When using a reverse execution command without execution history, GDB
might end up in a state where replaying has been started but remains
at the current instruction. This state is illegal.
Do not step if there is no execution history to avoid this.
2014-05-20 Markus Metzger <markus.t.metzger@intel.com>
* record-btrace.c (record_btrace_step_thread): Check for empty history.
testsuite/
* gdb.btrace/nohist.exp: New.
The root cause of this issue is unwinder of "#3 <signal handler called>"
doesn't supply right values of registers.
When GDB want to get the previous frame of "#3 <signal handler called>",
it will call cache init function of unwinder "aarch64_linux_sigframe_init".
The address or the value of the registers is get from this function.
So the bug is inside thie function.
I check the asm code of "#3 <signal handler called>":
(gdb) frame 3
(gdb) p $pc
$1 = (void (*)()) 0x7f931fa4d0
(gdb) disassemble $pc, +10
Dump of assembler code from 0x7f931fa4d0 to 0x7f931fa4da:
=> 0x0000007f931fa4d0: mov x8, #0x8b // #139
0x0000007f931fa4d4: svc #0x0
0x0000007f931fa4d8: nop
This is the syscall sys_rt_sigreturn, Linux kernel function "restore_sigframe"
will set the frame:
for (i = 0; i < 31; i++)
__get_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i],
err);
__get_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err);
__get_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err);
The struct of uc_mcontext is:
struct sigcontext {
__u64 fault_address;
/* AArch64 registers */
__u64 regs[31];
__u64 sp;
__u64 pc;
__u64 pstate;
/* 4K reserved for FP/SIMD state and future expansion */
__u8 __reserved[4096] __attribute__((__aligned__(16)));
};
But in GDB function "aarch64_linux_sigframe_init", the code the get address
of registers is:
for (i = 0; i < 31; i++)
{
trad_frame_set_reg_addr (this_cache,
AARCH64_X0_REGNUM + i,
sigcontext_addr + AARCH64_SIGCONTEXT_XO_OFFSET
+ i * AARCH64_SIGCONTEXT_REG_SIZE);
}
trad_frame_set_reg_addr (this_cache, AARCH64_FP_REGNUM, fp);
trad_frame_set_reg_addr (this_cache, AARCH64_LR_REGNUM, fp + 8);
trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM, fp + 8);
The code that get pc and sp is not right, so I change the code according
to Linux kernel code:
trad_frame_set_reg_addr (this_cache, AARCH64_SP_REGNUM,
sigcontext_addr + AARCH64_SIGCONTEXT_XO_OFFSET
+ 31 * AARCH64_SIGCONTEXT_REG_SIZE);
trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM,
sigcontext_addr + AARCH64_SIGCONTEXT_XO_OFFSET
+ 32 * AARCH64_SIGCONTEXT_REG_SIZE);
The issue was fixed by this change, and I did the regression test. It
also fixed a lot of other XFAIL and FAIL.
2014-05-20 Hui Zhu <hui@codesourcery.com>
Yao Qi <yao@codesourcery.com>
PR backtrace/16558
* aarch64-linux-tdep.c (aarch64_linux_sigframe_init): Update comments
and change address of sp and pc.
* dwarf2read.c (build_type_psymtabs_1): Renamed from
build_type_unit_groups and moved closer to only caller. Remove
arguments. All references updated. Remove outdated .gdb_index
comment.
(struct tu_abbrev_offset, sort_tu_by_abbrev_offset): Move with
build_type_psymtabs_1.
I'm checking this in as obvious.
I was looking at instances of "alloc.*sizeof" and noticed a couple
where the types in question are incorrect.
In gdbtypes, the code allocates sizeof(int) to represent a struct rank.
In mi-cmds, the code uses "struct mi_cmd **" -- one "*" too many.
In both cases the problems are latent because in practice the sizes
are the same as the sizes of the correct types. Still, it's better to
be correct.
I think gdb would be improved by a wholesale change from explicit
sizeofs to using the libiberty.h allocation macros. In most cases
they are both shorter and have better type safety. However, the
resulting patch is rather large.
Built and regtested on x86-64 Fedora 20.
2014-05-19 Tom Tromey <tromey@redhat.com>
* gdbtypes.c (rank_function): Use XNEWVEC.
* mi/mi-cmds.c (build_table): Use XCNEWVEC.
Pierre proposed this patch
https://sourceware.org/ml/gdb-patches/2013-10/msg00011.html and
Tom gave a suggestion that it's better to do check \t in print_wchar
<https://sourceware.org/ml/gdb-patches/2013-11/msg00148.html>
However, I don't see the follow-up to this discussion.
We encounter two fails in printcmds.exp on mingw host, and Pierre's
patch fixes them. I pick it up, update a little per Tom's
comments, and post it here for review. This patch fixes these fails
below on mingw32 host.
FAIL: gdb.base/charset.exp: print string in ASCII
FAIL: gdb.base/charset.exp: try printing '\t' in ASCII
FAIL: gdb.base/charset.exp: print string in ISO-8859-1
FAIL: gdb.base/charset.exp: try printing '\t' in ISO-8859-1
FAIL: gdb.base/charset.exp: print string in UTF-32
FAIL: gdb.base/charset.exp: try printing '\t' in UTF-32
FAIL: gdb.base/printcmds.exp: p ctable1[9]
FAIL: gdb.base/printcmds.exp: p &ctable1[1*8]
Also regression tested on x86_64-linux. Is it OK?
gdb:
2014-05-16 Pierre Muller <muller@sourceware.org>
Yao Qi <yao@codesourcery.com>
* valprint.c (print_wchar): Move the code on checking whether
W is a printable wide char to the default branch of switch
statement below. Call wchar_printable instead of gdb_iswprint.
Prologue analysis for ldr.w and ldrd instruction obtains offset from
first two bytes that contains opcode of instruction. It should obtain
offset from next two bytes that actually contain operands.
* arm-tdep.c (thumb_analyze_prologue): Fix offset calculation for
ldr.w and ldrd instructions.
Signed-off-by: Taimoor Mirza <tmirza@codesourcery.com>
I happened to notice that print_macro_definition is indented
improperly. All the lines were a few extra spaces to the right.
This patch fixes the indentation.
Tested by rebuilding, committed.
2014-05-14 Tom Tromey <tromey@redhat.com>
* macrocmd.c (print_macro_definition): Reindent.
should_resume is set to 1 at the beginning and never changed.
gdb/ChangeLog:
2014-05-13 Simon Marchi <simon.marchi@ericsson.com>
* infrun.c (resume): Remove should_resume (unused). Move up
declaration of resume_ptid.
This patch removes an unused macro from language.h. It also removes
the declaration of a function which is not defined.
I'm checking this in as obvious.
Tested by rebuilding.
2014-05-13 Tom Tromey <tromey@redhat.com>
* language.h (unop_type_check): Remove.
(binop_type_check): Don't declare.
In mi_interpreter_init, multiple MI consoles/channels are created and a quoting
character is given. In mi_console_raw_packet, we check if the value is not 0
to decide if we should quote the string, but we don't use the value. It is
hardcoded to ". We might never use another quoting character than an actual
quote, but I suggest we change it, for correctness. There is not visible
behavior change.
I changed the latest fputs_unfiltered changed to fputc_unfiltered just to stay
consistent.
gdb/ChangeLog:
2014-05-12 Simon Marchi <simon.marchi@ericsson.com>
* mi/mi-console.c (mi_console_raw_packet): Use the value from
mi_console->quote as the quoting character.
I think "set debugvarobj" has the wrong name.
It ought to be "set debug varobj", like gdb's other debug settings.
This patch makes the change.
