This patch replaces VEC(static_tracepoint_marker_p) with std::vector,
and does some c++ification around that. I thought a new overload of
hex2str was useful, so I added it as well as corresponding unit tests.
I also added an overload of ui_out::field_string that takes an
std::string directly.
gdb/ChangeLog:
* tracepoint.h (struct static_tracepoint_marker): Initialize
fields, define default constructor, move constructor and move
assignment, disable the rest.
<str_id, extra>: Make std::string.
(release_static_tracepoint_marker): Remove.
(free_current_marker): Remove.
* tracepoint.c (free_current_marker): Remove.
(parse_static_tracepoint_marker_definition): Adjust to
std::string, use new hex2str overload.
(release_static_tracepoint_marker): Remove.
(print_one_static_tracepoint_marker): Get marker by reference
and adjust to std::string.
(info_static_tracepoint_markers_command): Adjust to std::vector
changes
* target.h (static_tracepoint_marker_p): Remove typedef.
(DEF_VEC_P(static_tracepoint_marker_p)): Remove.
(struct target_ops) <to_static_tracepoint_marker_at>: Return
bool.
<to_static_tracepoint_markers_by_strid>: Return std::vector.
* target-debug.h
(target_debug_print_VEC_static_tracepoint_marker_p_p): Remove.
(target_debug_print_std_vector_static_tracepoint_marker): New.
(target_debug_print_struct_static_tracepoint_marker_p): Rename
to...
(target_debug_print_static_tracepoint_marker_p): ... this.
* target-delegates.c: Re-generate.
* breakpoint.h (struct tracepoint) <static_trace_marker_id>:
Make std::string.
* breakpoint.c (init_breakpoint_sal): Adjust to std::string.
(decode_static_tracepoint_spec): Adjust to std::vector.
(tracepoint_print_one_detail): Adjust to std::string.
(strace_marker_decode_location): Adjust to std::string.
(update_static_tracepoint): Adjust to std::string, remove call
to release_static_tracepoint_marker.
* linux-nat.c (linux_child_static_tracepoint_markers_by_strid):
Adjust to std::vector.
* remote.c (remote_static_tracepoint_marker_at): Return bool.
(remote_static_tracepoint_markers_by_strid): Adjust to
std::vector.
* common/rsp-low.h (hex2str): New overload with explicit count
of bytes.
* common/rsp-low.c (hex2str): New overload with explicit count
of bytes.
* unittests/rsp-low-selftests.c (test_hex2str): New function.
(_initialize_rsp_low_selftests): Add test_hex2str test.
* unittests/tracepoint-selftests.c
(test_parse_static_tracepoint_marker_definition): Adjust to
std::string.
This changes to_fileio_readlink and target_fileio_readlink to return a
gdb::optional<std::sring>, and then fixes up the callers and
implementations. This allows the removal of some cleanups.
Regression tested by the buildbot.
gdb/ChangeLog
2018-03-07 Tom Tromey <tom@tromey.com>
* linux-tdep.c (linux_info_proc): Update.
* target.h (struct target_ops) <to_fileio_readlink>: Return
optional<string>.
(target_fileio_readlink): Return optional<string>.
* remote.c (remote_hostio_readlink): Return optional<string>.
* inf-child.c (inf_child_fileio_readlink): Return
optional<string>.
* target.c (target_fileio_readlink): Return optional<string>.
This patch gets rid of linux-nat.c's custom
target_terminal_inferior/target_terminal_ours implementations.
The only remaining reason those overrides exist is to install
clear_sigint_trap in order to pass Ctrl-C/SIGINT to the inferior
process in case the inferior is not sharing GDB's terminal (and
target_wait was called without TARGET_WNOHANG).
However, I think that's better handled by QUIT / target_pass_ctrlc
nowadays. Going that route avoids the issue with set_sigint_trap only
looking at the current inferior to know whether to override SIGINT or
not, which doesn't really work correctly with multi-inferior in the
picture. Also centralizing on a single SIGINT handler as much as
possible seems better considering a future multi-target world.
Tested on x86-64 GNU/Linux.
gdb/ChangeLog:
2018-01-30 Pedro Alves <palves@redhat.com>
* linux-nat.c (wait_for_signal): New function.
(wait_lwp, linux_nat_wait_1): Use it instead of calling sigsuspend
directly.
(async_terminal_is_ours)
(linux_nat_terminal_inferior, linux_nat_terminal_ours): Delete.
(linux_nat_add_target): Don't override
to_terminal_inferior/to_terminal_ours.
This patch makes these two functions actually use the inferior parameter
added by the previous patch, instead of reading inferior_ptid. I chose
these two, because they are the one actually used when I detach on my
GNU/Linux system, so they were easy to test.
I took the opportunity to pass the inferior being detached to
inf_ptrace_detach_success, so it could use it too. From there, it made
sense to add an overload of detach_inferior that takes the inferior
directly rather than the pid, to avoid having to pass inf->pid only for
the callee to look up the inferior structure by pid.
gdb/ChangeLog:
* inf-ptrace.c (inf_ptrace_detach): Adjust call to
inf_ptrace_detach_success.
(inf_ptrace_detach_success): Add inferior parameter, use it
instead of inferior_ptid, pass it to detach_inferior.
* inf-ptrace.h (inf_ptrace_detach_success): Add inferior
parameter.
* inferior.c (detach_inferior): Add overload that takes an
inferior object.
* inferior.h (detach_inferior): Likewise.
* linux-nat.c (linux_nat_detach): Use the inf parameter, don't
use inferior_ptid, adjust call to inf_ptrace_detach_success.
* linux-thread-db.c (thread_db_detach): Use inf parameter.
The to_detach target_ops method implementations are currently expected
to work on current_inferior/inferior_ptid. In order to make things more
explicit, and remove some "shadow" parameter passing through globals,
this patch adds an "inferior" parameter to to_detach. Implementations
will be expected to use this instead of relying on the global. However,
to keep things simple, this patch only does the minimum that is
necessary to add the parameter. The following patch gives an example of
how one such implementation would be adapted. If the approach is deemed
good, we can then look into adapting more implementations. Until then,
they'll continue to work as they do currently.
gdb/ChangeLog:
* target.h (struct target_ops) <to_detach>: Add inferior
parameter.
(target_detach): Likewise.
* target.c (dispose_inferior): Pass inferior down.
(target_detach): Pass inferior down. Assert that it is equal to
the current inferior.
* aix-thread.c (aix_thread_detach): Pass inferior down.
* corefile.c (core_file_command): Pass current_inferior() down.
* corelow.c (core_detach): Add inferior parameter.
* darwin-nat.c (darwin_detach): Likewise.
* gnu-nat.c (gnu_detach): Likewise.
* inf-ptrace.c (inf_ptrace_detach): Likewise.
* infcmd.c (detach_command): Pass current_inferior() down to
target_detach.
* infrun.c (follow_fork_inferior): Pass parent_inf to
target_detach.
(handle_vfork_child_exec_or_exit): Pass inf->vfork_parent to
target_detach.
* linux-nat.c (linux_nat_detach): Add inferior parameter.
* linux-thread-db.c (thread_db_detach): Likewise.
* nto-procfs.c (procfs_detach): Likewise.
* procfs.c (procfs_detach): Likewise.
* record.c (record_detach): Likewise.
* record.h (struct inferior): Forward-declare.
(record_detach): Add inferior parameter.
* remote-sim.c (gdbsim_detach): Likewise.
* remote.c (remote_detach_1): Likewise.
(remote_detach): Likewise.
(extended_remote_detach): Likewise.
