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2015-08-06gdbserver: fix silent error exitPedro Alves1-0/+6
Running gdb.threads/process-dies-while-handling-bp.exp against gdbserver sometimes FAILs because GDBserver drops the connection, but the logs leave no clue on what the reason could be. Running manually a few times, I saw the same: $ ./gdbserver/gdbserver --multi :9999 testsuite/gdb.threads/process-dies-while-handling-bp Process testsuite/gdb.threads/process-dies-while-handling-bp created; pid = 12766 Listening on port 9999 Remote debugging from host 127.0.0.1 Listening on port 9999 Child exited with status 0 Child exited with status 0 What happened is that an exception escaped and gdbserver reopened the connection, which led to that second "Listening on port 9999" output. The error was a failure to access registers from a now-dead thread. The exception probably shouldn't have escaped here, but meanwhile, this at least makes the issue less mysterious. Tested on x86_64 Fedora 20. gdb/gdbserver/ChangeLog: 2015-08-06 Pedro Alves <palves@redhat.com> * server.c (captured_main): On error, print the exception message to stderr, and if run_once is set, throw a quit.
2015-08-04Disable Z0 packet on aarch64 on multi-arch debuggingYao Qi1-1/+1
In multi-arch debugging, if GDB sends Z0 packet, GDBserver should be able to do several things below: - choose the right breakpoint instruction to insert according to the information available, such as 'kind' in Z0 packet and address, - choose the right breakpoint instruction to check memory writes and validate inserted memory breakpoint - be aware of different breakpoint instructions in $ARCH_breakpoint_at. unfortunately GDBserver can't do them now. Although x86 GDBserver supports multi-arch, it doesn't need to support them above because breakpoint instruction on i686 and x86_64 is the same. However, breakpoint instructions on aarch64 and arm (arm mode, thumb1, and thumb2) are different. I tried to teach aarch64 GDBserver backend to be really multi-arch-capable in the following ways, - linux_low_target return the right breakpoint instruction according to the 'kind' in Z0 packet, and insert_memory_breakpoint can do the right thing. - once breakpoint is inserted, the breakpoint data and length is recorded in each breakpoint object, so that validate_breakpoint and check_mem_write can get the right breakpoint instruction from each breakpoint object, rather than from global variable breakpoint_data. - linux_low_target needs another hook function for pc increment after hitting a breakpoint. - let set_breakpoint_at, which is widely used for tracepoint, use the 'default' breakpoint instruction. We can always use aarch64 breakpoint instruction since arm doesn't support tracepoint yet. looks it is not a small piece of work, so I decide to disable Z0 packet on multi-arch, which means aarch64 GDBserver only supports Z0 packet if it is started to debug only one process (extended protocol is not used) and process target description is 64-bit. gdb/gdbserver: 2015-08-04 Yao Qi <yao.qi@linaro.org> * linux-aarch64-low.c (aarch64_supports_z_point_type): Return 0 for Z_PACKET_SW_BP if it may be used in multi-arch debugging. * server.c (extended_protocol): Remove "static". * server.h (extended_protocol): Declare it.
2015-07-24Initialise target descrption after skipping extra traps for --wrapperYao Qi1-0/+3
Nowadays, when --wrapper is used, GDBserver skips extra traps/stops in the wrapper program, and stops at the first instruction of the program to be debugged. However, GDBserver created target description in the first stop of inferior, and the executable of the inferior is the wrapper program rather than the program to be debugged. In this way, the target description can be wrong if the architectures of wrapper program and program to be debugged are different. This is shown by some fails in gdb.server/wrapper.exp on buildbot. We are testing i686-linux GDB (Fedora-i686) on an x86_64-linux box (fedora-x86-64-4) in buildbot, such configuration causes fails in gdb.server/wrapper.exp like this: spawn /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/../../gdb/gdbserver/gdbserver --once --wrapper env TEST=1 -- :2346 /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/outputs/gdb.server/wrapper/wrapper Process /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/outputs/gdb.server/wrapper/wrapper created; pid = 8795 Can't debug 64-bit process with 32-bit GDBserver Exiting target remote localhost:2346 localhost:2346: Connection timed out. (gdb) FAIL: gdb.server/wrapper.exp: setting breakpoint at marker See https://sourceware.org/ml/gdb-testers/2015-q3/msg01541.html In this case, program to be debugged ("wrapper") is 32-bit but wrapper program ("/usr/bin/env") is 64-bit, so GDBserver gets the 64-bit target description instead of 32-bit. The root cause of this problem is that GDBserver creates target description too early, and the rationale of fix could be creating target description once the GDBserver skips extra traps and inferior stops at the first instruction of the program we want to debug. IOW, when GDBserver skips extra traps, the inferior's tdesc is NULL, and mywait and its callees shouldn't use inferior's tdesc, so in this patch, we skip code that requires register access, see changes in linux_resume_one_lwp_throw and need_step_over_p. In linux_low_filter_event, if target description isn't initialised and GDBserver attached the process, we create target description immediately, because GDBserver don't have to skip extra traps for attach, IOW, it makes no sense to use --attach and --wrapper together. Otherwise, the process is launched by GDBserver, we keep the status pending, and return. After GDBserver skipped extra traps in start_inferior, we call a target_ops hook arch_setup to initialise target description there. gdb/gdbserver: 2015-07-24 Yao Qi <yao.qi@linaro.org> * linux-low.c (linux_arch_setup): New function. (linux_low_filter_event): If proc->tdesc is NULL and proc->attached is true, call the_low_target.arch_setup. Otherwise, keep status pending, and return. (linux_resume_one_lwp_throw): Don't call get_pc if thread->while_stepping isn't NULL. Don't call get_thread_regcache if proc->tdesc is NULL. (need_step_over_p): Return 0 if proc->tdesc is NULL. (linux_target_ops): Install arch_setup. * server.c (start_inferior): Call the_target->arch_setup. * target.h (struct target_ops) <arch_setup>: New field. (target_arch_setup): New marco. * lynx-low.c (lynx_target_ops): Update. * nto-low.c (nto_target_ops): Update. * spu-low.c (spu_target_ops): Update. * win32-low.c (win32_target_ops): Update.
2015-07-24Refactor start_inferiorYao Qi1-12/+11
This patch is to refactor function start_inferior that signal_pid is return in one place. gdb/gdbserver: 2015-07-24 Yao Qi <yao.qi@linaro.org> * server.c (start_inferior): Code refactor.
2015-07-24Set general_thread after restartYao Qi1-1/+14
When I run gdb.server/ext-restart.exp, I get the following GDB internal error, run^M The program being debugged has been started already.^M Start it from the beginning? (y or n) y^M Sending packet: $vKill;53c5#3d...Packet received: OK^M Packet vKill (kill) is supported^M Sending packet: $vFile:close:6#b6...Packet received: F0^M Sending packet: $vFile:close:3#b3...Packet received: F0^M Starting program: /scratch/yao/gdb/build-git/x86_64/gdb/testsuite/gdb.server/ext-restart ^M Sending packet: $QDisableRandomization:1#cf...Packet received: OK^M Sending packet: $R0#82...Sending packet: $qC#b4...Packet received: QCp53c5.53c5^M <-- [1] Sending packet: $qAttached:53c5#c9...Packet received: E01^M warning: Remote failure reply: E01^M .... 0x00002aaaaaaac2d0 in ?? () from target:/lib64/ld-linux-x86-64.so.2^M /home/yao/SourceCode/gnu/gdb/git/gdb/thread.c:88: internal-error: inferior_thread: Assertion `tp' failed.^M A problem internal to GDB has been detected,^M further debugging may prove unreliable.^M Quit this debugging session? (y or n) FAIL: gdb.server/ext-restart.exp: run to main (GDB internal error) Resyncing due to internal error. the test is to restart the program, to make sure GDBserver handles packet 'R' correctly. From the GDBserver output, we can see, Remote debugging from host 127.0.0.1^M Process /scratch/yao/gdb/build-git/x86_64/gdb/testsuite/gdb.server/ext-restart created; pid = 21445^M GDBserver restarting^M Process /scratch/yao/gdb/build-git/x86_64/gdb/testsuite/gdb.server/ext-restart created; pid = 21446^M Killing process(es): 21446 we first start process 21445(0x53c5), kill it and restart a new process 21446. However, in the gdb output above [1], we can see that the reply of qC is still the old process id rather than the new one. Looks general_thread isn't up to date after GDBserver receives R packet. This patch is to update general_thread after call start_inferior. gdb/gdbserver: 2015-07-24 Yao Qi <yao.qi@linaro.org> * server.c (process_serial_event): Set general_thread. gdb/testsuite: 2015-07-24 Yao Qi <yao.qi@linaro.org> * gdb.server/ext-restart.exp: New file.
2015-07-02btrace: support Intel(R) Processor TraceMarkus Metzger1-2/+49
Adds a new command "record btrace pt" to configure the kernel to use Intel(R) Processor Trace instead of Branch Trace Strore. The "record btrace" command chooses the tracing format automatically. Intel(R) Processor Trace support requires Linux 4.1 and libipt. gdb/ * NEWS: Announce new commands "record btrace pt" and "record pt". Announce new options "set|show record btrace pt buffer-size". * btrace.c: Include "rsp-low.h". Include "inttypes.h". (btrace_add_pc): Add forward declaration. (pt_reclassify_insn, ftrace_add_pt, btrace_pt_readmem_callback) (pt_translate_cpu_vendor, btrace_finalize_ftrace_pt) (btrace_compute_ftrace_pt): New. (btrace_compute_ftrace): Support BTRACE_FORMAT_PT. (check_xml_btrace_version): Update version check. (parse_xml_raw, parse_xml_btrace_pt_config_cpu) (parse_xml_btrace_pt_raw, parse_xml_btrace_pt) (btrace_pt_config_cpu_attributes, btrace_pt_config_children) (btrace_pt_children): New. (btrace_children): Add support for "pt". (parse_xml_btrace_conf_pt, btrace_conf_pt_attributes): New. (btrace_conf_children): Add support for "pt". * btrace.h: Include "intel-pt.h". (btrace_pt_error): New. * common/btrace-common.c (btrace_format_string, btrace_data_fini) (btrace_data_empty): Support BTRACE_FORMAT_PT. * common/btrace-common.h (btrace_format): Add BTRACE_FORMAT_PT. (struct btrace_config_pt): New. (struct btrace_config)<pt>: New. (struct btrace_data_pt_config, struct btrace_data_pt): New. (struct btrace_data)<pt>: New. * features/btrace-conf.dtd (btrace-conf)<pt>: New. (pt): New. * features/btrace.dtd (btrace)<pt>: New. (pt, pt-config, cpu): New. * nat/linux-btrace.c (perf_event_read, perf_event_read_all) (perf_event_pt_event_type, kernel_supports_pt) (linux_supports_pt): New. (linux_supports_btrace): Support BTRACE_FORMAT_PT. (linux_enable_bts): Free tinfo on error. (linux_enable_pt): New. (linux_enable_btrace): Support BTRACE_FORMAT_PT. (linux_disable_pt): New. (linux_disable_btrace): Support BTRACE_FORMAT_PT. (linux_fill_btrace_pt_config, linux_read_pt): New. (linux_read_btrace): Support BTRACE_FORMAT_PT. * nat/linux-btrace.h (struct btrace_tinfo_pt): New. (struct btrace_target_info)<pt>: New. * record-btrace.c (set_record_btrace_pt_cmdlist) (show_record_btrace_pt_cmdlist): New. (record_btrace_print_pt_conf): New. (record_btrace_print_conf): Support BTRACE_FORMAT_PT. (btrace_ui_out_decode_error): Support BTRACE_FORMAT_PT. (cmd_record_btrace_pt_start): New. (cmd_record_btrace_start): Support BTRACE_FORMAT_PT. (cmd_set_record_btrace_pt, cmd_show_record_btrace_pt): New. (_initialize_record_btrace): Add new commands. * remote.c (PACKET_Qbtrace_pt, PACKET_Qbtrace_conf_pt_size): New. (remote_protocol_features): Add "Qbtrace:pt". Add "Qbtrace-conf:pt:size". (remote_supports_btrace): Support BTRACE_FORMAT_PT. (btrace_sync_conf): Support PACKET_Qbtrace_conf_pt_size. (remote_enable_btrace): Support BTRACE_FORMAT_PT. (_initialize_remote): Add new commands. gdbserver/ * linux-low.c: Include "rsp-low.h" (linux_low_encode_pt_config, linux_low_encode_raw): New. (linux_low_read_btrace): Support BTRACE_FORMAT_PT. (linux_low_btrace_conf): Support BTRACE_FORMAT_PT. (handle_btrace_enable_pt): New. (handle_btrace_general_set): Support "pt". (handle_btrace_conf_general_set): Support "pt:size". doc/ * gdb.texinfo (Process Record and Replay): Spell out that variables and registers are not available during btrace replay. Describe the new "record btrace pt" command. Describe the new "set|show record btrace pt buffer-size" options. (General Query Packets): Describe the new Qbtrace:pt and Qbtrace-conf:pt:size packets. Expand "bts" to "Branch Trace Store". Update the branch trace DTD.
