Git commit 3c14e5a39b added a declaration for
gdb_agent_get_raw_reg to tracepoint.h, and this now caught that the
32-bit x86 implementation has the wrong prototype:
../../../src/gdb/gdbserver/linux-i386-ipa.c:103:1: error: conflicting types for ‘gdb_agent_get_raw_reg’
gdb_agent_get_raw_reg (unsigned char *raw_regs, int regnum)
^
In file included from ../../../src/gdb/gdbserver/linux-i386-ipa.c:24:0:
../../../src/gdb/gdbserver/tracepoint.h:168:31: note: previous declaration of ‘gdb_agent_get_raw_reg’ was here
IP_AGENT_EXPORT_FUNC ULONGEST gdb_agent_get_raw_reg
^
make[2]: *** [linux-i386-ipa.o] Error 1
gdb/gdbserver/
2015-03-01 Pedro Alves <palves@redhat.com>
* linux-i386-ipa.c (gdb_agent_get_raw_reg): Constify 'raw_regs'
parameter.
In C++ mode, we get:
gdb/gdbserver/linux-x86-low.c: In function ‘void x86_linux_dr_set(ptid_t, int, long unsigned int)’:
gdb/gdbserver/linux-x86-low.c:558:38: error: ‘regnum’ cannot appear in a constant-expression
offsetof (struct user, u_debugreg[regnum]), value);
^
gdb/gdbserver/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* linux-x86-low.c (u_debugreg_offset): New function.
(x86_linux_dr_get, x86_linux_dr_set): Use it.
gdb/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* x86-linux-nat.c (u_debugreg_offset): New function.
(x86_linux_dr_get, x86_linux_dr_set): Use it.
libthread_db.so calls symbols in the client (GDB), through the
proc-service interface. These routines must have extern "C" linkage
so their symbol names are not mangled when GDB is built as a C++
program. On the GDBserver side, we were missing fallback declarations for
all these symbols.
gdb/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* gdb_proc_service.h: Wrap with EXTERN_C_PUSH/EXTERN_C_POP.
gdb/gdbserver/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* gdb_proc_service.h: Wrap with EXTERN_C_PUSH/EXTERN_C_POP.
[!HAVE_PROC_SERVICE_H] (struct ps_prochandle): Forward declare.
[!HAVE_PROC_SERVICE_H] (ps_pdread, ps_pdwrite, ps_ptread)
ps_ptwrite, ps_lgetregs, ps_lsetregs, ps_lgetfpregs)
(ps_lsetfpregs, ps_getpid)
(ps_get_thread_area, ps_pglobal_lookup, ps_pstop, ps_pcontinue)
(ps_lstop, ps_lcontinue, ps_lgetxregsize, ps_lgetxregs)
(ps_lsetxregs, ps_plog): Declare.
Functions and variables that are exported by the IPA DSO (that
GDBserver needs to look up) should have "C" mangling, thus be declared
with extern "C".
Function and variable declarations need the extern "C" marker, but
variable definitions can't be marked extern, so the patch splits
IP_AGENT_EXPORT into three.
Building in C++ mode revealed that a few variables were missing
IP_AGENT_EXPORT, thus the IPA has been broken when stripped, even in C
mode... So this ends being a bug fix as well.
gdb/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* common/agent.h (IPA_SYM_EXPORTED_NAME): New.
(IPA_SYM): Use it.
* common/common-defs.h (EXTERN_C_PUSH, EXTERN_C_POP): New macros.
gdb/gdbserver/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* linux-amd64-ipa.c (gdb_agent_get_raw_reg): Use
IP_AGENT_EXPORT_FUNC.
* linux-i386-ipa.c (gdb_agent_get_raw_reg): Use
IP_AGENT_EXPORT_FUNC.
* tracepoint.c (ATTR_USED, ATTR_NOINLINE, ATTR_CONSTRUCTOR)
(IP_AGENT_EXPORT): Delete.
(gdb_tp_heap_buffer, gdb_jump_pad_buffer, gdb_jump_pad_buffer_end)
(gdb_trampoline_buffer, gdb_trampoline_buffer_end)
(gdb_trampoline_buffer_error, collecting, gdb_collect)
(stop_tracing, flush_trace_buffer, about_to_request_buffer_space)
(trace_buffer_is_full, stopping_tracepoint, expr_eval_result)
(error_tracepoint, tracepoints, tracing, trace_buffer_ctrl)
(trace_buffer_ctrl_curr, trace_buffer_lo, trace_buffer_hi)
(traceframe_read_count, traceframe_write_count)
(traceframes_created, trace_state_variables, get_raw_reg)
(get_trace_state_variable_value, set_trace_state_variable_value)
(ust_loaded, helper_thread_id, cmd_buf): Use
IPA_SYM_EXPORTED_NAME.
(stop_tracing, flush_trace_buffer): Use IP_AGENT_EXPORT_FUNC.
(tracepoints) Use IP_AGENT_EXPORT_VAR.
(stopping_tracepoint, trace_buffer_is_full, expr_eval_result): Use
IP_AGENT_EXPORT_VAR and wrap in EXTERN_C_PUSH/EXTERN_C_POP.
(last_tracepoint): Move into !IN_PROCESS_AGENT block.
(error_tracepoint): Use IP_AGENT_EXPORT_VAR and wrap in
EXTERN_C_PUSH/EXTERN_C_POP.
(trace_state_variables): Use IP_AGENT_EXPORT_VAR.
(trace_buffer_lo, trace_buffer_hi): Use IP_AGENT_EXPORT_VAR and
wrap in EXTERN_C_PUSH/EXTERN_C_POP.
(trace_buffer_ctrl, trace_buffer_ctrl_curr)
(traceframe_write_count, traceframe_read_count)
(traceframes_created, tracing): Use IP_AGENT_EXPORT_VAR.
(about_to_request_buffer_space, get_trace_state_variable_value)
(set_trace_state_variable_value): Use IP_AGENT_EXPORT_FUNC.
(collecting): Use IP_AGENT_EXPORT_VAR and wrap in
EXTERN_C_PUSH/EXTERN_C_POP.
(gdb_collect): Use IP_AGENT_EXPORT_FUNC.
(ust_loaded, cmd_buf): Use IP_AGENT_EXPORT_VAR.
(helper_thread_id, gdb_agent_capability): Use IP_AGENT_EXPORT_VAR
and wrap in EXTERN_C_PUSH/EXTERN_C_POP.
(gdb_tp_heap_buffer, gdb_jump_pad_buffer, gdb_jump_pad_buffer_end)
(gdb_trampoline_buffer, gdb_trampoline_buffer_end)
(gdb_trampoline_buffer_error): Use IP_AGENT_EXPORT_VAR.
* tracepoint.h (ATTR_USED, ATTR_NOINLINE, EXPORTED_SYMBOL):
Define.
(IP_AGENT_EXPORT_FUNC, IP_AGENT_EXPORT_VAR)
(IP_AGENT_EXPORT_VAR_DECL): Define.
(tracing): Declare.
(gdb_agent_get_raw_reg): Declare.
This patch renames symbols that happen to have names which are
reserved keywords in C++.
Most of this was generated with Tromey's cxx-conversion.el script.
Some places where later hand massaged a bit, to fix formatting, etc.
And this was rebased several times meanwhile, along with re-running
the script, so re-running the script from scratch probably does not
result in the exact same output. I don't think that matters anyway.
gdb/
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
Rename symbols whose names are reserved C++ keywords throughout.
gdb/gdbserver/
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
Rename symbols whose names are reserved C++ keywords throughout.
This new option, disabled by default for now, allows specifying
whether to build GDB, GDBserver, and friends with a C++ (98/03)
compiler.
The name of the switch should be familiar to those who followed GCC's
own C++ conversion process.
. Adding -fpermissive to COMPILER in C++ mode (see the new
build-with-cxx.m4 file) makes errors like these be warnings instead:
gdb/infrun.c:6597:1: error: initializing argument 1 of ‘void sig_print_info(gdb_signal)’ [-fpermissive]
sig_print_info (enum gdb_signal oursig)
^
gdb/infrun.c: In function ‘void do_restore_infcall_suspend_state_cleanup(void*)’:
gdb/infrun.c:7164:39: error: invalid conversion from ‘void*’ to ‘infcall_suspend_state*’ [-fpermissive]
restore_infcall_suspend_state (state);
^
so that the compiler carries on compiling the file. -Werror still
catches the warnings, so nothing is lost, only our lifes are made
easier by concentrating on getting other more important things out of
the way first.
There's no way to quiet those warnings. Until they're all fixed, when
building in C++ mode, -Werror is disabled by default.
. Adding -Wno-narrowing suppresses thousands of instances of this warning:
gdb/arm-linux-tdep.c:439:1: error: narrowing conversion of ‘-1’ from ‘int’ to ‘ULONGEST {aka long unsigned int}’ inside { } is ill-formed in C++11 [-Werror=narrowing]
gdb/arm-linux-tdep.c:439:1: error: narrowing conversion of ‘-1l’ from ‘LONGEST {aka long int}’ to ‘ULONGEST {aka long unsigned int}’ inside { } is ill-formed in C++11 [-Werror=narrowing]
gdb/arm-linux-tdep.c:450:1: error: narrowing conversion of ‘-1’ from ‘int’ to ‘ULONGEST {aka long unsigned int}’ inside { } is ill-formed in C++11 [-Werror=narrowing]
We can defer handling those until we target C++11.
. Adding -Wno-sign-compare suppresses thousands of instances of this warning:
gdb/linux-record.c:1763:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if (tmpulongest == tdep->fcntl_F_GETLK64)
^
. Adding -Wno-write-strings suppresses thousands of instances of this warning:
gdb/mi/mi-cmd-var.c: In function ‘void mi_cmd_var_show_attributes(char*, char**, int)’:
gdb/mi/mi-cmd-var.c:514:12: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
attstr = "editable";
^
gdb/mi/mi-cmd-var.c:516:12: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
attstr = "noneditable";
^
For now, it's best to hide these warnings from view until we're
'-fpermissive'-clean, and can thus start building with -Werror.
The C compiler has always managed to build working GDBs with these
issues in the code, so a C++ compiler should too.
gdb/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* Makefile.in (COMPILER): New, get it from autoconf.
