When we're looking at a tracefile trace frame where registers are not
available, and the tracepoint has only one location, we supply
the location's address as the PC register. However, this only works
if PC is not a pseudo register, and individual architectures may want
to guess more registers. Add a gdbarch hook that will handle that.
gdb/ChangeLog:
* arch-utils.c (default_guess_tracepoint_registers): New function.
* arch-utils.h (default_guess_tracepoint_registers): New prototype.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh: Add guess_tracepoint_registers hook.
* tracefile.c (tracefile_fetch_registers): Use the new gdbarch hook.
exec_file_locate_attach allocates memory for full_exec_path (using
either exec_file_find, source_full_path_of or xstrdup) but this
memory is never freed. This commit adds the necessary cleanup.
gdb/ChangeLog:
* exec.c (exec_file_locate_attach): Add missing cleanup.
This patch fixes an internal error that occurs in
gdb.threads/forking-threads-plus-breakpoint.exp:
/blah/binutils-gdb/gdb/target.c:2723: internal-error: Can't determine the
current address space of thread Thread 3170.3170
In default_thread_address_space, find_inferior_ptid couldn't find 3170.3170
because it had been overwritten in inferior_appeared, called as follows:
inferior_appeared
remote_add_inferior
remote_notice_new_inferior
remote_update_thread_list
The cause of the problem was the following sequence of events:
* GDB knows only about the main thread
* the first fork event is reported to GDB, saved as pending_event
* qXfer:threads:read gets the threads from the remote.
remove_new_fork_children id's the fork child from the pending event
and removes it from the list reported to GDB. All the rest of the
threads, including the fork parent, are added to the GDB thread list.
* GDB stops all the threads. All the stop events are pushed onto the
stop reply queue behind the pending fork event. The fork waitstatus
is saved in the fork parent thread's pending status field
thread_info.suspend.
* remote_wait_ns calls queued_stop_reply and process_stop_reply to
remove the fork event from the front of the stop reply queue and save
event information in the thread_info structure for the fork parent
thread. Unfortunately, none of the information saved in this way is
the fork-specific information.
* A subsequent qXfer:threads:read packet gets the thread list including
the fork parent and fork child. remove_new_fork_children checks the
thread list to see if there is a fork parent, doesn't find one, checks
the stop reply queue for a pending fork event, doesn't find one, and
allows the fork child thread to be reported to GDB before the fork
event has been handled. remote_update_thread_list calls
remote_notice_new_thread and overwrites the current (main) thread in
inferior_appeared.
So the fork event has been reported out of target_wait but it was left
pending on the infrun side (infrun.c:save_waitstatus). IOW, the fork
event hasn't been processed by handle_inferior_event yet, so it hasn't
made it to tp->pending_follow yet.
The fix is to check thread_info.suspend along with the
thread_info.pending_follow in remote.c:remove_new_fork_children, to
prevent premature reporting of the fork child thread creation.
gdb/ChangeLog:
PR remote/19496
* remote.c (remove_new_fork_children): Check for pending
fork status in thread_info.suspend.
gdb/testsuite/ChangeLog:
PR remote/19496
* gdb.threads/forking-threads-plus-breakpoint.exp (do_test):
Remove kfail for PR remote/19496.
I see the following error in testing aarch64 GDB debugging arm
program.
(gdb) PASS: gdb.reverse/readv-reverse.exp: set breakpoint at marker2
continue
Continuing.
=================================================================
==32273==ERROR: AddressSanitizer: attempting free on address which was not malloc()-ed: 0x000000ce4c00 in thread T0
#0 0x2ba5615645c7 in __interceptor_free (/usr/lib/x86_64-linux-gnu/libasan.so.1+0x545c7)^M
#1 0x4be8b5 in VEC_CORE_ADDR_cleanup /home/yao/SourceCode/gnu/gdb/git/gdb/common/gdb_vecs.h:34^M
#2 0x5e6d95 in do_my_cleanups /home/yao/SourceCode/gnu/gdb/git/gdb/common/cleanups.c:154^M
#3 0x64c99a in fetch_inferior_event /home/yao/SourceCode/gnu/gdb/git/gdb/infrun.c:3975^M
#4 0x678437 in inferior_event_handler /home/yao/SourceCode/gnu/gdb/git/gdb/inf-loop.c:44^M
#5 0x5078f6 in remote_async_serial_handler /home/yao/SourceCode/gnu/gdb/git/gdb/remote.c:13223^M
#6 0x4cecfd in run_async_handler_and_reschedule /home/yao/SourceCode/gnu/gdb/git/gdb/ser-base.c:137^M
#7 0x676864 in gdb_wait_for_event /home/yao/SourceCode/gnu/gdb/git/gdb/event-loop.c:834^M
#8 0x676a27 in gdb_do_one_event /home/yao/SourceCode/gnu/gdb/git/gdb/event-loop.c:323^M
#9 0x676aed in start_event_loop /home/yao/SourceCode/gnu/gdb/git/gdb/event-loop.c:347^M
#10 0x6706d2 in captured_command_loop /home/yao/SourceCode/gnu/gdb/git/gdb/main.c:318^M
#11 0x66db8c in catch_errors /home/yao/SourceCode/gnu/gdb/git/gdb/exceptions.c:240^M
#12 0x6716dd in captured_main /home/yao/SourceCode/gnu/gdb/git/gdb/main.c:1157^M
#13 0x66db8c in catch_errors /home/yao/SourceCode/gnu/gdb/git/gdb/exceptions.c:240^M
#14 0x671b7a in gdb_main /home/yao/SourceCode/gnu/gdb/git/gdb/main.c:1165^M
#15 0x467684 in main /home/yao/SourceCode/gnu/gdb/git/gdb/gdb.c:32^M
#16 0x2ba563ed7ec4 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21ec4)^M
#17 0x4676b2 (/scratch/yao/gdb/build-git/aarch64-linux-gnu/gdb/gdb+0x4676b2)
looks we should discard cleanup if function
arm_linux_software_single_step returns early, or create cleanup when
it is needed.