2015-06-18remote: consider addressable unit size when reading/writing memorySimon Marchi1-2/+2
Adapt code in remote.c to take into account addressable unit size when reading/writing memory. A few variables are renamed and suffixed with _bytes or _units. This way, it's more obvious if there is any place where we add or compare values of different kinds (which would be a mistake). gdb/ChangeLog: * common/rsp-low.c (needs_escaping): New. (remote_escape_output): Add unit_size parameter. Refactor to support multi-byte addressable units. Rename parameters. * common/rsp-low.h (remote_escape_output): Add unit_size parameter and rename others. Update doc. * remote.c (align_for_efficient_write): New. (remote_write_bytes_aux): Add unit_size parameter and use it. Rename some variables. Update doc. (remote_xfer_partial): Get unit size and use it. (remote_read_bytes_1): Add unit_size parameter and use it. Rename some variables. Update doc. (remote_write_bytes): Same. (remote_xfer_live_readonly_partial): Same. (remote_read_bytes): Same. (remote_flash_write): Update call to remote_write_bytes_aux. (remote_write_qxfer): Update call to remote_escape_output. (remote_search_memory): Same. (remote_hostio_pwrite): Same. gdb/gdbserver/ChangeLog: * server.c (write_qxfer_response): Update call to remote_escape_output.
2015-06-10Fix gdbserver <library-list> and its #FIXED version="1.0"Jan Kratochvil1-1/+1
While reimplementing <library-list/> I found from expat-2.0.1-11.fc15.x86_64: warning: while parsing target library list (at line 1): Required attribute "version" of <library-list-svr4> not specified I believe the same bug has to apply for existing FSF gdbserver but I do not have any <library-list/> platform to test it (I did not try to build MinGW). features/library-list.dtd: <!ATTLIST library-list version CDATA #FIXED "1.0"> http://www.xml.com/pub/a/98/10/guide0.html?page=3 says: In this case, the attribute is not required, but if it occurs, it must have the specified value. Which would suggest gdbserver is right but solib-target.c is wrong. One could also make gdbserver explicit for the version (if those 14 bytes are not of a concern). gdb/ChangeLog 2015-06-10 Jan Kratochvil <jan.kratochvil@redhat.com> * solib-target.c (library_list_start_list): Do not dereference variable version in its initialization. Make the VERSION check handle NULL. (library_list_attributes): Make "version" GDB_XML_AF_OPTIONAL. gdb/gdbserver/ChangeLog 2015-06-10 Jan Kratochvil <jan.kratochvil@redhat.com> * server.c (handle_qxfer_libraries): Set `version' attribute for <library-list>.
2015-06-10Implement vFile:setfs in gdbserverGary Benson1-1/+2
This commit implements the "vFile:setfs" packet in gdbserver. gdb/gdbserver/ChangeLog: * target.h (struct target_ops) <multifs_open>: New field. <multifs_unlink>: Likewise. <multifs_readlink>: Likewise. * linux-low.c (nat/linux-namespaces.h): New include. (linux_target_ops): Initialize the_target->multifs_open, the_target->multifs_unlink and the_target->multifs_readlink. * hostio.h (hostio_handle_new_gdb_connection): New declaration. * hostio.c (hostio_fs_pid): New static variable. (hostio_handle_new_gdb_connection): New function. (handle_setfs): Likewise. (handle_open): Use the_target->multifs_open as appropriate. (handle_unlink): Use the_target->multifs_unlink as appropriate. (handle_readlink): Use the_target->multifs_readlink as appropriate. (handle_vFile): Handle vFile:setfs packets. * server.c (handle_query): Call hostio_handle_new_gdb_connection after target_handle_new_gdb_connection.
2015-05-12Extended-remote Linux follow forkDon Breazeal1-0/+3
This patch implements basic support for follow-fork and detach-on-fork on extended-remote Linux targets. Only 'fork' is supported in this patch; 'vfork' support is added n a subsequent patch. This patch depends on the previous patches in the patch series. Sufficient extended-remote functionality has been implemented here to pass gdb.base/multi-forks.exp, as well as gdb.base/foll-fork.exp with the catchpoint tests commented out. Some other fork tests fail with this patch because it doesn't provide the architecture support needed for watchpoint inheritance or fork catchpoints. The implementation follows the same general structure as for the native implementation as much as possible. This implementation includes: * enabling fork events in linux-low.c in initialize_low and linux_enable_extended_features * handling fork events in gdbserver/linux-low.c:handle_extended_wait - when a fork event occurs in gdbserver, we must do the full creation of the new process, thread, lwp, and breakpoint lists. This is required whether or not the new child is destined to be detached-on-fork, because GDB will make target calls that require all the structures. In particular we need the breakpoint lists in order to remove the breakpoints from a detaching child. If we are not detaching the child we will need all these structures anyway. - as part of this event handling we store the target_waitstatus in a new member of the parent lwp_info structure, 'waitstatus'. This is used to store extended event information for reporting to GDB. - handle_extended_wait is given a return value, denoting whether the handled event should be reported to GDB. Previously it had only handled clone events, which were never reported. * using a new predicate in gdbserver to control handling of the fork event (and eventually all extended events) in linux_wait_1. The predicate, extended_event_reported, checks a target_waitstatus.kind for an extended ptrace event. * implementing a new RSP 'T' Stop Reply Packet stop reason: "fork", in gdbserver/remote-utils.c and remote.c. * implementing new target and RSP support for target_follow_fork with target extended-remote. (The RSP components were actually defined in patch 1, but they see their first use here). - remote target routine remote_follow_fork, which just sends the 'D;pid' detach packet to detach the new fork child cleanly. We can't just call target_detach because the data structures for the forked child have not been allocated on the host side. Tested on x64 Ubuntu Lucid, native, remote, extended-remote. gdb/gdbserver/ChangeLog: * linux-low.c (handle_extended_wait): Implement return value, rename argument 'event_child' to 'event_lwp', handle PTRACE_EVENT_FORK, call internal_error for unrecognized event. (linux_low_ptrace_options): New function. (linux_low_filter_event): Call linux_low_ptrace_options, use different argument fo linux_enable_event_reporting, use return value from handle_extended_wait. (extended_event_reported): New function. (linux_wait_1): Call extended_event_reported and set status to report fork events. (linux_write_memory): Add pid to debug message. (reset_lwp_ptrace_options_callback): New function. (linux_handle_new_gdb_connection): New function. (linux_target_ops): Initialize new structure member. * linux-low.h (struct lwp_info) <waitstatus>: New member. * lynx-low.c: Initialize new structure member. * remote-utils.c (prepare_resume_reply): Implement stop reason "fork" for "T" stop message. * server.c (handle_query): Call handle_new_gdb_connection. * server.h (report_fork_events): Declare global flag. * target.h (struct target_ops) <handle_new_gdb_connection>: New member. (target_handle_new_gdb_connection): New macro. * win32-low.c: Initialize new structure member. gdb/ChangeLog: * linux-nat.c (linux_nat_ptrace_options): New function. (linux_init_ptrace, wait_lwp, linux_nat_filter_event): Call linux_nat_ptrace_options and use different argument to linux_enable_event_reporting. (_initialize_linux_nat): Delete call to linux_ptrace_set_additional_flags. * nat/linux-ptrace.c (current_ptrace_options): Rename to supported_ptrace_options. (additional_flags): Delete variable. (linux_check_ptrace_features): Use supported_ptrace_options. (linux_test_for_tracesysgood, linux_test_for_tracefork): Likewise, and remove additional_flags check. (linux_enable_event_reporting): Change 'attached' argument to 'options'. Use supported_ptrace_options. (ptrace_supports_feature): Change comment. Use supported_ptrace_options. (linux_ptrace_set_additional_flags): Delete function. * nat/linux-ptrace.h (linux_ptrace_set_additional_flags): Delete function prototype. * remote.c (remote_fork_event_p): New function. (remote_detach_pid): New function. (remote_detach_1): Call remote_detach_pid, don't mourn inferior if doing detach-on-fork. (remote_follow_fork): New function. (remote_parse_stop_reply): Handle new "T" stop reason "fork". (remote_pid_to_str): Print "process" strings for pid/0/0 ptids. (init_extended_remote_ops): Initialize to_follow_fork.
2015-05-12Identify remote fork event supportDon Breazeal1-0/+22
This patch implements a mechanism for GDB to determine whether fork events are supported in gdbserver. This is a preparatory patch for remote fork and exec event support. Two new RSP packets are defined to represent fork and vfork event support. These packets are used just like PACKET_multiprocess_feature to denote whether the corresponding event is supported. GDB sends fork-events+ and vfork-events+ to gdbserver to inquire about fork event support. If the response enables these packets, then GDB knows that gdbserver supports the corresponding events and will enable them. Target functions used to query for support are included along with each new packet. In order for gdbserver to know whether the events are supported at the point where the qSupported packet arrives, the code in nat/linux-ptrace.c had to be reorganized. Previously it would test for fork/exec event support, then enable the events using the pid of the inferior. When the qSupported packet arrives there may not be an inferior. So the mechanism was split into two parts: a function that checks whether the events are supported, called when gdbserver starts up, and another that enables the events when the inferior stops for the first time. Another gdbserver change was to add some global variables similar to multi_process, one per new packet. These are used to control whether the corresponding fork events are enabled. If GDB does not inquire about the event support in the qSupported packet, then gdbserver will not set these "report the event" flags. If the flags are not set, the events are ignored like they were in the past. Thus, gdbserver will never send fork event notification to an older GDB that doesn't recognize fork events. Tested on Ubuntu x64, native/remote/extended-remote, and as part of subsequent patches in the series. gdb/gdbserver/ChangeLog: * linux-low.c (linux_supports_fork_events): New function. (linux_supports_vfork_events): New function. (linux_target_ops): Initialize new structure members. (initialize_low): Call linux_check_ptrace_features. * lynx-low.c (lynx_target_ops): Initialize new structure members. * server.c (report_fork_events, report_vfork_events): New global flags. (handle_query): Add new features to qSupported packet and response. (captured_main): Initialize new global variables. * target.h (struct target_ops) <supports_fork_events>: New member. <supports_vfork_events>: New member. (target_supports_fork_events): New macro. (target_supports_vfork_events): New macro. * win32-low.c (win32_target_ops): Initialize new structure members. gdb/ChangeLog: * nat/linux-ptrace.c (linux_check_ptrace_features): Change from static to extern. * nat/linux-ptrace.h (linux_check_ptrace_features): Declare. * remote.c (anonymous enum): <PACKET_fork_event_feature, * PACKET_vfork_event_feature>: New enumeration constants. (remote_protocol_features): Add table entries for new packets. (remote_query_supported): Add new feature queries to qSupported packet. (_initialize_remote): Exempt new packets from the requirement to have 'set remote' commands.
