi/mi-out.h (class mi_ui_out) <do_message>: Add style
parameter.
* mi/mi-out.c (mi_ui_out::do_message): Add style parameter.
* gdbsupport/format.h (class format_pieces) <format_pieces>: Add
gdb_extensions parameter.
(class format_piece): Add parameter to constructor.
(n_int_args): New field.
* gdbsupport/format.c (format_pieces::format_pieces): Add
gdb_extensions parameter. Handle '*'.
* cli-out.h (class cli_ui_out) <do_message>: Add style parameter.
* cli-out.c (cli_ui_out::do_message): Add style parameter. Call
vfprintf_styled_no_gdbfmt.
(cli_ui_out::do_field_string, cli_ui_out::do_spaces)
(cli_ui_out::do_text, cli_ui_out::field_separator): Allow
unfiltered output.
* ui-style.h (struct ui_file_style) <ptr>: New method.
gdb/testsuite/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* gdb.base/style.exp: Update tests.
I noticed that format_pieces can create an empty literal piece.
However, there's never a need for one, so this patch removes the
possibility.
gdb/ChangeLog
2019-10-01 Tom Tromey <tom@tromey.com>
* unittests/format_pieces-selftests.c: Update. Add final format.
* gdbsupport/format.c (format_pieces::format_pieces): Don't add
empty literal pieces.
The pretty-print test case fails on s390/s390x because it relies on a
little-endian representation of bit fields. Little-endian architectures
typically allocate bit fields from least to most significant bit, but
big-endian architectures typically use the reverse order, allocating the
most significant bit first. Thus the two bit fields in each of the test
case's unions overlap either in their lower or in their higher bits,
depending on the target's endianness:
union {
int three : 3;
int four : 4;
};
Now, when initializing 'three' with 3, 'four' will become 3 on little
endian targets, but 6 on big-endian targets, making it FAIL there.
Fix this by initializing the longer bit field instead and using an
all-ones bit pattern. In this way the result does not depend on
endianness. Use 'unsigned' instead of int for one of the bit fields in
each of the unions, to increase the variety of resulting values.
gdb/testsuite/ChangeLog:
* gdb.base/pretty-print.c (struct s1_t): Change fields 'three' and
'six' to unsigned.
(s1): Initialize fields 'four' and 'six' instead of 'three' and
'five'. Use an all-ones bit pattern for each.
* gdb.base/pretty-print.exp: Adjust expected output of "print s1"
to its changed values.
Valgrind reports the following leak:
==32623== 56 bytes in 1 blocks are definitely lost in loss record 1,099 of 6,654
==32623== at 0x4835753: malloc (vg_replace_malloc.c:307)
==32623== by 0x25CF67: xmalloc (alloc.c:60)
==32623== by 0x65FBD9: xstrdup (xstrdup.c:34)
==32623== by 0x413D9E: captured_main_1(captured_main_args*) (main.c:553)
==32623== by 0x414FFA: captured_main (main.c:1172)
==32623== by 0x414FFA: gdb_main(captured_main_args*) (main.c:1197)
==32623== by 0x22531A: main (gdb.c:32)
Commit f2aec7f6d1 changed gdb_datadir to std::string.
So, xstrdup-ing the result of relocate_gdb_directory (returning a std::string)
is not needed and creates a leak.
Fix the leak by removing the xstrdup and the not needed c_str ().
Also removes a useless conversion of gdb_datadir to std::string.
gdb/ChangeLog
2019-10-01 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* main.c (relocate_gdbinit_path_maybe_in_datadir): Remove std::string
conversion of gdb_datadir.
(captured_main_1): Remove xstrdup when assigning to gdb_datadir,
remove not needed c_str ().
* Handle DW_FORM_strx forms everywhere.
Tested with CC=/usr/bin/gcc (version 8.3.0) against master branch (also with
-gsplit-dwarf and -gdwarf-4 flags) and there was no increase in the set of
tests that fails.
This is part of an effort to support DWARF 5 in gdb.
gdb/ChangeLog:
* dwarf2read.c (skip_one_die): Handle DW_FORM_strx forms.
(dwarf2_string_attr): Likewise.
This has better typesafety and is also marginally faster (either
due to inlining or because it avoids indirection through a
function pointer).