gdb:
2016-02-16 Yao Qi <yao.qi@linaro.org>
* arm-linux-tdep.c (arm_linux_software_single_step): Assign
'old_chain' later.
Method syscall_next_pc of struct arm_get_next_pcs_ops has an argument
PC, which is not necessary, because PC can be got from regcache in
'struct arm_get_next_pcs'. This patch removes the PC argument of
syscall_next_pc.
gdb:
2016-02-16 Yao Qi <yao.qi@linaro.org>
* arch/arm-get-next-pcs.h (struct arm_get_next_pcs_ops)
<syscall_next_pc>: Remove argument PC. Callers updated.
* arm-linux-tdep.c (arm_linux_get_next_pcs_syscall_next_pc):
Remove argument PC. Get pc from regcache_read_pc.
* arm-tdep.c (arm_get_next_pcs_syscall_next_pc): Remove
argument PC.
gdb/gdbserver:
2016-02-16 Yao Qi <yao.qi@linaro.org>
* linux-arm-low.c (get_next_pcs_syscall_next_pc): Remove argument
PC. Get pc from regcache_read_pc.
core_addr_to_string_nz returns string which has "0x" prefix, so don't
need to print "0x" again. This patch is to remove the "0x".
gdb:
2016-02-15 Yao Qi <yao.qi@linaro.org>
* aarch64-tdep.c (aarch64_analyze_prologue): Remove "0x".
GDB step cross kernel helpers only works if the kernel helpers are tail
called, which is the case how it is used in glibc. See __aeabi_read_tp
in sysdeps/unix/sysv/linux/arm/aeabi_read_tp.S. In __aeabi_read_tp,
branch/jump to the kernel helper is the last instruction, and the next
instruction address is in LR, which is in caller function. GDB can
handle this correctly. For example, glibc function __GI___ctype_init
calls __aeabi_read_tp
0xb6e19b30 <__GI___ctype_init+4>: ldr r3, [pc, #80] ;
0xb6e19b34 <__GI___ctype_init+8>: bl 0xb6e0a6e0 <__aeabi_read_tp>
0xb6e19b38 <__GI___ctype_init+12>: ldr r3, [pc, r3]
and __aeabi_read_tp calls kernel helper,
(gdb) disassemble __aeabi_read_tp
0xb6fef5d0 <+0>: mvn r0, #61440 ; 0xf000
0xb6fef5d4 <+4>: sub pc, r0, #31
once GDB or GDBserver single step instruction on 0xb6fef5d4, LR is
0xb6e19b38, which is right address of next instruction to set breakpoint
on.
However, if the kernel helpers are not tail-called, the LR is still the
address in the caller function of kernel helper's caller, which isn't
the right address of next instruction to set breakpoint on. For example,
we use kernel helper in main,
(gdb) disassemble main
....
0x00008624 <+32>: mov r3, #4064 ; 0xfe0^M
0x00008628 <+36>: movt r3, #65535 ; 0xffff^M
0x0000862c <+40>: blx r3
0x00008630 <+44>: ldr r3, [r11, #-8]
kernel helper is called on 0x0000862c and the expected next instruction
address is 0x00008630, but the LR now is the return address of main.
The problem here is LR may not have the right address because when we
single step the instruction, it isn't executed yet, so the LR isn't
updated. This patch fix this problem by decoding instruction, if the
instruction updates LR (BL and BLX), the next instruction address is
PC + INSN_SIZE, otherwise, get the address of next instruction from LR.
gdb:
2016-02-12 Yao Qi <yao.qi@linaro.org>
* arch/arm-linux.c (arm_linux_get_next_pcs_fixup): Calculate
nextpc according to instruction.
gdb/testsuite:
2016-02-12 Yao Qi <yao.qi@linaro.org>
* gdb.arch/arm-single-step-kernel-helper.c: New.
* gdb.arch/arm-single-step-kernel-helper.exp: New.
When I exercise GDBserver software single step, I see the following
error, which has been already handled by GDB properly.