2015-05-12Locate executables on remote stubs without multiprocess extensionsGary Benson1-5/+20
This commit allows GDB to determine filenames of main executables when debugging using remote stubs without multiprocess extensions. The qXfer:exec-file:read packet is extended to allow an empty annex, with the meaning that the remote stub should supply the filename of whatever it thinks is the current process. gdb/ChangeLog: * remote.c (remote_add_inferior): Call exec_file_locate_attach for fake PIDs as well as real ones. (remote_pid_to_exec_file): Send empty annex if PID is fake. gdb/doc/ChangeLog: * gdb.texinfo (General Query Packets): Document qXfer:exec-file:read with empty annex. gdb/gdbserver/ChangeLog: * server.c (handle_qxfer_exec_file): Use current process if annex is empty.
2015-05-08[gdbserver] Disable conditional breakpoints on no-hardware-single-step targetsYao Qi1-1/+2
GDBserver steps over breakpoint if the condition is false, but if target doesn't support hardware single step, the step over is very simple, if not incorrect, in linux-arm-low.c: /* We only place breakpoints in empty marker functions, and thread locking is outside of the function. So rather than importing software single-step, we can just run until exit. */ static CORE_ADDR arm_reinsert_addr (void) { struct regcache *regcache = get_thread_regcache (current_thread, 1); unsigned long pc; collect_register_by_name (regcache, "lr", &pc); return pc; } and linux-mips-low.c does the same. GDBserver sets a breakpoint at the return address of the current function, resume and wait the program hits the breakpoint in order to achieve "breakpoint step over". What if program hits other user breakponits during this "step over"? It is worse if the arm/thumb interworking is considered. Nowadays, GDBserver arm backend unconditionally inserts arm breakpoint, /* Define an ARM-mode breakpoint; we only set breakpoints in the C library, which is most likely to be ARM. If the kernel supports clone events, we will never insert a breakpoint, so even a Thumb C library will work; so will mixing EABI/non-EABI gdbserver and application. */ (const unsigned char *) &arm_breakpoint, (const unsigned char *) &arm_eabi_breakpoint, note that the comments are no longer valid as C library can be compiled in thumb mode. When GDBserver steps over a breakpoint in arm mode function, which returns to thumb mode, GDBserver will insert arm mode breakpoint by mistake and the program will crash. GDBserver alone is unable to determine the arm/thumb mode given a PC address. See how GDB does it in arm-tdep.c:arm_pc_is_thumb. After thinking about how to teach GDBserver inserting right breakpoint (arm or thumb) for a while, I reconsider it from a different direction that it may be unreasonable to run target-side conditional breakpoint for targets without hardware single step. Pedro also pointed this out here https://sourceware.org/ml/gdb-patches/2015-04/msg00337.html This patch is to add a new target_ops hook supports_conditional_breakpoints, and only reply ";ConditionalBreakpoints+" if it is true. On linux targets, supports_conditional_breakpoints returns true if target has hardware single step, on other targets, (win32, lynx, nto, spu), set it to NULL, because conditional breakpoint is a linux-specific feature. gdb/gdbserver: 2015-05-08 Yao Qi <yao.qi@linaro.org> * linux-low.c (linux_supports_conditional_breakpoints): New function. (linux_target_ops): Install new target method. * lynx-low.c (lynx_target_ops): Install NULL hook for supports_conditional_breakpoints. * nto-low.c (nto_target_ops): Likewise. * spu-low.c (spu_target_ops): Likewise. * win32-low.c (win32_target_ops): Likewise. * server.c (handle_query): Check target_supports_conditional_breakpoints. * target.h (struct target_ops) <supports_conditional_breakpoints>: New field. (target_supports_conditional_breakpoints): New macro.
2015-05-06PR server/18081: gdbserver crashes when providing an unexisting binaryPedro Alves1-0/+2
$ ./gdbserver :1234 blah Process blah created; pid = 16471 Cannot exec blah: No such file or directory. Child exited with status 127 Killing process(es): 16471 ../../../../src/binutils-gdb/gdb/gdbserver/linux-low.c:920: A problem internal to GDBserver has been detected. kill_wait_lwp: Assertion `res > 0' failed. GDBserver shouldn't even be trying to kill that process. GDBserver kills or detaches from all processes on exit, and due to a missing mourn_inferior call, GDBserver tries to kill the process that it had already seen exit. Tested on x86_64 Fedora 20. New test included. I emulated what Windows outputs by hacking an error call in linux_create_inferior. gdb/gdbserver/ChangeLog: 2015-05-06 Pedro Alves <palves@redhat.com> PR server/18081 * server.c (start_inferior): If the process exits, mourn it. gdb/testsuite/ChangeLog: 2015-05-06 Pedro Alves <palves@redhat.com> PR server/18081 * gdb.server/non-existing-program.exp: New file.
2015-04-17Implement qXfer:exec-file:read in gdbserverGary Benson1-0/+40
This commit implements the "qXfer:exec-file:read" packet in gdbserver. gdb/gdbserver/ChangeLog: * target.h (struct target_ops) <pid_to_exec_file>: New field. * linux-low.c (linux_target_ops): Initialize pid_to_exec_file. * server.c (handle_qxfer_exec_file): New function. (qxfer_packets): Add exec-file entry. (handle_query): Report qXfer:exec-file:read as supported packet.
2015-04-01GDBServer: give more complete usage informationPedro Alves1-7/+33
--attach/--multi are currently only mentioned on the usage info first lines, the meaning of PROG is completely absent and the COMM text does not mention '-/stdio'. A few options are missing: . --disable-randomization / --no-disable-randomization is not mentioned. Although the manual has a comment saying these are superceded by QDisableRandomization, that only makes sense for "run" in extended-remote mode. When we start gdbserver passing it a PROG, --disable-randomization / --no-disable-randomization do take effect. So I think we should document these. . We show --debug / --remote-debug, so might as well show --disable-packet too. GDB's --help has this "For more information, consult the GDB manual" blurb that is missing in GDBserver's --help. Then shuffle things around a bit into "Operating modes", "Other options" and "Debug options" sections, similarly to GDB's --help structure. Before: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ $ ./gdbserver/gdbserver --help Usage: gdbserver [OPTIONS] COMM PROG [ARGS ...] gdbserver [OPTIONS] --attach COMM PID gdbserver [OPTIONS] --multi COMM COMM may either be a tty device (for serial debugging), or HOST:PORT to listen for a TCP connection. Options: --debug Enable general debugging output. --debug-format=opt1[,opt2,...] Specify extra content in debugging output. Options: all none timestamp --remote-debug Enable remote protocol debugging output. --version Display version information and exit. --wrapper WRAPPER -- Run WRAPPER to start new programs. --once Exit after the first connection has closed. Report bugs to "<http://www.gnu.org/software/gdb/bugs/>". ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ After: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ $ ./gdbserver/gdbserver --help Usage: gdbserver [OPTIONS] COMM PROG [ARGS ...] gdbserver [OPTIONS] --attach COMM PID gdbserver [OPTIONS] --multi COMM COMM may either be a tty device (for serial debugging), HOST:PORT to listen for a TCP connection, or '-' or 'stdio' to use stdin/stdout of gdbserver. PROG is the executable program. ARGS are arguments passed to inferior. PID is the process ID to attach to, when --attach is specified. Operating modes: --attach Attach to running process PID. --multi Start server without a specific program, and only quit when explicitly commanded. --once Exit after the first connection has closed. --help Print this message and then exit. --version Display version information and exit. Other options: --wrapper WRAPPER -- Run WRAPPER to start new programs. --disable-randomization Run PROG with address space randomization disabled. --no-disable-randomization Don't disable address space randomization when starting PROG. Debug options: --debug Enable general debugging output. --debug-format=opt1[,opt2,...] Specify extra content in debugging output. Options: all none timestamp --remote-debug Enable remote protocol debugging output. --disable-packet=opt1[,opt2,...] Disable support for RSP packets or features. Options: vCont, Tthread, qC, qfThreadInfo and threads (disable all threading packets). For more information, consult the GDB manual (available as on-line info or a printed manual). Report bugs to "<http://www.gnu.org/software/gdb/bugs/>". ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ gdb/gdbserver/ChangeLog: 2015-04-01 Pedro Alves <palves@redhat.com> Cleber Rosa <crosa@redhat.com> * server.c (gdbserver_usage): Reorganize and extend the usage message.
2015-03-20constify gdbserver/server.cPedro Alves1-1/+1
gdb/gdbserver/ 2015-03-20 Pedro Alves <palves@redhat.com> * server.c (handle_general_set): Make "req_str" const.
2015-03-18Reimplement "vFile:fstat" without qSupportedGary Benson1-2/+0
This commit makes support for the "vFile:fstat" packet be detected by probing rather than using qSupported, for consistency with the other vFile: packets. gdb/ChangeLog: (remote_protocol_features): Remove the "vFile:fstat" feature. (remote_hostio_fstat): Probe for "vFile:fstat" support. gdb/doc/ChangeLog: * gdb.texinfo (General Query Packets): Remove documentation for now-removed vFile:fstat qSupported features. gdb/gdbserver/ChangeLog: * server.c (handle_query): Do not report vFile:fstat as supported.
2015-03-11Implement vFile:fstat: in gdbserverGary Benson1-0/+2
This commit implements the "vFile:fstat:" packet in gdbserver. gdb/gdbserver/ChangeLog: * hostio.c (sys/types.h): New include. (sys/stat.h): Likewise. (common-remote-fileio.h): Likewise. (handle_fstat): New function. (handle_vFile): Handle vFile:fstat packets. * server.c (handle_query): Report vFile:fstat as supported.