I chose not to install deprecated aliases, since this is only a debug
setting; but if someone feels strongly about it I will add them.
Built and regtested on x86-64 Fedora 20.
2014-04-29 Tom Tromey <tromey@redhat.com>
* varobj.c (_initialize_varobj): Rename to "set debug varobj" and
"show debug varobj".
2014-04-29 Tom Tromey <tromey@redhat.com>
* gdb.texinfo (Debugging Output): Rename to "set debug varobj" and
"show debug varobj".
gdb/Changelog:
* aarch64-tdep.c (aarch64_software_single_step): New function.
(aarch64_gdbarch_init): Handle single stepping of atomic sequences
with aarch64_software_single_step.
gdb/testsuite/ChangeLog:
* gdb.arch/aarch64-atomic-inst.c: New file.
* gdb.arch/aarch64-atomic-inst.exp: New file.
2014-05-05 Keith Seitz <keiths@redhat.com>
* linespec.c (linespec_parse_basic): Run cleanups if a convenience
variable or history value is successfully parsed.
2014-05-05 Keith Seitz <keiths@redhat.com>
* gdb.linespec/ls-dollar.exp: Add test for linespec
file:convenience_variable.
In gdb.trace/unavailable.exp, an action is defined to collect
struct_b.struct_a.array[2] and struct_b.struct_a.array[100],
struct StructB
{
int d, ef;
StructA struct_a;
int s:1;
static StructA static_struct_a;
const char *string;
};
and the other files are not collected.
When GDB examine traceframe collected by the action, "struct_b" is
unavailable completely, which is wrong.
(gdb) p struct_b
$1 = <unavailable>
When GDB reads 'struct_b', it will request to read memory at struct_b's address
of length LEN. Since struct_b.d is not collected, no 'M' block
includes the first part of the desired range, so tfile_xfer_partial returns
TARGET_XFER_UNAVAILABLE and GDB thinks the whole requested range is unavailable.
In order to fix this problem, in the iteration to 'M' blocks, we record the
lowest address of blocks within the request range. If it has, the requested
range isn't unavailable completely. This applies to ctf too. With this patch
applied, the result looks good and fails in unavailable.exp is fixed.
(gdb) p struct_b
$1 = {d = <unavailable>, ef = <unavailable>, struct_a = {a = <unavailable>, b = <unavailable>, array = {<unavailable>,
<unavailable>, -1431655766, <unavailable> <repeats 97 times>, -1431655766, <unavailable> <repeats 9899 times>}, ptr = <unavailable>, bitfield = <unavailable>}, s = <unavailable>, static static_struct_a = {a = <unavailable>, b = <unavailable>, array = {<unavailable> <repeats 10000 times>}, ptr = <unavailable>,
bitfield = <unavailable>}, string = <unavailable>}
gdb:
2014-05-05 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* tracefile-tfile.c (tfile_xfer_partial): Record the lowest
address of blocks that intersects the requested range. Trim
LEN up to LOW_ADDR_AVAILABLE if read from executable read-only
sections.
* ctf.c (ctf_xfer_partial): Likewise.
gdb/testsuite:
2014-05-05 Yao Qi <yao@codesourcery.com>
* gdb.trace/unavailable.exp (gdb_collect_args_test): Save
traceframes into tfile and ctf trace files. Read data from
trace file and test collected data.
(gdb_collect_locals_test): Likewise.
(gdb_unavailable_registers_test): Likewise.
(gdb_unavailable_floats): Likewise.
(gdb_collect_globals_test): Likewise.
(top-level): Append "ctf" to trace_file_targets if GDB
supports.
When I run refactored unavailable.exp, I find
command display behaves a little different on live inferior and on
examining traceframes. In live inferior, when command "display argc"
is typed, the value of "argc" is shown.
(gdb) display argc
1: argc = 1 '\001'
however, on tfile target, when command "display argc" is typed, the
value of "argc" is not shown.
(gdb) tfind
Found trace frame 0, tracepoint 1
at ../../../../git/gdb/testsuite/gdb.trace/unavailable.cc:198
198 i = (int) argc + argi + argf + argd + argstruct.memberi + argarray[1];
(gdb) display argc
I also notice that on "core" target, the value of "argc" isn't shown
either. This difference is caused by the code below in printcmd.c:display_command,
if (from_tty && target_has_execution)
do_one_display (new);
Looks the value of each display is shown if the target has execution.
Source code archaeology doesn't tell much about this requirement.
However, if we type command "display" then on "core" or "tfile"
target, the value of "argc" is still displayed,
for "core" target,
(gdb) display argc
(gdb) display
1: argc = 1 '\001'
for "tfile" target,
(gdb) display argc
(gdb) display
1: argc = <unavailable>
I feel that it is not necessary to have such "target has execution"
requirement to show the value of new created display. Auto-display is
a feature to show the value of expression frequently, has nothing to
do with whether target has execution or not. On the other hand, GDB
has the requirement for new created display, but command "display" can
still show them, this is an inconsistency, which should be fixed.
This patch is to remove the checking to target_has_execution from the
condition.
gdb:
2014-05-05 Yao Qi <yao@codesourcery.com>
* printcmd.c (display_command): Remove the check to
target_has_execution.
This commit is actually an update to make the parser in
gdb/stap-probe.c be aware of all the possible prefixes that a probe
argument can have. According to the section "Argument Format" in:
<https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation>
The bitness of the arguments can be 8, 16, 32 or 64 bits, signed or
unsigned. Currently GDB recognizes only 32 and 64-bit arguments.
This commit extends this. It also provides a testcase, only for
x86_64 systems.
gdb/
2014-05-02 Sergio Durigan Junior <sergiodj@redhat.com>
* stap-probe.c (enum stap_arg_bitness): New enums to represent 8
and 16-bit signed and unsigned arguments. Update comment.
(stap_parse_probe_arguments): Extend code to handle such
arguments. Use warning instead of complaint to notify about
unrecognized bitness.
gdb/testsuite/
2014-05-02 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.arch/amd64-stap-optional-prefix.S (main): Add several
probes to test for bitness recognition.
* gdb.arch/amd64-stap-optional-prefix.exp
(test_probe_value_without_reg): New procedure.
Add code to test for different kinds of bitness.
This commit fixes PR breakpoints/16889, which is about a bug that
triggers when GDB tries to parse probes whose arguments do not contain
the initial (and optional) "N@" part. For reference sake, the de
facto format is described here:
<https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation>
Anyway, this PR actually uncovered two bugs (related) that were
happening while parsing the arguments. The first one was that the
parser *was* catching *some* arguments that were missing the "N@"
part, but it wasn't correctly setting the argument's type. This was
causing a NULL pointer being dereferenced, ouch...
The second bug uncovered was that the parser was not catching all of
the cases for a probe which did not provide the "N@" part. The fix
for that was to simplify the check that the code was making to
identify non-prefixed probes. The code is simpler and easier to read
now.
I am also providing a testcase for this bug, only for x86_64
architectures.
gdb/
2014-05-02 Sergio Durigan Junior <sergiodj@redhat.com>
PR breakpoints/16889
* stap-probe.c (stap_parse_probe_arguments): Simplify
check for non-prefixed probes (i.e., probes whose
arguments do not start with "N@"). Always set the
argument type to a sane value.
gdb/testsuite/
2014-05-02 Sergio Durigan Junior <sergiodj@redhat.com>
PR breakpoints/16889
* gdb.arch/amd64-stap-optional-prefix.S: New file.
* gdb.arch/amd64-stap-optional-prefix.exp: Likewise.
When connecting to a remote system, we use the compare-sections
command to verify that the box is running the code that we think it is
running. Since the system is up and running and *NOT* 'freshly
downloaded without yet executing anything', read-write sections, of
course, differ from what they were in the executable file.