In GDBserver log, we can see, GDBserver tries to single step instruction
on 0xb6e0a6e4, and destination address is 0xffff0fe0,
stop pc is 0xb6e0a6e4
Writing f001f0e7 to 0xffff0fe0 in process 7132
Failed to insert breakpoint at 0xffff0fe0 (Input/output error).
Failed to insert breakpoint at 0xffff0fe0 (-1).
(gdb) disassemble __aeabi_read_tp,+8
Dump of assembler code from 0xb6e0a6e0 to 0xb6e0a6e8:
0xb6e0a6e0 <__aeabi_read_tp+0>: mvn r0, #61440 ; 0xf000
0xb6e0a6e4 <__aeabi_read_tp+4>: sub pc, r0, #31
however, it fails inserting breakpoint there. This problem has already
fixed by GDB, see comments in arm-linux-tdep.c:arm_linux_software_single_step
/* The Linux kernel offers some user-mode helpers in a high page. We can
not read this page (as of 2.6.23), and even if we could then we
couldn't set breakpoints in it, and even if we could then the atomic
operations would fail when interrupted. They are all called as
functions and return to the address in LR, so step to there
instead. */
so we need to do the same thing in GDB side as well. This patch adds
a new field fixup in arm_get_next_pcs_ops, so that we can fix up PC
for arm-linux target. In this way, both GDB and GDBserver can single
step instructions going to kernel helpers.
gdb:
2016-02-12 Yao Qi <yao.qi@linaro.org>
* arch/arm-get-next-pcs.c (arm_get_next_pcs): Call
self->ops->fixup if it isn't NULL.
* arch/arm-get-next-pcs.h: Include gdb_vecs.h.
(struct arm_get_next_pcs_ops) <fixup>: New field.
* arch/arm-linux.c: Include common-regcache.h and
arch/arm-get-next-pcs.h.
(arm_linux_get_next_pcs_fixup): New function.
* arch/arm-linux.h (arm_linux_get_next_pcs_fixup): Declare.
* arm-linux-tdep.c (arm_linux_get_next_pcs_ops): Initialize
it with arm_linux_get_next_pcs_fixup.
(arm_linux_software_single_step): Move code to
arm_linux_get_next_pcs_fixup.
* arm-tdep.c (arm_get_next_pcs_ops): Initialize it.
gdb/gdbserver:
2016-02-12 Yao Qi <yao.qi@linaro.org>
* linux-arm-low.c (get_next_pcs_ops): Initialize it with
arm_linux_get_next_pcs_fixup.
In skip_artificial_frames we repeatedly call get_prev_frame_always until we get
a non-inline and non-tailcall frame assuming that there must be such a frame
eventually.
For record targets, however, we may have a frame chain that consists only of
artificial frames. This leads to a crash in get_frame_type when dereferencing a
NULL frame pointer.
Change skip_artificial_frames and skip_tailcall_frames to return NULL in such a
case and modify each caller to cope with a NULL return.
In frame_unwind_caller_pc and frame_unwind_caller_arch, we simply assert that
the returned value is not NULL. Their caller was supposed to check
frame_unwind_caller_id before calling those functions.
In other cases, we thrown an error.
In infcmd further move the skip_tailcall_frames call to the forward-stepping
case since we don't need a frame for reverse execution and we don't want to fail
because of that. Reverse-finish does make sense for a tailcall frame.
gdb/
* frame.h (skip_tailcall_frames): Update comment.
* frame.c (skip_artificial_frames, skip_tailcall_frames): Return NULL
if only artificial frames are found. Update comment.
(frame_unwind_caller_id): Handle NULL return.
(frame_unwind_caller_pc, frame_unwind_caller_arch): Assert that
skip_artificial_frames does not return NULL.
(frame_pop): Add an error if only tailcall frames are found.
* infcmd.c (finish_command): Move skip_tailcall_frames call into forward-
execution case. Add an error if only tailcall frames are found.
testsuite/
* gdb.btrace/tailcall-only.exp: New.
* gdb.btrace/tailcall-only.c: New.
* gdb.btrace/x86_64-tailcall-only.S: New.
* gdb.btrace/i686-tailcall-only.S: New.
Callers of frame_unwind_caller_* functions are supposed to check
frame_unwind_caller_id.
Add such a check to frame_info and treat an invalid caller ID as if the caller
PC were not available.
gdb/
* stack.c (frame_info): Check frame_unwind_caller_id.
Currently, you can cd to the gdb/testsuite/ dir and use
make check-parallel, instead of using FORCE_PARALLEL:
$ make -j8 check-parallel RUNTESTFLAGS="--target_board=native-gdbserver"
$ make -j8 check RUNTESTFLAGS="--target_board=native-gdbserver" FORCE_PARALLEL=1
But you can't do that in the build/gdb/ dir:
$ make check-parallel RUNTESTFLAGS="--target_board=native-gdbserver"
make: *** No rule to make target `check-parallel'. Stop.
I find check-parallel a bit more convenient, and more typo-proof, so
this patch makes it work from the gdb build dir too.
