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.
This function is now basically identical to write_inferior_data_pointer,
remove it and change all references.
gdb/gdbserver/ChangeLog:
* tracepoint.c (x_tracepoint_action_download): Change
write_inferior_data_ptr to write_inferior_data_pointer.
(cmd_qtstart): Likewise.
(write_inferior_data_ptr): Remove.
(download_agent_expr): Change write_inferior_data_ptr to
write_inferior_data_pointer.
(download_tracepoint_1): Likewise.
(download_tracepoint): Likewise.
(download_trace_state_variables): Likewise.
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.
Before binutils 2.26, -Bsymbolic and -Bsymbolic-functions were also
applied to PIE so that "ld -pie -Bsymbolic -E" can be used to export
symbols in PIE with local binding. This patch re-enables -Bsymbolic
and -Bsymbolic-functions for PIE.
PR ld/19615
* ld.texinfo: Document -Bsymbolic and -Bsymbolic-functions for
PIE.
* lexsup.c (parse_args): Enable -Bsymbolic and
-Bsymbolic-functions for PIE.
* testsuite/ld-i386/i386.exp: Run pr19175.
* testsuite/ld-i386/pr19615.d: New file.
* testsuite/ld-i386/pr19615.s: Likewise.
* testsuite/ld-x86-64/pr19615.d: Likewise.
* testsuite/ld-x86-64/pr19615.s: Likewise.
This patch removes 'ops' in tracepoint, and uses helper functions to
call action handler instead.
The object layout of tracepoint_action may differ in gdbserver and
inferior depend on the alignment rule of target ABI, so gdbserver cannot
simply copy the object from its memory to inferior memory.
For example,
struct collect_memory_action
{
struct tracepoint_action base;
{
#ifndef IN_PROCESS_AGENT
const struct tracepoint_action_ops *ops;
#if
- char type;
| }
| ULONGEST addr;
| ULONGEST len;
- int32_t basereg;
};
and on PowerPC,
Wihtout ops with ops
0 1 2 3 0 1 2 3
0 |type| PADDING... 0 |ops-------------|
4 ................. 4 |type|PADDING....|
8 |addr------------ 8 |addr-------------
c ----------------| c -----------------|
10 |len------------- 10 |len--------------
14 ----------------| 14 -----------------|
18 |basereg--------| 18 |basereg---------|
so we cannot directly copy the object.
In this patch, 'ops' is removed in order to make the objects identical.
gdb/gdbserver/ChangeLog:
2016-02-11 Wei-cheng Wang <cole945@gmail.com>
Marcin Kościelnicki <koriakin@0x04.net>
* tracepoint.c (struct tracepoint_action_ops): Remove.
(struct tracepoint_action): Remove ops.
(m_tracepoint_action_download, r_tracepoint_action_download)
(x_tracepoint_action_download, l_tracepoint_action_download): Adjust
size and offset accordingly.
(m_tracepoint_action_ops, r_tracepoint_action_ops)
(x_tracepoint_action_ops, l_tracepoint_action_ops): Remove.
(tracepoint_action_send, tracepoint_action_download): New functions.
Helpers for trace action handlers.
(add_tracepoint_action): Remove setup actions ops.
(download_tracepoint_1, tracepoint_send_agent): Call helper functions.
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.
2016-02-11 Rahul Chaudhry <rahulchaudhry@google.com>
* aarch64.cc (Target_aarch64::scan_erratum_843419_span):
Remove info message for every erratum 843419 found and fixed.
PR gas/19614
* dw2gencfi.c (cfi_sections_set): Delay setting this variable
until it is actually used.
(cfi_set_sections): Set cfi_sections_set to true.
(dot_cfi_startproc): Likewise.
(dot_cfi_endproc): Likewise.
(dot_cfi_fde_data): Likewise.
(cfi_finish): Likewise.
(dot_cfi_sections): Do not set cfi_sections_set.
* doc/as.texinfo (.cfi_sections): Note that targets can provide
their own cfi section name. Also note that the directive can be
reissued provided that CFI generation has not started.
* testsuite/gas/mips/compact-eh-err2.s: Add .cfi_startproc and
.cfi_endproc directives so that the redefinition of .cfi_sections
will trigger the generation of the error message.
* testsuite/gas/mips/compact-eh-err2.l: Update expected line
number of error message.
This tests whether $ymm15 can be correctly collected and printed from
tfile. It covers:
- storing tdesc in tfile (without that, $ymm15 doesn't exist)
- ax_pseudo_register_collect for x86 (without that, $ymm15 cannot be
collected)
- register order in tfile_fetch_registers (without that, $ymm15h is
fetched from wrong position)
- off-by-one in tfile_fetch_registers (without that, $ymm15h is
incorrectly considered to be out of bounds)
- using proper tdesc in encoding tracepoint actions (without that,
internal error happens due to $ymm15h being considered unavailable)
gdb/testsuite/ChangeLog:
* gdb.trace/tfile-avx.c: New test.