Comparing read-write sections takes time and more importantly the
MIS-MATCHED output is confusing to some users.
The compare-sections command compares all loadable sections including
read-write sections. This patch gives the user the option to compare
just the loadable read-only sections.
gdb/
2014-05-01 David Taylor <dtaylor@emc.com>
* remote.c (compare_sections_command): Add -r option to compare
all loadable read-only sections.
gdb/doc/
2014-05-01 David Taylor <dtaylor@emc.com>
* gdb.texinfo (compare-sections): Document the new -r (read-only)
option.
... and others. The recent patch that fixed several "set remote
foo-packet on/off" commands introduced a regression, observable when
connecting GDB to QEMU. For instance:
(gdb) set debug remote 1
(gdb) tar rem :4444
Remote debugging using :4444
Sending packet: $qSupported:multiprocess+;qRelocInsn+#2a...Ack
Packet received: PacketSize=1000;qXfer:features:read+
Packet qSupported (supported-packets) is supported
Sending packet: $Hgp0.0#ad...Ack
Packet received: OK
Sending packet: $qXfer:features:read:target.xml:0,ffb#79...Ack
Packet received: [...]
Sending packet: $qXfer:features:read:arm-core.xml:0,ffb#08...Ack
Packet received: [...]
!!! -> Sending packet: $QNonStop:0#8c...Ack
Packet received:
Remote refused setting all-stop mode with:
The "QNonStop" feature is associated with the PACKET_QNonStop packet,
with a default of PACKET_DISABLE, so GDB should not be sending the
packet at all.
The patch that introduced the regression decoupled packet_config's
'detect' and 'support' fields, making the former (an auto_boolean)
purely the associated "set remote foo-packet" command's variable. In
the example above, the packet config's 'supported' field does end up
correctly set to PACKET_DISABLE. However, nothing is presently
initializing packet configs that don't actually have a command
associated. Those configs's 'detect' field then ends up set to
AUTO_BOOLEAN_TRUE, simply because that happens to be 0. This forces
GDB to assume the packet is supported, irrespective of what the target
claims it supports, just like if the user had done "set remote
foo-packet on" (this being the associated command, if there was one).
Ideally, all packet configs would have a command associated. While
that isn't true, make sure all packet configs are initialized, even if
no command is associated, and add an assertion that prevents adding
more packets/features without an associated command.
Tested on x86_64 Fedora 17, against pristine gdbserver, and against a
gdbserver with the QNonStop packet/feature disabled with a local hack.
gdb/
2014-04-29 Pedro Alves <palves@redhat.com>
* remote.c (struct packet_config) <detect>: Extend comment.
(add_packet_config_cmd): Don't set the config's detect or support
fields here.
(init_all_packet_configs): Also initialize the config's 'detect'
field.
(reset_all_packet_configs_support): New function.
(remote_open_1): Call reset_all_packet_configs_support instead of
init_all_packet_configs.
(_initialize_remote): Initialize all packet configs. Assert that
all packets have an associated command, except a few known
outliers.
Currently, read_subrange_type handles dynamicity only in the case of
the upper bound, and assumes that the lower bound is always static.
That's rooted in the fact that dynamicity was added to support C99
variable-length arrays, where the lower bound is always zero, and
therefore never dynamic. But the lower bound can, in fact, be dynamic
in other languages such as Ada.
Consider for instance the following declaration in Ada...
type Array_Type is array (L .. U) of Natural;
... where L and U are parameters of the function where the declaration
above was made, and whose value are 5 and 10. Currently, the debugger
is able to print the value of the upper bound correctly, but not the
lower bound:
(gdb) ptype array_type
type = array (1 .. 10) of natural
After this patch, the debugger now prints:
(gdb) ptype array_type
type = array (5 .. 10) of natural
gdb/ChangeLog:
* dwarf2read.c (read_subrange_type): Handle dynamic
DW_AT_lower_bound attributes.
Consider the following declaration in Ada...
type Array_Type is array (L .. U) of Natural;
... where L and U are parameters of the function where the declaration
above was made. At the moment, GDB relies on descriptive types in order
to properly decode the array bounds. For instance, if L was 5, and U
was 10, we would see the following:
(gdb) ptype array_type
type = array (5 .. 10) of natural
(gdb) maintenance set ada ignore-descriptive-types
(gdb) ptype array_type
type = array (1 .. 28544912) of natural
This patch enhances ada_discrete_type_{high,low}_bound to resolve
any dynamicity. This is sufficient to fix the case of the upper bound.
For the lower bound, the dwarf2read module does not handle dynamic
lower bounds yet, but once it does, the lower bound should be correctly
handled as well [1].
gdb/ChangeLog:
* ada-lang.c (ada_discrete_type_high_bound): Resolve the type's
dynamic bounds before computing its upper bound.
(ada_discrete_type_low_bound): Same as above with the lower bound.
[1]: The reason why we do not enhance dwarf2read to handle dynamic
lower bounds ahead of this patch is because it unveils some latent
issues such as this one.
This change breaks down the resolve_dynamic_bounds function which
works only on arrays and its index range types into two functions,
one that resolves range types, and one that resolves arrays (using
the new routine to resolve the array's index range type). The
is_dynamic_type and resolve_dynamic_type function are then re-organized
to handle range types as well.
One small change worth mentioning is the fact that, now that range
types are resolved on their own (rather than in the limited context
of array index types), the resolved range types are created from
a copy of the dynamic range type, rather than from scratch (first
parameter of create_range_type). This allows us to preserve as many
original properties in the resolved type as possible (Eg. the type's
name).
This is preparation work that will help better support dynamic range
types for languages that allow the declaration of such types (Eg. Ada).
gdb/ChangeLog:
* dwarf2read.c (is_dynamic_type): Return true for dynamic
range types. Adjust the array handling implementation to
take advantage of this change.
(resolve_dynamic_range): New function, mostly extracted from
resolve_dynamic_bounds.
(resolve_dynamic_array): New function, mostly extracted from
resolve_dynamic_bounds.
(resolve_dynamic_bounds): Delete.
(resolve_dynamic_type): Reimplement. Add handling of
TYPE_CODE_RANGE types.
ada-varobj.c::ada_varobj_describe_simple_array_child only ever gets
called after all GNAT encodings have been applied to (parent_value,
parent_type). So there is no point in redoing it partially by
checking for parallel XA types again.
gdb/ChangeLog:
* ada-varobj.c (ada_varobj_describe_simple_array_child): Remove
handling of parallel ___XA types.
In ada-lang.c::ada_evaluate_subexp, case OP_VAR_VALUE, when noside
is EVAL_AVOID_SIDE_EFFECTS, the first thing we do is set type as
follow:
type = static_unwrap_type (SYMBOL_TYPE (exp->elts[pc + 2].symbol));
Later on in the same block, we make the same call:
return value_zero
(to_static_fixed_type
(static_unwrap_type (SYMBOL_TYPE (exp->elts[pc + 2].symbol))),
not_lval);
This patch removes the second call, since it should result in the same
type being returned, so no point in making that call again.
gdb/ChangeLog:
* ada-lang.c (ada_evaluate_subexp) <OP_VAR_VALUE>: Remove
unnecessary second call to static_unwrap_type.