While documenting this in testsuite/README, I found that the parallel
testing mode would better be pulled out to its own section and
extended.
gdb/ChangeLog:
2016-02-11 Pedro Alves <palves@redhat.com>
* Makefile.in (check-parallel): New rule.
gdb/testsuite/ChangeLog:
2016-02-11 Pedro Alves <palves@redhat.com>
* README (Parallel testing): New section.
(GDB_PARALLEL): Rewrite.
(FORCE_PARALLEL): Document.
This function is never used, since it is superseded by
arm_linux_displaced_step_copy_insn.
gdb/ChangeLog:
* arm-tdep.c (arm_displaced_step_copy_insn): Remove.
(ARM displaced stepping support): Remove reference to
arm_displaced_step_copy_insn in comment.
* arm-tdep.h (arm_displaced_step_copy_insn): Remove.
* arm-linux-tdep.c (arm_linux_displaced_step_copy_insn): Remove
reference to arm_displaced_step_copy_insn in comment.
Almost obvious... change the type of some insn parameters, so that it
matches the rest of the code.
gdb/ChangeLog:
* arm-tdep.c (thumb_copy_unmodified_16bit): Change type of insn.
(thumb_copy_b): Likewise.
(arm_decode_b_bl_ldmstm): Likewise.
(thumb_copy_16bit_ldr_literal): Likewise.
(thumb_copy_pop_pc_16bit): Likewise.
This patch uses the target architecture rather then the objfile
architecture when encoding tracepoint actions.
The target architecture may contain additional registers. E.g. ARM VFP
registers. This information is needed to allow their collection. Since we
can never know whether the registers numbers in the target match the
binary's we have to use tdesc here.
One note about combined debuggers / multi-inferior from Pedro Alves:
In the combined debugger case taking Cell as the practical example that
gdb supports currently:
In that case, the main target_gdbarch() will be powerpc, but you may have set a
tracepoint on _spu_ code, which has a different gdbarch. so for that case,
target_gdbarch would be wrong. I think that in that case, we'd need to
find __the_ target/tdesc gdbarch that is (bfd) compatible with the
objfile's gdbarch.
I think cell/spu gdbserver doesn't support tracepoints, so we can ignore
this for now.
The multi-inferior/process case is somewhat related, but its simpler.
each inferior has its own gdbarch.
That is, target_gdbarch depends on the current inferior selected.
In fact, that just returns inferior->gdbarch nowaways.
No regressions, tested on ubuntu 14.04 ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }
gdb/ChangeLog:
* tracepoint.c (encode_actions_1): Use target_gdbarch () rather
than loc->gdbarch.
tfile_fetch_registers currently wrongly fetches registers using
gdb order instead of g packet order. On x86_64 with AVX, this causes
problems with ymm*h and orig_rax registers: gdb has ymm*h first, while
g packet has orig_rax first.
gdb/ChangeLog:
* tracefile-tfile.c (tfile_fetch_registers): Use g packet order
instead of gdb order.
gdb/doc/ChangeLog:
* gdb.texinfo (Trace File Format): Remove misleading information
about register block ordering.
This resulted in the last register being considered unavailable.
On plain x86_64 (without AVX), this happened to be orig_rax.
gdb/ChangeLog:
* tracefile-tfile.c (tfile_fetch_registers): Fix off-by-one in bounds
check.
Now that the GDB 7.11 branch has been created, we can
bump the version number.
gdb/ChangeLog:
GDB 7.11 branch created (9ef9e6a6a0):
* version.in: Bump version to 7.11.50.DATE-git.
One of the last checks update_breakpoints_after_exec does while looping
over the list of breakpoints is check that the breakpoint has a valid
location spec. It uses event_location_empty_p to check if the location spec
is "empty", and if it is, the breakpoint is deleted.
momentary_breakpoint types rely on setting the breakpoint structure's
location spec to NULL, thereby causing an update to delete the breakpoint.
However, event_location_empty_p assumed that locations were never NULL.
As a result, GDB would crash dereferencing a NULL pointer whenever
update_breakpoints_after_exec would encounter a momentary_breakpoint.
This patch creates a new wrapper/helper function which tests that the given
breakpoint's location spec is non-NULL and if it is not "empty"
or "unspecified."
gdb/ChangeLog
PR breakpoints/19546
* breakpoint.c (breakpoint_event_location_empty_p): New function.
(update_breakpoints_after_exec, bkpt_re_set): Use this new function
instead of event_location_empty_p.
gdb/testsuite/ChangeLog
PR breakpoints/19546
* gdb.base/infcall-exec.c: New file.
* gdb.base/infcall-exec2.c: New file.
* gdb.base/infcall-exec.exp: New file.
MI is currently using string_to_event_location to enable the use of legacy
linespecs, but using this function (until this patchset) had the (as yet
unnoticed) side effect of allowing both MI and CLI representation for
explicit locations.
This patch simply changes MI to use the same legacy linespec functions
that the python and guile interpreters use. This eliminates the CLI syntax
for explicit locations (in MI).
gdb/ChangeLog
* mi/mi-cmd-break.c (mi_cmd_break_insert_1): Use
string_to_event_location_basic instead of string_to_event_location.