2015-03-07Split TRY_CATCH into TRY + CATCHPedro Alves1-19/+19
This patch splits the TRY_CATCH macro into three, so that we go from this: ~~~ volatile gdb_exception ex; TRY_CATCH (ex, RETURN_MASK_ERROR) { } if (ex.reason < 0) { } ~~~ to this: ~~~ TRY { } CATCH (ex, RETURN_MASK_ERROR) { } END_CATCH ~~~ Thus, we'll be getting rid of the local volatile exception object, and declaring the caught exception in the catch block. This allows reimplementing TRY/CATCH in terms of C++ exceptions when building in C++ mode, while still allowing to build GDB in C mode (using setjmp/longjmp), as a transition step. TBC, after this patch, is it _not_ valid to have code between the TRY and the CATCH blocks, like: TRY { } // some code here. CATCH (ex, RETURN_MASK_ERROR) { } END_CATCH Just like it isn't valid to do that with C++'s native try/catch. By switching to creating the exception object inside the CATCH block scope, we can get rid of all the explicitly allocated volatile exception objects all over the tree, and map the CATCH block more directly to C++'s catch blocks. The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was done with a script, rerun from scratch at every rebase, no manual editing involved. After the mechanical conversion, a few places needed manual intervention, to fix preexisting cases where we were using the exception object outside of the TRY_CATCH block, and cases where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH after this patch]. The result was folded into this patch so that GDB still builds at each incremental step. END_CATCH is necessary for two reasons: First, because we name the exception object in the CATCH block, which requires creating a scope, which in turn must be closed somewhere. Declaring the exception variable in the initializer field of a for block, like: #define CATCH(EXCEPTION, mask) \ for (struct gdb_exception EXCEPTION; \ exceptions_state_mc_catch (&EXCEPTION, MASK); \ EXCEPTION = exception_none) would avoid needing END_CATCH, but alas, in C mode, we build with C90, which doesn't allow mixed declarations and code. Second, because when TRY/CATCH are wired to real C++ try/catch, as long as we need to handle cleanup chains, even if there's no CATCH block that wants to catch the exception, we need for stop at every frame in the unwind chain and run cleanups, then rethrow. That will be done in END_CATCH. After we require C++, we'll still need TRY/CATCH/END_CATCH until cleanups are completely phased out -- TRY/CATCH in C++ mode will save/restore the current cleanup chain, like in C mode, and END_CATCH catches otherwise uncaugh exceptions, runs cleanups and rethrows, so that C++ cleanups and exceptions can coexist. IMO, this still makes the TRY/CATCH code look a bit more like a newcomer would expect, so IMO worth it even if we weren't considering C++. gdb/ChangeLog. 2015-03-07 Pedro Alves <palves@redhat.com> * common/common-exceptions.c (struct catcher) <exception>: No longer a pointer to volatile exception. Now an exception value. <mask>: Delete field. (exceptions_state_mc_init): Remove all parameters. Adjust. (exceptions_state_mc): No longer pop the catcher here. (exceptions_state_mc_catch): New function. (throw_exception): Adjust. * common/common-exceptions.h (exceptions_state_mc_init): Remove all parameters. (exceptions_state_mc_catch): Declare. (TRY_CATCH): Rename to ... (TRY): ... this. Remove EXCEPTION and MASK parameters. (CATCH, END_CATCH): New. All callers adjusted. gdb/gdbserver/ChangeLog: 2015-03-07 Pedro Alves <palves@redhat.com> Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH instead.
2015-03-06New common function "startswith"Gary Benson1-33/+26
This commit introduces a new inline common function "startswith" which takes two string arguments and returns nonzero if the first string starts with the second. It also updates the 295 places where this logic was written out longhand to use the new function. gdb/ChangeLog: * common/common-utils.h (startswith): New inline function. All places where this logic was used updated to use the above.
2015-03-04gdbserver: Support the "swbreak"/"hwbreak" stop reasonsPedro Alves1-0/+25
This patch teaches the core of gdbserver about the new "swbreak" and "hwbreak" stop reasons, and adds the necessary hooks a backend needs to implement to support the feature. gdb/gdbserver/ChangeLog: 2015-03-04 Pedro Alves <palves@redhat.com> * remote-utils.c (prepare_resume_reply): Report swbreak/hbreak. * server.c (swbreak_feature, hwbreak_feature): New globals. (handle_query) <qSupported>: Handle "swbreak+" and "hwbreak+". (captured_main): Clear swbreak_feature and hwbreak_feature. * server.h (swbreak_feature, hwbreak_feature): Declare. * target.h (struct target_ops) <stopped_by_sw_breakpoint, supports_stopped_by_sw_breakpoint, stopped_by_hw_breakpoint, supports_stopped_by_hw_breakpoint>: New fields. (target_supports_stopped_by_sw_breakpoint) (target_stopped_by_sw_breakpoint) (target_supports_stopped_by_hw_breakpoint) (target_stopped_by_hw_breakpoint): Declare.
2015-02-09record-btrace: add bts buffer size configuration optionMarkus Metzger1-1/+59
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.
2015-02-09record btrace: add configuration structMarkus Metzger1-4/+74
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 &current_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.
2015-02-09btrace: add format argument to supports_btraceMarkus Metzger1-12/+15
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.
2015-01-01Update year range in copyright notice of all files owned by the GDB project.Joel Brobecker1-1/+1
gdb/ChangeLog: Update year range in copyright notice of all files.
2015-01-01Update copyright year printed by gdb, gdbserver and gdbreplay.Joel Brobecker1-1/+1
gdb/ChangeLog: * top.c (print_gdb_version): Update copyright year to 2015. gdbserver/ChangeLog: * gdbreplay.c (gdbreplay_version): Update copyright year to 2015. * server.c (gdbserver_version): Likewise.
2014-11-12GDBserver: clean up 'cont_thread' handlingPedro Alves1-24/+2
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.
2014-09-16Rename current_inferior as current_thread in gdbserverGary Benson1-23/+23
GDB has a function named "current_inferior" and gdbserver has a global variable named "current_inferior", but the two are not equivalent; indeed, gdbserver does not have any real equivalent of what GDB calls an inferior. What gdbserver's "current_inferior" is actually pointing to is a structure describing the current thread. This commit renames current_inferior as current_thread in gdbserver to clarify this. It also renames the function "set_desired_inferior" to "set_desired_thread" and renames various local variables from foo_inferior to foo_thread. gdb/gdbserver/ChangeLog: * inferiors.h (current_inferior): Renamed as... (current_thread): New variable. All uses updated. * linux-low.c (get_pc): Renamed saved_inferior as saved_thread. (maybe_move_out_of_jump_pad): Likewise. (cancel_breakpoint): Likewise. (linux_low_filter_event): Likewise. (wait_for_sigstop): Likewise. (linux_resume_one_lwp): Likewise. (need_step_over_p): Likewise. (start_step_over): Likewise. (linux_stabilize_threads): Renamed save_inferior as saved_thread. * linux-x86-low.c (x86_linux_update_xmltarget): Likewise. * proc-service.c (ps_lgetregs): Renamed reg_inferior as reg_thread and save_inferior as saved_thread. * regcache.c (get_thread_regcache): Renamed saved_inferior as saved_thread. (regcache_invalidate_thread): Likewise. * remote-utils.c (prepare_resume_reply): Likewise. * thread-db.c (thread_db_get_tls_address): Likewise. (disable_thread_event_reporting): Likewise. (remove_thread_event_breakpoints): Likewise. * tracepoint.c (gdb_agent_about_to_close): Renamed save_inferior as saved_thread. * target.h (set_desired_inferior): Renamed as... (set_desired_thread): New declaration. All uses updated. * server.c (myresume): Updated comment to reference thread instead of inferior. (handle_serial_event): Likewise. (handle_target_event): Likewise.
2014-09-11Introduce show_debug_regsGary Benson1-5/+2
This commit adds a new global flag show_debug_regs to common-debug.h to replace the flag debug_hw_points used by gdbserver and by the Linux x86 and AArch64 ports, and to replace the flag maint_show_dr used by the Linux MIPS port. Note that some debug printing in the AArch64 port was enabled only if debug_hw_points > 1 but no way to set debug_hw_points to values other than 0 and 1 was provided; that code was effectively dead. This commit enables all debug printing if show_debug_regs is nonzero, so the AArch64 output will be more verbose than previously. gdb/ChangeLog: * common/common-debug.h (show_debug_regs): Declare. * common/common-debug.c (show_debug_regs): Define. * aarch64-linux-nat.c (debug_hw_points): Don't define. Replace all uses with show_debug_regs. Replace all uses that considered debug_hw_points as a multi-value integer with straight boolean uses. * x86-nat.c (debug_hw_points): Don't define. Replace all uses with show_debug_regs. * nat/x86-dregs.c (debug_hw_points): Don't declare. Replace all uses with show_debug_regs. * mips-linux-nat.c (maint_show_dr): Don't define. Replace all uses with show_debug_regs. gdb/gdbserver/ChangeLog: * server.h (debug_hw_points): Don't declare. * server.c (debug_hw_points): Don't define. Replace all uses with show_debug_regs. * linux-aarch64-low.c (debug_hw_points): Don't define. Replace all uses with show_debug_regs.
2014-08-29Use exceptions and cleanups in gdbserverGary Benson1-86/+106
This commit replaces the hacky "exception" system in gdbserver with the exceptions and cleanups subsystem from GDB. Only the catch/cleanup code in what was "main" has been updated to use the new system. Other parts of gdbserver can now be converted to use TRY_CATCH and cleanups on an as-needed basis. A side-effect of this commit is that some error messages will change slightly, and in cases with multiple errors the error messages will be printed in a different order. gdb/gdbserver/ChangeLog: * server.h (setjmp.h): Do not include. (toplevel): Do not declare. (common-exceptions.h): Include. (cleanups.h): Likewise. * server.c (toplevel): Do not define. (exit_code): New static global. (detach_or_kill_for_exit_cleanup): New function. (main): New function. Original main renamed to... (captured_main): New function. * utils.c (verror) [!IN_PROCESS_AGENT]: Use throw_verror.
2014-06-12link gdbserver against libibertyTom Tromey1-6/+0
This builds a libiberty just for gdbserver and arranges for gdbserver to use it. I've tripped across the lack of libiberty in gdbserver at least once, and I have seen other threads where it would have been useful. 2014-06-12 Tom Tromey <tromey@redhat.com> * debug.c (debug_printf): Remove HAVE_GETTIMEOFDAY checks. * server.c (monitor_show_help): Remove HAVE_GETTIMEOFDAY check. (parse_debug_format_options): Likewise. (gdbserver_usage): Likewise. * Makefile.in (LIBIBERTY_BUILDDIR, LIBIBERTY): New variables. (SUBDIRS, REQUIRED_SUBDIRS): Add libiberty. (gdbserver$(EXEEXT), gdbreplay$(EXEEXT)): Depend on and link against libiberty. ($(LIBGNU)): Depend on libiberty. (all-lib): Recurse into all subdirs. (install-only): Invoke "install" target in subdirs. (vasprintf.o, vsnprintf.o, safe-ctype.o, lbasename.o): Remove targets. * configure: Rebuild. * configure.ac: Add ACX_CONFIGURE_DIR for libiberty. Don't check for vasprintf, vsnprintf, or gettimeofday. * configure.srv: Don't add safe-ctype.o or lbasename.o to srv_tgtobj.
2014-06-02gdbserver: on GDB breakpoint reinsertion, also delete the breakpoint's commands.Pedro Alves1-1/+1
If GDB decides to change the breakpoint's conditions or commands, it'll reinsert the same breakpoint again, with the new options attached, without deleting the previous breakpoint. E.g., (gdb) set breakpoint always-inserted on (gdb) b main if 0 Breakpoint 1 at 0x400594: file foo.c, line 21. Sending packet: $Z0,400594,1;X3,220027#68...Packet received: OK (gdb) b main Breakpoint 15 at 0x400594: file foo.c, line 21. Sending packet: $Z0,400594,1#49...Packet received: OK GDBserver understands this and deletes the breakpoint's previous conditions. But, it forgets to delete the previous commands. gdb/gdbserver/ 2014-06-02 Pedro Alves <palves@redhat.com> * ax.c (gdb_free_agent_expr): New function. * ax.h (gdb_free_agent_expr): New declaration. * mem-break.c (delete_gdb_breakpoint_1): Also clear the commands list. (clear_breakpoint_conditions, clear_breakpoint_commands): Make static. (clear_breakpoint_conditions_and_commands): New function. * mem-break.h (clear_breakpoint_conditions): Delete declaration. (clear_breakpoint_conditions_and_commands): New declaration.
