On s390x targets GDB can not handle displaced stepping correctly for some
relative branch instructions, such as cij (compare immediate and branch
relative). When setting a breakpoint on such an instruction and
single-stepping over it, the branch is never taken. This is because the
check in s390_displaced_step_fixup for relative branch instructions is
incomplete.
Instead of completing the list of relative branch instructions to check
against, this patch just treats relative branches and non-branching
instructions in the same way and adjusts the PC with the negated
displacement in both cases.
gdb/ChangeLog:
* s390-linux-tdep.c (is_rsi, is_rie): Remove functions.
(s390_displaced_step_fixup): Cover relative branches with the
default fixup handling. This fixes lack of support for some
relative branch instructions.
This is one of the rare to_fetch/store_registers implementations that will
still rely (for now) on inferior_ptid (because of the memory read/write
operations). We therefore have to add a save/restore of inferior_ptid. We'll
be able to remove it when we make the memory operations accept the ptid as a
parameter.
gdb/ChangeLog:
* bsd-uthread.c (bsd_uthread_fetch_registers,
bsd_uthread_store_registers): Use ptid from regcache, set and
restore inferior_ptid.
As Gareth McMullin <gareth@blacksphere.co.nz> reports at
<https://sourceware.org/ml/gdb-patches/2017-02/msg00560.html>, the
timeout mechanism in ser-unix.c was broken by commit 048094acc
("target remote: Don't rely on immediate_quit (introduce quit
handlers)").
Instead of applying a local fix, and since we now finally always use
interrupt_select [1], let's get rid of hardwire_readchar entirely, and
use ser_base_readchar instead, which has similar timeout handling,
except for the bug.
Smoke tested with:
$ socat -d -d pty,raw,echo=0 pty,raw,echo=0
2017/03/14 14:08:13 socat[4994] N PTY is /dev/pts/14
2017/03/14 14:08:13 socat[4994] N PTY is /dev/pts/15
2017/03/14 14:08:13 socat[4994] N starting data transfer loop with FDs [3,3] and [5,5]
$ gdbserver /dev/pts/14 PROG
$ gdb PROG -ex "tar rem /dev/pts/15"
and then a few continues/ctrl-c's, plus killing gdbserver and socat.
[1] - See FIXME comments being removed.
gdb/ChangeLog:
2017-03-17 Pedro Alves <palves@redhat.com>
PR remote/21188
* ser-base.c (ser_base_wait_for): Add comment.
(do_ser_base_readchar): Improve comment based on the ser-unix.c's
version.
* ser-unix.c (hardwire_raw): Remove reference to
scb->current_timeout.
(wait_for, do_hardwire_readchar, hardwire_readchar): Delete.
(hardwire_ops): Install ser_base_readchar instead of
hardwire_readchar.
* serial.h (struct serial) <current_timeout, timeout_remaining>:
Remove fields.
Fix this the same way gdb/python/lib/gdb/printing.py handles it.
gdb/Changelog:
2017-03-17 Jonah Graham <jonah@kichwacoders.com>
PR gdb/19637
* python/lib/gdb/printer/bound_registers.py: Add support for
Python 3.
Recently I fixed a bug that caused a DW_OP_implicit_pointer with non-zero
offset into a DW_OP_implicit_value to be handled incorrectly on big-endian
targets. GDB ignored the offset and copied the wrong bytes:
https://sourceware.org/ml/gdb-patches/2017-01/msg00251.html
But there is still a similar issue when a DW_OP_implicit_pointer points
into a DW_OP_stack_value instead; and again, the offset is ignored. There
is an important difference, though: While implicit values are treated like
blocks of data and anchored at the lowest-addressed byte, stack values
traditionally contain integer numbers and are anchored at the *least
significant* byte. Also, stack values do not come in varying sizes, but
are cut down appropriately when used. Thus, on big-endian targets the
scenario looks like this (higher addresses shown right):
|<- - - - - Stack value - - - - - - ->|
| |
|<- original object ->|
|
| offset ->|####|
^^^^
de-referenced
implicit pointer
(Note how the original object's size influences the position of the
de-referenced implicit pointer within the stack value. This is not the
case for little-endian targets, where the original object starts at offset
zero within the stack value.)