(COMPILE.pre, CC_LD): Use COMPILER.
(CXX): Get from autoconf instead.
(CXX_FOR_TARGET): Default to g++ instead of gcc.
* acinclude.m4: Include build-with-cxx.m4.
* build-with-cxx.m4: New file.
* configure.ac: Call AC_PROG_CXX and GDB_AC_BUILD_WITH_CXX.
Disable -Werror by default if building in C++ mode.
(build_warnings): Add -Wno-sign-compare, -Wno-write-strings and
-Wno-narrowing in C++ mode. Only enable -Wpointer-sign in C mode.
Run supported-warning-flags tests with the C++ compiler.
Save/restore CXXFLAGS too.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* Makefile.in (COMPILER): New, get it from autoconf.
(CXX): Get from autoconf instead.
(COMPILE.pre): Use COMPILER.
(CC-LD): Rename to ...
(CC_LD): ... this. Use COMPILER.
(gdbserver$(EXEEXT), gdbreplay$(EXEEXT), $(IPA_LIB)): Adjust.
(CXX_FOR_TARGET): Default to g++ instead of gcc.
* acinclude.m4: Include build-with-cxx.m4.
* configure.ac: Call AC_PROG_CXX and GDB_AC_BUILD_WITH_CXX.
Disable -Werror by default if building in C++ mode.
(build_warnings): Add -Wno-sign-compare, -Wno-write-strings and
-Wno-narrowing in C++ mode. Run supported-warning-flags tests with
the C++ compiler. Save/restore CXXFLAGS too.
* configure: Regenerate.
Converting GDB to be a C++ program, I stumbled on 'basename' issues,
like:
src/gdb/../include/ansidecl.h:169:64: error: new declaration ‘char* basename(const char*)’
/usr/include/string.h:597:26: error: ambiguates old declaration ‘const char* basename(const char*)’
which I believe led to this bit in gold's configure.ac:
dnl We have to check these in C, not C++, because autoconf generates
dnl tests which have no type information, and current glibc provides
dnl multiple declarations of functions like basename when compiling
dnl with C++.
AC_CHECK_DECLS([basename, ffs, asprintf, vasprintf, snprintf, vsnprintf, strverscmp])
These checks IIUC intend to generate all the HAVE_DECL_FOO symbols
that libiberty.h and ansidecl.h check.
GDB is missing these checks currently, which results in the conflict
shown above.
This adds an m4 file that both GDB and GDBserver's configury use to
pull in the autoconf checks that libiberty clients needs done in order
to use these libiberty.h/ansidecl.h.
gdb/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* libiberty.m4: New file.
* acinclude.m4: Include libiberty.m4.
* configure.ac: Call libiberty_INIT.
* config.in, configure: Regenerate.
gdb/gdbserver/
2015-02-27 Pedro Alves <palves@redhat.com>
* acinclude.m4: Include libiberty.m4.
* configure.ac: Call libiberty_INIT.
* config.in, configure: Regenerate.
.decr_pc_after_break is never higher than .breakpoint_len, so use
.breakpoint_len directly. Based on idea from Yao here:
https://sourceware.org/ml/gdb-patches/2015-02/msg00689.html
gdb/gdbserver/ChangeLog:
2015-02-26 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_wait_1): When incrementing the PC past a
program breakpoint always use the_low_target.breakpoint_len as
increment, rather than the maximum between that and
the_low_target.decr_pc_after_break.
I'm going to add an alternate mechanism of breakpoint trap
identification to 'check_stopped_by_breakpoint' that does not rely on
checking the instruction at PC. The mechanism currently used to tell
whether we're stepping over a permanent breakpoint doesn't fit in that
new method. This patch redoes the whole logic in a different way that
works with both old and new methods, in essence moving the "stepped
permanent breakpoint" detection "one level up". It makes lower level
check_stopped_by_breakpoint always the adjust the PC, and then has
linux_wait_1 advance the PC past the breakpoint if necessary. This
ends up being better also because this now handles
non-decr_pc_after_break targets too. Before, such targets would get
stuck forever reexecuting the breakpoint instruction.
Tested on x86_64 Fedora 20.
gdb/gdbserver/ChangeLog:
2015-02-23 Pedro Alves <palves@redhat.com>
* linux-low.c (check_stopped_by_breakpoint): Don't check if the
thread was doing a step-over; always adjust the PC if
we stepped over a permanent breakpoint.
(linux_wait_1): If we stepped over breakpoint that was on top of a
permanent breakpoint, manually advance the PC past it.
$ make check RUNTESTFLAGS="--target_board=native-gdbserver/-m32 clone-thread_db.exp"
gdb.log shows:
Running target native-gdbserver/-m32
...
clone-thread_db: src/gdb/testsuite/gdb.threads/clone-thread_db.c:57: thread_fn: Assertion `res != -1' failed.
...
(gdb) FAIL: gdb.threads/clone-thread_db.exp: continue to end
That was waitpid returning -1 / EINTR. We don't see that when testing
with unix/-m32 (native debugging). Turns out to be that when
debugging a 32-bit inferior, a 64-bit GDBserver is reading/writing
$orig_eax from/to the wrong ptrace register buffer offset. When
gdbserver is 64-bit, the ptrace register buffer is in 64-bit layout,
so the register is found at "ORIG_EAX * 8", not at "ORIG_EAX * 4".
Fixes these with --target_board=native-gdbserver/-m32 on x86_64 Fedora 20:
-FAIL: gdb.threads/clone-thread_db.exp: continue to end
+PASS: gdb.threads/clone-thread_db.exp: continue to end
-FAIL: gdb.threads/hand-call-in-threads.exp: all dummies popped
+PASS: gdb.threads/hand-call-in-threads.exp: all dummies popped
PASS: gdb.threads/hand-call-in-threads.exp: breakpoint on all_threads_running
PASS: gdb.threads/hand-call-in-threads.exp: breakpoint on hand_call
PASS: gdb.threads/hand-call-in-threads.exp: disable scheduler locking
@@ -29339,15 +29331,15 @@ PASS: gdb.threads/hand-call-in-threads.e
PASS: gdb.threads/hand-call-in-threads.exp: discard hand call, thread 4
PASS: gdb.threads/hand-call-in-threads.exp: discard hand call, thread 5
PASS: gdb.threads/hand-call-in-threads.exp: dummy stack frame number, thread 1
-FAIL: gdb.threads/hand-call-in-threads.exp: dummy stack frame number, thread 2
-FAIL: gdb.threads/hand-call-in-threads.exp: dummy stack frame number, thread 3
-FAIL: gdb.threads/hand-call-in-threads.exp: dummy stack frame number, thread 4
+PASS: gdb.threads/hand-call-in-threads.exp: dummy stack frame number, thread 2
+PASS: gdb.threads/hand-call-in-threads.exp: dummy stack frame number, thread 3
+PASS: gdb.threads/hand-call-in-threads.exp: dummy stack frame number, thread 4
PASS: gdb.threads/hand-call-in-threads.exp: dummy stack frame number, thread 5
PASS: gdb.threads/hand-call-in-threads.exp: enable scheduler locking
PASS: gdb.threads/hand-call-in-threads.exp: hand call, thread 1
-FAIL: gdb.threads/hand-call-in-threads.exp: hand call, thread 2
-FAIL: gdb.threads/hand-call-in-threads.exp: hand call, thread 3
-FAIL: gdb.threads/hand-call-in-threads.exp: hand call, thread 4
+PASS: gdb.threads/hand-call-in-threads.exp: hand call, thread 2
+PASS: gdb.threads/hand-call-in-threads.exp: hand call, thread 3
+PASS: gdb.threads/hand-call-in-threads.exp: hand call, thread 4
PASS: gdb.threads/hand-call-in-threads.exp: hand call, thread 5
PASS: gdb.threads/hand-call-in-threads.exp: prepare to discard hand call, thread 1
PASS: gdb.threads/hand-call-in-threads.exp: prepare to discard hand call, thread 2
gdb/gdbserver/ChangeLog
2015-02-23 Pedro Alves <palves@redhat.com>
* linux-x86-low.c (REGSIZE): Define in both 32-bit and 64-bit
modes.
(x86_fill_gregset, x86_store_gregset): Use it when handling
$orig_eax.
TL;DR - GDB can hang if something refreshes the thread list out of the
target while the target is running. GDB hangs inside td_ta_thr_iter.
The fix is to not use that libthread_db function anymore.
Long version:
Running the testsuite against my all-stop-on-top-of-non-stop series is
still exposing latent non-stop bugs.
I was originally seeing this with the multi-create.exp test, back when
we were still using libthread_db thread event breakpoints. The
all-stop-on-top-of-non-stop series forces a thread list refresh each
time GDB needs to start stepping over a breakpoint (to pause all
threads). That test hits the thread event breakpoint often, resulting
in a bunch of step-over operations, thus a bunch of thread list
refreshes while some threads in the target are running.
The commit adds a real non-stop mode test that triggers the issue,
based on multi-create.exp, that does an explicit "info threads" when a
breakpoint is hit. IOW, it does the same things the as-ns series was
doing when testing multi-create.exp.
The bug is a race, so it unfortunately takes several runs for the test
to trigger it. In fact, even when setting the test running in a loop,
it sometimes takes several minutes for it to trigger for me.
The race is related to libthread_db's td_ta_thr_iter. This is
libthread_db's entry point for walking the thread list of the
inferior.
Sometimes, when GDB refreshes the thread list from the target,
libthread_db's td_ta_thr_iter can somehow see glibc's thread list as a
cycle, and get stuck in an infinite loop.
The issue is that when a thread exits, its thread control structure in
glibc is moved from a "used" list to a "cache" list. These lists are
simply circular linked lists where the "next/prev" pointers are
embedded in the thread control structure itself. The "next" pointer
of the last element of the list points back to the list's sentinel
"head". There's only one set of "next/prev" pointers for both lists;
thus a thread can only be in one of the lists at a time, not in both
simultaneously.
So when thread C exits, simplifying, the following happens. A-C are
threads. stack_used and stack_cache are the list's heads.