2014-05-20[GDBserver] Make Zx/zx packet handling idempotent.Pedro Alves1-35/+22
This patch fixes hardware breakpoint regressions exposed by my fix for "PR breakpoints/7143 - Watchpoint does not trigger when first set", at https://sourceware.org/ml/gdb-patches/2014-03/msg00167.html The testsuite caught them on Linux/x86_64, at least. gdb.sum: gdb.sum: FAIL: gdb.base/hbreak2.exp: next over recursive call FAIL: gdb.base/hbreak2.exp: backtrace from factorial(5.1) FAIL: gdb.base/hbreak2.exp: continue until exit at recursive next test gdb.log: (gdb) next Program received signal SIGTRAP, Trace/breakpoint trap. factorial (value=4) at ../../../src/gdb/testsuite/gdb.base/break.c:113 113 if (value > 1) { /* set breakpoint 7 here */ (gdb) FAIL: gdb.base/hbreak2.exp: next over recursive call Actually, that patch just exposed a latent issue to "breakpoints always-inserted off" mode, not really caused it. After that patch, GDB no longer removes breakpoints at each internal event, thus making some scenarios behave like breakpoint always-inserted on. The bug is easy to trigger with always-inserted on. The issue is that since the target-side breakpoint conditions support, if the stub/server supports evaluating breakpoint conditions on the target side, then GDB is sending duplicate Zx packets to the target without removing them before, and GDBserver is not really expecting that for Z packets other than Z0/z0. E.g., with "set breakpoint always-inserted on" and "set debug remote 1": (gdb) b main Sending packet: $m410943,1#ff...Packet received: 48 Breakpoint 4 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028. Sending packet: $Z0,410943,1#48...Packet received: OK ^^^^^^^^^^^^ (gdb) b main Note: breakpoint 4 also set at pc 0x410943. Sending packet: $m410943,1#ff...Packet received: 48 Breakpoint 5 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028. Sending packet: $Z0,410943,1#48...Packet received: OK ^^^^^^^^^^^^ (gdb) b main Note: breakpoints 4 and 5 also set at pc 0x410943. Sending packet: $m410943,1#ff...Packet received: 48 Breakpoint 6 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028. Sending packet: $Z0,410943,1#48...Packet received: OK ^^^^^^^^^^^^ (gdb) del Delete all breakpoints? (y or n) y Sending packet: $Z0,410943,1#48...Packet received: OK Sending packet: $Z0,410943,1#48...Packet received: OK Sending packet: $z0,410943,1#68...Packet received: OK And for Z1, similarly: (gdb) hbreak main Sending packet: $m410943,1#ff...Packet received: 48 Hardware assisted breakpoint 4 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028. Sending packet: $Z1,410943,1#49...Packet received: OK ^^^^^^^^^^^^ Packet Z1 (hardware-breakpoint) is supported (gdb) hbreak main Note: breakpoint 4 also set at pc 0x410943. Sending packet: $m410943,1#ff...Packet received: 48 Hardware assisted breakpoint 5 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028. Sending packet: $Z1,410943,1#49...Packet received: OK ^^^^^^^^^^^^ (gdb) hbreak main Note: breakpoints 4 and 5 also set at pc 0x410943. Sending packet: $m410943,1#ff...Packet received: 48 Hardware assisted breakpoint 6 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028. Sending packet: $Z1,410943,1#49...Packet received: OK ^^^^^^^^^^^^ (gdb) del Delete all breakpoints? (y or n) y Sending packet: $Z1,410943,1#49...Packet received: OK ^^^^^^^^^^^^ Sending packet: $Z1,410943,1#49...Packet received: OK ^^^^^^^^^^^^ Sending packet: $z1,410943,1#69...Packet received: OK ^^^^^^^^^^^^ So GDB sent a bunch of Z1 packets, and then when finally removing the breakpoint, only one z1 packet was sent. On the GDBserver side (with monitor set debug-hw-points 1), in the Z1 case, we see: $ ./gdbserver :9999 ./gdbserver Process ./gdbserver created; pid = 8629 Listening on port 9999 Remote debugging from host 127.0.0.1 insert_watchpoint (addr=410943, len=1, type=instruction-execute): CONTROL (DR7): 00000101 STATUS (DR6): 00000000 DR0: addr=0x410943, ref.count=1 DR1: addr=0x0, ref.count=0 DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0 insert_watchpoint (addr=410943, len=1, type=instruction-execute): CONTROL (DR7): 00000101 STATUS (DR6): 00000000 DR0: addr=0x410943, ref.count=2 DR1: addr=0x0, ref.count=0 DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0 insert_watchpoint (addr=410943, len=1, type=instruction-execute): CONTROL (DR7): 00000101 STATUS (DR6): 00000000 DR0: addr=0x410943, ref.count=3 DR1: addr=0x0, ref.count=0 DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0 insert_watchpoint (addr=410943, len=1, type=instruction-execute): CONTROL (DR7): 00000101 STATUS (DR6): 00000000 DR0: addr=0x410943, ref.count=4 DR1: addr=0x0, ref.count=0 DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0 insert_watchpoint (addr=410943, len=1, type=instruction-execute): CONTROL (DR7): 00000101 STATUS (DR6): 00000000 DR0: addr=0x410943, ref.count=5 DR1: addr=0x0, ref.count=0 DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0 remove_watchpoint (addr=410943, len=1, type=instruction-execute): CONTROL (DR7): 00000101 STATUS (DR6): 00000000 DR0: addr=0x410943, ref.count=4 DR1: addr=0x0, ref.count=0 DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0 That's one insert_watchpoint call for each Z1 packet, and then one remove_watchpoint call for the z1 packet. Notice how ref.count increased for each insert_watchpoint call, and then in the end, after GDB told GDBserver to forget about the hardware breakpoint, GDBserver ends with the the first debug register still with ref.count=4! IOW, the hardware breakpoint is left armed on the target, while on the GDB end it's gone. If the program happens to execute 0x410943 afterwards, then the CPU traps, GDBserver reports the trap to GDB, and GDB not having a breakpoint set at that address anymore, reports to the user a spurious SIGTRAP. This is exactly what is happening in the hbreak2.exp test, though in that case, it's a shared library event that triggers a breakpoint_re_set, when breakpoints are still inserted (because nowadays GDB doesn't remove breakpoints while handling internal events), and that recreates breakpoint locations, which likewise forces breakpoint reinsertion and Zx packet resends... That is a lot of bogus Zx duplication that should possibly be addressed on the GDB side. GDB resends Zx packets because the way to change the target-side condition, is to resend the breakpoint to the server with the new condition. (That's an option in the packet: e.g., "Z1,410943,1;X3,220027" for "hbreak main if 0". The packets in the examples above are shorter because the breakpoints don't have conditions attached). GDB doesn't remove the breakpoint first before reinserting it because that'd be bad for non-stop, as it'd open a window where the inferior could miss the breakpoint. The conditions actually haven't changed between the resends, but GDB isn't smart enough to realize that. (TBC, if the target doesn't support target-side conditions, then GDB doesn't trigger these resends (init_bp_location calls mark_breakpoint_location_modified, and that does nothing if condition evaluation is on the host side. The resends are caused by the 'loc->condition_changed = condition_modified.' line.) But, even if GDB was made smarter, GDBserver should really still handle the resends anyway. So target-side conditions also aren't really to blame. The documentation of the Z/z packets says: "To avoid potential problems with duplicate packets, the operations should be implemented in an idempotent way." As such, we may want to fix GDB, but we should definitely fix GDBserver. The fix is a prerequisite for target-side conditions on hardware breakpoints anyway (and while at it, on watchpoints too). GDBserver indeed already treats duplicate Z0 packets in an idempotent way. mem-break.c has the concept of high-level and low-level breakpoints, somewhat similar to GDB's split of breakpoints vs breakpoint locations, and keeps track of multiple breakpoints referencing the same address/location, for the case of an internal GDBserver breakpoint or a tracepoint being set at the same address as a GDB breakpoint. But, it only allows GDB to ever contribute one reference to a software breakpoint location. IOW, if gdbserver sees a Z0 packet for the same address where it already had a GDB breakpoint set, then GDBserver won't create another high-level GDB breakpoint. However, mem-break.c only tracks GDB Z0 breakpoints. The same logic should apply to all kinds of Zx packets. Currently, gdbserver passes down each duplicate Zx (other than Z0) request directly to the target->insert_point routine. The x86 watchpoint support itself refcounts watchpoint / hw breakpoint requests, to handle overlapping watchpoints, and save debug registers. But that code doesn't (and really shouldn't) handle the duplicate requests, assuming that for each insert there will be a corresponding remove. So the fix is to generalize mem-break.c to track all kinds of Zx breakpoints, and filter out duplicates. As mentioned, this ends up adding support for target-side conditions on hardware breakpoints and watchpoints too (though GDB itself doesn't support the latter yet). Probably the least obvious change in the patch is that it kind of turns the breakpoint insert/remove APIs inside out. Before, the target methods were only called for GDB breakpoints. The internal breakpoint set/delete methods inserted memory breakpoints directly bypassing the insert/remove target methods. That's not good when the target should use a debug API to set software breakpoints, instead of relying on GDBserver patching memory with breakpoint instructions, as is the case of NTO. Now removal/insertion of all kinds of breakpoints/watchpoints, either internal, or from GDB, always go through the target methods. The insert_point/remove_point methods no longer get passed a Z packet type, but an internal/raw breakpoint type. They're also passed a pointer to the raw breakpoint itself (note that's still opaque outside mem-break.c), so that insert_memory_breakpoint / remove_memory_breakpoint have access to the breakpoint's shadow buffer. I first tried passing down a new structure based on GDB's "struct bp_target_info" (actually with that name exactly), but then decided against it as unnecessary complication. As software/memory breakpoints work by poking at memory, when setting a GDB Z0 breakpoint (but not internal breakpoints, as those can assume the conditions are already right), we need to tell the target to prepare to access memory (which on Linux means stop threads). If that operation fails, we need to return error to GDB. Seeing an error, if this is