* sol-thread.c (sol_thread_detach): Likewise.
* target-debug.h (target_debug_print_inferior_p): New macro.
* target-delegates.c: Re-generate.
* top.c (kill_or_detach): Pass inferior down to target_detach.
* windows-nat.c (windows_detach): Add inferior parameter.
I was looking into adding a parameter to target_detach, and was
wondering what the args parameter was. It seems like in the distant
past, it was possible to specify a signal number when detaching. That
signal was injected in the process before it was detached. There is an
example of code handling this in linux_nat_detach. With today's GDB, I
can't get this to work. Doing "detach 15" (15 == SIGTERM) doesn't work,
because detach is a prefix command and doesn't recognize the sub-command
15. Doing "detach inferiors 15" doesn't work because it expects a list
of inferior id to detach. Therefore, I don't think there's a way of
invoking detach_command with a non-NULL args. I also didn't find any
documentation related to this feature.
I assume that this feature stopped working when detach was made a prefix
command, which is in f73adfeb8bae36885e6ea248d12223ab0d5eb9cb (sorry,
there's no commit title) from 2006. Given that this feature was broken
for such a long time and we haven't heard anything (AFAIK, I did not
find any related bug), I think it's safe to remove it, as well as the
args parameter to target_detach. If someone wants to re-introduce it, I
would suggest rethinking the user interface, and in particular would
suggest using signal name instead of numbers.
I tried to fix all the impacted code, but I might have forgotten some
spots. It shouldn't be hard to fix if that's the case. I also couldn't
build-test everything I changed, especially the nto and solaris stuff.
gdb/ChangeLog:
* target.h (struct target_ops) <to_detach>: Remove args
parameter.
(target_detach): Likewise.
* target.c (dispose_inferior): Adjust.
(target_detach): Remove args parameter, adjust.
* aix-thread.c (aix_thread_detach): Adjust.
* corefile.c (core_file_command): Adjust.
* corelow.c (core_detach): Adjust.
* darwin-nat.c (darwin_detach): Adjust.
* gnu-nat.c (gnu_detach): Adjust.
* inf-ptrace.c (inf_ptrace_detach): Adjust.
* infcmd.c (detach_command): Adjust
* infrun.c (follow_fork_inferior): Adjust.
(handle_vfork_child_exec_or_exit): Adjust.
* linux-fork.c (linux_fork_detach): Remove args parameter.
* linux-fork.h (linux_fork_detach): Likewise.
* linux-nat.c (linux_nat_detach): Likewise, and adjust.
* linux-thread-db.c (thread_db_detach): Likewise.
* nto-procfs.c (procfs_detach): Likewise.
* procfs.c (procfs_detach): Likewise.
(do_detach): Remove signo parameter.
* record.c (record_detach): Remove args parameter.
* record.h (record_detach): Likewise.
* remote-sim.c (gdbsim_detach): Likewise.
* remote.c (remote_detach_1): Likewise.
(remote_detach): Likewise.
(extended_remote_detach): Likewise.
* sol-thread.c (sol_thread_detach): Likewise.
* target-delegates.c: Re-generate.
* top.c (struct qt_args) <args>: Remove field.
(kill_or_detach): Don't pass args.
(quit_force): Don't set args.
* windows-nat.c (windows_detach): Remove args parameter.
This patch makes linux_ptrace_attach_fail_reason and
linux_ptrace_attach_fail_reason_string return std::string. It also
replaces usages of struct buffer with std::string. This allows getting
rid of a cleanup in in linux_ptrace_attach_fail_reason_string and
simplifies the code in general.
Something that looks odd to me is that in
linux_ptrace_attach_fail_reason, if the two messages are appended, there
is no separating space or \n, so the result won't be very nice. I left
it as-is for now though.
gdb/ChangeLog:
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason): Return
std::string.
(linux_ptrace_attach_fail_reason_string): Likewise.
* nat/linux-ptrace.c (linux_ptrace_attach_fail_reason):
Likewise.
(linux_ptrace_attach_fail_reason_string): Likewise.
* linux-nat.c (attach_proc_task_lwp_callback): Adjust.
gdb/gdbserver/ChangeLog:
* linux-low.c (attach_proc_task_lwp_callback): Adjust to
linux_ptrace_attach_fail_reason_string now returning an
std::string.
(linux_attach): Likewise.
* thread-db.c (attach_thread): Likewise.
I think this xstrdup is not useful. We can pass ex.message directly to
throw_error instead.
gdb/ChangeLog:
* linux-nat.c (linux_nat_attach): Remove xstrdup.
I noticed that we're passing down a data/size pair to
target_ops::to_set_syscall_catchpoint. This commit makes use of
gdb::array_view instead. While at it, use bool where appropriate as
well.
gdb/ChangeLog:
* break-catch-syscall.c (insert_catch_syscall)
(remove_catch_syscall): Adjust to pass reference to
inf_data->syscalls_counts directly via gdb::array_view.
* fbsd-nat.c (fbsd_set_syscall_catchpoint): Adjust to use bool
and gdb::array_view.
* linux-nat.c (linux_child_set_syscall_catchpoint): Likewise.
* remote.c (remote_set_syscall_catchpoint): Likewise.
* target-debug.h (target_debug_print_bool): New.
(define target_debug_print_gdb_array_view_const_int): New.
* target-delegates.c: Regenerate.
* target.h (target_ops) <to_set_syscall_catchpoint>: Use
gdb::array_view and bool.
(target_set_syscall_catchpoint): Likewise.
This changes maybe_disable_address_space_randomization to be an RAII
class, rather than having it return a cleanup.
Regression tested by the buildbot.
ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* nat/linux-personality.h (class
maybe_disable_address_space_randomization): New class.
(maybe_disable_address_space_randomization): Don't declare
function.
* nat/linux-personality.c (restore_personality)
(make_disable_asr_cleanup): Remove.
(maybe_disable_address_space_randomization): Now a constructor.
(~maybe_disable_address_space_randomization): New destructor.
* linux-nat.c (linux_nat_create_inferior): Update.
gdbserver/ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* linux-low.c (linux_create_inferior): Update.
I have the goal of "poisoning" the XNEW/xfree-family of functions, so
that we catch their usages with non-POD types. A few things need to be
fixed in the mean time, this is one.
The common lwp code in linux-nat.c and gdbserver/linux-low.c xfrees the
private lwp data of type arch_lwp_info. However, that type is opaque
from its point of view, as its defined differently in each arch-specific
implementation. This trips on the std::is_pod<T> check, since the
compiler can't tell whether the type is POD or not if it doesn't know
about it.
My initial patch [1] made a class hierarchy with a virtual destructor.
However, as Pedro pointed out, we only have one native architecture at
the time built in gdb and gdbserver, so that's overkill. Instead, we
can move the responsibility of free'ing arch_lwp_info to the arch code
(which is also the one that allocated it in the first place). This is
what this patch does.
Also, I had the concern that if we wanted to use C++ features in these
structures, we would have a problem with the one-definition rule.
However, since a build will only have one version of arch_lwp_info,
that's not a problem.
There are changes in arch-specific files, I was only able to built-test
this patch with the following cross-compilers:
aarch64-linux-gnu
alpha-linux-gnu
arm-linux-gnueabihf
hppa-linux-gnu
m68k-linux-gnu
mips64el-linux-gnuabi64
powerpc64-linux-gnu
s390x-linux-gnu
sh4-linux-gnu
sparc64-linux-gnu
x86_64-linux-gnu
x86_64-w64-mingw32
A buildbot run didn't find any regression.