When GDB debug DUMMY_FRAME, SIGTRAMP_FRAME and ARCH_FRAME, even if
"set disassemble-next-line on", it will not output the asm code:
(gdb) set disassemble-next-line on
(gdb) si
<signal handler called>
(gdb)
<signal handler called>
(gdb)
<signal handler called>
So make this patch make they can work together, it will become:
(gdb) si
<signal handler called>
=> 0xffffffff816bfb09 <int_with_check+0>: 65 48 8b 0c 25 c8 c7 00 00 mov %gs:0xc7c8,%rcx
(gdb)
<signal handler called>
=> 0xffffffff816bfb12 <int_with_check+9>: 48 81 e9 d8 1f 00 00 sub $0x1fd8,%rcx
(gdb)
<signal handler called>
=> 0xffffffff816bfb19 <int_with_check+16>: 8b 51 10 mov 0x10(%rcx),%edx
2014-04-27 Hui Zhu <hui@codesourcery.com>
* stack.c (print_frame_info): Call do_gdb_disassembly with
DUMMY_FRAME, SIGTRAMP_FRAME and ARCH_FRAME.
On Linux, we need to explicitly ptrace attach to all lwps of a
process. Because GDB might not be connected yet when an attach is
requested, and thus it may not be possible to activate thread_db, as
that requires access to symbols (IOW, gdbserver --attach), a while ago
we make linux_attach loop over the lwps as listed by /proc/PID/task to
find the lwps to attach to.
linux_attach_lwp_1 has:
...
if (initial)
/* If lwp is the tgid, we handle adding existing threads later.
Otherwise we just add lwp without bothering about any other
threads. */
ptid = ptid_build (lwpid, lwpid, 0);
else
{
/* Note that extracting the pid from the current inferior is
safe, since we're always called in the context of the same
process as this new thread. */
int pid = pid_of (current_inferior);
ptid = ptid_build (pid, lwpid, 0);
}
That "safe" comment referred to linux_attach_lwp being called by
thread-db.c. But this was clearly missed when a new call to
linux_attach_lwp_1 was added to linux_attach. As a result,
current_inferior will be set to some random process, and non-initial
lwps of the second inferior get assigned the pid of the wrong
inferior. E.g., in the case of attaching to two inferiors, for the
second inferior (and so on), non-initial lwps of the second inferior
get assigned the pid of the first inferior. This doesn't trigger on
the first inferior, when current_inferior is NULL, add_thread switches
the current inferior to the newly added thread.
Rather than making linux_attach switch current_inferior temporarily
(thus avoiding further reliance on global state), or making
linux_attach_lwp_1 get the tgid from /proc, which add extra syscalls,
and will be wrong in case of the user having originally attached
directly to a non-tgid lwp, and then that lwp spawning new clones (the
ptid.pid field of further new clones should be the same as the
original lwp's pid, which is not the tgid), we note that callers of
linux_attach_lwp/linux_attach_lwp_1 always have the right pid handy
already, so they can pass it down along with the lwpid.
The only other reason for the "initial" parameter is to error out
instead of warn in case of attach failure, when we're first attaching
to a process. There are only three callers of
linux_attach_lwp/linux_attach_lwp_1, and each wants to print a
different warn/error string, so we can just move the error/warn out of
linux_attach_lwp_1 to the callers, thus getting rid of the "initial"
parameter.
There really nothing gdbserver-specific about attaching to two
threaded processes, so this adds a new test under gdb.multi/. The
test passes cleanly against the native GNU/Linux target, but
fails/triggers the bug against GDBserver (before the patch), with the
native-extended-remote board (as plain remote doesn't support
multi-process).
Tested on x86_64 Fedora 17, with the native-extended-gdbserver board.
gdb/gdbserver/
2014-04-25 Pedro Alves <palves@redhat.com>
PR server/16255
* linux-low.c (linux_attach_fail_reason_string): New function.
(linux_attach_lwp): Delete.
(linux_attach_lwp_1): Rename to ...
(linux_attach_lwp): ... this. Take a ptid instead of a pid as
argument. Remove "initial" parameter. Return int instead of
void. Don't error or warn here.
(linux_attach): Adjust to call linux_attach_lwp. Call error on
failure to attach to the tgid. Call warning when failing to
attach to an lwp.
* linux-low.h (linux_attach_lwp): Take a ptid instead of a pid as
argument. Remove "initial" parameter. Return int instead of
void. Don't error or warn here.
(linux_attach_fail_reason_string): New declaration.
* thread-db.c (attach_thread): Adjust to linux_attach_lwp's
interface change. Use linux_attach_fail_reason_string.
gdb/
2014-04-25 Pedro Alves <palves@redhat.com>
PR server/16255
* common/linux-ptrace.c (linux_ptrace_attach_warnings): Rename to ...
(linux_ptrace_attach_fail_reason): ... this. Remove "warning: "
and newline from built string.
* common/linux-ptrace.h (linux_ptrace_attach_warnings): Rename to ...
(linux_ptrace_attach_fail_reason): ... this.
* linux-nat.c (linux_nat_attach): Adjust to use
linux_ptrace_attach_fail_reason.
gdb/testsuite/
2014-04-25 Simon Marchi <simon.marchi@ericsson.com>
Pedro Alves <palves@redhat.com>
PR server/16255
* gdb.multi/multi-attach.c: New file.
* gdb.multi/multi-attach.exp: New file.
For several RSP packets, there's a corresponding "set remote
foo-packet on/off/auto" command that one can use do bypass
auto-detection of support for the packet or feature. However, I
noticed that setting several of these commands to 'on' or 'off'
doesn't actually have any effect. These are, at least:
set remote breakpoint-commands-packet
set remote conditional-breakpoints-packet
set remote fast-tracepoints-packet
set remote static-tracepoints-packet
set remote install-in-trace-packet
These are commands that control a remote protocol feature that doesn't
have a corresponding regular packet, and because of that we cache the
knowledge of the remote side support as returned by the qSupported
packet in the remote_state object.
E.g., in the case of the 'set remote breakpoint-commands-packet'
command, whether the feature is supported is recorded in the
'breakpoint_commands' field of the remote_state object.
Whether to bypass packet support auto-detection or not is controlled
by the 'detect' field of the corresponding packet's packet_config
structure. That field is the variable associated directly with the
"set remote foo-packet" command. Actual remote stub support for the
packet (or feature) is recorded in the 'support' field of the same
structure.
However, when the user toggles the command, the 'support' field is
also correspondingly updated to PACKET_ENABLE/DISABLE/SUPPORT_UNKNOWN,
discarding the knowledge of whether the target actually supports the
feature. If one toggles back to 'auto', it's no big issue for real
packets, as they'll just end up re-probed the next time they might be
necessary. But features whose support is only reported through
qSupported don't get their corresponding (manually added/maintained)
fields in remote_state objected updated. As we lost the actual status
of the target support for the feature, GDB would need to probe the
qSupported features again, which GDB doesn't do.
But we can avoid that extra traffic, and clean things up, IMO.
Instead of going in that direction, this patch completely decouples
struct packet_config's 'detect' and 'support' fields. E.g., when the
user does "set remote foo-packet off", instead of setting the packet
config's 'support' field to PACKET_DISABLE, the 'support' field is not
touched at all anymore. That is, we end up respecting this simple
table:
| packet_config->detect | packet_config->support | should use packet/feature? |
|-----------------------+------------------------+----------------------------|
| auto | PACKET_ENABLE | PACKET_ENABLE |
| auto | PACKET_DISABLE | PACKET_DISABLE |
| auto | PACKET_UNKNOWN | PACKET_UNKNOWN |
| yes | don't care | PACKET_ENABLE |
| no | don't care | PACKET_DISABLE |
This is implemented by the new packet_support function. With that, we
need to update this pattern throughout:
if (remote_protocol_packets[PACKET_foo].support == PACKET_DISABLE)
to do this instead:
if (packet_support (PACKET_qAttached) == PACKET_DISABLE)
where as mentioned, the packet_support function takes struct
packet_config's 'detect' field into account, like in the table above.