the first breakpoint of that type that GDB tries to insert, GDB would then assume the breakpoint type is supported, but it may actually not be. So we need to check whether the type is supported at all before preparing to access memory. And to solve that, the patch adds a new target->supports_z_point_type method that is called before actually trying to insert the breakpoint. Other than that, hopefully the change is more or less obvious. New test added that exercises the hbreak2.exp regression in a more direct way, without relying on a breakpoint re-set happening before main is reached. Tested by building GDBserver for: aarch64-linux-gnu arm-linux-gnueabihf i686-pc-linux-gnu i686-w64-mingw32 m68k-linux-gnu mips-linux-gnu mips-uclinux nios2-linux-gnu powerpc-linux-gnu sh-linux-gnu tilegx-unknown-linux-gnu x86_64-redhat-linux x86_64-w64-mingw32 And also regression tested on x86_64 Fedora 20. gdb/gdbserver/ 2014-05-20 Pedro Alves <palves@redhat.com> * linux-aarch64-low.c (aarch64_insert_point) (aarch64_remove_point): No longer check whether the type is supported here. Adjust to new interface. (the_low_target): Install aarch64_supports_z_point_type as supports_z_point_type method. * linux-arm-low.c (raw_bkpt_type_to_arm_hwbp_type): New function. (arm_linux_hw_point_initialize): Take an enum raw_bkpt_type instead of a Z packet char. Adjust. (arm_supports_z_point_type): New function. (arm_insert_point, arm_remove_point): Adjust to new interface. (the_low_target): Install arm_supports_z_point_type. * linux-crisv32-low.c (cris_supports_z_point_type): New function. (cris_insert_point, cris_remove_point): Adjust to new interface. Don't check whether the type is supported here. (the_low_target): Install cris_supports_z_point_type. * linux-low.c (linux_supports_z_point_type): New function. (linux_insert_point, linux_remove_point): Adjust to new interface. * linux-low.h (struct linux_target_ops) <insert_point, remove_point>: Take an enum raw_bkpt_type instead of a char. Add raw_breakpoint pointer parameter. <supports_z_point_type>: New method. * linux-mips-low.c (mips_supports_z_point_type): New function. (mips_insert_point, mips_remove_point): Adjust to new interface. Use mips_supports_z_point_type. (the_low_target): Install mips_supports_z_point_type. * linux-ppc-low.c (the_low_target): Install NULL as supports_z_point_type method. * linux-s390-low.c (the_low_target): Install NULL as supports_z_point_type method. * linux-sparc-low.c (the_low_target): Install NULL as supports_z_point_type method. * linux-x86-low.c (x86_supports_z_point_type): New function. (x86_insert_point): Adjust to new insert_point interface. Use insert_memory_breakpoint. Adjust to new i386_low_insert_watchpoint interface. (x86_remove_point): Adjust to remove_point interface. Use remove_memory_breakpoint. Adjust to new i386_low_remove_watchpoint interface. (the_low_target): Install x86_supports_z_point_type. * lynx-low.c (lynx_target_ops): Install NULL as supports_z_point_type callback. * nto-low.c (nto_supports_z_point_type): New. (nto_insert_point, nto_remove_point): Adjust to new interface. (nto_target_ops): Install nto_supports_z_point_type. * mem-break.c: Adjust intro comment. (struct raw_breakpoint) <raw_type, size>: New fields. <inserted>: Update comment. <shlib_disabled>: Delete field. (enum bkpt_type) <gdb_breakpoint>: Delete value. <gdb_breakpoint_Z0, gdb_breakpoint_Z1, gdb_breakpoint_Z2, gdb_breakpoint_Z3, gdb_breakpoint_Z4>: New values. (raw_bkpt_type_to_target_hw_bp_type): New function. (find_enabled_raw_code_breakpoint_at): New function. (find_raw_breakpoint_at): New type and size parameters. Use them. (insert_memory_breakpoint): New function, based off set_raw_breakpoint_at. (remove_memory_breakpoint): New function. (set_raw_breakpoint_at): Reimplement. (set_breakpoint): New, based on set_breakpoint_at. (set_breakpoint_at): Reimplement. (delete_raw_breakpoint): Go through the_target->remove_point instead of assuming memory breakpoints. (find_gdb_breakpoint_at): Delete. (Z_packet_to_bkpt_type, Z_packet_to_raw_bkpt_type): New functions. (find_gdb_breakpoint): New function. (set_gdb_breakpoint_at): Delete. (z_type_supported): New function. (set_gdb_breakpoint_1): New function, loosely based off set_gdb_breakpoint_at. (check_gdb_bp_preconditions, set_gdb_breakpoint): New functions. (delete_gdb_breakpoint_at): Delete. (delete_gdb_breakpoint_1): New function, loosely based off delete_gdb_breakpoint_at. (delete_gdb_breakpoint): New function. (clear_gdb_breakpoint_conditions): Rename to ... (clear_breakpoint_conditions): ... this. Don't handle a NULL breakpoint. (add_condition_to_breakpoint): Make static. (add_breakpoint_condition): Take a struct breakpoint pointer instead of an address. Adjust. (gdb_condition_true_at_breakpoint): Rename to ... (gdb_condition_true_at_breakpoint_z_type): ... this, and add z_type parameter. (gdb_condition_true_at_breakpoint): Reimplement. (add_breakpoint_commands): Take a struct breakpoint pointer instead of an address. Adjust. (gdb_no_commands_at_breakpoint): Rename to ... (gdb_no_commands_at_breakpoint_z_type): ... this. Add z_type parameter. Return true if no breakpoint was found. Change debug output. (gdb_no_commands_at_breakpoint): Reimplement. (run_breakpoint_commands): Rename to ... (run_breakpoint_commands_z_type): ... this. Add z_type parameter, and change return type to boolean. (run_breakpoint_commands): New function. (gdb_breakpoint_here): Also check for Z1 breakpoints. (uninsert_raw_breakpoint): Don't try to reinsert a disabled breakpoint. Go through the_target->remove_point instead of assuming memory breakpoint. (uninsert_breakpoints_at, uninsert_all_breakpoints): Uninsert software and hardware breakpoints. (reinsert_raw_breakpoint): Go through the_target->insert_point instead of assuming memory breakpoint. (reinsert_breakpoints_at, reinsert_all_breakpoints): Reinsert software and hardware breakpoints. (check_breakpoints, breakpoint_here, breakpoint_inserted_here): Check both software and hardware breakpoints. (validate_inserted_breakpoint): Assert the breakpoint is a software breakpoint. Set the inserted flag to -1 instead of setting shlib_disabled. (delete_disabled_breakpoints): Adjust. (validate_breakpoints): Only validate software breakpoints. Adjust to inserted flag change. (check_mem_read, check_mem_write): Skip breakpoint types other than software breakpoints. Adjust to inserted flag change. * mem-break.h (enum raw_bkpt_type): New enum. (raw_breakpoint, struct process_info): Forward declare. (Z_packet_to_target_hw_bp_type): Delete declaration. (raw_bkpt_type_to_target_hw_bp_type, Z_packet_to_raw_bkpt_type) (set_gdb_breakpoint, delete_gdb_breakpoint) (clear_breakpoint_conditions): New declarations. (set_gdb_breakpoint_at, clear_gdb_breakpoint_conditions): Delete. (breakpoint_inserted_here): Update comment. (add_breakpoint_condition, add_breakpoint_commands): Replace address parameter with a breakpoint pointer parameter. (gdb_breakpoint_here): Update comment. (delete_gdb_breakpoint_at): Delete. (insert_memory_breakpoint, remove_memory_breakpoint): Declare. * server.c (process_point_options): Take a struct breakpoint pointer instead of an address. Adjust. (process_serial_event) <Z/z packets>: Use set_gdb_breakpoint and delete_gdb_breakpoint. * spu-low.c (spu_target_ops): Install NULL as supports_z_point_type method. * target.h: Include mem-break.h. (struct target_ops) <prepare_to_access_memory>: Update comment. <supports_z_point_type>: New field. <insert_point, remove_point>: Take an enum raw_bkpt_type argument instead of a char. Also take a raw breakpoint pointer. * win32-arm-low.c (the_low_target): Install NULL as supports_z_point_type. * win32-i386-low.c (i386_supports_z_point_type): New function. (i386_insert_point, i386_remove_point): Adjust to new interface. (the_low_target): Install i386_supports_z_point_type. * win32-low.c (win32_supports_z_point_type): New function. (win32_insert_point, win32_remove_point): Adjust to new interface. (win32_target_ops): Install win32_supports_z_point_type. * win32-low.h (struct win32_target_ops): <supports_z_point_type>: New method. <insert_point, remove_point>: Take an enum raw_bkpt_type argument instead of a char. Also take a raw breakpoint pointer. gdb/testsuite/ 2014-05-20 Pedro Alves <palves@redhat.com> * gdb.base/break-idempotent.c: New file. * gdb.base/break-idempotent.exp: New file.
2014-04-10Conditional Z1 breakpoint hangs GDBserver.Pedro Alves1-4/+14
While trying to fix hbreak2.exp against GDBserver I noticed this... (gdb) hbreak main if 1 Sending packet: $m400580,40#2e...Packet received: e8d2ffffff5dc3554889e54883ec10c745fc00000000eb0eb800000000e8c1ffffff8345fc01817dfce70300007ee9b800000000c9c3662e0f1f840000000000 Sending packet: $m40058f,1#31...Packet received: c7 Hardware assisted breakpoint 1 at 0x40058f: file ../../../src/gdb/testsuite/gdb.base/break-idempotent.c, line 46. Sending packet: $Z1,40058f,1;X3,220127#9b... *hangs forever* The issue is that nothing advances the packet pointer if add_breakpoint_condition either fails to parse the agent expression, or fails to find the breakpoint, resulting in an infinite loop in process_point_options. The latter case should really be fixed by GDBserver tracking GDB Z1 breakpoints in its breakpoint structures like Z0 breakpoints are, but the latter case still needs handling. add_breakpoint_commands has the same issue, though at present I don't know any way to trigger it other than sending a manually cooked packet. Unbelievably, it doesn't look like we have any test that tries setting a conditional hardware breakpoint. Looking at cond-eval-mode.exp, it looks like the file was meant to actually test something, but it's mostly empty today. This patch adds tests that tries all sorts of conditional breakpoints and watchpoints. The test hangs/fails without the GDBserver fix. Tested on x86_64 Fedora 17. gdb/gdbserver/ 2014-04-10 Pedro Alves <palves@redhat.com> * mem-break.c (add_breakpoint_condition, add_breakpoint_commands): Check if the condition or command is NULL before checking if the breakpoint is known. On success, return true. * mem-break.h (add_breakpoint_condition): Document return. (add_breakpoint_commands): Add describing comment. * server.c (skip_to_semicolon): New function. (process_point_options): Use it. gdb/testsuite/ 2014-04-10 Pedro Alves <palves@redhat.com> * gdb.base/cond-eval-mode.c: New file. * gdb.base/cond-eval-mode.exp: Use standard_testfile. Adjust prepare_for_testing to build the new file. Check result of runto_main. (test_break, test_watch): New procedures. (top level): Use them.