[1] https://sourceware.org/ml/gdb-patches/2017-08/msg00255.html
gdb/ChangeLog:
* linux-nat.h (linux_nat_set_delete_thread): New declaration.
* linux-nat.c (linux_nat_delete_thread): New variable.
(lwp_free): Invoke linux_nat_delete_thread if set.
(linux_nat_set_delete_thread): New function.
* aarch64-linux-nat.c (_initialize_aarch64_linux_nat): Assign
thread delete callback.
* arm-linux-nat.c (arm_linux_delete_thread): New function.
(_initialize_arm_linux_nat): Assign thread delete callback.
* s390-linux-nat.c (s390_delete_thread): New function.
(_initialize_s390_nat): Assign thread delete callback.
* x86-linux-nat.c (x86_linux_add_target): Likewise.
* nat/aarch64-linux.c (aarch64_linux_delete_thread): New
function.
* nat/aarch64-linux.h (aarch64_linux_delete_thread): New
declaration.
* nat/x86-linux.c (x86_linux_delete_thread): New function.
* nat/x86-linux.h (x86_linux_delete_thread): New declaration.
gdb/gdbserver/ChangeLog:
* linux-aarch64-low.c (the_low_target): Add thread delete
callback.
* linux-arm-low.c (arm_delete_thread): New function.
(the_low_target): Add thread delete callback.
* linux-bfin-low.c (the_low_target): Likewise.
* linux-crisv32-low.c (the_low_target): Likewise.
* linux-low.c (delete_lwp): Invoke delete_thread callback if
set.
* linux-low.h (struct linux_target_ops) <delete_thread>: New
field.
* linux-m32r-low.c (the_low_target): Add thread delete callback.
* linux-mips-low.c (mips_linux_delete_thread): New function.
(the_low_target): Add thread delete callback.
* linux-ppc-low.c (the_low_target): Likewise.
* linux-s390-low.c (the_low_target): Likewise.
* linux-sh-low.c (the_low_target): Likewise.
* linux-tic6x-low.c (the_low_target): Likewise.
* linux-tile-low.c (the_low_target): Likewise.
* linux-x86-low.c (the_low_target): Likewise.
* linux-xtensa-low.c (the_low_target): Likewise.
Commit 5cd63fda035d ("Fix "Remote 'g' packet reply is too long"
problems with multiple inferiors") caused a number of regressions on
native GNU/Linux, all related to follow-fork support. E.g.:
src/gdb/target.c:3141: internal-error: gdbarch* default_thread_architecture(target_ops*, ptid_t): Assertion `inf != NULL' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
Resyncing due to internal error.
FAIL: gdb.base/catch-signal-fork.exp: got SIGHUP after fork (GDB internal error)
This commit fixes it.
gdb/ChangeLog:
2017-10-05 Pedro Alves <palves@redhat.com>
* linux-nat.c (linux_child_follow_fork): When following the parent
and detaching the child, consult the parent thread's architecture
instead of the child's.
This removes save_inferior_ptid, a cleanup function, in favor of
scoped_restore.
This also fixes a possible (it seems unlikely that it could happen in
practice) memory leak -- save_inferior_ptid should have used
make_cleanup_dtor, because it allocated memory.
I tested this on the buildbot. However, there are two caveats to
this. First, sometimes it seems I misread the results. Second, I
think this patch touches some platforms that can't be tested by the
buildbot. So, extra care seems warranted.
ChangeLog
2017-08-18 Tom Tromey <tom@tromey.com>
Pedro Alves <palves@redhat.com>
* spu-multiarch.c (parse_spufs_run): Use scoped_restore.
* sol-thread.c (sol_thread_resume, sol_thread_wait)
(sol_thread_xfer_partial, rw_common): Use scoped_restore.
* procfs.c (procfs_do_thread_registers): Use scoped_restore.
* proc-service.c (ps_xfer_memory): Use scoped_restore.
* linux-tdep.c (linux_corefile_thread): Remove a cleanup.
(linux_get_siginfo_data): Add "thread" argument. Use
scoped_restore.
* linux-nat.c (linux_child_follow_fork)
(check_stopped_by_watchpoint): Use scoped_restore.
* infrun.c (displaced_step_prepare_throw, write_memory_ptid)
(THREAD_STOPPED_BY, handle_signal_stop): Use scoped_restore.
(restore_inferior_ptid, save_inferior_ptid): Remove.
* btrace.c (btrace_fetch): Use scoped_restore.
* bsd-uthread.c (bsd_uthread_fetch_registers)
(bsd_uthread_store_registers): Use scoped_restore.
* breakpoint.c (reattach_breakpoints, detach_breakpoints): Use
scoped_restore.
* aix-thread.c (aix_thread_resume, aix_thread_wait)
(aix_thread_xfer_partial): Use scoped_restore.
* inferior.h (save_inferior_ptid): Remove.
The parameter "first" of linux_nat_post_attach_wait is unused, remove
it.
gdb/ChangeLog:
* linux-nat.c (linux_nat_post_attach_wait): Remove FIRST
parameter.
(linux_nat_attach): Adjust call to linux_nat_post_attach_wait.
As a preparation for the next patch, which will move fork_inferior
from GDB to common/ (and therefore share it with gdbserver), it is
interesting to convert a few functions to C++.
This patch touches functions related to parsing command-line arguments
to the inferior (see gdb/fork-child.c:breakup_args), the way the
arguments are stored on fork_inferior (using std::vector instead of
char **), and the code responsible for dealing with argv also on
gdbserver.
I've taken this opportunity and decided to constify a few arguments to
fork_inferior/create_inferior as well, in order to make the code
cleaner. And now, on gdbserver, we're using xstrdup everywhere and
aren't checking for memory allocation failures anymore, as requested
by Pedro:
<https://sourceware.org/ml/gdb-patches/2017-03/msg00191.html>
Message-Id: <025ebdb9-90d9-d54a-c055-57ed2406b812@redhat.com>
Pedro Alves wrote:
> On the "== NULL" check: IIUC, the old NULL check was there to
> handle strdup returning NULL due to out-of-memory.
> See NULL checks and comments further above in this function.
> Now that you're using a std::vector, that doesn't work or make
> sense any longer, since if push_back fails to allocate space for
> its internal buffer (with operator new), our operator new replacement
> (common/new-op.c) calls malloc_failure, which aborts gdbserver.
>
> Not sure it makes sense to handle out-of-memory specially in
> the gdb/rsp-facing functions nowadays (maybe git blame/log/patch
> submission for that code shows some guidelines). Maybe (or, probably)
> it's OK to stop caring about it, but then we should consistently remove
> left over code, by using xstrdup instead and remove the NULL checks.
IMO this refactoring was very good to increase the readability of the
code as well, because some parts of the argument handling were
unnecessarily confusing before.
gdb/ChangeLog:
2017-04-12 Sergio Durigan Junior <sergiodj@redhat.com>
* common/common-utils.c (free_vector_argv): New function.
* common/common-utils.h: Include <vector>.
(free_vector_argv): New prototype.
* darwin-nat.c (darwin_create_inferior): Rewrite function
prototype in order to constify "exec_file" and accept a
"std::string" for "allargs".
* fork-child.c: Include <vector>.
(breakup_args): Rewrite function, using C++.
(fork_inferior): Rewrite function header, constify "exec_file_arg"
and accept "std::string" for "allargs". Update the code to
calculate "argv" based on "allargs". Update calls to "exec_fun"
and "execvp".
* gnu-nat.c (gnu_create_inferior): Rewrite function prototype in
order to constify "exec_file" and accept a "std::string" for
"allargs".