This patch, analogous to the previous python patch, implements proper
legacy linespec support in guile code using the newly introduced
string_to_event_location_basic.
gdb/ChangeLog
* guile/scm-breakpoint.c (gdbscm_register_breakpoint_x): Skip
leading whitespace and use string_to_event_location_basic instead
of new_linespec_location.
gdb/testsuite/ChangeLog
* gdb.guile/scm-breakpoint.exp (test_bkpt_address): New procedure.
(toplevel): Call test_bkpt_address.
Now that "legacy" linespecs benefit from consolidated support in
string_to_event_location_basic, python's Breakpoint command should use this
function to turn strings into event locations.
As a result, this patch fixes python/19506. Before:
(gdb) python gdb.Breakpoint("*main")
Traceback (most recent call last):
File "<string>", line 1, in <module>
RuntimeError: Function "*main" not defined.
Error while executing Python code.
After:
(gdb) python gdb.Breakpoint("*main")
Breakpoint 1 at 0x4005fb: file ../../../src/gdb/testsuite/gdb.python/py-breakpoint.c, line 32.
gdb/ChangeLog
PR python/19506
* python/py-breakpoint.c (bppy_init): Use
string_to_event_location_basic instead of new_linespec_location.
gdb/testsuite/ChangeLog
PR python/19506
* gdb.python/py-breakpoint.exp (test_bkpt_address): New procedure.
(toplevel): Call test_bkpt_address.
This patch refactors string_to_event_location, breaking it into two
separate functions:
1) string_to_event_location_basic
A "basic" string parser that implements support for "legacy" linespecs
(linespec, address, and probe locations). This function is intended to
be used by any UI wishing/needing to support this legacy behavior.
2) string_to_event_location
This is now intended as a CLI-only function which adds explicit location
parsing in a CLI-appropriate manner (in the form of traditional option/value
pairs).
Together these patches serve to simplify string-to-event location parsing
for all existing non-CLI interfaces (MI, guile, and python).
gdb/ChangeLog
* location.c (string_to_explicit_location): Note that "-p" is
reserved for probe locations and return NULL for any input
that starts with that.
(string_to_event_location): Move "legacy" linespec code to ...
(string_to_event_location_basic): ... here.
* location.h (string_to_event_location): Update comment.
(string_to_event_location_basic): New function.
Using AC_OUTPUT with arguments has been deprecated for some time in
autoconf, even in version 2.64, which we are using. This change should
not affect functionality.
I also removed the "exit 0"'s, they shouldn't be necessary.
gdb/ChangeLog:
* configure.ac: Use AC_CONFIG_FILES instead of passing arguments
to AC_OUTPUT. Remove "exit 0" at the end.
* configure: Regenerate.
gdb/testsuite/ChangeLog:
* configure.ac: Use AC_CONFIG_FILES instead of passing arguments
to AC_OUTPUT.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
* configure.ac: Use AC_CONFIG_FILES instead of passing arguments
to AC_OUTPUT.
* configure: Regenerate.
PR19548 shows that we still have problems related to 13fd3ff343:
[PR17431: following execs with "breakpoint always-inserted on"]
https://sourceware.org/ml/gdb-patches/2014-09/msg00733.html
The problem this time is that we currently update the global location
list and try to insert breakpoint locations after re-setting _each_
breakpoint in turn.
Say:
- We have _more_ than one breakpoint set. Let's assume 2.
- There's a breakpoint with a pre-exec address that ends up being an
unmapped address after the exec.
- That breakpoint is NOT the first in the breakpoint list.
Then when handling an exec, and we re-set the first breakpoint in the
breakpoint list, we mistakently try to install the old pre-exec /
un-re-set locations of the other breakpoint, which fails:
(gdb) continue
Continuing.
process 28295 is executing new program: (...)/execl-update-breakpoints2
Error in re-setting breakpoint 1: Warning:
Cannot insert breakpoint 2.
Cannot access memory at address 0x1000764
Breakpoint 1, main (argc=1, argv=0x7fffffffd368) at /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.base/execl-update-breakpoints.c:34
34 len = strlen (argv[0]);
(gdb)
Fix this by deferring the global location list update till after all
breakpoints are re-set.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/ChangeLog:
2016-02-09 Pedro Alves <palves@redhat.com>
PR breakpoints/19548
* breakpoint.c (create_overlay_event_breakpoint): Don't update
global location list here.
(create_longjmp_master_breakpoint)
(create_std_terminate_master_breakpoint)
(create_exception_master_breakpoint, create_jit_event_breakpoint)
(update_breakpoint_locations):
(breakpoint_re_set): Update global location list after all
breakpoints are re-set.
gdb/testsuite/ChangeLog:
2016-02-09 Pedro Alves <palves@redhat.com>
PR breakpoints/19548
* gdb.base/execl-update-breakpoints.c (some_function): New
function.
(main): Call it.
* gdb.base/execl-update-breakpoints.exp: Add a second breakpoint.
Tighten expected GDB output.