Note that in this change:
- return 1; /* fn1 has no name, so it is "less". */
+ return true; /* fn1 has no name, so it is "less". */
else if (name1) /* fn2 has no name, so it is "less". */
- return -1;
+ return false;
I am fairly sure the old code was wrong (ie. code didn't match the
comment and the comment seemed correct), so I fixed it.
gdb/ChangeLog:
2019-09-28 Christian Biesinger <cbiesinger@google.com>
* minsyms.c (compare_minimal_symbols): Rename to...
(minimal_symbol_is_less_than): ...this, and adjust to STL
conventions (return bool, take arguments as references)
(minimal_symbol_reader::install): Call std::sort instead
of qsort.
With rustc 1.37, I started seeing compiler warnings from the traits.rs
test case:
warning: trait objects without an explicit `dyn` are deprecated
It seems to me that we generally do not want warnings in these test
cases. At some point, we'll probably have to patch traits.rs to use
the "dyn" keyword; by that time I expect that all the Rust compilers
in common use will support it. In the meantime it seemed simplest to
simply disable all warnings in this file.
gdb/testsuite/ChangeLog
2019-09-30 Tom Tromey <tromey@adacore.com>
* gdb.rust/traits.rs: Disable all warnings.
This just clarifies some comments about the hashtables involved
in msymbols.
gdb/ChangeLog:
2019-09-29 Christian Biesinger <cbiesinger@google.com>
* minsyms.h (msymbol_hash): Document that this is a case-insensitive
hash and why.
* objfiles.h (struct objfile_per_bfd_storage) <demangled_names_hash,
msymbol_hash, msymbol_demangled_hash>: Improve comments.
The comment above the add_psymbol_to_list function seems outdated and
misleading, here's an attempt at improving it.
gdb/ChangeLog:
* psymtab.c (add_psymbol_to_list): Move comment to psympriv.h.
* psympriv.h (add_psymbol_to_list): Move comment here and update
it.
When running a test-case gdb.base/foo.exp with cc-with-dwz-m, a file
build/gdb/testsuite/outputs/gdb.base/foo/foo.dwz will be created, alongside
executable build/gdb/testsuite/outputs/gdb.base/foo/foo.
This can cause problems in f.i. test-cases that test file name completion.
Make these problems less likely by moving foo.dwz to a .tmp subdir:
build/gdb/testsuite/outputs/gdb.base/foo/.tmp/foo.dwz.
Tested on x86_64-linux.
gdb/ChangeLog:
2019-09-29 Tom de Vries <tdevries@suse.de>
* contrib/cc-with-tweaks.sh (get_tmpdir): New function.
Use $tmpdir/$(basename "$output_file").dwz instead of
"${output_file}.dwz".
gdb/testsuite/ChangeLog:
2019-09-29 Tom de Vries <tdevries@suse.de>
* gdb.dwarf2/gdb-index.exp: Handle new location of .dwz file.
With cc-with-dwz-m, we get:
...
PASS: gdb.dwarf2/gdb-index.exp: objcopy
PASS: gdb.dwarf2/gdb-index.exp: objcopy
...
Make the pass message unique by using with_test_prefix:
...
PASS: gdb.dwarf2/gdb-index.exp: objcopy
PASS: gdb.dwarf2/gdb-index.exp: modify dwz file: objcopy
...
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2019-09-29 Tom de Vries <tdevries@suse.de>
* gdb.dwarf2/gdb-index.exp: Use with_test_prefix for second objcopy.
hppa-linux-nat.c fails to build due to the gdbarch stuff not being
declared, for example:
hppa-linux-nat.c: In function ‘void fetch_register(regcache*, int)’:
hppa-linux-nat.c:230:7: error: ‘gdbarch_cannot_fetch_register’ was not declared in this scope
if (gdbarch_cannot_fetch_register (gdbarch, regno))
Include gdbarch.h to fix it.
gdb/ChangeLog:
PR gdb/25045
* hppa-linux-nat.c: Include gdbarch.h.
An R_386_GOTOFF relocation has an addend, typically used when a
symbol can be replaced by its section symbol plus an offset.
psymval->value(object,0) is quite wrong then, fix it.
PR 16794
* i386.cc (Target_i386::Relocate::relocate <R_386_GOTOFF>): Don't
ignore addend, apply using pcrel32.
* x86_64.cc (Target_x86_64::Relocate::relocate <R_X86_64_GOTOFF64>):
Similarly use pcrel64.