* go32-nat.c (go32_create_inferior): Likewise.
* inf-ptrace.c (inf_ptrace_create_inferior): Likewise.
* infcmd.c (run_command_1): Constify "exec_file". Use
"std::string" for inferior arguments.
* inferior.h (fork_inferior): Update prototype.
* linux-nat.c (linux_nat_create_inferior): Rewrite function
prototype in order to constify "exec_file" and accept a
"std::string" for "allargs".
* nto-procfs.c (procfs_create_inferior): Likewise.
* procfs.c (procfs_create_inferior): Likewise.
* remote-sim.c (gdbsim_create_inferior): Likewise.
* remote.c (extended_remote_run): Update code to accept
"std::string" as argument.
(extended_remote_create_inferior): Rewrite function prototype in
order to constify "exec_file" and accept a "std::string" for
"allargs".
* rs6000-nat.c (super_create_inferior): Likewise.
(rs6000_create_inferior): Likewise.
* target.h (struct target_ops) <to_create_inferior>: Likewise.
* windows-nat.c (windows_create_inferior): Likewise.
gdb/gdbserver/ChangeLog:
2017-04-12 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c: Include <vector>.
<program_argv, wrapper_argv>: Convert to std::vector.
(start_inferior): Rewrite function to use C++.
(handle_v_run): Likewise. Update code that calculates the argv
based on the vRun packet; use C++.
(captured_main): Likewise.
At the end of linux_nat_detach the main_lwp is deleted (delete_lwp).
This is problematic as during detach (detach_one_lwp and
linux_fork_detach) main_lwp already gets freed. Thus calling
delete_lwp causes a read after free. Fix it by removing the
unnecessary delete_lwp.
gdb/ChangeLog:
2017-04-11 Philipp Rudo <prudo@linux.vnet.ibm.com>
* linux-nat.c (linux_nat_detach): Remove delete_lwp call.
The linux_nat_xfer_partial does a conversion of inferior_ptid: if it's
an LWP (ptid::lwp != 0), it builds a new ptid with the lwp as
the pid and assigns that temporarily to inferior_ptid. For example, if
inferior_ptid is:
{ .pid = 1234, .lwp = 1235 }
it will assign this to inferior_ptid for the duration of the call:
{ .pid = 1235, .lwp = 0 }
Instead of doing this, this patch teaches the inf-ptrace implementation
of xfer_partial to deal with ptids representing lwps by using
get_ptrace_pid.
Also, in linux_proc_xfer_spu and linux_proc_xfer_partial, we use ptid_get_lwp
instead of ptid_get_pid. While not strictly necessary, since the content of
/proc/<pid> and /proc/<lwp> should be the same, it's a bit safer, because:
- some files under /proc/<pid>/ may not work if the <pid> thread is
running, just like ptrace requires a stopped thread. The current
thread's lwp id is more likely to be in the necessary state (stopped).
- if the leader (<pid>) had exited and is thus now zombie, then several
files under "/proc/<pid>" won't work, while they will if you use
"/proc/<lwp>".
The testsuite found no regression on native amd64 linux.
gdb/ChangeLog:
* inf-ptrace.c (inf_ptrace_xfer_partial): Get pid from ptid
using get_ptrace_pid.
* linux-nat.c (linux_nat_xfer_partial): Don't set/restore
inferior_ptid.
(linux_proc_xfer_partial, linux_proc_xfer_spu): Use lwp of
inferior_ptid instead of pid.
So far linux_proc_xfer_partial refused to handle write requests. This is
still based on the assumption that the Linux kernel does not support
writes to /proc/<pid>/mem. That used to be true, but has changed with
Linux 2.6.39 released in May 2011.
This patch lifts this restriction and now exploits /proc/<pid>/mem for
writing to inferior memory as well, if possible.
gdb/ChangeLog:
* linux-nat.c (linux_proc_xfer_partial): Handle write operations
as well.
I think this comment is outdated. Nowadays, linux-nat is always async,
unless the user has explictly turned it off with
"maint set target-async off".
gdb/ChangeLog:
* linux-nat.c (linux_nat_can_async_p): Update comment.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
This patch consolidates the API of target_mourn_inferior between GDB
and gdbserver, in my continuing efforts to make sharing the
fork_inferior function possible between both.
GDB's version of the function did not care about the inferior's ptid
being mourned, but gdbserver's needed to know this information. Since
it actually makes sense to pass the ptid as an argument, instead of
depending on a global value directly (which GDB's version did), I
decided to make the generic API to accept it. I then went on and
extended all calls being made on GDB to include a ptid argument (which
ended up being inferior_ptid most of the times, anyway), and now we
have a more sane interface.
On GDB's side, after talking to Pedro a bit about it, we decided that
just an assertion to make sure that the ptid being passed is equal to
inferior_ptid would be enough for now, on the GDB side. We can remove
the assertion and perform more operations later if we ever pass
anything different than inferior_ptid.
Regression tested on our BuildBot, everything OK.
I'd appreciate a special look at gdb/windows-nat.c's modification
because I wasn't really sure what to do there. It seemed to me that
maybe I should build a ptid out of the process information there, but
then I am almost sure the assertion on GDB's side would trigger.
gdb/ChangeLog:
2016-09-19 Sergio Durigan Junior <sergiodj@redhat.com>
* darwin-nat.c (darwin_kill_inferior): Adjusting call to
target_mourn_inferior to include ptid_t argument.
* fork-child.c (startup_inferior): Likewise.
* gnu-nat.c (gnu_kill_inferior): Likewise.
* inf-ptrace.c (inf_ptrace_kill): Likewise.
* infrun.c (handle_inferior_event_1): Likewise.
* linux-nat.c (linux_nat_attach): Likewise.
(linux_nat_kill): Likewise.
* nto-procfs.c (interrupt_query): Likewise.
(procfs_interrupt): Likewise.
(procfs_kill_inferior): Likewise.
* procfs.c (procfs_kill_inferior): Likewise.
* record.c (record_mourn_inferior): Likewise.
* remote-sim.c (gdbsim_kill): Likewise.
* remote.c (remote_detach_1): Likewise.
(remote_kill): Likewise.
* target.c (target_mourn_inferior): Change declaration to accept
new ptid_t argument; use gdb_assert on it.
* target.h (target_mourn_inferior): Move function prototype from
here...
* target/target.h (target_mourn_inferior): ... to here. Adjust it
to accept new ptid_t argument.
* windows-nat.c (get_windows_debug_event): Adjusting call to
target_mourn_inferior to include ptid_t argument.
gdb/gdbserver/ChangeLog:
2016-09-19 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c (start_inferior): Call target_mourn_inferior instead of
mourn_inferior; pass ptid_t argument to it.
(resume): Likewise.
(handle_target_event): Likewise.
* target.c (target_mourn_inferior): New function.
* target.h (mourn_inferior): Delete macro.
Add the function lwp_is_stepping which indicates whether the given LWP
is currently single-stepping. This is a common interface, usable from
native GDB as well as from gdbserver.
gdb/gdbserver/ChangeLog:
* linux-low.c (lwp_is_stepping): New function.
gdb/ChangeLog:
* nat/linux-nat.h (lwp_is_stepping): New declaration.
* linux-nat.c (lwp_is_stepping): New function.
This commit implements a new function, target_continue, on top of the
target_resume function. Then, it replaces all calls to target_resume
by calls to target_continue or to the already existing
target_continue_no_signal.
This is one of the (many) necessary steps needed to consolidate the
target interface between GDB and gdbserver. In particular, I am
interested in the impact this change will have on the unification of
the fork_inferior function (which I have been working on).