As when the packet is force-disabled or force-enabled, the 'support'
field is just ignored, if the command is set back to auto, we'll
resume respecting whatever the target said it supports. IOW, the end
result is that the 'support' field always represents whether the
target actually supports the packet or not.
After all that, the manually maintained breakpoint_commands and
equivalent fields of struct remote_state can then be eliminated, with
references replaced by checking the result of calling the
packet_support function on the corresponding packet or feature. This
required adding new PACKET_foo enum values for several features that
didn't have it yet. (The patch does not add corresponding "set remote
foo-packet" style commands though, focusing only on bug fixing and
laying the groundwork).
Tested on x86_64 Fedora 17, native GDBserver. The new tests all fail
without this patch.
gdb/
2014-04-25 Pedro Alves <palves@redhat.com>
* remote.c (struct remote_state): Remove multi_process_aware,
non_stop_aware, cond_tracepoints, cond_breakpoints,
breakpoint_commands, fast_tracepoints, static_tracepoints,
install_in_trace, disconnected_tracing,
enable_disable_tracepoints, string_tracing, and
augmented_libraries_svr4_read fields.
(remote_multi_process_p): Move further below in the file.
(struct packet_config): Add comments.
(update_packet_config): Delete function.
(show_packet_config_cmd): Use packet_config_support.
(add_packet_config_cmd): Use NULL as set callback.
(packet_ok): "set remote foo-packet"-style commands no longer
change config->supported -- adjust.
(PACKET_ConditionalTracepoints, PACKET_ConditionalBreakpoints)
(PACKET_BreakpointCommands, PACKET_FastTracepoints)
(PACKET_StaticTracepoints, PACKET_InstallInTrace): Add comments.
(PACKET_QNonStop, PACKET_multiprocess_feature)
(PACKET_EnableDisableTracepoints_feature, PACKET_tracenz_feature)
(PACKET_DisconnectedTracing_feature)
(PACKET_augmented_libraries_svr4_read_feature): New enum values.
(set_remote_protocol_packet_cmd): Delete function.
(packet_config_support, packet_support): New functions.
(set_remote_protocol_Z_packet_cmd): Don't call
update_packet_config.
(remote_query_attached, remote_pass_signals)
(remote_program_signals, remote_threads_info)
(remote_threads_extra_info, remote_start_remote): Use
packet_support.
(remote_start_remote): Use packet_config_support and
packet_support.
(init_all_packet_configs): Set all packets to unknown support,
instead of calling update_packet_config.
(remote_check_symbols): Use packet_support.
(remote_supported_packet): Unconditionally set the packet config's
support status.
(remote_multi_process_feature, remote_non_stop_feature)
(remote_cond_tracepoint_feature, remote_cond_breakpoint_feature)
(remote_breakpoint_commands_feature)
(remote_fast_tracepoint_feature, remote_static_tracepoint_feature)
(remote_install_in_trace_feature)
(remote_disconnected_tracing_feature)
(remote_enable_disable_tracepoint_feature)
(remote_string_tracing_feature)
(remote_augmented_libraries_svr4_read_feature): Delete functions.
(remote_protocol_features): Adjust to use remote_supported_packet
for "augmented-libraries-svr4-read", "multiprocess", "QNonStop",
"ConditionalTracepoints", "ConditionalBreakpoints",
"BreakpointCommands", "FastTracepoints", "StaticTracepoints",
"InstallInTrace", "DisconnectedTracing", "DisconnectedTracing",
"EnableDisableTracepoints", and "tracenz".
(remote_query_supported): Use packet_support.
(remote_open_1): Adjust.
(extended_remote_attach_1): Use packet_support. Switch on the
result of packet_ok instead of checking whether the packet ended
up disabled.
(remote_vcont_resume): Use packet_support.
(remote_resume, remote_stop_ns, fetch_register_using_p)
(remote_prepare_to_store, store_register_using_P)
(check_binary_download, remote_write_bytes): Use packet_support.
(remote_vkill): Use packet_support. Switch on the result of
packet_ok instead of checking whether the packet ended up
disabled.
(extended_remote_supports_disable_randomization): Use
packet_support.
(extended_remote_run): Switch on the result of packet_ok instead
of checking whether the packet ended up disabled.
(remote_insert_breakpoint, remote_remove_breakpoint)
(remote_insert_watchpoint, remote_remove_watchpoint)
(remote_insert_hw_breakpoint, remote_remove_hw_breakpoint): Use
packet_support.
(remote_search_memory): Use packet_config_support.
(remote_get_thread_local_address, remote_get_tib_address)
(remote_hostio_send_command, remote_can_execute_reverse): Use
packet_support.
(remote_supports_cond_tracepoints)
(remote_supports_cond_breakpoints)
(remote_supports_fast_tracepoints)
(remote_supports_static_tracepoints)
(remote_supports_install_in_trace)
(remote_supports_enable_disable_tracepoint)
(remote_supports_string_tracing)
(remote_can_run_breakpoint_commands): Rewrite, checking whether
the packet config says the feature is enabled or disabled.
(remote_download_tracepoint, remote_trace_set_readonly_regions)
(remote_get_trace_status): Use packet_support.
(remote_set_disconnected_tracing): Adjust to check whether the
feature is enabled with packet_support.
(remote_set_trace_buffer_size, remote_use_agent)
(remote_can_use_agent, remote_supports_btrace): Use
packet_support.
(remote_enable_btrace, remote_disable_btrace, remote_read_btrace):
Use packet_config_support.
(remote_augmented_libraries_svr4_read): Rewrite, checking whether
the packet config says the feature is enabled or disabled.
(set_range_stepping): Use packet_support.
gdb/testsuite/
2014-04-25 Pedro Alves <palves@redhat.com>
* gdb.base/cond-eval-mode.exp (warning): Move trailing \r\n to
user.
(top level): Test that "set remote conditional-breakpoints-packet
off" works as intended.
* gdb.base/dprintf.exp: Test that "set remote
breakpoint-commands-packet off" works as intended.
* gdb.trace/change-loc.exp (tracepoint_install_in_trace_disabled):
New function.
(top level): Call it.
* gdb.trace/ftrace.exp (test_fast_tracepoints): Test that "set
remote fast-tracepoints-packet off" works as intended.
* gdb.trace/qtro.exp (gdb_is_target_remote): Moved ...
* lib/gdb.exp (gdb_is_target_remote): ... here.
This patch expands standard_exc's introductory comment to explain
why this table does not include Numeric_Error.
gdb/ChangeLog:
* ada-lang.c (standard_exc): Expand introductory comment.
This patch adds support for the Intel(R) Advanced Vector
Extensions 512 (Intel(R) AVX-512) registers. Native and remote
debugging are covered by this patch.
Intel(R) AVX-512 is an extension to AVX to support 512-bit wide
SIMD registers in 64-bit mode (XMM0-XMM31, YMM0-YMM31, ZMM0-ZMM31).
The number of available registers in 32-bit mode is still 8
(XMM0-7, YMM0-7, ZMM0-7). The lower 256-bits of the ZMM registers
are aliased to the respective 256-bit YMM registers. The lower
128-bits are aliased to the respective 128-bit XMM registers.
There are also 8 new, dedicated mask registers (K0-K7) in both 32-bit
mode and 64-bit mode.
For more information please see
Intel(R) Developer Zone: Intel(R) AVX
http://software.intel.com/en-us/intel-isa-extensions#pid-16007-1495
Intel(R) Architecture Instruction Set Extensions Programming Reference:
http://software.intel.com/en-us/file/319433-017pdf
2014-04-24 Michael Sturm <michael.sturm@mintel.com>
Walfred Tedeschi <walfred.tedeschi@intel.com>
* amd64-linux-nat.c (amd64_linux_gregset32_reg_offset): Add
AVX512 registers.