The commit 68f7d34dd5 "[gdb/testsuite] Add KFAIL for missing support of
reverse-debugging of vmovd" rewrites a gdb_test into a gdb_test_multiple but
forgets to add the $gdb_prompt part in the regexp.
Add the missing parts of the regexps.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2019-09-27 Tom de Vries <tdevries@suse.de>
* gdb.reverse/step-precsave.exp: Add missing $gdb_prompt in regexps.
On my openSUSE Leap 15.1 system I run into:
...
(gdb) PASS: gdb.reverse/step-precsave.exp: turn on process record
break 76^M
Breakpoint 2 at 0x400654: file step-reverse.c, line 76.^M
(gdb) PASS: gdb.reverse/step-precsave.exp: breakpoint at end of main
continue^M
Continuing.^M
Process record does not support instruction 0xc5 at address 0x7ffff783fc70.^M
Process record: failed to record execution log.^M
^M
Program stopped.^M
0x00007ffff783fc70 in __memset_avx2_unaligned_erms () from /lib64/libc.so.6^M
(gdb) FAIL: gdb.reverse/step-precsave.exp: run to end of main
...
The problem is that the vmovd instruction is not supported in
reverse-debugging (PR record/23188).
Add a KFAIL for this PR.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2019-09-27 Tom de Vries <tdevries@suse.de>
PR record/23188
* gdb.reverse/step-precsave.exp: Add kfail for PR record/23188.
In Fedora GDB, we carry the following patch:
8ac06474ff/f/gdb-attach-fail-reasons-5of5.patch
Its purpose is to try to detect a specific scenario where SELinux's
'deny_ptrace' option is enabled, which prevents GDB from ptrace'ing in
order to debug the inferior (PTRACE_ATTACH and PTRACE_TRACEME will
fail with EACCES in this case).
I like the idea of improving error detection and providing more
information to the user (a simple "Permission denied" can be really
frustrating), but I don't fully agree with the way the patch was
implemented: it makes GDB link against libselinux only for the sake of
consulting the 'deny_ptrace' setting, and then prints a warning if
ptrace failed and this setting is on.
My first thought (and attempt) was to make GDB print a generic warning
when a ptrace error happened; this message would just point the user
to our documentation, where she could find more information about
possible causes for the error (and try to diagnose/fix the problem).
This proved to be too simple, and I was convinced that it is actually
a good idea to go the extra kilometre and try to pinpoint the specific
problem (or problems) preventing ptrace from working, as well as
provide useful suggestions on how the user can fix things.
Here is the patch I came up with. It implements a new function,
'linux_ptrace_restricted_fail_reason', which does a few things to
check what's wrong with ptrace:
- It dlopen's "libselinux.so.1" and checks if the "deny_ptrace"
option is enabled.
- It reads the contents of "/proc/sys/kernel/yama/ptrace_scope" and
checks if it's different than 0.
For each of these checks, if it succeeds, the user will see a message
informing about the restriction in place, and how it can be disabled.
For example, if "deny_ptrace" is enabled, the user will see:
# gdb /usr/bin/true
...
Starting program: /usr/bin/true
warning: Could not trace the inferior process.
warning: ptrace: Permission denied
The SELinux 'deny_ptrace' option is enabled and preventing GDB
from using 'ptrace'. You can disable it by executing (as root):
setsebool deny_ptrace off
If you are debugging the inferior remotely, the ptrace restriction(s) need
to be disabled in the target system (e.g., where GDBserver is running).
During startup program exited with code 127.
(gdb)
In case "/proc/sys/kernel/yama/ptrace_scope" is > 0:
# gdb /usr/bin/true
...
Starting program: /usr/bin/true
warning: Could not trace the inferior process.
warning: ptrace: Operation not permitted
The Linux kernel's Yama ptrace scope is in effect, which can prevent
GDB from using 'ptrace'. You can disable it by executing (as root):
echo 0 > /proc/sys/kernel/yama/ptrace_scope
If you are debugging the inferior remotely, the ptrace restriction(s) need
to be disabled in the target system (e.g., where GDBserver is running).
During startup program exited with code 127.
(gdb)
If both restrictions are enabled, both messages will show up.