Tested on the BuildBot, no regressions introduced.
gdb/gdbserver/ChangeLog:
2016-09-31 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c (start_inferior): New variable 'ptid'. Replace calls
to the_target->resume by target_continue{,_no_signal}, depending
on the case.
* target.c (target_stop_and_wait): Call target_continue_no_signal
instead of the_target->resume.
(target_continue): New function.
gdb/ChangeLog:
2016-09-31 Sergio Durigan Junior <sergiodj@redhat.com>
* fork-child.c (startup_inferior): Replace calls to target_resume
by target_continue{,_no_signal}, depending on the case.
* linux-nat.c (cleanup_target_stop): Call
target_continue_no_signal instead of target_resume.
* procfs.c (procfs_wait): Likewise.
* target.c (target_continue): New function.
* target/target.h (target_continue): New prototype.
This commit fixes detaching on Linux when some thread exits the whole
thread group (process) just while we're detaching.
On Linux, a ptracer must detach from each LWP individually, with
PTRACE_DETACH. Since PTRACE_DETACH sets the thread running free, if
one of the already-detached threads causes the whole thread group to
exit (e.g., simply calls exit), the kernel force-kills the other
threads in the group, making them zombie, just as we're still
detaching them. Since PTRACE_DETACH against a zombie thread fails
with ESRCH, and gdb/gdbserver are not expecting this, the detach fails
with an error like: "Can't detach process: No such process.".
This patch detects this detach failure as normal, and instead of
erroring out, reaps the now-dead thread.
New test included, that exercises several different scenarios that
cause GDB/GDBserver to error out when it should not.
Tested on x86-64 GNU/Linux with {unix, native-gdbserver,
native-extended-gdbserver}
Note: without the previous fix, the "single-process + continue"
variant of the new test would fail with:
(gdb) PASS: gdb.threads/process-dies-while-detaching.exp: single-process: continue: watchpoint: switch to parent
continue
Continuing.
Warning:
Could not insert hardware watchpoint 3.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.
Command aborted.
(gdb) FAIL: gdb.threads/process-dies-while-detaching.exp: single-process: continue: watchpoint: continue
gdb/gdbserver/ChangeLog:
2016-07-01 Pedro Alves <palves@redhat.com>
Antoine Tremblay <antoine.tremblay@ericsson.com>
* linux-low.c: Change interface to take the target lwp_info
pointer directly and return void. Handle detaching from a zombie
thread.
(linux_detach_lwp_callback): New function.
(linux_detach): Detach from the leader thread after detaching from
the clone threads.
gdb/ChangeLog:
2016-07-01 Pedro Alves <palves@redhat.com>
Antoine Tremblay <antoine.tremblay@ericsson.com>
* inf-ptrace.c (inf_ptrace_detach_success): New function, factored
out from ...
(inf_ptrace_detach): ... here.
* inf-ptrace.h (inf_ptrace_detach_success): New declaration.
* linux-nat.c (get_pending_status): Rename to ...
(get_detach_signal): ... this, and return a host signal instead of
filling in a wait status.
(detach_one_lwp): New function, factored out from detach_callback
and adjusted to handle detaching from a zombie thread.
(detach_callback): Skip the leader thread.
(linux_nat_detach): No longer defer to inf_ptrace_detach to detach
the leader thread, nor build a signal string to pass down.
Instead, use target_announce_detach, detach_one_lwp and
inf_ptrace_detach_success.
gdb/testsuite/ChangeLog:
2016-07-01 Pedro Alves <palves@redhat.com>
Antoine Tremblay <antoine.tremblay@ericsson.com>
* gdb.threads/process-dies-while-detaching.c: New file.
* gdb.threads/process-dies-while-detaching.exp: New file.
And with that, we can switch the current UI to the UI whose input
descriptor woke up the event loop. IOW, if the user types in UI 2,
the event loop wakes up, switches to UI 2, and processes the input.
Next the user types in UI 3, the event loop wakes up and switches to
UI 3, etc.
gdb/ChangeLog:
2016-06-21 Pedro Alves <palves@redhat.com>
* event-top.c (input_fd): Delete.
(stdin_event_handler): Switch to the UI whose input descriptor got
the event. Adjust to per-UI input_fd.
(gdb_setup_readline): Don't set the input_fd global. Adjust to
per-UI input_fd.
(gdb_disable_readline): Adjust to per-UI input_fd.
* event-top.h (input_fd): Delete declaration.
* linux-nat.c (linux_nat_terminal_inferior): Don't remove input_fd
from the event-loop here.
(linux_nat_terminal_ours): Don't register input_fd in the
event-loop here.
* main.c (captured_main): Adjust to per-UI input_fd.
* remote.c (remote_terminal_inferior): Don't remove input_fd from
the event-loop here.
(remote_terminal_ours): Don't register input_fd in the event-loop
here.
* target.c: Include top.h and event-top.h.
(target_terminal_inferior): Remove input_fd from the event-loop
here.
(target_terminal_ours): Register input_fd in the event-loop.
* top.h (struct ui) <input_fd>: New field.
When GDB attaches to a process, it looks at the /proc/PID/task/ dir
for all clone threads of that process, and attaches to each of them.
Usually, if there is more than one clone thread, it means the program
is multi threaded and linked with pthreads. Thus when GDB soon after
attaching finds and loads a libthread_db matching the process, it'll
add a thread to the thread list for each of the initially found
lower-level LWPs.
If, however, GDB fails to find/load a matching libthread_db, nothing
is adding the LWPs to the thread list. And because of that, "detach"
hits an internal error:
(gdb) PASS: gdb.threads/clone-attach-detach.exp: fg attach 1: attach
info threads
Id Target Id Frame
* 1 LWP 6891 "clone-attach-de" 0x00007f87e5fd0790 in __nanosleep_nocancel () at ../sysdeps/unix/syscall-template.S:84
(gdb) FAIL: gdb.threads/clone-attach-detach.exp: fg attach 1: info threads shows two LWPs
detach
.../src/gdb/thread.c:1010: internal-error: is_executing: Assertion `tp' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
FAIL: gdb.threads/clone-attach-detach.exp: fg attach 1: detach (GDB internal error)
From here:
...
#8 0x00000000007ba7cc in internal_error (file=0x98ea68 ".../src/gdb/thread.c", line=1010, fmt=0x98ea30 "%s: Assertion `%s' failed.")
at .../src/gdb/common/errors.c:55
#9 0x000000000064bb83 in is_executing (ptid=...) at .../src/gdb/thread.c:1010
#10 0x00000000004c23bb in get_pending_status (lp=0x12c5cc0, status=0x7fffffffdc0c) at .../src/gdb/linux-nat.c:1235
#11 0x00000000004c2738 in detach_callback (lp=0x12c5cc0, data=0x0) at .../src/gdb/linux-nat.c:1317
#12 0x00000000004c1a2a in iterate_over_lwps (filter=..., callback=0x4c2599 <detach_callback>, data=0x0) at .../src/gdb/linux-nat.c:899
#13 0x00000000004c295c in linux_nat_detach (ops=0xe7bd30, args=0x0, from_tty=1) at .../src/gdb/linux-nat.c:1358
#14 0x000000000068284d in delegate_detach (self=0xe7bd30, arg1=0x0, arg2=1) at .../src/gdb/target-delegates.c:34
#15 0x0000000000694141 in target_detach (args=0x0, from_tty=1) at .../src/gdb/target.c:2241
#16 0x0000000000630582 in detach_command (args=0x0, from_tty=1) at .../src/gdb/infcmd.c:2975
...