Before:
stack_used -> A -> B -> C -> (&stack_used)
stack_cache -> (&stack_cache)
After:
stack_used -> A -> B -> (&stack_used)
stack_cache -> C -> (&stack_cache)
td_ta_thr_iter starts by iterating at the list's head's next, and
iterates until it sees a thread whose next pointer points to the
list's head again. Thus in the before case above, C's next points to
stack_used, indicating end of list. In the same case, the stack_cache
list is empty.
For each thread being iterated, td_ta_thr_iter reads the whole thread
object out of the inferior. This includes the thread's "next"
pointer.
In the scenario above, it may happen that td_ta_thr_iter is iterating
thread B and has already read B's thread structure just before thread
C exits and its control structure moves to the cached list.
Now, recall that td_ta_thr_iter is running in the context of GDB, and
there's no locking between GDB and the inferior. From it's local copy
of B, td_ta_thr_iter believes that the next thread after B is thread
C, so it happilly continues iterating to C, a thread that has already
exited, and is now in the stack cache list.
After iterating C, td_ta_thr_iter finds the stack_cache head, which
because it is not stack_used, td_ta_thr_iter assumes it's just another
thread. After this, unless the reverse race triggers, GDB gets stuck
in td_ta_thr_iter forever walking the stack_cache list, as no thread
in thatlist has a next pointer that points back to stack_used (the
terminating condition).
Before fully understanding the issue, I tried adding cycle detection
to GDB's td_ta_thr_iter callback. However, td_ta_thr_iter skips
calling the callback in some cases, which means that it's possible
that the callback isn't called at all, making it impossible for GDB to
break the loop. I did manage to get GDB stuck in that state more than
once.
Fortunately, we can avoid the issue altogether. We don't really need
td_ta_thr_iter for live debugging nowadays, given PTRACE_EVENT_CLONE.
We already know how to map and lwp id to a thread id without iterating
(thread_from_lwp), so use that more.
gdb/ChangeLog:
2015-02-20 Pedro Alves <palves@redhat.com>
* linux-nat.c (linux_handle_extended_wait): Call
thread_db_notice_clone whenever a new clone LWP is detected.
(linux_stop_and_wait_all_lwps, linux_unstop_all_lwps): New
functions.
* linux-nat.h (thread_db_attach_lwp): Delete declaration.
(thread_db_notice_clone, linux_stop_and_wait_all_lwps)
(linux_unstop_all_lwps): Declare.
* linux-thread-db.c (struct thread_get_info_inout): Delete.
(thread_get_info_callback): Delete.
(thread_from_lwp): Use td_thr_get_info and record_thread.
(thread_db_attach_lwp): Delete.
(thread_db_notice_clone): New function.
(try_thread_db_load_1): If /proc is mounted and shows the
process'es task list, walk over all LWPs and call thread_from_lwp
instead of relying on td_ta_thr_iter.
(attach_thread): Don't call check_thread_signals here. Split the
tail part of the function (which adds the thread to the core GDB
thread list) to ...
(record_thread): ... this function. Call check_thread_signals
here.
(thread_db_wait): Don't call thread_db_find_new_threads_1. Always
call thread_from_lwp.
(thread_db_update_thread_list): Rename to ...
(thread_db_update_thread_list_org): ... this.
(thread_db_update_thread_list): New function.
(thread_db_find_thread_from_tid): Delete.
(thread_db_get_ada_task_ptid): Simplify.
* nat/linux-procfs.c: Include <sys/stat.h>.
(linux_proc_task_list_dir_exists): New function.
* nat/linux-procfs.h (linux_proc_task_list_dir_exists): Declare.
gdb/gdbserver/ChangeLog:
2015-02-20 Pedro Alves <palves@redhat.com>
* thread-db.c: Include "nat/linux-procfs.h".
(thread_db_init): Skip listing new threads if the kernel supports
PTRACE_EVENT_CLONE and /proc/PID/task/ is accessible.
gdb/testsuite/ChangeLog:
2015-02-20 Pedro Alves <palves@redhat.com>
* gdb.threads/multi-create-ns-info-thr.exp: New file.
Another fix I'm working made schedlock.exp fail with gdbserver
frequently. Looking deeper, it turns out to be a pre-existing bug.
status_pending_p_callback is filtering out LWPs incorrectly. The
result is that that sometimes status_pending_p_callback returns a
pending event for an LWP that isn't expected, and then GDBserver gets
very confused.
E.g,. when doing a step-over, linux_wait_for_event is called with a
particular LWP's ptid, meaning events for all other LWPs should be
left pending, but here we see it retuning an event for some other LWP:
linux_wait_1: [<all threads>]
step_over_bkpt set [LWP 29577.29577], doing a blocking wait <--------
my_waitpid (-1, 0x40000001)
my_waitpid (-1, 0x80000001): status(57f), 0
LWFE: waitpid(-1, ...) returned 0, ERRNO-OK
pc is 0x4007a0
src/gdb/gdbserver/linux-low.c:2587: A problem internal to GDBserver has been detected.
linux_wait_1: got event for 29581 <--------
Remote connection closed
(gdb) FAIL: gdb.threads/schedlock.exp: continue to breakpoint: return to loop (initial)
delete breakpoints
Tested on x86_64 Fedora 20.
gdb/gdbserver/ChangeLog:
2015-02-20 Pedro Alves <palves@redhat.com>
* linux-low.c (status_pending_p_callback): Use ptid_match.
When gdb creates a dummy frame to execute a function in the inferior,
the process may generate a SIGSEGV, SIGTRAP or SIGILL because the stack
is non executable. If the signal handler set in gdb has option print
or stop enabled for these signals gdb handles this correctly.
However, in the case of noprint and nostop the signal is short-circuited
and the inferior process is sent the signal directly. This causes the
inferior to crash because of gdb.
This patch adds a check for SIGSEGV, SIGTRAP or SIGILL so that these
signals are sent to gdb rather than short-circuited in the inferior.
gdb then handles them properly and the inferior process does not
crash.
This patch also fixes the same behavior in gdbserver.
Also added a small testcase to test the issue called catch-gdb-caused-signals.
This applies to Linux only, tested on Linux.
gdb/ChangeLog:
PR breakpoints/16812
* linux-nat.c (linux_nat_filter_event): Report SIGTRAP,SIGILL,SIGSEGV.
* nat/linux-ptrace.c (linux_wstatus_maybe_breakpoint): Add.
* nat/linux-ptrace.h: Add linux_wstatus_maybe_breakpoint.
gdb/gdbserver/ChangeLog:
PR breakpoints/16812
* linux-low.c (wstatus_maybe_breakpoint): Remove.
(linux_low_filter_event): Update wstatus_maybe_breakpoint name.
(linux_wait_1): Report SIGTRAP,SIGILL,SIGSEGV.
gdb/testsuite/ChangeLog:
PR breakpoints/16812
* gdb.base/catch-gdb-caused-signals.c: New file.
* gdb.base/catch-gdb-caused-signals.exp: New file.
When gdbserver is called with --multi and attach has not been called yet
and tstart is called on the gdb client, gdbserver would crash.
This patch fixes gdbserver so that it returns E01 to the gdb client.
Also this patch adds a testcase to verify this bug named no-attach-trace.exp
gdb/gdbserver/ChangeLog:
PR breakpoints/15956
* tracepoint.c (cmd_qtinit): Add check for current_thread.
gdb/testsuite/ChangeLog:
* gdb.trace/no-attach-trace.c: New file.
* gdb.trace/no-attach-trace.exp: New file.
Allow the size of the branch trace ring buffer to be defined by the
user. The specified buffer size will be used when BTS tracing is
enabled for new threads.
The obtained buffer size may differ from the requested size. The
actual buffer size for the current thread is shown in the "info record"
command.
Bigger buffers mean longer traces, but also longer processing time.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c (parse_xml_btrace_conf_bts): Add size.
(btrace_conf_bts_attributes): New.
(btrace_conf_children): Add attributes.
* common/btrace-common.h (btrace_config_bts): New.
(btrace_config)<bts>: New.
(btrace_config): Update comment.
* nat/linux-btrace.c (linux_enable_btrace, linux_enable_bts):
Use config.
* features/btrace-conf.dtd: Increment version. Add size
attribute to bts element.
* record-btrace.c (set_record_btrace_bts_cmdlist,
show_record_btrace_bts_cmdlist): New.
(record_btrace_adjust_size, record_btrace_print_bts_conf,
record_btrace_print_conf, cmd_set_record_btrace_bts,
cmd_show_record_btrace_bts): New.
(record_btrace_info): Call record_btrace_print_conf.
(_initialize_record_btrace): Add commands.
* remote.c: Add PACKET_Qbtrace_conf_bts_size enum.
(remote_protocol_features): Add Qbtrace-conf:bts:size packet.
(btrace_sync_conf): Synchronize bts size.
(_initialize_remote): Add Qbtrace-conf:bts:size packet.
* NEWS: Announce new commands and new packets.
doc/
* gdb.texinfo (Branch Trace Configuration Format): Add size.
(Process Record and Replay): Describe new set|show commands.
(General Query Packets): Describe Qbtrace-conf:bts:size packet.
testsuite/
* gdb.btrace/buffer-size: New.
gdbserver/
* linux-low.c (linux_low_btrace_conf): Print size.
* server.c (handle_btrace_conf_general_set): New.
(hanle_general_set): Call handle_btrace_conf_general_set.
(handle_query): Report Qbtrace-conf:bts:size as supported.
Add a struct to describe the branch trace configuration and use it for
enabling branch tracing.
The user will be able to set configuration fields for each tracing format
to be used for new threads.
The actual configuration that is active for a given thread will be shown
in the "info record" command.
At the moment, the configuration struct only contains a format field
that is set to the only available format.
The format is the only configuration option that can not be set via set
commands. It is given as argument to the "record btrace" command when
starting recording.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* Makefile.in (XMLFILES): Add btrace-conf.dtd.
* x86-linux-nat.c (x86_linux_enable_btrace): Update parameters.
(x86_linux_btrace_conf): New.
(x86_linux_create_target): Initialize to_btrace_conf.
* nat/linux-btrace.c (linux_enable_btrace): Update parameters.
Check format. Split into this and ...
(linux_enable_bts): ... this.
(linux_btrace_conf): New.
(perf_event_skip_record): Renamed into ...
(perf_event_skip_bts_record): ... this. Updated users.
(linux_disable_btrace): Split into this and ...
(linux_disable_bts): ... this.