2014-02-27Teach GDBserver's Linux backend about no unwaited-for children ↵Pedro Alves1-2/+16
(TARGET_WAITKIND_NO_RESUMED). GDBserver currently hangs forever in waitpid if the leader thread exits before other threads, or if all resumed threads exit - e.g., next over a thread exit with sched-locking on. This is exposed by leader-exit.exp. leader-exit.exp is part of a series of tests for a set of related problems. See <http://www.sourceware.org/ml/gdb-patches/2011-10/msg00704.html>: " To recap, on the Linux kernel, ptrace/waitpid don't allow reaping the leader thread until all other threads in the group are reaped. When the leader exits, it goes zombie, but waitpid will not return an exit status until the other threads are gone. This is presently exercised by the gdb.threads/leader-exit.exp test. The fix for that test, in linux-nat.c:wait_lwp, handles the case where we see the leader gone when we're stopping all threads to report an event to some other thread to the core. (...) The latter bit about not blocking if there no resumed threads in the process also applies to some other thread exiting, not just the main thread. E.g., this test starts a thread, and runs to a breakpoint in that thread: ... (gdb) c Continuing. [New Thread 0x7ffff75a4700 (LWP 23397)] [Switching to Thread 0x7ffff75a4700 (LWP 23397)] Breakpoint 2, thread_a (arg=0x0) at ../../../src/gdb/testsuite/gdb.threads/no-unwaited-for-left.c:28 28 return 0; /* break-here */ (gdb) info threads * 2 Thread 0x7ffff75a4700 (LWP 23397) thread_a (arg=0x0) at ../../../src/gdb/testsuite/gdb.threads/no-unwaited-for-left.c:28 1 Thread 0x7ffff7fcb720 (LWP 23391) 0x00007ffff7bc606d in pthread_join (threadid=140737343276800, thread_return=0x0) at pthread_join.c:89 The thread will exit as soon as we resume it. But if we only resume that thread, leaving the rest of the threads stopped: (gdb) set scheduler-locking on (gdb) c Continuing. ^C^C^C^C^C^C^C^C " This patch fixes the issues by implementing TARGET_WAITKIND_NO_RESUMED on GDBserver, similarly to what the patch above did for native Linux GDB. gdb.threads/leader-exit.exp now passes. gdb.threads/no-unwaited-for-left.exp now at least errors out instead of hanging: continue Continuing. warning: Remote failure reply: E.No unwaited-for children left. [Thread 15454] #1 stopped. 0x00000034cf408e60 in pthread_join (threadid=140737353922368, thread_return=0x0) at pthread_join.c:93 93 lll_wait_tid (pd->tid); (gdb) FAIL: gdb.threads/no-unwaited-for-left.exp: continue stops when the main thread exits The gdb.threads/non-ldr-exc-*.exp tests are skipped because GDBserver unfortunately doesn't support fork/exec yet, but I'm confident this fixes the related issues. I'm leaving modeling TARGET_WAITKIND_NO_RESUMED in the RSP for a separate pass. (BTW, in case of error in response to a vCont, it would be better for GDB to query the target for the current thread, or re-select one, instead of assuming current inferior_ptid is still the selected thread.) This implementation is a little different from GDB's, because I'm avoiding bringing in more of this broken use of waitpid(PID) into GDBserver. Specifically, this avoids waitpid(PID) when stopping all threads. There's really no need for wait_for_sigstop to wait for each LWP in turn. Instead, with some refactoring, we make it reuse linux_wait_for_event. gdb/gdbserver/ 2014-02-27 Pedro Alves <palves@redhat.com> PR 12702 * inferiors.h (A_I_NEXT, ALL_INFERIORS_TYPE, ALL_PROCESSES): New macros. * linux-low.c (delete_lwp, handle_extended_wait): Add debug output. (last_thread_of_process_p): Take a PID argument instead of a thread pointer. (linux_wait_for_lwp): Delete. (num_lwps, check_zombie_leaders, not_stopped_callback): New functions. (linux_low_filter_event): New function, party factored out from linux_wait_for_event. (linux_wait_for_event): Rename to ... (linux_wait_for_event_filtered): ... this. Add new filter ptid argument. Partly rewrite. Always use waitpid(-1, WNOHANG) and sigsuspend. Check for zombie leaders. (linux_wait_for_event): Reimplement as wrapper around linux_wait_for_event_filtered. (linux_wait_1): Handle TARGET_WAITKIND_NO_RESUMED. Assume that if a normal or signal exit is seen, it's the whole process exiting. (wait_for_sigstop): No longer a for_each_inferior callback. Rewrite on top of linux_wait_for_event_filtered. (stop_all_lwps): Call wait_for_sigstop directly. * server.c (resume, handle_target_event): Handle TARGET_WAITKIND_NO_RESUMED.
2014-02-19Replace code accessing list implementation details with API calls.Doug Evans1-72/+119
* dll.c (clear_dlls): Replace accessing list implemention details with API function. * gdbthread.h (get_first_thread): Declare. * inferiors.c (for_each_inferior_with_data): New function. (get_first_thread): New function. (find_thread_ptid): Simplify. (get_first_inferior): New function. (clear_list): Delete. (one_inferior_p): New function. (clear_inferior_list): New function. (clear_inferiors): Update. * inferiors.h (for_each_inferior_with_data): Declare. (clear_inferior_list): Declare. (one_inferior_p): Declare. (get_first_inferior): Declare. * linux-low.c (linux_wait_for_event): Replace accessing list implemention details with API function. * server.c (target_running): Ditto. (accumulate_file_name_length): New function. (emit_dll_description): New function. (handle_qxfer_libraries): Replace accessing list implemention details with API function. (handle_qxfer_threads_worker): New function. (handle_qxfer_threads_proper): Replace accessing list implemention details with API function. (handle_query): Ditto. (visit_actioned_threads_callback_ftype): New typedef. (visit_actioned_threads_data): New struct. (visit_actioned_threads): Rewrite to be find_inferior callback. (resume): Call find_inferior. (handle_status): Replace accessing list implemention details with API function. (process_serial_event): Replace accessing list implemention details with API function. * target.c (set_desired_inferior): Replace accessing list implemention details with API function. * tracepoint.c (same_process_p): New function. (gdb_agent_about_to_close): Replace accessing list implemention details with API function. * win32-low.c (child_delete_thread): Replace accessing list implemention details with API function. (match_dll_by_basename): New function. (dll_is_loaded_by_basename): New function. (win32_ensure_ntdll_loaded): Replace accessing list implemention details call to dll_is_loaded_by_basename.
2014-02-19Rename inferior_list_entry uses from "head" to "entry" for consistency.Doug Evans1-5/+5
* dll.h (struct dll_info): Add comment. * gdbthread.h (struct thread_info): Add comment. (current_ptid): Simplify. * inferiors.c (add_process): Update. (remove_process): Update. * inferiors.h (struct process_info): Rename member "head" to "entry". * linux-low.c (delete_lwp): Update. (add_lwp): Update. (last_thread_of_process_p): Update. (kill_one_lwp_callback, linux_kill): Update. (status_pending_p_callback): Update. (wait_for_sigstop): Update. Simplify read of ptid. (start_step_over): Update. * linux-low.h (ptid_of, pid_of, lwpid_of): Update. (get_lwp_thread): Update. (struct lwp_info): Rename member "head" to "entry". * regcache.h (inferior_list_entry): Delete. * server.c (kill_inferior_callback): Update. (detach_or_kill_inferior_callback): Update. (print_started_pid): Update. (print_attached_pid): Update. (process_serial_event): Simplify read of ptid. * thread-db.c (thread_db_create_event): Update. (thread_db_get_tls_address): Update. * win32-low.c (current_inferior_ptid): Simplify.
2014-02-12replace convert_ascii_to_int with hex2binTom Tromey1-2/+2
convert_ascii_to_int is identical to hex2bin. This removes the former. 2014-02-12 Tom Tromey <tromey@redhat.com> * common/rsp-low.c (convert_ascii_to_int): Remove. * common/rsp-low.h (convert_ascii_to_int): Don't declare. 2014-02-12 Tom Tromey <tromey@redhat.com> * ax.c (gdb_parse_agent_expr): Use hex2bin, not convert_ascii_to_int. * regcache.c (registers_to_string): Likewise. * remote-utils.c (decode_M_packet): Likewise. * server.c (process_serial_event): Likewise.
2014-02-12replace unhexify with hex2binTom Tromey1-2/+3
unhexify and hex2bin are identical, so this removes unhexify. The particular choice of which to keep was made on the basis of parallelism with the earlier patch that removed hexify. 2014-02-12 Tom Tromey <tromey@redhat.com> * common/rsp-low.h (unhexify): Don't declare. * common/rsp-low.c (unhexify): Remove. 2014-02-12 Tom Tromey <tromey@redhat.com> * server.c (handle_query, handle_v_run): Use hex2bin, not unhexify. * tracepoint.c (cmd_qtdpsrc, cmd_qtdv, cmd_qtnotes): Likewise.
2014-02-12replace convert_int_to_ascii with bin2hexTom Tromey1-1/+1
convert_int_to_ascii is identical to bin2hex. This removes the former. In this case I made the choice of which to keep on the basis that I consider the name bin2hex to be superior to convert_int_to_ascii. 2014-02-12 Tom Tromey <tromey@redhat.com> * common/rsp-low.h (convert_int_to_ascii): Don't declare. * common/rsp-low.c (convert_int_to_ascii): Remove. 2014-02-12 Tom Tromey <tromey@redhat.com> * ax.c (gdb_unparse_agent_expr): Use bin2hex, not convert_int_to_ascii. * regcache.c (registers_to_string, collect_register_as_string): Likewise. * remote-utils.c (look_up_one_symbol, relocate_instruction): Likewise. * server.c (process_serial_event): Likewise. * tracepoint.c (cmd_qtstatus, response_source, response_tsv) (cmd_qtbuffer, cstr_to_hexstr): Likewise.
2014-02-12move some rsp bits into rsp-low.hTom Tromey1-0/+1
This moves various low-level remote serial protocol bits into common/rsp-low.[ch]. This is as close to a pure move as possible. There are some redundancies remaining but those will be dealt with in a subsequent patch. Note that the two variants of remote_escape_output disagreed on the treatment of "*". On the theory that quoting cannot hurt but the absence possibly can, I chose the gdbserver variant to be the canonical one. 2014-02-12 Tom Tromey <tromey@redhat.com> * tracepoint.c: Include rsp-low.h. * remote.h (hex2bin, bin2hex, unpack_varlen_hex): Don't declare. * remote.c: Include rsp-low.h. (hexchars, ishex, unpack_varlen_hex, pack_nibble, pack_hex_byte) (fromhex, hex2bin, tohex, bin2hex, remote_escape_output) (remote_unescape_input): Move to common/rsp-low.c. * common/rsp-low.h: New file. * common/rsp-low.c: New file. * Makefile.in (SFILES): Add common/rsp-low.c. (HFILES_NO_SRCDIR): Add common/rsp-low.h. (COMMON_OBS): Add rsp-low.o. (rsp-low.o): New target. 2014-02-12 Tom Tromey <tromey@redhat.com> * tracepoint.c: Include rsp-low.h. * server.c: Include rsp-low.h. * remote-utils.h (convert_ascii_to_int, convert_int_to_ascii) (unhexify, hexify, remote_escape_output, unpack_varlen_hex): Don't declare. * remote-utils.c: Include rsp-low.h. (fromhex, hexchars, ishex, unhexify, tohex, hexify) (remote_escape_output, remote_unescape_input, unpack_varlen_hex) (convert_int_to_ascii, convert_ascii_to_int): Move to common/rsp-low.c. * regcache.c: Include rsp-low.h. * ax.c: Include rsp-low.h. * Makefile.in (SFILES): Add common/rsp-low.c. (OBS): Add rsp-low.o. (rsp-low.o): New target.