Tested on x86-64 Fedora 23. Also confirmed the test passes against
gdbserver with "maint set target-non-stop".
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (attach_proc_task_lwp_callback): Mark the lwp
resumed, and add the thread to GDB's thread list.
testsuite/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* gdb.threads/clone-attach-detach.c: New file.
* gdb.threads/clone-attach-detach.exp: New file.
Working on the fix for gdb/19828, I saw
gdb.threads/attach-many-short-lived-threads.exp fail once in an
unusual way. Unfortunately I didn't keep debug logs, but it's an
issue similar to what's been fixed in remote.c a while ago --
linux-nat.c was not fetching the pending status from the right place.
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (get_pending_status): If the thread reported the
event to the core and it's pending, use the pending status signal
number.
Hacking the gdb.threads/attach-many-short-lived-threads.exp test to
spawn thousands of threads instead of dozens, and running gdb under
perf, I saw that GDB was spending most of the time in find_lwp_pid:
- captured_main
- 93.61% catch_command_errors
- 87.41% attach_command
- 87.40% linux_nat_attach
- 87.40% linux_proc_attach_tgid_threads
- 82.38% attach_proc_task_lwp_callback
- 81.01% find_lwp_pid
5.30% ptid_get_lwp
+ 0.10% ptid_lwp_p
+ 0.64% add_thread
+ 0.26% set_running
+ 0.24% set_executing
0.12% ptid_get_lwp
+ 0.01% ptrace
+ 0.01% add_lwp
attach_proc_task_lwp_callback is called once for each LWP that we
attach to, found by listing the /proc/PID/task/ directory. In turn,
attach_proc_task_lwp_callback calls find_lwp_pid to check whether the
LWP we're about to try to attach to is already known. Since
find_lwp_pid does a linear walk over the whole LWP list, this becomes
quadratic. We do the /proc/PID/task/ listing until we get two
iterations in a row where we found no new threads. So the second and
following times we walk the /proc/PID/task/ dir, we're going to take
an even worse find_lwp_pid hit.
Fix this by adding a hash table keyed by LWP PID, for fast lookup.
The linked list embedded in the LWP structure itself is kept, and made
a double-linked list, so that removals from that list are O(1). An
earlier version of this patch got rid of this list altogether, but
that revealed hidden dependencies / assumptions on how the list is
sorted. For example, killing a process and then waiting for all the
LWPs status using iterate_over_lwps only works as is because the
leader LWP is always last in the list. So I thought it better to take
an incremental approach and make this patch concern itself _only_ with
the PID lookup optimization.
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (lwp_lwpid_htab): New htab.
(lwp_info_hash, lwp_lwpid_htab_eq, lwp_lwpid_htab_create)
(lwp_lwpid_htab_add_lwp): New functions.
(lwp_list): Tweak comment.
(lwp_list_add, lwp_list_remove, lwp_lwpid_htab_remove_pid): New
functions.
(purge_lwp_list): Rewrite, using htab_traverse_noresize.
(add_initial_lwp): Add lwp to htab too. Use lwp_list_add.
(delete_lwp): Use lwp_list_remove. Remove htab too.
(find_lwp_pid): Search in htab.
(_initialize_linux_nat): Call lwp_lwpid_htab_create.
* linux-nat.h (struct lwp_info) <prev>: New field.
Hacking the gdb.threads/attach-many-short-lived-threads.exp test to
spawn thousands of threads instead of dozens, I saw GDB having trouble
keeping up with threads being spawned too fast, when it tried to stop
them all. This was because while gdb is doing that, it updates the
thread list to make sure no new thread has sneaked in that might need
to be paused. It does this a few times until it sees no-new-threads
twice in a row. The thread listing update itself is not that
expensive, however, in the Linux backend, updating the threads list
calls linux_common_core_of_thread for each LWP to record on which core
each LWP was last seen running, which opens/reads/closes a /proc file
for each LWP which becomes expensive when you need to do it for
thousands of LWPs.
perf shows gdb in linux_common_core_of_thread 44% of the time, in the
stop_all_threads -> update_thread_list path in this use case.
This patch simply makes linux_common_core_of_thread avoid updating the
core the thread is bound to if the thread hasn't run since the last
time we updated that info. This makes linux_common_core_of_thread
disappear into the noise in the perf report.
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (linux_resume_one_lwp_throw): Clear the LWP's core
field.
(linux_nat_update_thread_list): Don't fetch the core if already
known.
A following patch (fix for gdb/19828) makes linux-nat.c add threads to
GDB's thread list earlier in the "attach" sequence, and that causes a
surprising regression on
gdb.threads/attach-many-short-lived-threads.exp on my machine. The
extra "thread x exited" handling and traffic slows down that test
enough that GDB core has trouble keeping up with new threads that are
spawned while trying to stop existing ones.
I saw the exact same issue with remote/gdbserver a while ago and fixed
it in 65706a29bac5 (Remote thread create/exit events) so part of the
fix here is the exact same -- add support for thread created events to
gdb/linux-nat.c. infrun.c:stop_all_threads enables those events when
it tries to stop threads, which ensures that new threads never get a
chance to themselves start new threads, thus fixing the race.
gdb/
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (report_thread_events): New global.
(linux_handle_extended_wait): Report
TARGET_WAITKIND_THREAD_CREATED if thread event reporting is
enabled.
(wait_lwp, linux_nat_filter_event): Report all thread exits if
thread event reporting is enabled. Remove comment.
(filter_exit_event): New function.
(linux_nat_wait_1): Use it.
(linux_nat_thread_events): New function.
(linux_nat_add_target): Install it as target_thread_events method.
In non-stop mode, "interrupt" results in a "stop with no signal",
while in all-stop mode, it results in a remote interrupt request /
stop with SIGINT. This is currently implemented in both the Linux and
remote target backends. Move it to the core code instead, making
target_interrupt specifically always about "Interrupting as if with
Ctrl-C", just like it is documented.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* infcmd.c (interrupt_target_1): Call target_stop is in non-stop
mode.
* linux-nat.c (linux_nat_interrupt): Delete.
(linux_nat_add_target): Don't install linux_nat_interrupt.
* remote.c (remote_interrupt_ns): Change return type to void.
Throw error if interrupting the target is not supported.
(remote_interrupt): Don't call the remote_stop_ns/remote_stop_as.
This unbreaks pending/delayed breakpoints handling, as well as
hardware watchpoints, on MIPS.
Ref: https://sourceware.org/ml/gdb-patches/2016-02/msg00681.html
The MIPS kernel reports SI_KERNEL for all kernel generated traps,
instead of TRAP_BRKPT / TRAP_HWBKPT, but GDB isn't aware of this.
Basically, this commit:
- Folds watchpoints logic into check_stopped_by_breakpoint, and
renames it to save_stop_reason.
- Adds GDB_ARCH_IS_TRAP_HWBKPT.
- Makes MIPS set both GDB_ARCH_IS_TRAP_BRPT and
GDB_ARCH_IS_TRAP_HWBKPT to SI_KERNEL. In save_stop_reason, we
handle the case of the same si_code returning true for both
TRAP_BRPT and TRAP_HWBKPT by looking at what the debug registers
say.
Tested on x86-64 Fedora 20, native and gdbserver.
gdb/ChangeLog:
2016-02-24 Pedro Alves <palves@redhat.com>
* linux-nat.c (save_sigtrap) Delete.
(stop_wait_callback): Call save_stop_reason instead of
save_sigtrap.
(check_stopped_by_breakpoint): Rename to ...
(save_stop_reason): ... this. Bits of save_sigtrap folded here.