(linux_read_btrace): Check format.
* nat/linux-btrace.h (linux_enable_btrace): Update parameters.
(linux_btrace_conf): New.
(btrace_target_info)<ptid>: Moved.
(btrace_target_info)<conf>: New.
(btrace_target_info): Split into this and ...
(btrace_tinfo_bts): ... this. Updated users.
* btrace.c (btrace_enable): Update parameters.
(btrace_conf, parse_xml_btrace_conf_bts, parse_xml_btrace_conf)
(btrace_conf_children, btrace_conf_attributes)
(btrace_conf_elements): New.
* btrace.h (btrace_enable): Update parameters.
(btrace_conf, parse_xml_btrace_conf): New.
* common/btrace-common.h (btrace_config): New.
* feature/btrace-conf.dtd: New.
* record-btrace.c (record_btrace_conf): New.
(record_btrace_cmdlist): New.
(record_btrace_enable_warn, record_btrace_open): Pass
&record_btrace_conf.
(record_btrace_info): Print recording format.
(cmd_record_btrace_bts_start): New.
(cmd_record_btrace_start): Call cmd_record_btrace_bts_start.
(_initialize_record_btrace): Add "record btrace bts" subcommand.
Add "record bts" alias command.
* remote.c (remote_state)<btrace_config>: New.
(remote_btrace_reset, PACKET_qXfer_btrace_conf): New.
(remote_protocol_features): Add qXfer:btrace-conf:read.
(remote_open_1): Call remote_btrace_reset.
(remote_xfer_partial): Handle TARGET_OBJECT_BTRACE_CONF.
(btrace_target_info)<conf>: New.
(btrace_sync_conf, btrace_read_config): New.
(remote_enable_btrace): Update parameters. Call btrace_sync_conf and
btrace_read_conf.
(remote_btrace_conf): New.
(init_remote_ops): Initialize to_btrace_conf.
(_initialize_remote): Add qXfer:btrace-conf packet.
* target.c (target_enable_btrace): Update parameters.
(target_btrace_conf): New.
* target.h (target_enable_btrace): Update parameters.
(target_btrace_conf): New.
(target_object)<TARGET_OBJECT_BTRACE_CONF>: New.
(target_ops)<to_enable_btrace>: Update parameters and comment.
(target_ops)<to_btrace_conf>: New.
* target-delegates: Regenerate.
* target-debug.h (target_debug_print_const_struct_btrace_config_p)
(target_debug_print_const_struct_btrace_target_info_p): New.
NEWS: Announce new command and new packet.
doc/
* gdb.texinfo (Process Record and Replay): Describe the "record
btrace bts" command.
(General Query Packets): Describe qXfer:btrace-conf:read packet.
(Branch Trace Configuration Format): New.
gdbserver/
* linux-low.c (linux_low_enable_btrace): Update parameters.
(linux_low_btrace_conf): New.
(linux_target_ops)<to_btrace_conf>: Initialize.
* server.c (current_btrace_conf): New.
(handle_btrace_enable): Rename to ...
(handle_btrace_enable_bts): ... this. Pass ¤t_btrace_conf
to target_enable_btrace. Update comment. Update users.
(handle_qxfer_btrace_conf): New.
(qxfer_packets): Add btrace-conf entry.
(handle_query): Report qXfer:btrace-conf:read as supported packet.
* target.h (target_ops)<enable_btrace>: Update parameters and comment.
(target_ops)<read_btrace_conf>: New.
(target_enable_btrace): Update parameters.
(target_read_btrace_conf): New.
testsuite/
* gdb.btrace/delta.exp: Update "info record" output.
* gdb.btrace/enable.exp: Update "info record" output.
* gdb.btrace/finish.exp: Update "info record" output.
* gdb.btrace/instruction_history.exp: Update "info record" output.
* gdb.btrace/next.exp: Update "info record" output.
* gdb.btrace/nexti.exp: Update "info record" output.
* gdb.btrace/step.exp: Update "info record" output.
* gdb.btrace/stepi.exp: Update "info record" output.
* gdb.btrace/nohist.exp: Update "info record" output.
Add a format argument to the various supports_btrace functions to check
for support of a specific btrace format. This is to prepare for a new
format.
Removed two redundant calls. The check will be made in the subsequent
btrace_enable call.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c (btrace_enable): Pass BTRACE_FORMAT_BTS.
* record-btrace.c (record_btrace_open): Remove call to
target_supports_btrace.
* remote.c (remote_supports_btrace): Update parameters.
* target.c (target_supports_btrace): Update parameters.
* target.h (to_supports_btrace, target_supports_btrace): Update
parameters.
* target-delegates.c: Regenerate.
* target-debug.h (target_debug_print_enum_btrace_format): New.
* nat/linux-btrace.c
(kernel_supports_btrace): Rename into ...
(kernel_supports_bts): ... this. Update users. Update warning text.
(intel_supports_btrace): Rename into ...
(intel_supports_bts): ... this. Update users.
(cpu_supports_btrace): Rename into ...
(cpu_supports_bts): ... this. Update users.
(linux_supports_btrace): Update parameters. Split into this and ...
(linux_supports_bts): ... this.
* nat/linux-btrace.h (linux_supports_btrace): Update parameters.
gdbserver/
* server.c (handle_btrace_general_set): Remove call to
target_supports_btrace.
(supported_btrace_packets): New.
(handle_query): Call supported_btrace_packets.
* target.h: include btrace-common.h.
(btrace_target_info): Removed.
(supports_btrace, target_supports_btrace): Update parameters.
Add a structure to hold the branch trace data and an enum to describe
the format of that data. So far, only BTS is supported. Also added
a NONE format to indicate that no branch trace data is available.
This will make it easier to support different branch trace formats in
the future.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* Makefile.in (SFILES): Add common/btrace-common.c.
(COMMON_OBS): Add common/btrace-common.o.
(btrace-common.o): Add build rules.
* btrace.c (parse_xml_btrace): Update parameters.
(parse_xml_btrace_block): Set format field.
(btrace_add_pc, btrace_fetch): Use struct btrace_data.
(do_btrace_data_cleanup, make_cleanup_btrace_data): New.
(btrace_compute_ftrace): Split into this and...
(btrace_compute_ftrace_bts): ...this.
(btrace_stitch_trace): Split into this and...
(btrace_stitch_bts): ...this.
* btrace.h (parse_xml_btrace): Update parameters.
(make_cleanup_btrace_data): New.
* common/btrace-common.c: New.
* common/btrace-common.h: Include common-defs.h.
(btrace_block_s): Update comment.
(btrace_format): New.
(btrace_format_string): New.
(btrace_data_bts): New.
(btrace_data): New.
(btrace_data_init, btrace_data_fini, btrace_data_empty): New.
* remote.c (remote_read_btrace): Update parameters.
* target.c (target_read_btrace): Update parameters.
* target.h (target_read_btrace): Update parameters.
(target_ops)<to_read_btrace>: Update parameters.
* x86-linux-nat.c (x86_linux_read_btrace): Update parameters.
* target-delegates.c: Regenerate.
* target-debug (target_debug_print_struct_btrace_data_p): New.
* nat/linux-btrace.c (linux_read_btrace): Split into this and...
(linux_read_bts): ...this.
* nat/linux-btrace.h (linux_read_btrace): Update parameters.
gdbserver/
* Makefile.in (SFILES): Add common/btrace-common.c.
(OBS): Add common/btrace-common.o.
(btrace-common.o): Add build rules.
* linux-low: Include btrace-common.h.
(linux_low_read_btrace): Use struct btrace_data. Call
btrace_data_init and btrace_data_fini.
Add a bit of debug output that made things a bit easier for me before.
gdb/
2015-02-06 Pedro Alves <palves@redhat.com>
* linux-thread-db.c (find_new_threads_callback): Add debug output.
gdb/gdbserver/
2015-02-06 Pedro Alves <palves@redhat.com>
* thread-db.c (find_new_threads_callback): Add debug output.
Since the starvation avoidance series
(https://sourceware.org/ml/gdb-patches/2014-12/msg00631.html), both
GDB and GDBserver pull all events out of ptrace before deciding which
event to process.
There's one problem with that though. Because we resume new threads
immediately when we see a PTRACE_EVENT_CLONE event, if the program
constantly spawns threads fast enough, new threads can spawn threads
faster we can pull events out of the kernel, and thus we'd get stuck
in an infinite loop, never returning any event to the core to process.
I occasionally see this happen with the
attach-many-short-lived-threads.exp test against gdbserver.
The fix is to delay resuming new threads until we've pulled out all
events out of the kernel.
On native, we already have the resume_stopped_resumed_lwps function
that knows to resume LWPs that are stopped with no event to report to
the core. So the patch just adds another use. GDBserver didn't have
the equivalent yet, so the patch adds one.
Tested on x86_64 Fedora 20, native and gdbserver (remote and
extended-remote).
gdb/gdbserver/ChangeLog:
2015-02-04 Pedro Alves <palves@redhat.com>
* linux-low.c (handle_extended_wait): Don't resume LWPs here.
(resume_stopped_resumed_lwps): New function.
(linux_wait_for_event_filtered): Use it.
gdb/ChangeLog:
2015-02-04 Pedro Alves <palves@redhat.com>
* linux-nat.c (handle_extended_wait): Don't resume LWPs here.
(wait_lwp): Don't call wait_lwp if linux_handle_extended_wait
returns true.
(resume_stopped_resumed_lwps): Don't check whether the thread is
marked as executing.
(linux_nat_wait_1): Use resume_stopped_resumed_lwps.
This patch moves the shared code present on
gdb/linux-nat.c:linux_nat_create_inferior and
gdb/gdbserver/linux-low.c:linux_create_inferior to
nat/linux-personality.c. This code is responsible for disabling
address space randomization based on user setting, and using
<sys/personality.h> to do that. I decided to put the prototype of the
maybe_disable_address_space_randomization on nat/linux-osdata.h
because it seemed the best place to put it.
I regression-tested this patch on Fedora 20 x86_64, and found no
regressions.
gdb/ChangeLog
2015-01-15 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (HFILES_NO_SRCDIR): Add nat/linux-personality.h.
(linux-personality.o): New rule.
* common/common-defs.h: Include <stdint.h>.