This patch implements the logic indicated in the above diagram and adds an
appropriate test case. A new function dwarf2_fetch_die_type_sect_off is
added; it is used for retrieving the original object's type, so its size
can be determined. That type is passed to dwarf2_evaluate_loc_desc_full
via a new parameter.
gdb/ChangeLog:
* dwarf2loc.c (indirect_synthetic_pointer): Get data type of
pointed-to DIE and pass it to dwarf2_evaluate_loc_desc_full.
(dwarf2_evaluate_loc_desc_full): New parameter subobj_type; rename
byte_offset to subobj_byte_offset. Fix the handling of
DWARF_VALUE_STACK on big-endian targets when coming via an
implicit pointer.
(dwarf2_evaluate_loc_desc): Adjust call to
dwarf2_evaluate_loc_desc_full.
* dwarf2loc.h (dwarf2_fetch_die_type_sect_off): New declaration.
* dwarf2read.c (dwarf2_fetch_die_type_sect_off): New function.
gdb/testsuite/ChangeLog:
* lib/dwarf.exp: Add support for DW_OP_implicit_pointer.
* gdb.dwarf2/nonvar-access.exp: Add test for stack value location
and implicit pointer into such a location.
This patch adds the support for these instructions in arm process
record.
gdb:
2017-03-16 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (thumb_record_misc): Decode CBNZ, CBZ, REV16,
and REVSH instructions.
I look at some fails in gdb.reverse/solib-precsave.exp in -mthumb,
they are caused by some bugs on decoding these three instructions,
uxtb, ldr and mrc. This patch adds unit tests against these three
instructions, and fix these bugs by re-organizing the code to match
the table in ARM ARM.
gdb:
2017-03-16 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c [GDB_SELF_TEST]: include "selftests.h".
(arm_record_test): Declare.
(_initialize_arm_tdep) [GDB_SELF_TEST]: call register_self_test.
(thumb_record_ld_st_reg_offset): Rewrite the opcode matching to
align with the manual.
(thumb_record_misc): Adjust the code order to align with the
manual.
(thumb2_record_decode_insn_handler): Fix instruction matching.
(instruction_reader_thumb): New class.
(arm_record_test): New function.
This patch adds an abstract class abstract_memory_reader a
and pass it to the code reading instructions in arm process record,
rather than using target_read_memory to read from real target. This
paves the way for adding more unit tests to arm process record.
gdb:
2017-03-16 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (abstract_memory_reader): New class.
(instruction_reader): New class.
(extract_arm_insn): Add argument 'reader'. Callers updated.
(decode_insn): Likewise.
This patch keeps the Scheme side of lazy string handling in sync
with the python size, bringing over fixes for
PRs python/17728, python/18439, python/18779.
gdb/ChangeLog:
* guile/scm-lazy-string.c (lazy_string_smob): Clarify use of LENGTH
member. Change type of TYPE member to SCM. All uses updated.
(lsscm_make_lazy_string_smob): Add assert.
(lsscm_make_lazy_string): Flag bad length values.
(lsscm_elt_type): New function.
(gdbscm_lazy_string_to_value): Rewrite to use
lsscm_safe_lazy_string_to_value.
(lsscm_safe_lazy_string_to_value): Fix handling of TYPE_CODE_PTR.
* guile/scm-value.c (gdbscm_value_to_lazy_string): Flag bad length
values. Fix TYPE_CODE_PTR. Handle TYPE_CODE_ARRAY. Handle typedefs
in incoming type.
* guile/guile-internal.h (tyscm_scm_to_type): Declare.
* guile/scm-type.c (tyscm_scm_to_type): New function.
gdb/testsuite/ChangeLog:
* gdb.guile/scm-value.c (main) Delete locals sptr, sn.
* gdb.guile/scm-lazy-string.c: New file.
* gdb.guile/scm-value.exp: Move lazy string tests to ...
* gdb.guile/scm-lazy-string.exp: ... here, new file. Add more tests
for pointer, array, typedef lazy strings.
gdb/ChangeLog:
PR python/17728, python/18439, python/18779
* python/py-lazy-string.c (lazy_string_object): Clarify use of LENGTH
member. Change type of TYPE member to PyObject *. All uses updated.
(stpy_convert_to_value): Fix handling of TYPE_CODE_PTR.
(gdbpy_create_lazy_string_object): Flag bad length values.
Handle TYPE_CODE_ARRAY with possibly different user-provided length.
Handle typedefs in incoming type.
(stpy_lazy_string_elt_type): New function.
(gdbpy_extract_lazy_string): Call it.
* python/py-value.c (valpy_lazy_string): Flag bad length values.