Use GDB_ARCH_IS_TRAP_HWBKPT and handle ambiguous
GDB_ARCH_IS_TRAP_BRKPT / GDB_ARCH_IS_TRAP_HWBKPT. Factor out
common code between the USE_SIGTRAP_SIGINFO and
!USE_SIGTRAP_SIGINFO blocks.
(linux_nat_filter_event): Call save_stop_reason instead of
save_sigtrap.
* nat/linux-ptrace.h: Check for both SI_KERNEL and TRAP_BRKPT
si_code for MIPS.
* nat/linux-ptrace.h: Fix "TRAP_HWBPT" typo in x86 table. Add
comments on MIPS behavior.
(GDB_ARCH_IS_TRAP_HWBKPT): Define for all archs.
gdb/gdbserver/ChangeLog:
2016-02-24 Pedro Alves <palves@redhat.com>
* linux-low.c (check_stopped_by_breakpoint): Rename to ...
(save_stop_reason): ... this. Use GDB_ARCH_IS_TRAP_HWBKPT and
handle ambiguous GDB_ARCH_IS_TRAP_BRKPT / GDB_ARCH_IS_TRAP_HWBKPT.
Factor out common code between the USE_SIGTRAP_SIGINFO and
!USE_SIGTRAP_SIGINFO blocks.
(linux_low_filter_event): Call save_stop_reason instead of
check_stopped_by_breakpoint and check_stopped_by_watchpoint.
Update comments.
(linux_wait_1): Update comments.
linux_nat_kill relies on get_last_target_status to determine whether
the current inferior is stopped at a unfollowed fork/vfork event.
This is bad because many things can happen ever since we caught the
fork/vfork event... This commit rewrites that code to instead walk
the thread list looking for unfollowed fork events, similarly to what
was done for remote.c.
New test included. The main idea of the test is make sure that when
the program stops for a fork catchpoint, and the user kills the
parent, gdb also kills the unfollowed fork child. Since the child
hasn't been added as an inferior at that point, we need some other
portable way to detect that the child is gone. The test uses a pipe
for that. The program forks twice, so you have grandparent, child and
grandchild. The grandchild inherits the write side of the pipe. The
grandparent hangs reading from the pipe, since nothing ever writes to
it. If, when GDB kills the child, it also kills the grandchild, then
the grandparent's pipe read returns 0/EOF and the test passes.
Otherwise, if GDB doesn't kill the grandchild, then the pipe read
never returns and the test times out, like:
FAIL: gdb.base/catch-fork-kill.exp: fork-kind=fork: exit-kind=kill: fork: kill parent (timeout)
FAIL: gdb.base/catch-fork-kill.exp: fork-kind=vfork: exit-kind=kill: vfork: kill parent (timeout)
No regressions on x86_64 Fedora 20. New test passes with gdbserver as
well.
gdb/ChangeLog:
2016-01-25 Pedro Alves <palves@redhat.com>
PR gdb/19494
* linux-nat.c (kill_one_lwp): New, factored out from ...
(kill_callback): ... this.
(kill_wait_callback): New, factored out from ...
(kill_wait_one_lwp): ... this.
(kill_unfollowed_fork_children): New function.
(linux_nat_kill): Use it.
gdb/testsuite/ChangeLog:
2016-01-25 Pedro Alves <palves@redhat.com>
PR gdb/19494
* gdb.base/catch-fork-kill.c: New file.
* gdb.base/catch-fork-kill.exp: New file.
Note: this applies on top of:
[PATCH] Remove support for LinuxThreads and vendor 2.4 kernels w/ backported NPTL
https://sourceware.org/ml/gdb-patches/2015-12/msg00214.html
We try to avoid using libthread_db.so to list threads in the inferior
when debugging live processes, but the code that decides whether to
use it decides incorrectly if you have more than one inferior, and the
current inferior doesn't have execution yet. The result is visible
as:
(gdb) add-inferior
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) info inferiors
Num Description Executable
1 process 15397 /home/pedro/gdb/tests/threads
* 2 <null>
(gdb) info threads
Cannot find new threads: generic error
(gdb)
Fix this by checking whether each inferior has execution rather than
just the current inferior.
By moving the core updating to linux-nat.c's update_thread_list
implementation, this also ends up fixing the
lwp-last-seen-running-on-core updating in the case we're debugging a
program that uses raw clone rather than pthreads, as linux-thread-db.c
isn't pushed in the target stack in that scenario.
Tested on x86_64 Fedora 20.
gdb/ChangeLog:
2015-12-17 Pedro Alves <palves@redhat.com>
PR threads/19354
* linux-nat.c (linux_nat_update_thread_list): Update process cores
each lwp was last seen running on here.
* linux-thread-db.c (update_thread_core): Delete.
(thread_db_update_thread_list_td_ta_thr_iter): Rename to ...
(thread_db_update_thread_list): ... this. Skip inferiors with
execution. Also call the target beneath.
(thread_db_update_thread_list): Delete.
gdb/testsuite/ChangeLog:
2015-12-17 Pedro Alves <palves@redhat.com>
PR threads/19354
* gdb.multi/info-threads.exp: New file.
Since we now rely on PTRACE_EVENT_CLONE being available (added in
Linux 2.5.46), we're relying on NPTL.
This commit removes the support for older LinuxThreads, as well as the
workarounds for vendor 2.4 kernels with NPTL backported.
- Rely on tkill being available.
- Assume gdb doesn't get cancel signals.
- Remove code that checks the LinuxThreads restart and cancel signals
in the inferior.
- Assume that __WALL is available.
- Assume that non-leader threads report WIFEXITED.
- Thus, no longer need to send signal 0 to check whether threads are
still alive.
- Update comments throughout.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/ChangeLog:
* configure.ac: Remove tkill checks.
* configure, config.in: Regenerate.
* linux-nat.c: Remove HAVE_TKILL_SYSCALL check. Update top level
comments.
(linux_nat_post_attach_wait): Remove 'cloned' parameter. Use
__WALL.
(attach_proc_task_lwp_callback): Don't set the cloned flag.
(linux_nat_attach): Adjust.
(kill_lwp): Remove HAVE_TKILL_SYSCALL check. No longer fall back
to 'kill'.
(linux_handle_extended_wait): Use __WALL. Don't set the cloned
flag.
(wait_lwp): Use __WALL. Update comments.
(running_callback, stop_and_resume_callback): Delete.
(linux_nat_filter_event): Don't stop and resume all lwps. Don't
check if the event LWP has previously exited.
(check_zombie_leaders): Update comments.
(linux_nat_wait_1): Use __WALL.
(kill_wait_callback): Don't handle clone processes separately.
Use __WALL instead.
(linux_thread_alive): Delete.
(linux_nat_thread_alive): Return true as long as the LWP is in the
LWP list.
(linux_nat_update_thread_list): Assume the kernel supports
PTRACE_EVENT_CLONE.
(get_signo): Delete.
(lin_thread_get_thread_signals): Remove LinuxThreads references.
No longer check __pthread_sig_restart / __pthread_sig_cancel in
the inferior.
* linux-nat.h (struct lwp_info) <cloned>: Delete field.
* linux-thread-db.c: Update comments.
(_initialize_thread_db): Remove LinuxThreads references.
* nat/linux-waitpid.c (my_waitpid): No longer emulate __WALL.
Pass down flags unmodified.
* linux-waitpid.h (my_waitpid): Update documentation.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_kill_one_lwp): Remove references to
LinuxThreads.
(kill_lwp): Remove HAVE_TKILL_SYSCALL check. No longer fall back
to 'kill'.