This works for gdbserver as well, and actually fixes a latent bug I
found: when ptrace is restricted, gdbserver would hang due to an
unchecked ptrace call:
# gdbserver :9988 /usr/bin/true
gdbserver: linux_ptrace_test_ret_to_nx: Cannot PTRACE_TRACEME: Operation not permitted
gdbserver: linux_ptrace_test_ret_to_nx: status 256 is not WIFSTOPPED!
gdbserver: linux_ptrace_test_ret_to_nx: failed to kill child pid 2668100 No such process
[ Here you would have to issue a C-c ]
Now, you will see:
# gdbserver :9988 /usr/bin/true
gdbserver: linux_ptrace_test_ret_to_nx: Cannot PTRACE_TRACEME: Permission denied
gdbserver: linux_ptrace_test_ret_to_nx: status 256 is not WIFSTOPPED!
gdbserver: linux_ptrace_test_ret_to_nx: failed to kill child pid 2766868 No such process
gdbserver: Could not trace the inferior process.
gdbserver: ptrace: Permission denied
The SELinux 'deny_ptrace' option is enabled and preventing GDB
from using 'ptrace'. You can disable it by executing (as root):
setsebool deny_ptrace off
If you are debugging the inferior remotely, the ptrace restriction(s) need
to be disabled in the target system (e.g., where GDBserver is running).
#
(I decided to keep all the other messages, even though I find them a
bit distracting).
If GDB can't determine the cause for the failure, it will still print
the generic error message which tells the user to check our
documentation:
There might be restrictions preventing ptrace from working. Please see
the appendix "Linux kernel ptrace restrictions" in the GDB documentation
for more details.
If you are debugging the inferior remotely, the ptrace restriction(s) need
to be disabled in the target system (e.g., where GDBserver is running).
This means that the patch expands our documentation and creates a new
appendix section named "Linux kernel ptrace restrictions", with
sub-sections for each possible restriction that might be in place.
Notice how, on every message, we instruct the user to "do the right
thing" if gdbserver is being used. This is because if the user
started gdbserver *before* any ptrace restriction was in place, and
then, for some reason, one or more restrictions get enabled, then the
error message will be displayed both on gdbserver *and* on the
connected GDB. Since the user will be piloting GDB, it's important to
explicitly say that the ptrace restrictions are enabled in the target,
where gdbserver is running.
The current list of possible restrictions is:
- SELinux's 'deny_ptrace' option (detected).
- YAMA's /proc/sys/kernel/yama/ptrace_scope setting (detected).
- seccomp on Docker containers (I couldn't find how to detect).
It's important to mention that all of this is Linux-specific; as far
as I know, SELinux, YAMA and seccomp are Linux-only features.
I tested this patch locally, on my Fedora 30 machine (actually, a
Fedora Rawhide VM), but I'm not proposing a testcase for it because of
the difficulty of writing one.
WDYT?
gdb/doc/ChangeLog:
2019-09-26 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.texinfo (Linux kernel ptrace restrictions): New appendix
section.
gdb/ChangeLog:
2019-09-26 Sergio Durigan Junior <sergiodj@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Pedro Alves <palves@redhat.com>
* gdbsupport/gdb-dlfcn.h (gdb_dlopen): Update comment and
mention that the function throws an error.
* inf-ptrace.c (default_inf_ptrace_me_fail_reason): New
function.
(inf_ptrace_me_fail_reason): New variable.
(inf_ptrace_me): Update call to 'trace_start_error_with_name'.
* inf-ptrace.h (inf_ptrace_me_fail_reason): New variable.
* linux-nat.c (attach_proc_task_lwp_callback): Call
'linux_ptrace_attach_fail_reason_lwp'.
(linux_nat_target::attach): Update call to
'linux_ptrace_attach_fail_reason'.
(_initialize_linux_nat): Set 'inf_ptrace_me_fail_reason'.
* nat/fork-inferior.c (trace_start_error_with_name): Add
optional 'append' argument.
* nat/fork-inferior.h (trace_start_error_with_name): Update
prototype.
* nat/linux-ptrace.c: Include "gdbsupport/gdb-dlfcn.h",
"gdbsupport/filestuff.h" and "nat/fork-inferior.h".
(selinux_ftype): New typedef.
(linux_ptrace_restricted_fail_reason): New function.
(linux_ptrace_attach_fail_reason_1): New function.