Fix handling of TYPE_CODE_PTR. Handle TYPE_CODE_ARRAY. Handle
typedefs in incoming type.
gdb/testsuite/ChangeLog:
PR python/17728, python/18439, python/18779
* gdb.python/py-value.c (main) Delete locals sptr, sn.
* gdb.python/py-lazy-string.c (pointer): New typedef.
(main): New locals ptr, array, typedef_ptr.
* gdb.python/py-value.exp: Move lazy string tests to ...
* gdb.python/py-lazy-string.exp: ... here. Add more tests for pointer,
array, typedef lazy strings.
The expectation in gdb.cp/m-static.exp for the ptype of
single_constructor is to get in the result of destructor with the
following prototype: ~single_constructor(int).
Yet, m-static.cc declares the destructor as ~single_constructor(). This
commit fixes the expectation.
2017-03-16 Thomas Preud'homme <thomas.preudhomme@arm.com>
gdb/testsuite/
* gdb.cp/m-static.exp: Fix expectation for prototype of
test5.single_constructor and single_constructor::single_constructor.
When inf_ptrace_xfer_partial performs a memory transfer via ptrace with
PT_READ_I, PT_WRITE_I (aka PTRACE_PEEKTEXT, PTRACE_POKETEXT), etc., then
it currently transfers at most one word. This behavior yields degraded
performance, particularly if the caller has significant preparation work
for each invocation. And indeed it has for writing, in
memory_xfer_partial in target.c, where all of the remaining data to be
transferred is copied to a temporary buffer each time, for breakpoint
shadow handling. Thus large writes have quadratic runtime and can take
hours.
Note: On GNU/Linux targets GDB usually does not use
inf_ptrace_xfer_partial for large memory transfers, but attempts a single
read/write from/to /proc/<pid>/mem instead. However, the kernel may
reject writes to /proc/<pid>/mem (such as kernels prior to 2.6.39), or
/proc may not be mounted. In both cases GDB falls back to the ptrace
mechanism.
This patch fixes the performance issue by attempting to fulfill the whole
transfer request in inf_ptrace_xfer_partial, using a loop around the
ptrace call.
gdb/ChangeLog:
PR gdb/21220
* inf-ptrace.c (inf_ptrace_xfer_partial): In "case
TARGET_OBJECT_MEMORY", extract the logic for ptrace peek/poke...
(inf_ptrace_peek_poke): ...here. New function. Now also loop
over ptrace peek/poke until end of buffer or error.
It isn't used anywhere else than the file it's defined in.
gdb/ChangeLog:
* parse.c (length_of_subexp): Make static.
* parser-defs.h (length_of_subexp): Remove.
An optional parameter TEST has been added to get_hexadecimal_valueof in commit:
https://sourceware.org/ml/gdb-patches/2016-06/msg00469.html
This patch adds a similar optional parameter to other related methods that
retrieve expression values: get_valueof, get_integer_valueof and get_sizeof.
Thus tests that evaluate same expression multiple times can provide custom
test names, ensuring that test names will be unique.
gdb/testsuite/ChangeLog:
2017-03-14 Anton Kolesov <anton.kolesov@synopsys.com>
* lib/gdb.exp (get_valueof, get_integer_valueof, get_sizeof):
Add optional 'test' parameter.
So far linux_proc_xfer_partial refused to handle write requests. This is
still based on the assumption that the Linux kernel does not support
writes to /proc/<pid>/mem. That used to be true, but has changed with
Linux 2.6.39 released in May 2011.
This patch lifts this restriction and now exploits /proc/<pid>/mem for
writing to inferior memory as well, if possible.
gdb/ChangeLog:
* linux-nat.c (linux_proc_xfer_partial): Handle write operations
as well.
Commit c8b23b3f89fbb0 ("Add constructor and destructor to
demangle_parse_info") a while ago broke the "test-cp-name-parser"
build:
$ make test-cp-name-parser
[...]