* config/aarch64/linux.mh (NATDEPFILES): Include
linux-personality.o.
* config/alpha/alpha-linux.mh (NATDEPFILES): Likewise.
* config/arm/linux.mh (NATDEPFILES): Likewise.
* config/i386/linux64.mh (NATDEPFILES): Likewise.
* config/i386/linux.mh (NATDEPFILES): Likewise.
* config/ia64/linux.mh (NATDEPFILES): Likewise.
* config/m32r/linux.mh (NATDEPFILES): Likewise.
* config/m68k/linux.mh (NATDEPFILES): Likewise.
* config/mips/linux.mh (NATDEPFILES): Likewise.
* config/pa/linux.mh (NATDEPFILES): Likewise.
* config/powerpc/linux.mh (NATDEPFILES): Likewise.
* config/powerpc/ppc64-linux.mh (NATDEPFILES): Likewise.
* config/powerpc/spu-linux.mh (NATDEPFILES): Likewise.
* config/s390/linux.mh (NATDEPFILES): Likewise.
* config/sparc/linux64.mh (NATDEPFILES): Likewise.
* config/sparc/linux.mh (NATDEPFILES): Likewise.
* config/tilegx/linux.mh (NATDEPFILES): Likewise.
* config/xtensa/linux.mh (NATDEPFILES): Likewise.
* defs.h: Remove #include <stdint.h> (moved to
common/common-defs.h).
* linux-nat.c: Include nat/linux-personality.h. Remove #include
<sys/personality.h>; do not define ADDR_NO_RANDOMIZE (moved to
nat/linux-personality.c).
(linux_nat_create_inferior): Remove code to disable address space
randomization (moved to nat/linux-personality.c). Create cleanup
to disable address space randomization.
* nat/linux-personality.c: New file.
* nat/linux-personality.h: Likewise.
gdb/gdbserver/ChangeLog
2015-01-15 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (SFILES): Add linux-personality.c.
(linux-personality.o): New rule.
* configure.srv (srv_linux_obj): Add linux-personality.o to the
list of objects to be built.
* linux-low.c: Include nat/linux-personality.h.
(linux_create_inferior): Remove code to disable address space
randomization (moved to ../nat/linux-personality.c). Create
cleanup to disable address space randomization.
This patch moves safe_strerror from the gdb/{posix,mingw}-hdep.c files
to the respective common/{posix,mingw}-strerror.c files. This is a
preparation for the next patch, which shares a common code (to disable
address space randomization when creating a new inferior).
The patch has been regtested on Fedora 20 x86_64, and no regressions
were found.
gdb/ChangeLog
2015-01-15 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (ALLDEPFILES): Including common/mingw-strerror.c and
common/posix-strerror.c.
(posix-strerror.o): New rule.
(mingw-strerror.o): Likewise.
* common/common-utils.h (safe_strerror): Move prototype to here,
from utils.h.
* common/common.host: New file.
* common/mingw-strerror.c: Likewise.
* common/posix-strerror.c: Likewise.
* configure: Regenerated.
* configure.ac: Source common/common.host. Add variable
common_host_obs to gdb_host_obs.
* contrib/ari/gdb_ari.sh: Mention gdb/common/mingw-strerror.c and
gdb/common/posix-strerror.c when warning about the use of
strerror.
* mingw-hdep.c (safe_strerror): Remove definition; move it to
common/mingw-strerror.c.
* posix-hdep.c (safe_strerror): Remove definition; move it to
common/posix-hdep.c.
* utils.h (safe_strerror): Remove prototype; move to
common/common-utils.h.
gdb/gdbserver/ChangeLog
2015-01-15 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (posix-strerror.o): New rule.
(mingw-strerror.o): Likewise.
* configure: Regenerated.
* configure.ac: Source file ../common/common.host. Initialize new
variable srv_host_obs. Add srv_host_obs to GDBSERVER_DEPFILES.
This patch is to teach both GDB and GDBServer to detect 64-bit inferior
correctly. We find a problem that GDBServer is unable to detect on a
e5500 core processor. Current GDBServer assumes that MSR is a 64-bit
register, but MSR is a 32-bit register in Book III-E. This patch is
to fix this problem by checking the right bit in MSR, in order to handle
both Book III-S and Book III-E. In order to detect Book III-S and
Book III-E, we check the PPC_FEATURE_BOOKE from the host's HWCAP (by
getauxval on glibc >= 2.16. If getauxval doesn't exist, we implement
the fallback by parsing /proc/self/auxv), because it should an invariant
on the same machine cross different processes.
In order to share code, I add nat/ppc-linux.c for both GDB and
GDBserver side.
gdb:
2015-01-14 Yao Qi <yao@codesourcery.com>
* Makefile.in (ppc-linux.o): New rule.
* config/powerpc/ppc64-linux.mh (NATDEPFILES): Add ppc-linux.o.
* configure.ac: AC_CHECK_FUNCS(getauxval).
* config.in: Re-generated.
* configure: Re-generated.
* nat/ppc-linux.h [__powerpc64__] (ppc64_64bit_inferior_p):
Declare.
* nat/ppc-linux.c: New file.
* ppc-linux-nat.c (ppc_linux_target_wordsize) [__powerpc64__]:
Call ppc64_64bit_inferior_p.
gdb/gdbserver:
2015-01-14 Yao Qi <yao@codesourcery.com>
* Makefile.in (SFILES): Add nat/ppc-linux.c.
(ppc-linux.o): New rule.
* configure.srv (powerpc*-*-linux*): Add ppc-linux.o.
* configure.ac: AC_CHECK_FUNCS(getauxval).
* config.in: Re-generated.
* configure: Re-generated.
* linux-ppc-low.c (ppc_arch_setup) [__powerpc64__]: Call
ppc64_64bit_inferior_p
When I use PPC_FEATURE_BOOKE in GDBserver, I find it is defined in GDB
but not in GDBserver. After taking a further look, I find some macros
are duplicated between ppc-linux-nat.c and linux-ppc-low.c, so this
patch is to move them into nat/ppc-linux.h.
gdb/gdbserver:
2015-01-14 Yao Qi <yao@codesourcery.com>
* linux-ppc-low.c: Include "nat/ppc-linux.h".
(PPC_FEATURE_HAS_VSX): Move to nat/ppc-linux.h.
(PPC_FEATURE_HAS_ALTIVEC, PPC_FEATURE_HAS_SPE): Likewise.
(PT_ORIG_R3, PT_TRAP): Likewise.
(PTRACE_GETVSXREGS, PTRACE_SETVSXREGS): Likewise.
(PTRACE_GETVRREGS, PTRACE_SETVRREGS): Likewise.
(PTRACE_GETEVRREGS, PTRACE_SETEVRREGS): Likewise.
gdb:
2015-01-14 Yao Qi <yao@codesourcery.com>
* ppc-linux-nat.c (PT_ORIG_R3, PT_TRAP): Move to
nat/ppc-linux.h.
(PPC_FEATURE_CELL, PPC_FEATURE_BOOKE): Likewise.
(PPC_FEATURE_HAS_DFP): Likewise.
(PTRACE_GETVRREGS, PTRACE_SETVRREGS): Likewise.
(PTRACE_GETVSXREGS, PTRACE_SETVSXREGS): Likewise.
(PTRACE_GETEVRREGS, PTRACE_SETEVRREGS): Likewise.
Include "nat/ppc-linux.h".
* nat/ppc-linux.h: New file.
* Makefile.in (HFILES_NO_SRCDIR): Add nat/ppc-linux.h.
gdb/gdbserver/ChangeLog:
* i387-fp.c (i387_cache_to_xsave): In look over
num_avx512_zmmh_high_registers, replace use of struct i387_xsave
zmmh_low_space field by use of zmmh_high_space.
Tested on x86_64-linux, using boards/native-gdbserver.exp.
This patch applies the same starvation avoidance improvements of the
previous patch to the Linux gdbserver side.
Without this, the test added by the following commit
(gdb.threads/non-stop-fair-events.exp) always fails with time outs.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-low.c (step_over_bkpt): Move higher up in the file.
(handle_extended_wait): Don't store the stop_pc here.
(get_stop_pc): Adjust comments and rename to ...
(check_stopped_by_breakpoint): ... this. Record whether the LWP
stopped for a software breakpoint or hardware breakpoint.
(thread_still_has_status_pending_p): New function.
(status_pending_p_callback): Use
thread_still_has_status_pending_p. If the event is no longer
interesting, resume the LWP.
(handle_tracepoints): Add assert.
(maybe_move_out_of_jump_pad): Remove cancel_breakpoints call.
(wstatus_maybe_breakpoint): New function.
(cancel_breakpoint): Delete function.
(check_stopped_by_watchpoint): New function, factored out from
linux_low_filter_event.
(lp_status_maybe_breakpoint): Delete function.
(linux_low_filter_event): Remove filter_ptid argument.
Leave thread group exits pending here. Store the LWP's stop PC.
Always leave events pending.
(linux_wait_for_event_filtered): Pull all events out of the
kernel, and leave them all pending.
(count_events_callback, select_event_lwp_callback): Consider all
events.
(cancel_breakpoints_callback, linux_cancel_breakpoints): Delete.
(select_event_lwp): Only give preference to the stepping LWP in
all-stop mode. Adjust comments.
(ignore_event): New function.
(linux_wait_1): Delete 'retry' label. Use ignore_event. Remove
references to cancel_breakpoints. Adjust to renames. Also give
equal priority to all LWPs that have had events in non-stop mode.
If reporting a software breakpoint event, unadjust the LWP's PC.
(linux_wait): If linux_wait_1 returned an ignored event, retry.
(stuck_in_jump_pad_callback, move_out_of_jump_pad_callback):
Adjust.
(linux_resume_one_lwp): Store the LWP's PC. Adjust.
(resume_status_pending_p): Use thread_still_has_status_pending_p.
(linux_stopped_by_watchpoint): Adjust.
(linux_target_ops): Remove reference to linux_cancel_breakpoints.
* linux-low.h (enum lwp_stop_reason): New.
(struct lwp_info) <stop_pc>: Adjust comment.
<stopped_by_watchpoint>: Delete field.
<stop_reason>: New field.
* linux-x86-low.c (x86_linux_prepare_to_resume): Adjust.