(amd64_linux_read_description): Add code to handle AVX512 xstate
mask and return respective tdesc.
* amd64-linux-tdep.c: Include features/i386/amd64-avx512-linux.c
and features/i386/x32-avx512-linux.c.
(amd64_linux_gregset_reg_offset): Add AVX512 registers.
(amd64_linux_core_read_description): Add code to handle AVX512
xstate mask and return respective tdesc.
(_initialize_amd64_linux_tdep): Initialize AVX512 tdesc.
* amd64-linux-tdep.h (AMD64_LINUX_ORIG_RAX_REGNUM): Adjust regnum
calculation.
(AMD64_LINUX_NUM_REGS): Adjust to new number of registers.
(tdesc_amd64_avx512_linux): New prototype.
(tdesc_x32_avx512_linux): Likewise.
* amd64-tdep.c: Include features/i386/amd64-avx512.c and
features/i386/x32-avx512.c.
(amd64_ymm_avx512_names): New register names for pseudo
registers YMM16-31.
(amd64_ymmh_avx512_names): New register names for raw registers
YMMH16-31.
(amd64_k_names): New register names for K registers.
(amd64_zmmh_names): New register names for ZMM raw registers.
(amd64_zmm_names): New registers names for ZMM pseudo registers.
(amd64_xmm_avx512_names): New register names for XMM16-31
registers.
(amd64_pseudo_register_name): Add code to return AVX512 pseudo
registers.
(amd64_init_abi): Add code to intitialize AVX512 tdep variables
if feature is present.
(_initialize_amd64_tdep): Call AVX512 tdesc initializers.
* amd64-tdep.h (enum amd64_regnum): Add AVX512 registers.
(AMD64_NUM_REGS): Adjust to new number of registers.
* i386-linux-nat.c (GETXSTATEREGS_SUPPLIES): Extend range of
registers supplied via XSTATE by AVX512 registers.
(i386_linux_read_description): Add case for AVX512.
* i386-linux-tdep.c: Include i386-avx512-linux.c.
(i386_linux_gregset_reg_offset): Add AVX512 registers.
(i386_linux_core_read_description): Add case for AVX512.
(i386_linux_init_abi): Install supported register note section
for AVX512.
(_initialize_i386_linux_tdep): Add call to tdesc init function for
AVX512.
* i386-linux-tdep.h (I386_LINUX_NUM_REGS): Set number of
registers to be number of zmm7h + 1.
(tdesc_i386_avx512_linux): Add tdesc for AVX512 registers.
* i386-tdep.c: Include features/i386/i386-avx512.c.
(i386_zmm_names): Add ZMM pseudo register names array.
(i386_zmmh_names): Add ZMM raw register names array.
(i386_k_names): Add K raw register names array.
(num_lower_zmm_regs): Add constant for the number of lower ZMM
registers. AVX512 has 16 more ZMM registers than there are YMM
registers.
(i386_zmmh_regnum_p): Add function to look up register number of
ZMM raw registers.
(i386_zmm_regnum_p): Likewise for ZMM pseudo registers.
(i386_k_regnum_p): Likewise for K raw registers.
(i386_ymmh_avx512_regnum_p): Likewise for additional YMM raw
registers added by AVX512.
(i386_ymm_avx512_regnum_p): Likewise for additional YMM pseudo
registers added by AVX512.
(i386_xmm_avx512_regnum_p): Likewise for additional XMM registers
added by AVX512.
(i386_register_name): Add code to hide YMMH16-31 and ZMMH0-31.
(i386_pseudo_register_name): Add ZMM pseudo registers.
(i386_zmm_type): Construct and return vector registers type for ZMM
registers.
(i386_pseudo_register_type): Return appropriate type for YMM16-31,
ZMM0-31 pseudo registers and K registers.
(i386_pseudo_register_read_into_value): Add code to read K, ZMM
and YMM16-31 registers from register cache.
(i386_pseudo_register_write): Add code to write K, ZMM and
YMM16-31 registers.
(i386_register_reggroup_p): Add code to include/exclude AVX512
registers in/from respective register groups.
(i386_validate_tdesc_p): Handle AVX512 feature, add AVX512
registers if feature is present in xcr0.
(i386_gdbarch_init): Add code to initialize AVX512 feature
variables in tdep structure, wire in pseudo registers and call
initialize_tdesc_i386_avx512.
* i386-tdep.h (struct gdbarch_tdep): Add AVX512 related
variables.
(i386_regnum): Add AVX512 registers.
(I386_SSE_NUM_REGS): New define for number of SSE registers.
(I386_AVX_NUM_REGS): Likewise for AVX registers.
(I386_AVX512_NUM_REGS): Likewise for AVX512 registers.
(I386_MAX_REGISTER_SIZE): Change to 64 bytes, ZMM registers are
512 bits wide.
(i386_xmm_avx512_regnum_p): New prototype for register look up.
(i386_ymm_avx512_regnum_p): Likewise.
(i386_k_regnum_p): Likewise.
(i386_zmm_regnum_p): Likewise.
(i386_zmmh_regnum_p): Likewise.
* i387-tdep.c : Update year in copyright notice.
(xsave_ymm_avx512_offset): New table for YMM16-31 offsets in
XSAVE buffer.
(XSAVE_YMM_AVX512_ADDR): New macro.
(xsave_xmm_avx512_offset): New table for XMM16-31 offsets in
XSAVE buffer.
(XSAVE_XMM_AVX512_ADDR): New macro.
(xsave_avx512_k_offset): New table for K register offsets in
XSAVE buffer.
(XSAVE_AVX512_K_ADDR): New macro.
(xsave_avx512_zmm_h_offset): New table for ZMM register offsets
in XSAVE buffer.
(XSAVE_AVX512_ZMM_H_ADDR): New macro.
(i387_supply_xsave): Add code to supply AVX512 registers to XSAVE
buffer.
(i387_collect_xsave): Add code to collect AVX512 registers from
XSAVE buffer.
* i387-tdep.h (I387_NUM_XMM_AVX512_REGS): New define for number
of XMM16-31 registers.
(I387_NUM_K_REGS): New define for number of K registers.
(I387_K0_REGNUM): New define for K0 register number.
(I387_NUM_ZMMH_REGS): New define for number of ZMMH registers.
(I387_ZMM0H_REGNUM): New define for ZMM0H register number.
(I387_NUM_YMM_AVX512_REGS): New define for number of YMM16-31
registers.
(I387_YMM16H_REGNUM): New define for YMM16H register number.
(I387_XMM16_REGNUM): New define for XMM16 register number.
(I387_YMM0_REGNUM): New define for YMM0 register number.
(I387_KEND_REGNUM): New define for last K register number.
(I387_ZMMENDH_REGNUM): New define for last ZMMH register number.
(I387_YMMH_AVX512_END_REGNUM): New define for YMM31 register
number.
(I387_XMM_AVX512_END_REGNUM): New define for XMM31 register
number.
* common/i386-xstate.h: Add AVX 3.1 feature bits, mask and XSTATE
size.
* features/Makefile: Add AVX512 related files.
* features/i386/32bit-avx512.xml: New file.
* features/i386/64bit-avx512.xml: Likewise.
* features/i386/amd64-avx512-linux.c: Likewise.
* features/i386/amd64-avx512-linux.xml: Likewise.
* features/i386/amd64-avx512.c: Likewise.
* features/i386/amd64-avx512.xml: Likewise.
* features/i386/i386-avx512-linux.c: Likewise.
* features/i386/i386-avx512-linux.xml: Likewise.
* features/i386/i386-avx512.c: Likewise.