* gdb.trace/tfile-avx.exp: New test.
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.
The least significant bit in GOT offset is to record whether we have
initialized the GOT entry in R_386_GOT32 processing. We need to mask
it off for R_386_GOT32X.
PR ld/19601
* elf32-i386.c (elf_i386_relocate_section): Mask off the least
significant bit in GOT offset for R_386_GOT32X.
We have function regcache_raw_read_unsigned defined in both GDB and
GDBserver, so that it is used in common like this,
ULONGEST value;
status = regcache_raw_read_unsigned (regcache, regnum, &value);
'value' is correctly set in GDB side, but may not be correctly set
in GDBserver, because &value is passed in regcache_raw_read_unsigned
but collect_register may only set part of the whole variable. In my
test, I see the top half of 'value' is garbage. This patch fixes this
problem by clearing *VAL before calling collect_register.
gdb/gdbserver:
2016-02-10 Yao Qi <yao.qi@linaro.org>
* regcache.c (regcache_raw_read_unsigned): Clear *VAL.
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.
PR 19405
* elf32-nios2.c (nios2_elf32_install_imm16): Allow for signed
immediate values.
* elf-eh-frame.c (_bfd_elf_discard_section_eh_frame): Limit the
number of messages about FDE encoding preventing .eh_frame_hdr
generation.
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 13fd3ff34329:
[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.
Change the signature of gdbserver's siginfo_fixup functions so that it's
in line with gdb's. This gets rid of the following build error in C++:
/home/emaisin/src/binutils-gdb/gdb/gdbserver/linux-x86-low.c: In function ‘int x86_siginfo_fixup(siginfo_t*, void*, int)’:
/home/emaisin/src/binutils-gdb/gdb/gdbserver/linux-x86-low.c:694:21: error: invalid conversion from ‘void*’ to ‘gdb_byte* {aka unsigned char*}’ [-fpermissive]
FIXUP_32);
^
In file included from /home/emaisin/src/binutils-gdb/gdb/gdbserver/linux-x86-low.c:31:0:
/home/emaisin/src/binutils-gdb/gdb/gdbserver/../nat/amd64-linux-siginfo.h:52:5: error: initializing argument 2 of ‘int amd64_linux_siginfo_fixup_common(siginfo_t*, gdb_byte*, int, amd64_siginfo_fixup_mode)’ [-fpermissive]
int amd64_linux_siginfo_fixup_common (siginfo_t *native, gdb_byte *inf,
^
/home/emaisin/src/binutils-gdb/gdb/gdbserver/linux-x86-low.c:698:20: error: invalid conversion from ‘void*’ to ‘gdb_byte* {aka unsigned char*}’ [-fpermissive]
FIXUP_X32);
^
In file included from /home/emaisin/src/binutils-gdb/gdb/gdbserver/linux-x86-low.c:31:0:
/home/emaisin/src/binutils-gdb/gdb/gdbserver/../nat/amd64-linux-siginfo.h:52:5: error: initializing argument 2 of ‘int amd64_linux_siginfo_fixup_common(siginfo_t*, gdb_byte*, int, amd64_siginfo_fixup_mode)’ [-fpermissive]
int amd64_linux_siginfo_fixup_common (siginfo_t *native, gdb_byte *inf,
^
gdb/gdbserver/ChangeLog:
* linux-aarch64-low.c (aarch64_linux_siginfo_fixup): Change
void * to gdb_byte *.
* linux-low.c (siginfo_fixup): Likewise.
(linux_xfer_siginfo): Likewise.
* linux-low.h (struct linux_target_ops) <siginfo_fixup>:
Likewise.
* linux-x86-low.c (x86_siginfo_fixup): Likewise.
bfd * elfnn-aarch64.c (elfNN_aarch64_relocate_section): Add a more
helpful warning message to explain why certain AArch64 relocs
might overflow.
ld * testsuite/ld-aarch64/reloc-overflow-bad.d: New test.
* testsuite/ld-aarch64/reloc-overflow-1.s: New source file.
* testsuite/ld-aarch64/reloc-overflow-2.s: New source file.
* testsuite/ld-aarch64/aarch64-elf.exp: Run the new test.
Add a cast to reinterpret a void* as a gdb_byte*.
2016-02-09 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/gdbserver/ChangeLog:
* linux-x86-low.c (x86_siginfo_fixup): Add cast to gdb_byte*.
bfd * elfnn-aarch64.c (elfNN_aarch64_relocate_section): Add a more
helpful warning message to explain why certain AArch64 relocs
might overflow.
ld * testsuite/ld-aarch64/reloc-overflow-bad.d: New test.
* testsuite/ld-aarch64/reloc-overflow-1.s: New source file.
* testsuite/ld-aarch64/reloc-overflow-2.s: New source file.
* testsuite/ld-aarch64/aarch64-elf.exp: Run the new test.