I built remote.c with -Wunused, to check a function I was working on,
turns out there is a bunch of unused variables.
gdb/ChangeLog:
* remote.c (remote_register_number_and_offset): Remove unused
variable(s).
(remote_thread_always_alive): Likewise.
(remote_update_thread_list): Likewise.
(process_initial_stop_replies): Likewise.
(remote_start_remote): Likewise.
(remote_check_symbols): Likewise.
(discard_pending_stop_replies): Likewise.
(process_stop_reply): Likewise.
(putpkt_binary): Likewise.
(getpkt): Likewise.
(remote_add_target_side_condition): Likewise.
(remote_insert_breakpoint): Likewise.
(remote_supports_stopped_by_sw_breakpoint): Likewise.
(remote_supports_stopped_by_hw_breakpoint): Likewise.
(remote_xfer_partial): Likewise.
(remote_read_btrace): Likewise.
(remote_async_serial_handler): Likewise.
(remote_thread_events): Likewise.
(_initialize_remote): Likewise.
This patch removes some dead code.
I noticed that varobj_delete was always called with dellist == NULL, so
I started removing that parameter. That allows removing a good chunk of
the code in varobj_delete, making it almost trivial. We can also remove
the resultp parameters in that whole trail. In turn, this shows that
struct cpstack, cppush and cppop were only used fo that mechanism, so
they can be removed as well.
I also moved the function comment to the header file to comply with
today's guideline, even though the rest of the file does not respect it
(yet).
gdb/ChangeLog:
* varobj.h (varobj_delete): Remove dellist parameter, update and
move documentation here.
* varobj.c (struct cpstack, cppush, cppop): Remove.
(delete_variable): Remove resultp (first) parameter.
(delete_variable_1): Likewise.
(varobj_delete): Remove dellist parameter and unused code.
(update_dynamic_varobj_children): Adjust varobj_delete call.
(update_type_if_necessary): Likewise.
(varobj_set_visualizer): Likewise.
(varobj_update): Likewise.
(value_of_root): Likewise.
(varobj_invalidate_iter): Likewise.
* mi/mi-cmd-var.c (mi_cmd_var_delete): Likewise.
Hi,
I see this error when GDB connects with qemu,
(gdb) n
....
Sending packet: $vCont;c#a8...Ack
Packet received: Ffstat,00000001,f6fff038
Cannot execute this command while the target is running.
Use the "interrupt" command to stop the target
and then try again.
looks we don't set rs->waiting_for_stop_reply to zero
before handle fileio request,
#10 0x00000000005edb64 in target_write (len=64, offset=4143968312, buf=0x7fffffffd570 "\375\377\377\377", annex=0x0, object=TARGET_OBJECT_MEMORY,
ops=<optimised out>) at /home/yao/SourceCode/gnu/gdb/git/gdb/target.c:1922
#11 target_write_memory (memaddr=memaddr@entry=4143968312, myaddr=myaddr@entry=0x7fffffffd6a0 "", len=len@entry=64)
at /home/yao/SourceCode/gnu/gdb/git/gdb/target.c:1500
#12 0x00000000004b2b41 in remote_fileio_func_fstat (buf=0x127b258 "") at /home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:1037
#13 0x00000000004b1878 in do_remote_fileio_request (uiout=<optimised out>, buf_arg=buf_arg@entry=0x127b240)
at /home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:1204
#14 0x00000000005b8c7c in catch_exceptions_with_msg (func_uiout=<optimised out>, func=func@entry=0x4b1800 <do_remote_fileio_request>,
func_args=func_args@entry=0x127b240, gdberrmsg=gdberrmsg@entry=0x0, mask=mask@entry=RETURN_MASK_ALL)
at /home/yao/SourceCode/gnu/gdb/git/gdb/exceptions.c:187
#15 0x00000000005b8dea in catch_exceptions (uiout=<optimised out>, func=func@entry=0x4b1800 <do_remote_fileio_request>, func_args=func_args@entry=0x127b240,
mask=mask@entry=RETURN_MASK_ALL) at /home/yao/SourceCode/gnu/gdb/git/gdb/exceptions.c:167
#16 0x00000000004b2fff in remote_fileio_request (buf=0x127b240 "Xf6fff038,0:", ctrlc_pending_p=0) at /home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:1255
#17 0x0000000000496f12 in remote_wait_as (ptid=..., status=0x7fffffffdb20, options=1) at /home/yao/SourceCode/gnu/gdb/git/gdb/remote.c:6997
however, we did set rs->waiting_for_stop_reply to zero before Luis's
patch https://sourceware.org/ml/gdb-patches/2015-10/msg00336.html
In fact, Luis's patch v1
https://sourceware.org/ml/gdb-patches/2015-08/msg00809.html is about
setting rs->waiting_for_stop_reply back to one after
remote_fileio_request, which is correct. However during the review, the
patch is changed and ends up with "not setting rs->waiting_for_stop_reply
to zero".
I manually test GDB, but I don't have a way to run regression tests.
gdb:
2016-02-04 Yao Qi <yao.qi@linaro.org>
* remote.c (remote_wait_as): Set rs->waiting_for_stop_reply to
0 before handling 'F' and set it back afterwards.