(linux_ptrace_attach_fail_reason): Change first argument type
from 'ptid_t' to 'pid_t'. Call
'linux_ptrace_attach_fail_reason_1' and
'linux_ptrace_restricted_fail_reason'.
(linux_ptrace_attach_fail_reason_lwp): New function.
(linux_ptrace_me_fail_reason): New function.
(errno_pipe): New variable.
(linux_fork_to_function): Initialize pipe before forking.
(linux_child_function): Deal with errno-passing from child.
Handle ptrace error.
(linux_check_child_ptrace_errno): New function.
(linux_check_child_ptrace_errno): Call
'linux_check_child_ptrace_errno'.
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason): Update
prototype.
(linux_ptrace_attach_fail_reason_lwp): New prototype.
(linux_ptrace_me_fail_reason): New prototype.
* remote.c (extended_remote_target::attach): Handle error
message passed by the server when attach fails.
gdb/gdbserver/ChangeLog:
2019-09-26 Sergio Durigan Junior <sergiodj@redhat.com>
Pedro Alves <palves@redhat.com>
* linux-low.c (linux_ptrace_fun): Call
'linux_ptrace_me_fail_reason'.
(attach_proc_task_lwp_callback): Call
'linux_ptrace_attach_fail_reason_lwp'.
(linux_attach): Call 'linux_ptrace_attach_fail_reason'.
* server.c (handle_v_attach): Use try..catch when calling
'attach_inferior', and send an error message to the client
when needed.
* thread-db.c (attach_thread): Call
'linux_ptrace_attach_fail_reason_lwp'.
I noticed that gdb_usleep is unused, so this patch removes it.
gdb/ChangeLog
2019-09-26 Tom Tromey <tom@tromey.com>
* Makefile.in (COMMON_SFILES): Remove gdb_usleep.c.
(HFILES_NO_SRCDIR): Remove gdb_usleep.h.
* gdb_usleep.h: Remove.
* gdb_usleep.c: Remove.
* utils.c: Don't include gdb_usleep.h.
dwarf2read.c will create stub types for Ada "Taft Amendment" types.
These stub types can currently be exposed to Python code, where they
show up as TYPE_CODE_VOID types (but that, mysteriously, can sometimes
be used in other ways).
While it's possible to work with such types by using strip_typedefs,
this seemed unpleasant to me. This patch takes another approach
instead, which is to try not to expose stub types to Python users.
gdb/ChangeLog
2019-09-26 Tom Tromey <tromey@adacore.com>
* python/py-type.c (type_to_type_object): Call check_typedef
for stub types.
gdb/testsuite/ChangeLog
2019-09-26 Tom Tromey <tromey@adacore.com>
* gdb.ada/py_taft.exp: New file.
* gdb.ada/py_taft/main.adb: New file.
* gdb.ada/py_taft/pkg.adb: New file.
* gdb.ada/py_taft/pkg.ads: New file.
initialize_utils only registers some commands, so it isn't necessary
to run it at any particular time during startup. This patch removes
it and merges its contents into _initialize_utils.
Tested by the buildbot.
gdb/ChangeLog
2019-09-26 Tom Tromey <tom@tromey.com>
* utils.h (initialize_utils): Don't declare.
* top.c (gdb_init): Don't call initialize_utils.
* utils.c (initialize_utils): Remove. Move contents...
(_initialize_utils): ... here.
I noticed that make_hex_string does essentially the same thing as
bin2hex, and furthermore is only called in a single spot. This patch
removes make_hex_string.
Tested by the builtbot.
gdb/ChangeLog
2019-09-25 Tom Tromey <tom@tromey.com>
* python/py-objfile.c (objfpy_get_build_id): Use bin2hex.
* utils.h (make_hex_string): Don't declare.
* utils.c (make_hex_string): Remove.
I was looking at the implementation of this script keyword today and
couldn't remember why we do what we do in get_init_priority, because
the comments explain how the init_priority is encoded but don't say
why it is necessary to extract the priority and sort on that. So
after figuring out why (again), I wrote some more comments.
Then I simplified get_init_priority a little, adding some sanity
checking on the strtoul result. This actually makes get_init_priority
support sorting by numerical suffix more generally, but I figure this
feature would be better as a new keyword (without the .ctors/.dtors
special case), so haven't documented the extension.
* ld.texi (SORT_BY_ALIGNMENT): Reword slightly.