* mem-break.c (software_breakpoint_inserted_here)
(hardware_breakpoint_inserted_here): New function.
* mem-break.h (software_breakpoint_inserted_here)
(hardware_breakpoint_inserted_here): Declare.
* target.h (struct target_ops) <cancel_breakpoints>: Remove field.
(cancel_breakpoints): Delete.
* tracepoint.c (clear_installed_tracepoints, stop_tracing)
(upload_fast_traceframes): Remove references to
cancel_breakpoints.
I wrote a test that attaches to a program that constantly spawns
short-lived threads, which exposed several issues. This is one of
them.
On GNU/Linux, attaching to a multi-threaded program sometimes prints
out warnings like:
...
[New LWP 20700]
warning: unable to open /proc file '/proc/-1/status'
[New LWP 20850]
[New LWP 21019]
...
That happens because when a thread exits, and is joined, glibc does:
nptl/pthread_join.c:
pthread_join ()
{
...
if (__glibc_likely (result == 0))
{
/* We mark the thread as terminated and as joined. */
pd->tid = -1;
...
/* Free the TCB. */
__free_tcb (pd);
}
So if we attach or interrupt the program (which does an implicit "info
threads") at just the right (or rather, wrong) time, we can find and
return threads in the libthread_db/pthreads thread list with kernel
thread ID -1. I've filed glibc PR nptl/17707 for this. You'll find
more info there.
This patch handles this as a special case in GDB.
This is actually more than just a cosmetic issue. lin_lwp_attach_lwp
will think that this -1 is an LWP we're not attached to yet, and after
failing to attach will try to check we were already attached to the
process, using a waitpid call, which in this case ends up being
"waitpid (-1, ...", which obviously results in GDB potentially
discarding an event when it shouldn't...
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* thread-db.c (find_new_threads_callback): Ignore thread if the
kernel thread ID is -1.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-nat.c (lin_lwp_attach_lwp): Assert that the lwp id we're
about to wait for is > 0.
* linux-thread-db.c (find_new_threads_callback): Ignore thread if
the kernel thread ID is -1.
... instead of relying on libthread_db.
I wrote a test that attaches to a program that constantly spawns
short-lived threads, which exposed several issues. This is one of
them.
On Linux, we need to attach to all threads of a process (thread group)
individually. We currently rely on libthread_db to list the threads,
but that is problematic, because libthread_db relies on reading data
structures out of the inferior (which may well be corrupted). If
threads are being created or exiting just while we try to attach, we
may trip on inconsistencies in the inferior's thread list. To work
around that, when we see a seemingly corrupt list, we currently retry
a few times:
static void
thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
{
...
if (until_no_new)
{
/* Require 4 successive iterations which do not find any new threads.
The 4 is a heuristic: there is an inherent race here, and I have
seen that 2 iterations in a row are not always sufficient to
"capture" all threads. */
...
That heuristic may well fail, and when it does, we end up with threads
in the program that aren't under GDB's control. That's obviously bad
and results in quite mistifying failures, like e.g., the process dying
for seeminly no reason when a thread that wasn't attached trips on a
breakpoint.
There's really no reason to rely on libthread_db for this nowadays
when we have /proc mounted. In that case, which is the usual case, we
can list the LWPs from /proc/PID/task/. In fact, GDBserver is already
doing this. The patch factors out that code that knows to walk the
task/ directory out of GDBserver, and makes GDB use it too.
Like GDBserver, the patch makes GDB attach to LWPs and _not_ wait for
them to stop immediately. Instead, we just tag the LWP as having an
expected stop. Because we can only set the ptrace options when the
thread stops, we need a new flag in the lwp structure to keep track of
whether we've already set the ptrace options, just like in GDBserver.
Note that nothing issues any ptrace command to the threads between the
PTRACE_ATTACH and the stop, so this is safe (unlike one scenario
described in gdbserver's linux-low.c).
When we attach to a program that has threads exiting while we attach,
it's easy to race with a thread just exiting as we try to attach to
it, like:
#1 - get current list of threads
#2 - attach to each listed thread
#3 - ooops, attach failed, thread is already gone
As this is pretty normal, we shouldn't be issuing a scary warning in
step #3.
When #3 happens, PTRACE_ATTACH usually fails with ESRCH, but sometimes
we'll see EPERM as well. That happens when the kernel still has the
thread in its task list, but the thread is marked as dead.
Unfortunately, EPERM is ambiguous and we'll get it also on other
scenarios where the thread isn't dead, and in those cases, it's useful
to get a warning. To distiguish the cases, when we get an EPERM
failure, we open /proc/PID/status, and check the thread's state -- if
the /proc file no longer exists, or the state is "Z (Zombie)" or "X
(Dead)", we ignore the EPERM error silently; otherwise, we'll warn.
Unfortunately, there seems to be a kernel race here. Sometimes I get
EPERM, and then the /proc state still indicates "R (Running)"... If
we wait a bit and retry, we do end up seeing X or Z state, or get an
ESRCH. I thought of making GDB retry the attach a few times, but even
with a 500ms wait and 4 retries, I still see the warning sometimes. I
haven't been able to identify the kernel path that causes this yet,
but in any case, it looks like a kernel bug to me. As this just
results failure to suppress a warning that we've been printing since
about forever anyway, I'm just making the test cope with it, and issue
an XFAIL.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_attach_fail_reason_string): Move to
nat/linux-ptrace.c, and rename.
(linux_attach_lwp): Update comment.
(attach_proc_task_lwp_callback): New function.
(linux_attach): Adjust to rename and use
linux_proc_attach_tgid_threads.
(linux_attach_fail_reason_string): Delete declaration.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-nat.c (attach_proc_task_lwp_callback): New function.
(linux_nat_attach): Use linux_proc_attach_tgid_threads.
(wait_lwp, linux_nat_filter_event): If not set yet, set the lwp's
ptrace option flags.
* linux-nat.h (struct lwp_info) <must_set_ptrace_flags>: New
field.
* nat/linux-procfs.c: Include <dirent.h>.
(linux_proc_get_int): New parameter "warn". Handle it.
(linux_proc_get_tgid): Adjust.
(linux_proc_get_tracerpid): Rename to ...
(linux_proc_get_tracerpid_nowarn): ... this.
(linux_proc_pid_get_state): New function, factored out from
(linux_proc_pid_has_state): ... this. Add new parameter "warn"
and handle it.
(linux_proc_pid_is_gone): New function.
(linux_proc_pid_is_stopped): Adjust.
(linux_proc_pid_is_zombie_maybe_warn)
(linux_proc_pid_is_zombie_nowarn): New functions.
(linux_proc_pid_is_zombie): Use
linux_proc_pid_is_zombie_maybe_warn.
(linux_proc_attach_tgid_threads): New function.
* nat/linux-procfs.h (linux_proc_get_tgid): Update comment.
(linux_proc_get_tracerpid): Rename to ...
(linux_proc_get_tracerpid_nowarn): ... this, and update comment.
(linux_proc_pid_is_gone): New declaration.
(linux_proc_pid_is_zombie): Update comment.
(linux_proc_pid_is_zombie_nowarn): New declaration.
(linux_proc_attach_lwp_func): New typedef.
(linux_proc_attach_tgid_threads): New declaration.
* nat/linux-ptrace.c (linux_ptrace_attach_fail_reason): Adjust to
use nowarn functions.
(linux_ptrace_attach_fail_reason_string): Move here from
gdbserver/linux-low.c and rename.
(ptrace_supports_feature): If the current ptrace options are not
known yet, check them now, instead of asserting.
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason_string):
Declare.
Hi,
This patch is a follow-up of the following discussions:
<https://sourceware.org/ml/gdb-patches/2014-12/msg00421.html>
<https://gcc.gnu.org/ml/gcc-patches/2014-12/msg01293.html>
input_interrupt is currently emiting non-printable characters, which
is confusing the dg-extract-results.sh script. This is obviously not
a good thing, and, by following Pedro's advices here:
<https://gcc.gnu.org/ml/gcc-patches/2014-12/msg01320.html>
I adapted the function to print "client connection closed" when it
receives a NUL character, or use the "isprint" function to decide how
to print the received char. I tested it by running the testcases that
were printing the non-printable chars before:
gdb.base/gdb-sigterm.exp
gdb.threads/non-ldr-exc-1.exp
gdb.threads/non-ldr-exc-2.exp
gdb.threads/non-ldr-exc-3.exp
gdb.threads/non-ldr-exc-4.exp
gdb.threads/thread-execl.exp
and confirming that they print the right message. I tried a bit to
come up with a testcase for this, but failed, and since I did not want
to spend too much time on it, I'm sending the patch anyway.
Comments are welcome, as usual.
gdb/gdbserver/ChangeLog:
2014-12-29 Sergio Durigan Junior <sergiodj@redhat.com>
* remote-utils.c: Include ctype.h.
(input_interrupt): Explicitly handle the case when the char
received is the NUL byte. Improve the printing of non-ASCII
characters.
This patch enhances GDB on GNU/Linux systems in the situation where
we are debugging an inferior that was created from GDB (as opposed
to attached to), by asking the kernel to kill the inferior if GDB
terminates without doing it itself.
This would typically happen when GDB encounters a problem and
crashes, or when it gets killed by an external process. This can
be observed by starting a program under GDB, and then killing
GDB with signal 9. After GDB is killed, the inferior still remains.
This patch also fixes GDBserver similarly.
This fix is conditional on the kernel supporting the PTRACE_O_EXITKILL
feature. On older kernels, the behavior remains unchanged.
gdb/ChangeLog:
* nat/linux-ptrace.h (PTRACE_O_EXITKILL): Define if not
already defined.
(linux_enable_event_reporting): Add parameter "attached".
* nat/linux-ptrace.c (linux_test_for_exitkill): New forward
declaration. New function.
(linux_check_ptrace_features): Add linux_test_for_exitkill call.
(linux_enable_event_reporting): Add new parameter "attached".
Do not call ptrace with the PTRACE_O_EXITKILL if ATTACHED is
nonzero.
* linux-nat.c (linux_init_ptrace): Add parameter "attached".
Use it. Update function description.
(linux_child_post_attach, linux_child_post_startup_inferior):
Update call to linux_enable_event_reporting.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_low_filter_event): Update call to
linux_enable_event_reporting following the addition of
a new parameter to that function.