src/gdb/cp-name-parser.y: In function ‘int main(int, char**)’:
src/gdb/cp-name-parser.y:2190:9: error: cannot convert ‘std::unique_ptr<demangle_parse_info>’ to ‘demangle_parse_info*’ in assignment
result = cp_demangled_name_to_comp (str2, &errmsg);
^
src/gdb/cp-name-parser.y:2199:38: error: ‘cp_demangled_name_parse_free’ was not declared in this scope
cp_demangled_name_parse_free (result);
^
src/gdb/cp-name-parser.y:2211:14: error: cannot convert ‘std::unique_ptr<demangle_parse_info>’ to ‘demangle_parse_info*’ in assignment
result = cp_demangled_name_to_comp (argv[arg], &errmsg);
^
src/gdb/cp-name-parser.y:2219:43: error: ‘cp_demangled_name_parse_free’ was not declared in this scope
cp_demangled_name_parse_free (result);
^
Makefile:2107: recipe for target 'test-cp-name-parser.o' failed
make: *** [test-cp-name-parser.o] Error 1
This commit restores it.
gdb/ChangeLog:
2017-03-14 Pedro Alves <palves@redhat.com>
* cp-name-parser.y (cp_demangled_name_to_comp): Update comment.
(main): Use std::unique_ptr. Remove calls to
cp_demangled_name_parse_free.
gdb/ChangeLog:
* amd64-linux-nat.c (amd64_linux_fetch_inferior_registers,
amd64_linux_fetch_inferior_registers): Use regcache->ptid
instead of inferior_ptid.
We are currently assuming that regcache->ptid is equal to inferior_ptid
when we call target_fetch/store_registers. These asserts just validate
that assumption. Also, since the following patches will change target
code to use regcache->ptid instead of inferior_ptid, asserting that they
are the same should ensure that our changes don't have any unintended
consequences.
gdb/ChangeLog:
* target.c (target_fetch_registers, target_store_registers): Add
assert.
This patch introduces the regcache_get_ptid function, which can be used
to retrieve the ptid a regcache is connected to. It is used in
subsequent patches.
gdb/ChangeLog:
* regcache.h (regcache_get_ptid): New function.
* regcache.c (regcache_get_ptid): New function.
I noticed that backslash_in_multi_line_command_test in
gdb.base/commands.exp failed on our RHEL6 servers. I traced it to the
old version of DejaGnu (1.4.4). I have found that instead of receiving
the expected:
"print \\\nargc\n"
gdb received:
"print argc\n"
thus breaking the test and its purpose. Versionof DejaGnu < 1.5 mess
up sending "\\\n", it somehow gets replaced with a space. I found that
the following commit in DejaGnu fixed the issue:
http://git.savannah.gnu.org/cgit/dejagnu.git/commit/lib/remote.exp?id=3f39294f5cd6802858838d3bcc0ccce847ae17f2
Even though the commit is almost 10 years old, the following release of
DejaGnu was only in 2013, which is why we still have systems with the
old code.
If the DejaGnu version is < 1.5, we just skip the test.
gdb/testsuite/ChangeLog:
* gdb.base/commands.exp (backslash_in_multi_line_command_test):
Skip for versions of DejaGnu < 1.5.
The next patch will require checking the DejaGnu version. There is
already a test that does this,
gdb.threads/attach-many-short-lived-threads.exp. This patch introduces
a new procedure, dejagnu_version, and makes that test use it.
The version number is "right-padded" with zeroes, to make sure that we
always return a triplet (major, minor, patch).
The procedure does not consider the DejaGnu versions from git. For
example, if you used DejaGnu from its current master branch, the version
would be "1.6.1-git", meaning that 1.6.1 will be the next release. I
figured we'll cross that bridge when (and if) we get there.
gdb/testsuite/ChangeLog:
* lib/gdb.exp (dejagnu_version): New proc.
* gdb.threads/attach-many-short-lived-threads.exp (bad_dejagnu):
Use dejagnu_version.
While integrating the d_printing recursion guard change into gdb I
noticed we forgot to initialize the demangle_component d_printing
field in cplus_demangle_fill_{name,extended_operator,ctor,dtor}.
As is done in cplus_demangle_fill_{component,builtin_type,operator}.
It happened to work because in gcc all demangle_components were
allocated through d_make_empty. But gdb has its own allocation
mechanism (as might other users).
libiberty/ChangeLog:
* cp-demangle.c (cplus_demangle_fill_name): Initialize
demangle_component d_printing.
(cplus_demangle_fill_extended_operator): Likewise.
(cplus_demangle_fill_ctor): Likewise.
(cplus_demangle_fill_dtor): Likewise.
gdb/ChangeLog:
* cp-name-parser.y (make_empty): Initialize d_printing to zero.