This is unused since 54eb231c4b, where
static arrays of ui_out_levels were replaced with vectors.
gdb/ChangeLog:
* ui-out.c (MAX_UI_OUT_LEVELS): Remove.
New bnds fields will be always present for x86 architecture.
Fixup for compatibility layer 32bits has to be fixed.
It was added the nat_siginfo to serving as intermediate step
between kernel provided siginfo and the fix up routine.
When executing compat_siginfo_from_siginfo or
compat_x32_siginfo_from_siginfo first the buffer read from the kernel are
converted into the nat_signfo for homogenization, then the fields of
nat_siginfo are use to set the compat and compat_x32 siginfo fields.
In other to make this conversion independent of the system where gdb
is compiled the most complete version of the siginfo, named as native
siginfo, is used internally as an intermediate step.
Conversion using nat_siginfo is exemplified below:
compat_siginfo_from_siginfo or compat_x32_siginfo_from_siginfo:
buffer (from the kernel) -> nat_siginfo -> 32 / X32 siginfo
(memcpy) (field by field)
siginfo_from_compat_x32_siginfo or siginfo_from_compat_siginfo:
32 / X32 siginfo -> nat_siginfo -> buffer (to the kernel)
(field by field) (memcpy)
Caveat: No support for MPX on x32.
2016-02-02 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/ChangeLog:
* amd64-linux-siginfo.c (nat_siginfo_t, nat_sigval_t, nat_timeval):
New types.
(compat_siginfo): New bound fields added.
(compat_x32_siginfo): New field added.
(cpt_si_addr_lsb): New define.
(compat_siginfo_from_siginfo): Use nat_siginfo.
(siginfo_from_compat_siginfo): Use nat_siginfo.
(compat_x32_siginfo_from_siginfo): Likewise.
(siginfo_from_compat_x32_siginfo): Likewise.
Both Linux and glibc have introduced bound related fields in the
segmentation fault fields of the siginfo_t type. Add the new fields
to our x86's siginfo_t type too.
Kernel patch:
http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=ee1b58d36aa1b5a79eaba11f5c3633c88231da83
Glibc patch:
d4358b51c2
2016-02-02 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/ChangeLog:
* linux-tdep.c (linux_get_siginfo_type): Add the _addr_bnd
structure to the siginfo if extra_fields contains
LINUX_SIGINFO_FIELD_ADDR_BND.
Use linux_get_siginfo_type_with_fields for adding bound fields on
segmentation fault for i386/amd64 siginfo.
2016-02-02 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/ChangeLog:
* linux-tdep.h (linux_get_siginfo_type_with_fields): Make extern.
* linux-tdep.c (linux_get_siginfo_type_with_fields): Make extern.
* i386-linux-tdep.h (x86_linux_get_siginfo_type): New
function.
* amd64-linux-tdep.c (amd64_linux_init_abi_common): Add
x86_linux_get_siginfo_type for the amd64 abi.
* i386-linux-tdep.c (x86_linux_get_siginfo_type): New
function.
(i386_linux_init_abi): Add new function at the i386 ABI
initialization.
First add new structure and function to allow architecture customization
for the siginfo structure.
2016-01-15 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/ChangeLog:
* linux-tdep.h (linux_siginfo_extra_field_values): New enum values.
(linux_siginfo_extra_fields): New enum type.
* linux-tdep.c (linux_get_siginfo_type_with_fields): New function.
(linux_get_siginfo_type): Use new function.
For languages with dynamic types, an incorrect program, or uninitialised
variables within a program, could result in an incorrect, overly large
type being associated with a value. Currently, attempting to print such
a variable will result in gdb trying to allocate an overly large buffer.
If this large memory allocation fails then the result can be gdb either
terminating, or (due to memory contention) becoming unresponsive for the
user.
A new user visible variable in gdb helps guard against such problems,
two new commands are available:
set max-value-size
show max-value-size
The 'max-value-size' is the maximum size of memory in bytes that gdb
will allocate for the contents of a value. Any attempt to allocate a
value with a size greater than this will result in an error. The
initial default for this limit is set at 64k, this is based on a similar
limit that exists within the ada specific code.
It is possible for the user to set max-value-size to unlimited, in which
case the old behaviour is restored.
gdb/ChangeLog:
* value.c (max_value_size): New variable.
(MIN_VALUE_FOR_MAX_VALUE_SIZE): New define.
(show_max_value_size): New function.
(check_type_length_before_alloc): New function.
(allocate_value_contents): Call check_type_length_before_alloc.
(set_value_enclosing_type): Likewise.
(_initialize_values): Add set/show handler for max-value-size.
* NEWS: Mention new set/show command.
gdb/doc/ChangeLog:
* gdb.texinfo (Value Sizes): New section.
(Data): Add the 'Value Sizes' node to the menu.
gdb/testsuite/ChangeLog:
* gdb.base/max-value-size.c: New file.
* gdb.base/max-value-size.exp: New file.
* gdb.base/huge.exp: Disable max-value-size for this test.