Tested on x86_64-linux, native and native-gdbserver.
I also verified by hand that the inferior gets killed when killing
GDB in the "run" case, while the inferior remains in the "attach"
case. Same for GDBserver.
When using aarch64 gdb with gdbserver, floating point registers are
not correctly displayed, as below:
(gdb) info registers fpsr fpcr
fpsr <unavailable>
fpcr <unavailable>
To fix these problems, the missing fpsr and fpcr registers are added
when floating point registers are read/write
Add test for aarch64 floating point
PR server/17457
gdb/gdbserver/
PR server/17457
* linux-aarch64-low.c (AARCH64_FPSR_REGNO): New define.
(AARCH64_FPCR_REGNO): Likewise.
(AARCH64_NUM_REGS): Update to include fpsr/fpcr registers.
(aarch64_fill_fpregset): Add missing fpsr/fpcr registers.
(aarch64_store_fpregset): Likewise.
gdb/testsuite/
PR server/17457
* gdb.arch/aarch64-fp.c: New file.
* gdb.arch/aarch64-fp.exp: New file.
Signed-off-by: Catalin Udma <catalin.udma@freescale.com>
Currently, when we receive a request to single-step one single thread
(Eg, when single-stepping out of a breakpoint), we use the
PTRACE_SINGLESTEP pthread request, which does single-step
the corresponding thread, but also resumes execution of all
other threads in the inferior.
This causes problems when debugging programs where another thread
receives multiple debug events while trying to single-step a specific
thread out of a breakpoint (with infrun traces turned on):
(gdb) continue
Continuing.
infrun: clear_proceed_status_thread (Thread 126)
[...]
infrun: clear_proceed_status_thread (Thread 142)
[...]
infrun: clear_proceed_status_thread (Thread 146)
infrun: clear_proceed_status_thread (Thread 125)
infrun: proceed (addr=0xffffffff, signal=GDB_SIGNAL_DEFAULT, step=0)
infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=1, current thread [Thread 142] at 0x10684838
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 42000 [Thread 146],
infrun: status->kind = stopped, signal = GDB_SIGNAL_REALTIME_34
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x10a187f4
infrun: context switch
infrun: Switching context from Thread 142 to Thread 146
infrun: random signal (GDB_SIGNAL_REALTIME_34)
infrun: switching back to stepped thread
infrun: Switching context from Thread 146 to Thread 142
infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=1, current thread [Thread 142] at 0x10684838
infrun: prepare_to_wait
[...handling of similar events for threads 145, 144 and 143 snipped...]
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 42000 [Thread 146],
infrun: status->kind = stopped, signal = GDB_SIGNAL_REALTIME_34
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x10a187f4
infrun: context switch
infrun: Switching context from Thread 142 to Thread 146
../../src/gdb/inline-frame.c:339: internal-error: skip_inline_frames: Assertion `find_inline_frame_state (ptid) == NULL' failed.
What happens is that GDB keeps sending requests to resume one specific
thread, and keeps receiving debugging events for other threads.
Things break down when the one of the other threads receives a debug
event for the second time (thread 146 in the example above).
This patch fixes the problem by making sure that only one thread
gets resumed, thus preventing the other threads from generating
an unexpected event.
gdb/gdbserver/ChangeLog:
* lynx-low.c (lynx_resume): Use PTRACE_SINGLESTEP_ONE if N == 1.
Remove FIXME comment about assumption about N.
This makes gdbserver actually provide values for the TDB registers
when the inferior was stopped in a transaction. The change in
linux-low.c is needed to suppress the warning for an unavailable TDB.
The test case 's390-tdbregs.exp' passes with this patch and fails
without.
gdb/gdbserver/ChangeLog:
* linux-low.c (regsets_fetch_inferior_registers): Suppress the
warning upon ENODATA from ptrace.
* linux-s390-low.c (s390_store_tdb): New.
(s390_regsets): Add regset for NT_S390_TDB.
For GNU/Linux targets using the regsets interface, this change
supports regsets that can be read but not written. The S390 "last
break" regset is an example. So far it had been defined with
regset->set_request == PTRACE_GETREGSET, such that the respective
ptrace call does not cause any harm. Now we just skip the whole
read/modify/write sequence for regsets that do not define a
fill_function.
gdb/gdbserver/ChangeLog:
* linux-low.c (regsets_store_inferior_registers): Skip regsets
without a fill_function.
* linux-s390-low.c (s390_fill_last_break): Remove.
(s390_regsets): Set fill_function to NULL for NT_S390_LAST_BREAK.
(s390_arch_setup): Use regset's size instead of fill_function for
loop end condition.
When fetch_inferior_registers does not update all registers, this
patch assures that no stale register values remain in the register
cache. On Linux platforms using the regsets interface, when one of
the ptrace calls used for fetching the register values returns an
error, this patch also avoids copying the random data returned from
ptrace into the register cache. All unfetched registers are marked
"unavailable" instead.
gdb/gdbserver/ChangeLog:
* linux-low.c (regsets_fetch_inferior_registers): Do not invoke
the regset's store function when ptrace returned an error.
* regcache.c (get_thread_regcache): Invalidate register cache
before fetching inferior's registers.
Replace the while-loops in linux-low.c that iterate over regsets by
for-loops. This makes it clearer what is iterated over. Also, since
"continue" now moves on to the next iteration without having to
increment the regset pointer first, the code is slightly reduced.
In case of EIO the old code did not increment the regset pointer, but
iterated over the same (now disabled) regset again. This extra
iteration is now avoided.
gdb/gdbserver/ChangeLog:
* linux-low.c (regsets_fetch_inferior_registers): Rephrase
while-loop as for-loop.
(regsets_store_inferior_registers): Likewise.
Since readlink module is imported, we can use it unconditionally.
This patch is to remove configure checks and HAVE_READLINK checks in
code. It was mentioned in the patch below
[RFA/commit] gdbserver: return ENOSYS if readlink not supported.
https://sourceware.org/ml/gdb-patches/2012-02/msg00148.html
to use readlink in gdbserver, but we chose something simple at that
moment.
gdb:
2014-11-28 Yao Qi <yao@codesourcery.com>
* configure.ac (AC_CHECK_FUNCS): Remove readlink.
* config.in, configure: Re-generate.
* inf-child.c (inf_child_fileio_readlink): Don't check
HAVE_READLINK is defined.
gdb/gdbserver:
2014-11-28 Yao Qi <yao@codesourcery.com>
* configure.ac(AC_CHECK_FUNCS): Remove readlink.
* config.in, configure: Re-generate.
* hostio.c (handle_unlink): Remove code checking HAVE_READLINK
is defined.
Since gnulib alloca module was imported, we can include alloca.h in
both gdb and gdbserver unconditionally, so this patch adds inclusion
of alloca.h in common-defs.h. This patch also removes AC_FUNC_ALLOCA
in configure.ac because we don't need to check alloca any more.
This patch below is removed in fact.
[RFA/commit] include alloca.h if available.
https://www.sourceware.org/ml/gdb-patches/2010-08/msg00566.html
Since alloca.h is from gnulib now, we don't have to check malloc.h in
configure and include malloc.h in code. This patch also remove them
too.
gdb:
2014-11-21 Yao Qi <yao@codesourcery.com>
* common/common-defs.h: Include alloca.h
* configure.ac: Don't invoke AC_FUNC_ALLOCA.
* configure: Re-generated.
* defs.h: Remove code handling alloca.
* utils.c (gdb_realpath): Don't check HAVE_ALLOCA is defined
or not.
gdb/gdbserver:
2014-11-21 Yao Qi <yao@codesourcery.com>
* configure.ac: Don't invoke AC_FUNC_ALLOCA.
(AC_CHECK_HEADERS): Remove malloc.h.
* configure: Re-generated.
* config.in: Re-generated.
* server.h: Don't include alloca.h and malloc.h.
* gdbreplay.c: Don't check HAVE_ALLOCA_H is defined.
Don't include malloc.h.
We noticed the following error on ppc-lynx178, using just about
any program:
(gdb) tar remote mytarget:4444
Remote debugging using mytarget:4444
0x000100c8 in _start ()
(gdb) b try
Breakpoint 1 at 0x10844: file try.adb, line 11.
(gdb) cont
Continuing.
!!!-> Cannot remove breakpoints because program is no longer writable.
!!!-> Further execution is probably impossible.
Breakpoint 1, try () at try.adb:11
11 Local : Integer := 18;
And, of course, trying to continue yielded the expected outcome:
(gdb) c
Continuing.
warning: Error removing breakpoint 1
Cannot remove breakpoints because program is no longer writable.
Further execution is probably impossible.
It turns out that the problem is caused by an intentional test
against a variable with an undefined value. After GDB receives
notification of the inferior stopping, it tries to remove the
breakpoint by sending a memory-write packet ("X10844,4:9 ").
This leads us to lynx_write_memory, where it tries to split
the memory-write into chunks of 4 bytes. And, in order to handle
writes which are not aligned on word boundaries, we have the
following code:
if (skip > 0 || truncate > 0)
/* We need to read the memory at this address in order to preserve
the data that we are not overwriting. */
lynx_read_memory (addr, (unsigned char *) &buf, xfer_size);
if (errno)
return errno;
(the comment explains what the code is about).
Unfortunately, the not-so-glaring error that we've made here is
that we're checking ERRNO regardless of whether we've called
lynx_read_memory. In our case, because we are writing 4 bytes
aligned on a word boundary, we do not call lynx_read_memory and
therefore test an ERRNO with an undefined value.
gdb/gdbserver/ChangeLog:
* lynx-low.c (lynx_write_memory): Put lynx_read_memory and
corresponding ERRNO check in same block.
As no place in the backends check cont_thread anymore, we can stop
setting and clearing it in places that resume the target and wait for
events. Instead simply clear it whenever a new GDB connects.
gdb/gdbserver/
2014-11-12 Pedro Alves <palves@redhat.com>
* server.c (cont_thread): Update comment.
(start_inferior, attach_inferior): No longer clear cont_thread.
(handle_v_cont): No longer set cont_thread.
(captured_main): Clear cont_thread each time a GDB connects.