* features/i386/i386-avx512.xml: Likewise.
* features/i386/x32-avx512-linux.c: Likewise.
* features/i386/x32-avx512-linux.xml: Likewise.
* features/i386/x32-avx512.c: Likewise.
* features/i386/x32-avx512.xml: Likewise.
* regformats/i386/amd64-avx512-linux.dat: New file.
* regformats/i386/amd64-avx512.dat: Likewise.
* regformats/i386/i386-avx512-linux.dat: Likewise.
* regformats/i386/i386-avx512.dat: Likewise.
* regformats/i386/x32-avx512-linux.dat: Likewise.
* regformats/i386/x32-avx512.dat: Likewise.
* NEWS: Add note about new support for AVX512.
testsuite/
* Makefile.in (EXECUTABLES): Added i386-avx512.
* gdb.arch/i386-avx512.c: New file.
* gdb.arch/i386-avx512.exp: Likewise.
gdbserver/
* Makefile.in: Added rules to handle new files
i386-avx512.c i386-avx512-linux.c amd64-avx512.c
amd64-avx512-linux.c x32-avx512.c x32-avx512-linux.c.
* configure.srv (srv_i386_regobj): Add i386-avx512.o.
(srv_i386_linux_regobj): Add i386-avx512-linux.o.
(srv_amd64_regobj): Add amd64-avx512.o and x32-avx512.o.
(srv_amd64_linux_regobj): Add amd64-avx512-linux.o and
x32-avx512-linux.o.
(srv_i386_32bit_xmlfiles): Add i386/32bit-avx512.xml.
(srv_i386_64bit_xmlfiles): Add i386/64bit-avx512.xml.
(srv_amd64_xmlfiles): Add i386/amd64-avx512.xml and
i386/x32-avx512.xml.
(srv_i386_linux_xmlfiles): Add i386/i386-avx512-linux.xml.
(srv_amd64_linux_xmlfiles): Add i386/amd64-avx512-linux.xml and
i386/x32-avx512-linux.xml.
* i387-fp.c (num_avx512_k_registers): New constant for number
of K registers.
(num_avx512_zmmh_low_registers): New constant for number of
lower ZMM registers (0-15).
(num_avx512_zmmh_high_registers): New constant for number of
higher ZMM registers (16-31).
(num_avx512_ymmh_registers): New contant for number of higher
YMM registers (ymm16-31 added by avx521 on x86_64).
(num_avx512_xmm_registers): New constant for number of higher
XMM registers (xmm16-31 added by AVX512 on x86_64).
(struct i387_xsave): Add space for AVX512 registers.
(i387_cache_to_xsave): Change raw buffer size to 64 characters.
Add code to handle AVX512 registers.
(i387_xsave_to_cache): Add code to handle AVX512 registers.
* linux-x86-low.c (init_registers_amd64_avx512_linux): New
prototypei from generated file.
(tdesc_amd64_avx512_linux): Likewise.
(init_registers_x32_avx512_linux): Likewise.
(tdesc_x32_avx512_linux): Likewise.
(init_registers_i386_avx512_linux): Likewise.
(tdesc_i386_avx512_linux): Likewise.
(x86_64_regmap): Add AVX512 registers.
(x86_linux_read_description): Add code to handle AVX512 XSTATE
mask.
(initialize_low_arch): Add code to initialize AVX512 registers.
doc/
* gdb.texinfo (i386 Features): Add description of AVX512
registers.
Change-Id: Ifc4c08c76b85dbec18d02efdbe6182e851584438
Signed-off-by: Michael Sturm <michael.sturm@intel.com>
Without the code portion of the patch, we get these failures:
FAIL: gdb.base/break-unload-file.exp: always-inserted on: break: continue
FAIL: gdb.base/break-unload-file.exp: always-inserted on: hbreak: continue
FAIL: gdb.base/sym-file.exp: stale bkpts: continue to breakpoint: end here
They all looks like random SIGTRAPs:
continue
Continuing.
Program received signal SIGTRAP, Trace/breakpoint trap.
0x0000000000400541 in foo () at ../../../src/gdb/testsuite/gdb.base/break-unload-file.c:21
21 }
(gdb) FAIL: gdb.base/break-unload-file.exp: always-inserted on: break: continue
(This is a regression caused by the remove-symbol-file command
series.)
break-unload-file.exp is about having breakpoints inserted, and then
doing "file". I caught this while writing a test that does "file
PROGRAM", while PROGRAM was already loaded, which internally does
"file" first, because I wanted to force a breakpoint_re_set, but the
test is more explicit in case GDB ever optimizes out that re-set.
The problem is that unloading the file with "file" ends up in
disable_breakpoints_in_freed_objfile, which marks all breakpoint
locations of the objfile as both shlib_disabled, _and_ clears the
inserted flag, without actually removing the breakpoints from the
inferior. Now, usually, in all-stop, breakpoints will already be
removed from the inferior before the user can issue the "file"
command, but, with non-stop, or breakpoints always-inserted on mode,
breakpoints stay inserted even while the user has the prompt. In the
latter case, then, if we let the program continue, and it executes the
address where we had previously set the breakpoint, it'll actually
execute the breakpoint instruction that we left behind...
Now, one issue is that the intent of
disable_breakpoints_in_freed_objfile is really to handle the unloading
of OBJF_USERLOADED objfiles. These are objfiles that were added with
add-symbol-file and that are removed with remove-symbol-file.
"add-symbol-file"'s docs in the manual clearly say these commands are
used to let GDB know about dynamically loaded code:
You would use this command when @var{filename} has been dynamically
loaded (by some other means) into the program that is running.
Similarly, the online help says:
(gdb) help add-symbol-file
Load symbols from FILE, assuming FILE has been dynamically loaded.
So it makes sense to, like when shared libraries are unloaded through
the generic solib machinery, mark the breakpoint locations as
shlib_disabled. But, the "file" command is not about dynamically
loaded code, it's about the main program. So the patch makes
disable_breakpoints_in_freed_objfile skip all objfiles but
OBJF_USERLOADED ones, thus skipping the main objfile.
Then, the reason that disable_breakpoints_in_freed_objfile was
clearing the inserted flag isn't clear, but likely to avoid breakpoint
removal errors, assuming remove-symbol-file was called after the
dynamic object was already unmapped from the inferior. In that case,
it'd okay to simply clear the inserted flag, but not so if the user
for example does remove-symbol-file to remove the library because he
made a mistake in the library's address, and wants to re-do
add-symbol-file with the correct address.
To address all that, I propose an alternative implementation, that
handles both cases. The patch includes changes to sym-file.exp to
cover them.
This implementation leaves the inserted flag alone, and handles
breakpoint insertion/removal failure gracefully when the locations are
in OBJF_USERLOADED objfiles, just like we handle insertion/removal
failure gracefully for locations in shared libraries.
To try to make sure we aren't patching back stale shadow memory
contents into the inferior, in case the program mapped a different
library at the same address where we had the breakpoint, without the
user having had a chance of remove-symbol-file'ing before, this adds a
new memory_validate_breakpoint function that checks if the breakpoint
instruction is still in memory. ppc_linux_memory_remove_breakpoint
does this unconditionally for all memory breakpoints, and questions
whether memory_remove_breakpoint should be changed to do this for all
breakpoints. Possibly yes, though I'm not certain, hence this
baby-steps patch.
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/
2014-04-23 Pedro Alves <palves@redhat.com>
* breakpoint.c (insert_bp_location): Tolerate errors if the
breakpoint is set in a user-loaded objfile.