(SORT_BY_INIT_PRIORITY): Elucidate.
* ldlang.c: Include limits.h.
(get_init_priority): Comment. Change param to a section,
return an int. Sanity check priority digits. Support sorting
more sections with trailing digits. Return -1 on error.
(compare_section): Adjust.
On my openSUSE Leap 15.1 x86_64 Skylake system with the default (4.12) kernel,
I run into:
...
FAIL: gdb.base/gcore.exp: corefile restored all registers
...
The problem is that there's a difference in the mxcsr register value before
and after the gcore command:
...
- mxcsr 0x0 [ ]
+ mxcsr 0x400440 [ DAZ OM ]
...
This can be traced back to amd64_linux_nat_target::fetch_registers, where
xstateregs is partially initialized by the ptrace call:
...
char xstateregs[X86_XSTATE_MAX_SIZE];
struct iovec iov;
amd64_collect_xsave (regcache, -1, xstateregs, 0);
iov.iov_base = xstateregs;
iov.iov_len = sizeof (xstateregs);
if (ptrace (PTRACE_GETREGSET, tid,
(unsigned int) NT_X86_XSTATE, (long) &iov) < 0)
perror_with_name (_("Couldn't get extended state status"));
amd64_supply_xsave (regcache, -1, xstateregs);
...
after which amd64_supply_xsave is called.
The amd64_supply_xsave call is supposed to only use initialized parts of
xstateregs, but due to a kernel bug on intel skylake (fixed from 4.14 onwards
by commit 0852b374173b "x86/fpu: Add FPU state copying quirk to handle XRSTOR
failure on Intel Skylake CPUs") it can happen that the mxcsr part of
xstateregs is not initialized, while amd64_supply_xsave expects it to be
initialized, which explains the FAIL mentioned above.
Fix the undetermined behaviour by initializing xstateregs before calling
ptrace, which makes sure we get a 0x0 for mxcsr when this kernel bug occurs,
and which also happens to fix the FAIL.
Furthermore, add an xfail for this FAIL which triggers the same kernel bug:
...
FAIL: gdb.arch/amd64-init-x87-values.exp: check_setting_mxcsr_before_enable: \
check new value of MXCSR is still in place
...
Both FAILs pass when using a 5.3 kernel instead on the system mentioned above.
Tested on x86_64-linux.
gdb/ChangeLog:
2019-09-24 Tom de Vries <tdevries@suse.de>
PR gdb/23815
* amd64-linux-nat.c (amd64_linux_nat_target::fetch_registers):
Initialize xstateregs before ptrace PTRACE_GETREGSET call.
gdb/testsuite/ChangeLog:
2019-09-24 Tom de Vries <tdevries@suse.de>
PR gdb/24598
* gdb.arch/amd64-init-x87-values.exp: Add xfail.
The fix for PR12848 introduced an off by one error in the mask, this corrected
the negative overflows but not the positive overflows. As a result the
conditional branch instructions accepted a too wide positive immediate which
resulted in it corrupting the instruction during encoding.
The relocation I believe has been incorrectly named, to be consistent with the
other relocations it should have been named BRANCH21 which is why the masks for
it are confusing.
I've replaced the masks with a function out_of_range_p which should make it
harder to make such mistakes.
The mask for BL/BLX on Armv6t+ is also wrong, the extended range is 25-bits
and so the mask should be checking for 24-bits for positive overflow.
gas/ChangeLog:
PR gas/24991
* config/tc-arm.c (out_of_range_p): New.
(md_apply_fix): Use it in BFD_RELOC_THUMB_PCREL_BRANCH9,
BFD_RELOC_THUMB_PCREL_BRANCH12, BFD_RELOC_THUMB_PCREL_BRANCH20,
BFD_RELOC_THUMB_PCREL_BRANCH23, BFD_RELOC_THUMB_PCREL_BRANCH25
* testsuite/gas/arm/pr24991.d: New test.
* testsuite/gas/arm/pr24991.l: New test.
* testsuite/gas/arm/pr24991.s: New test.
Using saved_format breaks when nm is presented with multiple object
files, some 32-bit and some 64-bit.
PR 25031
* nm.c (print_format_string): New.
(get_print_format): Delete saved_format. Move earlier.
(set_print_width): Call get_print_format.
(print_value): Use print_format_string.