A few typos. The comment about varobj_create has been misplaced since
the dawn of time.
gdb/ChangeLog:
* varobj.h (struct varobj): Fix typos in comments.
(struct lang_varobj_ops): Likewise.
* varobj.c (VAROBJ_TABLE_SIZE): Likewise.
(varobj_create): Move misplaced comment.
Two small changes so everything builds with latest GCC and its
-Wmisleading-indentation.
In the aarch64-tdep.c case, the two misindented lines should actually be
part of the for loop. It looks like the indentation is all done using
spaces in that file though... I fixed it (changed for tabs + spaces) for
the lines I touched.
In the xcoffread.c case, we can simply remove the braces and fix the
indentation.
gdb/ChangeLog:
* aarch64-tdep.c (aarch64_record_asimd_load_store): Add braces
to for include additional lines.
* xcoffread.c (scan_xcoff_symtab): Remove unnecessary braces.
rawmemchr is a dependency of strchrnul, so it should be explicitly
listed.
gdb/ChangeLog:
* gnulib/import/Makefile.am: Regenerate.
* gnulib/import/Makefile.in: Regenerate.
* gnulib/import/m4/gnulib-cache.m4: Regenerate.
* gnulib/update-gnulib.sh (IMPORTED_GNULIB_MODULES): Add rawmemchr.
For a forthcoming patch, I need a "skip_to_colon" function. I noticed
there are two skip_to_semicolon (one in gdb and one in gdbserver). I
thought we could put it in common/, and generalize it for any character.
It turns out that the strchrnul function does exactly that. I imported
the corresponding module from gnulib, for those systems that do not have
it.
There are probably more places where this function can be used instead
of doing the work by hand (I am looking at
remote-utils.c::look_up_one_symbol).
gdb/ChangeLog:
* remote.c (skip_to_semicolon): Remove.
(remote_parse_stop_reply): Use strchrnul instead of
skip_to_semicolon.
* gnulib/update-gnulib.sh (IMPORTED_GNULIB_MODULES): Add
strchrnul.
* gnulib/aclocal.m4: Regenerate.
* gnulib/config.in: Regenerate.
* gnulib/configure: Regenerate.
* gnulib/import/Makefile.am: Regenerate.
* gnulib/import/Makefile.in: Regenerate.
* gnulib/import/m4/gnulib-cache.m4: Regenerate.
* gnulib/import/m4/gnulib-comp.m4: Regenerate.
* gnulib/import/m4/rawmemchr.m4: New file.
* gnulib/import/m4/strchrnul.m4: New file.
* gnulib/import/rawmemchr.c: New file.
* gnulib/import/rawmemchr.valgrind: New file.
* gnulib/import/strchrnul.c: New file.
* gnulib/import/strchrnul.valgrind: New file.
gdb/gdbserver/ChangeLog:
* server.c (skip_to_semicolon): Remove.
(process_point_options): Use strchrnul instead of
skip_to_semicolon.
I see GDB crashes in dprintf.exp on aarch64-linux testing,
(gdb) PASS: gdb.base/dprintf.exp: agent: break 29
set dprintf-style agent^M
(gdb) PASS: gdb.base/dprintf.exp: agent: set dprintf style to agent
continue^M
Continuing.
ASAN:SIGSEGV
=================================================================
==22475==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x000000494820 sp 0x7fff389b83a0 bp 0x62d000082417 T0)
#0 0x49481f in remote_add_target_side_commands /home/yao/SourceCode/gnu/gdb/git/gdb/remote.c:9190^M
#1 0x49e576 in remote_add_target_side_commands /home/yao/SourceCode/gnu/gdb/git/gdb/remote.c:9174^M
#2 0x49e576 in remote_insert_breakpoint /home/yao/SourceCode/gnu/gdb/git/gdb/remote.c:9240^M
#3 0x5278b7 in insert_bp_location /home/yao/SourceCode/gnu/gdb/git/gdb/breakpoint.c:2734^M
#4 0x52ac09 in insert_breakpoint_locations /home/yao/SourceCode/gnu/gdb/git/gdb/breakpoint.c:3159^M
#5 0x52ac09 in update_global_location_list /home/yao/SourceCode/gnu/gdb/git/gdb/breakpoint.c:12686
the root cause of this problem in this case is about linespec and
symtab which produces additional incorrect location and a NULL is added to
bp_tgt->tcommands. I posted a patch
https://sourceware.org/ml/gdb-patches/2015-12/msg00321.html to fix it
in linespec (the fix causes regression), but GDB still shouldn't add
NULL into bp_tgt->tcommands. The logic of build_target_command_list
looks odd to me. If we get something wrong in parse_cmd_to_aexpr (it
returns NULL), we shouldn't continue, instead we should set flag
null_command_or_parse_error. This is what this patch does. In the
meantime, we find build_target_condition_list has the same problem, so
fix it too.
gdb:
2016-01-28 Yao Qi <yao.qi@linaro.org>
* breakpoint.c (build_target_command_list): Don't call continue
if aexpr is NULL.
(build_target_condition_list): Likewise.