2014-01-22 New gdbserver option --debug-format=timestamp.Doug Evans1-22/+137
* NEWS: Mention it. gdbserver/ * configure.ac (AC_CHECK_FUNCS): Add test for gettimeofday. * configure: Regenerate. * config.in: Regenerate. * Makefile.in (SFILES): Add debug.c. (OBS): Add debug.o. * debug.c: New file. * debug.h: New file. * linux-aarch64-low.c (*): Update all debugging printfs to use debug_printf instead of fprintf. * linux-arm-low.c (*): Ditto. * linux-cris-low.c (*): Ditto. * linux-crisv32-low.c (*): Ditto. * linux-m32r-low.c (*): Ditto. * linux-sparc-low.c (*): Ditto. * linux-x86.c (*): Ditto. * linux-low.c (*): Ditto. (linux_wait_1): Add calls to debug_enter, debug_exit. (linux_wait): Remove redundant debugging printf. (stop_all_lwps): Add calls to debug_enter, debug_exit. (linux_resume, unstop_all_lwps): Ditto. * mem-break.c (*): Update all debugging printfs to use debug_printf instead of fprintf. * remote-utils.c (*): Ditto. * thread-db.c (*): Ditto. * server.c #include <ctype.h>, "gdb_vecs.h". (debug_threads): Moved to debug.c. (*): Update all debugging printfs to use debug_printf instead of fprintf. (start_inferior): Replace call to fflush with call to debug_flush. (monitor_show_help): Mention set debug-format. (parse_debug_format_options): New function. (handle_monitor_command): Handle "monitor set debug-format". (gdbserver_usage): Mention --debug-format. (main): Parse --debug-format. * server.h (debug_threads): Declaration moved to debug.h. #include "debug.h". * tracepoint.c (trace_debug_1) [!IN_PROCESS_AGENT]: Add version of trace_debug_1 that uses debug_printf. (tracepoint_look_up_symbols): Update all debugging printfs to use debug_printf instead of fprintf. doc/ * gdb.texinfo (Server): Mention --debug-format=all|none|timestamp. (gdbserver man): Ditto. testsuite/ * gdb.server/server-mon.exp: Add tests for "set debug-format".
2014-01-16btrace, gdbserver: read branch trace incrementallyMarkus Metzger1-2/+9
Read branch trace data incrementally and extend the current trace rather than discarding it and reading the entire trace buffer each time. If the branch trace buffer overflowed, we can't extend the current trace so we discard it and start anew by reading the entire branch trace buffer. 2014-01-16 Markus Metzger <markus.t.metzger@intel.com> * common/linux-btrace.c (perf_event_read_bts, linux_read_btrace): Support delta reads. (linux_disable_btrace): Change return type. * common/linux-btrace.h (linux_read_btrace): Change parameters and return type to allow error reporting. Update users. (linux_disable_btrace): Change return type. Update users. * common/btrace-common.h (btrace_read_type) <BTRACE_READ_DELTA>: New. (btrace_error): New. (btrace_block) <begin>: Comment on BEGIN == 0. * btrace.c (btrace_compute_ftrace): Start from the end of the current trace. (btrace_stitch_trace, btrace_clear_history): New. (btrace_fetch): Read delta trace, return if replaying. (btrace_clear): Move clear history code to btrace_clear_history. (parse_xml_btrace): Throw an error if parsing failed. * target.h (struct target_ops) <to_read_btrace>: Change parameters and return type to allow error reporting. (target_read_btrace): Change parameters and return type to allow error reporting. * target.c (target_read_btrace): Update. * remote.c (remote_read_btrace): Support delta reads. Pass errors on. * NEWS: Announce it. gdbserver/ * target.h (target_ops) <read_btrace>: Change parameters and return type to allow error reporting. * server.c (handle_qxfer_btrace): Support delta reads. Pass trace reading errors on. * linux-low.c (linux_low_read_btrace): Pass trace reading errors on. (linux_low_disable_btrace): New.
2014-01-16btrace: uppercase btrace_read_typeMarkus Metzger1-2/+2
2014-01-16 Markus Metzger <markus.t.metzger@intel.com> * common/btrace-common.h (btrace_read_type) <btrace_read_all>: Change to ... (btrace_read_type) <BTRACE_READ_ALL>: ... this. Update users. (btrace_read_type) <btrace_read_new>: Change to ... (btrace_read_type) <BTRACE_READ_NEW>: ... this. Update users.
2014-01-08GDBserver: Discard previous queued events when GDB disconnects.Pedro Alves1-3/+6
... not when a new GDB connection sends the status packet ('?'). Mainly just a cleanup/simplification, as GDB always sends '?' first. Tested on x86_64 Fedora 17. 2014-01-08 Pedro Alves <palves@redhat.com> * server.c (handle_status): Don't discard previous queued stop replies or thread's pending status here. (main) <disconnection>: Do it here instead.
2014-01-08[remote/gdbserver] Don't lose signals when reconnecting.Pedro Alves1-42/+170
Currently, when GDB connects in all-stop mode, GDBserver always responds to the status packet with a GDB_SIGNAL_TRAP, even if the program is actually stopped for some other signal. (gdb) tar rem ... ... (gdb) c Program received signal SIGUSR1, User defined signal 1. (gdb) disconnect (gdb) tar rem ... (gdb) c (Or a GDB crash instead of an explicit disconnect.) This results in the program losing that signal on that last continue, because gdb will tell the target to resume with no signal (to suppress the GDB_SIGNAL_TRAP, due to 'handle SISGTRAP nopass'), and that will actually suppress the real signal the program had stopped for (SIGUSR1). To fix that, I think we should make GDBserver report the real signal the thread had stopped for in response to the status packet: @item ? @cindex @samp{?} packet Indicate the reason the target halted. The reply is the same as for step and continue. But, that raises the question -- which thread are we reporting the status for? Due to how the RSP in all-stop works, we can only report one status. The status packet's response is a stop reply packet, so it includes the thread identifier, so it's not a problem packet-wise. However, GDBserver is currently always reporting the status for first thread in the thread list, even though that may well not be the thread that got the signal that caused the program to stop. So the next logical step would be to report the status for the last_ptid/last_status thread (the last event reported to gdb), if it's still around; and if not, fallback to some other thread. There's an issue on the GDB side with that, though... GDB currently always adds the thread reported in response to the status query as the first thread in its list. That means that if we start with e.g., (gdb) info threads 3 Thread 1003 ... * 2 Thread 1002 ... 1 Thread 1001 ... And reconnect: (gdb) disconnect (gdb) tar rem ... We end up with: (gdb) info threads 3 Thread 1003 ... 2 Thread 1001 ... * 1 Thread 1002 ... Not a real big issue, but it's reasonably fixable, by having GDB fetch/sync the thread list before fetching the status/'?', and then using the status to select the right thread as current on the GDB side. Holes in the thread numbers are squashed before/after reconnection (e.g., 2,3,5 becomes 1,2,3), but the order is preserved, which I think is both good, and good enough. However (yes, there's more...), the previous GDB that was connected might have had gdbserver running in non-stop mode, or could have left gdbserver doing disconnected tracing (which also forces non-stop), and if the new gdb/connection is in all-stop mode, we can end up with more than one thread with a signal to report back to gdb. As we can only report one thread/status (in the all-stop RSP variant; the non-stop variant doesn't have this issue), we get to do what we do at every other place we have this situation -- leave events we can't report right now as pending, so that the next resume picks them up. Note all this ammounts to a QoI change, within the existing framework. There's really no RSP change here. The only user visible change (other than that the signal is program is stopped at isn't lost / is passed to the program), is in "info program", that now can show the signal the program stopped for. Of course, the next resume will respect the pass/nopass setting for the signal in question. It'd be reasonable to have the initial connection tell the user the program was stopped with a signal, similar to when we load a core to debug, but I'm leaving that out for a future change. I think we'll need to either change how handle_inferior_event & co handle stop_soon, or maybe bypass them completely (like fork-child.c:startup_inferior) for that. Tested on x86_64 Fedora 17. gdb/gdbserver/ 2014-01-08 Pedro Alves <palves@redhat.com> * gdbthread.h (struct thread_info) <status_pending_p>: New field. * server.c (visit_actioned_threads, handle_pending_status): New function. (handle_v_cont): Factor out parts to ... (resume): ... this new function. If in all-stop, and a thread being resumed has a pending status, report it without actually resuming. (myresume): Adjust to use the new 'resume' function. (clear_pending_status_callback, set_pending_status_callback) (find_status_pending_thread_callback): New functions. (handle_status): Handle the case of multiple threads having interesting statuses to report. Report threads' real last signal instead of always reporting GDB_SIGNAL_TRAP. Look for a thread with an interesting thread to report the status for, instead of always reporting the status of the first thread. gdb/ 2014-01-08 Pedro Alves <palves@redhat.com> * remote.c (remote_add_thread): Add threads silently if starting up. (remote_notice_new_inferior): If in all-stop, and starting up, don't call notice_new_inferior. (get_current_thread): New function, factored out from ... (add_current_inferior_and_thread): ... this. Adjust. (remote_start_remote) <all-stop>: Fetch the thread list. If we found any thread, then select the remote's current thread as GDB's current thread too. gdb/testsuite/ 2014-01-08 Pedro Alves <palves@redhat.com> * gdb.threads/reconnect-signal.c: New file. * gdb.threads/reconnect-signal.exp: New file.
2014-01-01Update Copyright year range in all files maintained by GDB.Joel Brobecker1-1/+1
2014-01-01Update copyright year in gdb/gdbserver/gdbreplay version output.Joel Brobecker1-1/+1
gdb/ChangeLog: * top.c (print_gdb_version): Set copyright year to 2014. gdb/gdbserver/ChangeLog: * gdbserver.c (gdbserver_version): Set copyright year to 2014. * gdbreplay.c (gdbreplay_version): Likewise.
2013-10-02[GDBserver]: Silence exits if GDB is connected through stdio.Pedro Alves1-1/+4
If we make gdbserver gdb_continue_to_end actually expect a process exit with GDBserver, we get many testsuite failures with the remote stdio board: -PASS: gdb.arch/amd64-disp-step.exp: continue until exit at amd64-disp-step +FAIL: gdb.arch/amd64-disp-step.exp: continue until exit at amd64-disp-step (the program exited) -PASS: gdb.base/break.exp: continue until exit at recursive next test +FAIL: gdb.base/break.exp: continue until exit at recursive next test (the program exited) -PASS: gdb.base/chng-syms.exp: continue until exit at breakpoint first time through +FAIL: gdb.base/chng-syms.exp: continue until exit at breakpoint first time through (the program exited) ... etc. ... This is what the log shows for all of them: (gdb) continue Continuing. Child exited with status 0 GDBserver exiting [Inferior 1 (process 22721) exited normally] (gdb) FAIL: gdb.arch/amd64-disp-step.exp: continue until exit (the program exited) The problem is the whole "Child exited ... GDBserver exiting" output, that comes out of GDBserver, and that the testsuite is not expecting. I pondered somehow making the testsuite adjust to this. But, testsuite aside, I think GDBserver should not be outputting this at all when GDB is connected through stdio. GDBserver will be printing this in GDB's console, but the user can already tell from the regular output that the inferior is gone. Again, manually: (gdb) tar remote | ./gdbserver/gdbserver - program Remote debugging using | ./gdbserver/gdbserver - program Process program created; pid = 22486 stdin/stdout redirected Remote debugging using stdio done. Loaded symbols for /lib64/ld-linux-x86-64.so.2 0x000000323d001530 in _start () from /lib64/ld-linux-x86-64.so.2 (gdb) c Continuing. Child exited with status 1 ^^^^^^^^^^^^^^^^^^^^^^^^^^ GDBserver exiting ^^^^^^^^^^^^^^^^^ [Inferior 1 (process 22486) exited with code 01] (gdb) Suppressing those two lines makes the output be exactly like when debugging against a remote tcp gdbserver: (gdb) c Continuing. [Inferior 1 (process 22914) exited with code 01] (gdb) 2013-10-02 Pedro Alves <palves@redhat.com> * server.c (process_serial_event): Don't output "GDBserver exiting" if GDB is connected through stdio. * target.c (mywait): Likewise, be silent if GDB is connected through stdio.