(linux_init_signals): Delete.
(initialize_low): Adjust.
* thread-db.c (thread_db_init): Remove LinuxThreads reference.
Before, on systems that did not support PTRACE_EVENT_CLONE, both GDB and
GDBServer coordinated with libthread_db.so to insert breakpoints at magic
locations in libpthread.so, in order to break at thread creation and
thread death.
Support for thread events was removed from GDBServer as patch:
https://sourceware.org/ml/gdb-patches/2015-11/msg00466.html
This patch removes support for thread events in GDB.
No regressions found on Ubuntu 14.04 x86_64.
gdb/ChangeLog:
* breakpoint.c (remove_thread_event_breakpoints): Remove.
* breakpoint.h (remove_thread_event_breakpoints): Remove
declaration.
* linux-nat.c (in_pid_list_p): Remove.
(lin_lwp_attach_lwp): Remove.
* linux-nat.h (lin_lwp_attach_lwp): Remove declaration.
* linux-thread-db.c (thread_db_use_events): Remove.
(struct thread_db_info) <td_create_bp_addr>: Remove.
<td_death_bp_addr>: Likewise.
<td_ta_event_addr_p>: Likewise.
<td_ta_set_event_p>: Likewise.
<td_ta_clear_event_p>: Likewise.
<td_ta_event_getmsg_p>: Likewise.
<td_thr_event_enable_p>: Likewise.
(attach_thread): Likewise.
(detach_thread): Likewise.
(have_threads_callback): Likewise.
(have_threads): Likewise.
(enable_thread_event): Likewise.
(enable_thread_event_reporting): Likewise.
(try_thread_db_load_1): Remove td_ta_event_addr, td_ta_set_event,
td_ta_clear_event, td_ta_event_getmsg, td_thr_event_enable
initializations.
(try_thread_db_load_1): Remove enable_thread_event_reporting call.
(disable_thread_event_reporting): Remove.
(record_thread): Adapt to thread_db_use_event removal.
(detach_thread): Remove.
(thread_db_detach): Adapt to thread_db_use_event removal.
(check_event): Remove.
(thread_db_wait): Adapt to thread events support removal.
(thread_db_mourn_inferior): Likewise.
(find_new_threads_callback): Likewise.
(find_new_threads_once): Likewise.
(thread_db_update_thread_list): Likewise.
This patch adds support for thread names in the remote protocol, and
updates gdb/gdbserver to use it. The information is added to the XML
description sent in response to the qXfer:threads:read packet.
gdb/ChangeLog:
* linux-nat.c (linux_nat_thread_name): Replace implementation by call
to linux_proc_tid_get_name.
* nat/linux-procfs.c (linux_proc_tid_get_name): New function,
implementation inspired by linux_nat_thread_name.
* nat/linux-procfs.h (linux_proc_tid_get_name): New declaration.
* remote.c (struct private_thread_info) <name>: New field.
(free_private_thread_info): Free name field.
(remote_thread_name): New function.
(thread_item_t) <name>: New field.
(clear_threads_listing_context): Free name field.
(start_thread): Get name xml attribute.
(thread_attributes): Add "name" attribute.
(remote_update_thread_list): Copy name field.
(init_remote_ops): Assign remote_thread_name callback.
* target.h (target_thread_name): Update comment.
* NEWS: Mention remote thread name support.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_target_ops): Use linux_proc_tid_get_name.
* server.c (handle_qxfer_threads_worker): Refactor to include thread
name in reply.
* target.h (struct target_ops) <thread_name>: New field.
(target_thread_name): New macro.
gdb/doc/ChangeLog:
* gdb.texinfo (Thread List Format): Mention thread names.
Since this code path returns a string owned by the target (we don't know how
it's allocated, could be a static read-only string), it's safer if we return
a constant string. If, for some reasons, the caller wishes to modify the
string, it should make itself a copy.
gdb/ChangeLog:
* linux-nat.c (linux_nat_thread_name): Constify return value.
* target.h (struct target_ops) <to_thread_name>: Likewise.
(target_thread_name): Likewise.
* target.c (target_thread_name): Likewise.
* target-delegates.c (debug_thread_name): Regenerate.
* python/py-infthread.c (thpy_get_name): Constify local variables.
* thread.c (print_thread_info): Likewise.
(thread_find_command): Likewise.
The existing logic was simply to flip syscall entry/return state when a
syscall trap was seen, and even then only with active 'catch syscall'.
That can get out of sync if 'catch syscall' is toggled at odd times.
This patch updates the entry/return state for all syscall traps,
regardless of catching state, and also updates known syscall state for
other kinds of traps. Almost all PTRACE_EVENT stops are delivered from
the middle of a syscall, so this can act like an entry. Every other
kind of ptrace stop is only delivered outside of syscall event pairs, so
marking them ignored ensures the next syscall trap looks like an entry.
Three new test scenarios are added to catch-syscall.exp:
- Disable 'catch syscall' from an entry to deliberately miss the return
event, then re-enable to make sure a new entry is recognized.
- Enable 'catch syscall' for the first time from a vfork event, which is
a PTRACE_EVENT_VFORK in the middle of the syscall. Make sure the next
syscall event is recognized as the return.
- Make sure entry and return are recognized for an ENOSYS syscall. This
is to defeat a common x86 hack that uses the pre-filled ENOSYS return
value as a sign of being on the entry side.
gdb/ChangeLog:
2015-10-19 Josh Stone <jistone@redhat.com>
* linux-nat.c (linux_handle_syscall_trap): Always update entry/
return state, even when not actively catching syscalls at all.
(linux_handle_extended_wait): Mark syscall_state like an entry.
(wait_lwp): Set syscall_state ignored for other traps.
(linux_nat_filter_event): Likewise.
gdb/testsuite/ChangeLog:
2015-10-19 Josh Stone <jistone@redhat.com>
* gdb.base/catch-syscall.c: Include <sched.h>.
(unknown_syscall): New variable.
(main): Trigger a vfork and an unknown syscall.
* gdb.base/catch-syscall.exp (vfork_syscalls): New variable.
(unknown_syscall_number): Likewise.
(check_call_to_syscall): Accept an optional syscall pattern.
(check_return_from_syscall): Likewise.
(check_continue): Likewise.
(test_catch_syscall_without_args): Check for vfork and ENOSYS.
(test_catch_syscall_skipping_return): New test toggling off 'catch
syscall' to step over the syscall return, then toggling back on.
(test_catch_syscall_mid_vfork): New test turning on 'catch syscall'
during a PTRACE_EVENT_VFORK stop, in the middle of a vfork syscall.
(do_syscall_tests): Call test_catch_syscall_without_args and
test_catch_syscall_mid_vfork.
(test_catch_syscall_without_args_noxml): Check for vfork and ENOSYS.
(fill_all_syscalls_numbers): Initialize unknown_syscall_number.
Since the record-btrace target now supports non-stop mode, we no
longer need to force-disable as-ns on x86.
gdb/ChangeLog:
2015-09-30 Pedro Alves <palves@redhat.com>
* linux-nat.c (linux_nat_always_non_stop_p): Always return 1.
* x86-linux-nat.c (x86_linux_always_non_stop_p): Delete.
(x86_linux_create_target): Don't install
x86_linux_always_non_stop_p.
Simon Marchi
Tom Tromey
Pedro Alves
Simon Marchi
Joel Brobecker
Yao Qi
John Baldwin
Sergio Durigan Junior
Philipp Rudo
Andreas Arnez
Trevor Saunders
Antoine Tremblay
Josh Stone