There's code in linux_wait_1 that resumes all threads if the Hc thread
disappears. It's the wrong thing to do, as GDB has told GDBserver to
resume only one thread, because e.g., the user has scheduler-locking
enabled, or because GDB was stepping the program over a breakpoint.
Resuming all threads behind GDB's back can't be good in either case.
The right thing to do is to detect that that the (only) resumed thread
is gone, and let GDB know about it. The Linux backend is already
doing that nowadays, since:
commit fa96cb382c
Author: Pedro Alves <palves@redhat.com>
AuthorDate: Thu Feb 27 14:30:08 2014 +0000
Teach GDBserver's Linux backend about no unwaited-for children (TARGET_WAITKIND_NO_RESUMED).
The backend detects that all resumed threads have disappeared, and
returns TARGET_WAITKIND_NO_RESUMED to the core of GDBserver, which
then reports an error to GDB.
There's no need to frob the passed in ptid to wait for the continue
thread either -- linux_wait_for_event only returns events for resumed
threads.
The badness (of resuming threads) can actually be observed in the
testsuite, if we force-disable vCont support in GDBserver -- before
the patch, gdb.threads/no-unwaited-for-left.exp hangs if we disable
vCont:
(gdb) continue
Continuing.
FAIL: gdb.threads/no-unwaited-for-left.exp: continue to breakpoint: break-here (timeout)
... more cascading timeouts ....
After the patch, gdb.threads/no-unwaited-for-left.exp behaves the same
with or without vCont support:
(gdb) continue
Continuing.
[New Thread 32226]
[Switching to Thread 32226]
Breakpoint 2, thread_a (arg=0x0) at /home/pedro/gdb/mygit/build/../src/gdb/testsuite/gdb.threads/no-unwaited-for-left.c:28
28 return 0; /* break-here */
(gdb) PASS: gdb.threads/no-unwaited-for-left.exp: continue to breakpoint: break-here
...
continue
Continuing.
warning: Remote failure reply: E.No unwaited-for children left.
[Thread 32222] #1 stopped.
(gdb) FAIL: gdb.threads/no-unwaited-for-left.exp: continue stops when the main thread exits
Overall, this is also good for getting rid of a RSP detail from the backend.
gdb/gdbserver/
2014-11-12 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_wait_1): Don't force a wait for the Hc
thread, and don't resume all threads if the Hc thread has exited.
The target->request_interrupt callback implements the handling for
ctrl-c. User types ctrl-c in GDB, GDB sends a \003 to the remote
target, and the remote targets stops the program with a SIGINT, just
like if the user typed ctrl-c in GDBserver's terminal.
The trouble is that using kill_lwp(signal_pid, SIGINT) sends the
SIGINT directly to the program's main thread. If that thread has
exited already, then that kill won't do anything.
Instead, send the SIGINT to the process group, just like GDB
does (see inf-ptrace.c:inf_ptrace_stop).
gdb.threads/leader-exit.exp is extended to cover the scenario. It
fails against GDBserver before the patch.
Tested on x86_64 Fedora 20, native and GDBserver.
gdb/gdbserver/
2014-11-12 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_request_interrupt): Always send a SIGINT to
the process group instead of to a specific LWP.
gdb/testsuite/
2014-11-12 Pedro Alves <palves@redhat.com>
* gdb.threads/leader-exit.exp: Test sending ctrl-c works after the
leader has exited.
Don't use debug_reg_state for both:
* "intent" - what we want the debug registers to look like
* "reality" - what/which were the contents of the DR registers when
the event triggered
Reserve it for the former only, like in the GNU/Linux port.
Otherwise the core x86 debug registers code can get confused if the
inferior itself changes the debug registers since GDB last set them.
This is also a requirement for being able to set watchpoints while the
target is running, if/when we get to it on Windows. See the big
comment in x86_dr_stopped_data_address.
Seems to me this may also fixes propagating watchpoints to all threads
-- continue_one_thread only calls win32_set_thread_context (what
copies the DR registers to the thread), if something already fetched
the thread's context before. Something else may be masking this
issue, I haven't checked.
Smoke tested by running gdbserver under Wine, connecting to it from
GNU/Linux, and checking that I could trigger a watchpoint as expected.
Joel tested it on x86-windows using AdaCore's testsuite.
gdb/gdbserver/
2014-10-15 Pedro Alves <palves@redhat.com>
PR server/17487
* win32-arm-low.c (arm_set_thread_context): Remove current_event
parameter.
(arm_set_thread_context): Delete.
(the_low_target): Adjust.
* win32-i386-low.c (debug_registers_changed)
(debug_registers_used): Delete.
(update_debug_registers_callback): New function.
(x86_dr_low_set_addr, x86_dr_low_set_control): Mark all threads as
needing to update their debug registers.
(win32_get_current_dr): New function.
(x86_dr_low_get_addr, x86_dr_low_get_control)
(x86_dr_low_get_status): Fetch the debug register from the thread
record's context.
(i386_initial_stuff): Adjust.
(i386_get_thread_context): Remove current_event parameter. Don't
clear debug_registers_changed nor copy DR values to
debug_reg_state.
(i386_set_thread_context): Delete.
(i386_prepare_to_resume): New function.
(i386_thread_added): Mark the thread as needing to update irs
debug registers.
(the_low_target): Remove i386_set_thread_context and install
i386_prepare_to_resume.
* win32-low.c (win32_get_thread_context): Adjust.
(win32_set_thread_context): Use SetThreadContext
directly.
(win32_prepare_to_resume): New function.
(win32_require_context): New function, factored out from ...
(thread_rec): ... this.
(continue_one_thread): Call win32_prepare_to_resume on each thread
we're about to continue.
(win32_resume): Call win32_prepare_to_resume on the event thread.
* win32-low.h (struct win32_thread_info)
<debug_registers_changed>: New field.
(struct win32_target_ops): Change prototype of set_thread_context,
delete set_thread_context and add prepare_to_resume.
(win32_require_context): New declaration.
This commit includes common-exceptions.h in common-defs.h and removes
all other inclusions.
gdb/ChangeLog:
* common/common-defs.h: Include common-exceptions.h.
* exceptions.h: Do not include common-exceptions.h.
gdb/gdbserver/ChangeLog:
* server.h: Do not include common-exceptions.h.
This commit includes cleanups.h in common-defs.h and removes all other
inclusions.
gdb/ChangeLog:
* common/common-defs.h: Include cleanups.h.
* common/common-exceptions.c: Do not include cleanups.h.
* utils.h: Likewise.
gdb/gdbserver/ChangeLog:
* server.h: Do not include cleanups.h.
I see the following fail on arm-none-linux-gnueabi testing,
(gdb) continue^M
Continuing.^M
^M
Program received signal SIGILL, Illegal instruction.^M
[Switching to Thread 1003]^M
handler (signo=10) at
/scratch/yqi/arm-none-linux-gnueabi/src/gdb-trunk/gdb/testsuite/gdb.threads/sigstep-threads.c:33^M
33 tgkill (getpid (), gettid (), SIGUSR1); /* step-2 */^M
(gdb) FAIL: gdb.threads/sigstep-threads.exp: continue
the cause is that GDBserver doesn't cancel the breakpoint if the stop
signal is SIGILL. The kernel used here is a little old, 2.6.x, and
doesn't translate SIGILL to SIGTRAP when program hits breakpoint
instruction (which is an illegal instruction actually). GDB and
GDBserver can translate SIGILL to SIGTRAP under certain circumstance,
so it is not a problem here. See gdbserver/linux-low.c:linux_wait_1
/* If this event was not handled before, and is not a SIGTRAP, we
report it. SIGILL and SIGSEGV are also treated as traps in case
a breakpoint is inserted at the current PC. If this target does
not support internal breakpoints at all, we also report the
SIGTRAP without further processing; it's of no concern to us. */
maybe_internal_trap
= (supports_breakpoints ()
&& (WSTOPSIG (w) == SIGTRAP
|| ((WSTOPSIG (w) == SIGILL
|| WSTOPSIG (w) == SIGSEGV)
&& (*the_low_target.breakpoint_at) (event_child->stop_pc))));
However, SIGILL and SIGSEGV is not considered when cancelling
breakpoint, which causes the fail above. That is, when GDB is doing
software single step on address ADDR, both thread A and thread B hits the
software single step breakpoint, and get SIGILL. GDB selects the event
from thread A, removes the software single step breakpoint, and resume
the program. The event (SIGILL) from thread B is reported to GDB, but
GDB doesn't regard this SIGILL as SIGTRAP, because the breakpoint on
address ADDR was removed, so GDB reports "Program received signal
SIGILL".
The patch is to allow calling cancel_breakpoint if the signal is
SIGILL and SIGSEGV. This patch fixes the fail above. Likewise, event
lwp selection should honour SIGILL and SIGSEGV too.
gdb/gdbserver:
2014-09-23 Yao Qi <yao@codesourcery.com>
* linux-low.c (lp_status_maybe_breakpoint): New function.
(linux_low_filter_event): Call lp_status_maybe_breakpoint.
(count_events_callback): Likewise.
(select_event_lwp_callback): Likewise.
(cancel_breakpoints_callback): Likewise.
This commit implements functions for identifying and extracting extended
ptrace event information from a Linux wait status. These are just
convenience functions intended to hide the ">> 16" used to extract the
event from the wait status word, replacing the hard-coded shift with a more
descriptive function call. This is preparatory work for implementation of
follow-fork and detach-on-fork for extended-remote linux targets.
gdb/ChangeLog:
* linux-nat.c (linux_handle_extended_wait): Call
linux_ptrace_get_extended_event.
(wait_lwp): Call linux_is_extended_waitstatus.
(linux_nat_filter_event): Call linux_ptrace_get_extended_event
and linux_is_extended_waitstatus.
* nat/linux-ptrace.c (linux_test_for_tracefork): Call
linux_ptrace_get_extended_event.
(linux_ptrace_get_extended_event): New function.
(linux_is_extended_waitstatus): New function.
* nat/linux-ptrace.h (linux_ptrace_get_extended_event)
(linux_is_extended_waitstatus): New declarations.
gdb/gdbserver/ChangeLog:
* linux-low.c (handle_extended_wait): Call
linux_ptrace_get_extended_event.
(get_stop_pc, get_detach_signal, linux_low_filter_event): Call
linux_is_extended_waitstatus.
---