(remove_breakpoint_1): Likewise. Also tolerate errors if the
location is marked shlib_disabled. If the breakpoint is set in a
user-loaded objfile is a GDB-side memory breakpoint, validate it
before uninsertion. (disable_breakpoints_in_freed_objfile): Skip
non-OBJF_USERLOADED objfiles. Don't clear the location's inserted
flag.
* mem-break.c (memory_validate_breakpoint): New function.
* objfiles.c (userloaded_objfile_contains_address_p): New
function.
* objfiles.h (userloaded_objfile_contains_address_p): Declare.
* target.h (memory_validate_breakpoint): New declaration.
gdb/testsuite/
2014-04-23 Pedro Alves <palves@redhat.com>
* gdb.base/break-unload-file.c: New file.
* gdb.base/break-unload-file.exp: New file.
* gdb.base/sym-file-lib.c (baz): New function.
* gdb.base/sym-file-loader.c (struct segment) <mapped_size>: New
field.
(load): Store the segment's mapped size.
(unload): New function.
(unload_shlib): New function.
* gdb.base/sym-file-loader.h (unload_shlib): New declaration.
* gdb.base/sym-file-main.c (main): Unload, and reload the library,
set a breakpoint at baz, and call it.
* gdb.base/sym-file.exp: New tests for stale breakpoint
instructions.
libraries.
As explained in
https://sourceware.org/ml/gdb-patches/2008-08/msg00361.html, after a
shared library was unloaded, we can no longer insert or remove
breakpoints into/from its (no longer present) code segment. That'll
fail with memory errors. However, that concern does not apply to
hardware breakpoints. By definition, hardware breakpoints are
implemented using a mechanism that is not dependent on being able to
modify the target's memory. Usually, by setting up CPU debug
registers. IOW, we should be able to set hw breakpoints in an
unmapped address. We don't seem to have a test that exercises that,
so this patch adds one.
I noticed the error supression because of a related issue -- the
target_insert_hw_breakpoint/target_remove_hw_breakpoint interfaces
don't really distinguish "not supported" from "error" return, and so
remote.c returns -1 in both cases. This results in hardware
breakpoints set in shared libraries silently ending up pending forever
even though the target doesn't actually support hw breakpoints.
(gdb) set breakpoint always-inserted on
(gdb) set remote Z-packet off
(gdb) info breakpoints
No breakpoints or watchpoints.
(gdb) hbreak shrfunc
Hardware assisted breakpoint 3 at 0x7ffff7dfb657: file ../../../src/gdb/testsuite/gdb.base/hbreak-in-shr-unsupported-shr.c, line 21.
(gdb) info break
Num Type Disp Enb Address What
3 hw breakpoint keep y <PENDING> shrfunc
After the patch we get the expected:
(gdb) hbreak shrfunc
Hardware assisted breakpoint 3 at 0x7ffff7dfb657: file ../../../src/gdb/testsuite/gdb.base/hbreak-in-shr-unsupported-shr.c, line 21.
Warning:
Cannot insert hardware breakpoint 3.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.
(gdb) info break
Num Type Disp Enb Address What
3 hw breakpoint keep y 0x00007ffff7dfb657 in shrfunc at ../../../src/gdb/testsuite/gdb.base/hbreak-in-shr-unsupported-shr.c:21
(HW breakpoints set in the main executable, when the target doesn't
support HW breakpoints always resulted in the latter output.)
We probably should improve the insert/remove interface to return a
different error code for unsupported. But I chose to fix the error
supression first, as it's a deeper and wider issue.
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/
2014-04-23 Pedro Alves <palves@redhat.com>
* breakpoint.c (insert_bp_location, remove_breakpoint_1): If
the breakpoint is set in a shared library, only suppress
errors for software breakpoints, not hardware breakpoints.
gdb/testsuite/
2014-04-23 Pedro Alves <palves@redhat.com>
* gdb.base/hbreak-in-shr-unsupported-shr.c: New file.
* gdb.base/hbreak-in-shr-unsupported.c: New file.
* gdb.base/hbreak-in-shr-unsupported.exp: New file.
* gdb.base/hbreak-unmapped.c: New file.
* gdb.base/hbreak-unmapped.exp: New file.
* gdb.trace/qtro.exp (gdb_is_target_remote): Move ...
* lib/gdb.exp (gdb_is_target_remote): ... here.
If a thread trips on a breakpoint that needs stepping over just after
finishing a step over, GDB currently fails an assertion. This is a
regression caused by the "Handle multiple step-overs." patch
(99619beac6) at
https://sourceware.org/ml/gdb-patches/2014-02/msg00765.html.
(gdb) x /4i $pc
=> 0x400540 <main+4>: movl $0x0,0x2003da(%rip) # 0x600924 <i>
0x40054a <main+14>: movl $0x1,0x2003d0(%rip) # 0x600924 <i>
0x400554 <main+24>: movl $0x2,0x2003c6(%rip) # 0x600924 <i>
0x40055e <main+34>: movl $0x3,0x2003bc(%rip) # 0x600924 <i>
(gdb) PASS: gdb.base/consecutive-step-over.exp: get breakpoint addresses
break *0x40054a
Breakpoint 2 at 0x40054a: file ../../../src/gdb/testsuite/gdb.base/consecutive-step-over.c, line 23.
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 1: set breakpoint
condition $bpnum condition
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 1: set condition
break *0x400554
Breakpoint 3 at 0x400554: file ../../../src/gdb/testsuite/gdb.base/consecutive-step-over.c, line 24.
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 2: set breakpoint
condition $bpnum condition
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 2: set condition
break *0x40055e
Breakpoint 4 at 0x40055e: file ../../../src/gdb/testsuite/gdb.base/consecutive-step-over.c, line 25.
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 3: set breakpoint
condition $bpnum condition
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 3: set condition
break 27
Breakpoint 5 at 0x400568: file ../../../src/gdb/testsuite/gdb.base/consecutive-step-over.c, line 27.
(gdb) continue
Continuing.
../../src/gdb/infrun.c:5200: internal-error: switch_back_to_stepped_thread: Assertion `!tp->control.trap_expected' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
FAIL: gdb.base/consecutive-step-over.exp: continue to breakpoint: break here (GDB internal error)
The assertion fails, because the code is not expecting that the event
thread itself might need another step over. IOW, not expecting that
TP in:
tp = find_thread_needs_step_over (stepping_thread != NULL,
stepping_thread);
could be the event thread.
A small fix for this would be to clear the event thread's
trap_expected earlier, before asserting. But looking deeper, although
currently_stepping_or_nexting_callback's intention is finding the
thread that is doing a step/next, it also returns the thread that is
doing a step-over dance, with trap_expected set. If there ever was a
reason for that (it was I who added
currently_stepping_or_nexting_callback , but I can't recall why I put
trap_expected there in the first place), the only remaining reason
nowadays is to aid in implementing switch_back_to_stepped_thread's
assertion that is now triggering, by piggybacking on the walk over all
threads, thus avoiding a separate walk. This is quite obscure, and I
think we can do even better, by merging the walks that look for the
stepping thread, and the walk that looks for some thread that might
need a step over.
Tested on x86_64 Fedora 17, native and gdbserver, and also native on
top of my "software single-step on x86_64" series.
gdb/
2014-04-22 Pedro Alves <palves@redhat.com>
* infrun.c (schedlock_applies): New function, factored out from
find_thread_needs_step_over.
(find_thread_needs_step_over): Use it.
(switch_back_to_stepped_thread): Always clear trap_expected if the
step over is finished. Return early if scheduler locking applies.
Look for the stepping thread and a potential step-over thread with
a single loop.
(currently_stepping_or_nexting_callback): Delete.
2014-04-22 Pedro Alves <palves@redhat.com>
* gdb.base/consecutive-step-over.c: New file.
* gdb.base/consecutive-step-over.exp: New file.