For a long time now, c++/8218 has noted that GDB is printing argument types
for destructors:
(gdb) ptype A
type = class A {
public:
~A(int);
}
This happens because cp_type_print_method_args doesn't ignore artificial
arguments. [It ignores the first `this' pointer because it simply skips
the first argument for any non-static function.]
This patch fixes this:
(gdb) ptype A
type = class A {
public:
~A();
}
I've adjusted gdb.cp/templates.exp to account for this and added a new
passing regexp.
gdb/ChangeLog
PR c++/8218
* c-typeprint.c (cp_type_print_method_args): Skip artificial arguments.
gdb/testsuite/ChangeLog
PR c++/8128
* gdb.cp/templates.exp (test_ptype_of_templates): Remove argument
type from destructor regexps.
Add a branch which actually passes the test.
Adjust "ptype t5i" test names.
Currently diffing testrun results shows:
-PASS: gdb.base/step-over-exit.exp: break *0x7ffff77e18c6 if main == 0
+PASS: gdb.base/step-over-exit.exp: break *0x2aaaab0988c6 if main == 0
gdb/testsuite/ChangeLog:
2017-03-08 Pedro Alves <palves@redhat.com>
* gdb.base/step-over-exit.exp: Add explicit test message.
If you do "interrupt -a" just while some thread is stepping over a
breakpoint, gdb trips on an internal error.
The test added by this patch manages to trigger this consistently by
spawning a few threads that are constantly tripping on a conditional
breakpoint whose condition always evaluates to false. With current
gdb, you get:
~~~
interrupt -a
.../src/gdb/inline-frame.c:343: internal-error: void skip_inline_frames(ptid_t): Assertion `find_inline_frame_state (ptid) == NULL' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) FAIL: gdb.threads/interrupt-while-step-over.exp: displaced-stepping=on: iter=0: interrupt -a (GDB internal error)
[...]
.../src/gdb/inline-frame.c:343: internal-error: void skip_inline_frames(ptid_t): Assertion `find_inline_frame_state (ptid) == NULL' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) FAIL: gdb.threads/interrupt-while-step-over.exp: displaced-stepping=off: iter=0: wait for stops (GDB internal error)
~~~
The assertion triggers because we're processing a stop for a thread
that had already stopped before and thus had already its inline-frame
state filled in.
Calling handle_inferior_event_1 directly within a
"thread_stop_requested" observer is something that I've wanted to get
rid of before, for being fragile. Nowadays, infrun is aware of
threads with pending events, so we can use that instead, and let the
normal fetch_inferior_event -> handle_inferior_event code path handle
the forced stop.
The change to finish_step_over is necessary because sometimes a thread
that was told to PTRACE_SINGLESTEP reports back a SIGSTOP instead of a
SIGTRAP (i.e., we tell it to single-step, and then interrupt it quick
enough that on the kernel side the thread dequeues the SIGTOP before
ever having had a chance of executing the instruction to be stepped).
SIGSTOP gets translated to a GDB_SIGNAL_0. And then finish_step_over
would miss calling clear_step_over_info, and thus miss restarting the
other threads (which in this case of threads with pending events,
means setting their "resumed" flag, so their pending events can be
consumed).
And now that we always restart threads in finish_step_over, we no
longer need to do that in handle_signal_stop.
Tested on x86_64 Fedora 23, native and gdbserver.
gdb/ChangeLog:
2017-03-08 Pedro Alves <palves@redhat.com>
PR gdb/18360
* infrun.c (start_step_over, do_target_resume, resume)
(restart_threads): Assert we're not resuming a thread that is
meant to be stopped.
(infrun_thread_stop_requested_callback): Delete.
(infrun_thread_stop_requested): If the thread is internally
stopped, queue a pending stop event and clear the thread's
inline-frame state.
(handle_stop_requested): New function.
(handle_syscall_event, handle_inferior_event_1): Use
handle_stop_requested.
(handle_stop_requested): New function.
(handle_signal_stop): Set the thread's stop_signal here instead of
at caller.
(finish_step_over): Clear step over info unconditionally.
(handle_signal_stop): If the user had interrupted the event
thread, consider the stop a random signal.
(handle_signal_stop) <signal arrived while stepping over
breakpoint>: Don't restart threads here.
(stop_waiting): Don't clear step-over info here.
gdb/testsuite/ChangeLog:
2017-03-08 Pedro Alves <palves@redhat.com>
PR gdb/18360
* gdb.threads/interrupt-while-step-over.c: New file.
* gdb.threads/interrupt-while-step-over.exp: New file.
