From 8228463cbca8d629572dbad99286c4e05886350b Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Tue, 15 Sep 2015 17:32:45 +0100 Subject: [PATCH] PR remote/18965: vforkdone stop reply should indicate parent PID The vforkdone stop reply misses indicating the thread ID of the vfork parent which the event relates to: @cindex vfork events, remote reply @item vfork The packet indicates that @code{vfork} was called, and @var{r} is the thread ID of the new child process. Refer to @ref{thread-id syntax} for the format of the @var{thread-id} field. This packet is only applicable to targets that support vfork events. @cindex vforkdone events, remote reply @item vforkdone The packet indicates that a child process created by a vfork has either called @code{exec} or terminated, so that the address spaces of the parent and child process are no longer shared. The @var{r} part is ignored. This packet is only applicable to targets that support vforkdone events. Unfortunately, this is not just a documentation issue. GDBserver is really not specifying the thread ID. I noticed because in non-stop mode, gdb complains: [Thread 6089.6089] #1 stopped. #0 0x0000003615a011f0 in ?? () 0x0000003615a011f0 in ?? () (gdb) set debug remote 1 (gdb) c Continuing. Sending packet: $QPassSignals:e;10;14;17;1a;1b;1c;21;24;25;2c;4c;#5f...Packet received: OK Sending packet: $vCont;c:p17c9.17c9#88...Packet received: OK Notification received: Stop:T05vfork:p17ce.17ce;06:40d7ffffff7f0000;07:30d7ffffff7f0000;10:e4c9eb1536000000;thread:p17c9.17c9;core:2; Sending packet: $vStopped#55...Packet received: OK Sending packet: $D;17ce#af...Packet received: OK Sending packet: $vCont;c:p17c9.17c9#88...Packet received: OK Notification received: Stop:T05vforkdone:; No process or thread specified in stop reply: T05vforkdone:; (gdb) This is not non-stop-mode-specific, however. Consider e.g., that in all-stop, you may be debugging more than one process at the same time. You continue, and both processes vfork. So when you next get a T05vforkdone, there's no way to tell which of the parent processes is done with the vfork. Tests will be added later. Tested on x86_64 Fedora 20. gdb/ChangeLog: 2015-09-15 Pedro Alves PR remote/18965 * remote-utils.c (prepare_resume_reply): Merge TARGET_WAITKIND_VFORK_DONE switch case with the TARGET_WAITKIND_FORKED case. gdb/doc/ChangeLog: 2015-09-15 Pedro Alves PR remote/18965 * gdb.texinfo (Stop Reply Packets): Explain that vforkdone's 'r' part indicates the thread ID of the parent process. --- gdb/ChangeLog | 7 +++++++ gdb/doc/ChangeLog | 6 ++++++ gdb/doc/gdb.texinfo | 11 ++++++----- gdb/gdbserver/remote-utils.c | 17 +++++++---------- 4 files changed, 26 insertions(+), 15 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 9932d60..d19c71a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2015-09-15 Pedro Alves + + PR remote/18965 + * remote-utils.c (prepare_resume_reply): Merge + TARGET_WAITKIND_VFORK_DONE switch case with the + TARGET_WAITKIND_FORKED case. + 2015-09-15 Yao Qi * aarch64-linux-nat.c (aarch64_linux_can_do_single_step): New diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index b5de969..2cc6039 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,9 @@ +2015-09-15 Pedro Alves + + PR remote/18965 + * gdb.texinfo (Stop Reply Packets): Explain that vforkdone's 'r' + part indicates the thread ID of the parent process. + 2015-09-15 Yao Qi * gdb.texinfo (General Query Packets): Add vContSupported to diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 4ecdb8f..e80e695 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -35498,11 +35498,12 @@ indicating support. @cindex vforkdone events, remote reply @item vforkdone -The packet indicates that a child process created by a vfork -has either called @code{exec} or terminated, so that the -address spaces of the parent and child process are no longer -shared. The @var{r} part is ignored. This packet is only -applicable to targets that support vforkdone events. +The packet indicates that a child process created by a vfork has +either called @code{exec} or terminated, so that the address spaces of +the parent and child process are no longer shared. The @var{r} part +is the thread ID of the parent process. Refer to @ref{thread-id +syntax} for the format of the @var{thread-id} field. This packet is +only applicable to targets that support vforkdone events. This packet should not be sent by default; older @value{GDBN} versions did not support it. @value{GDBN} requests it, by supplying an diff --git a/gdb/gdbserver/remote-utils.c b/gdb/gdbserver/remote-utils.c index ac86dd5..78fbfac 100644 --- a/gdb/gdbserver/remote-utils.c +++ b/gdb/gdbserver/remote-utils.c @@ -1117,6 +1117,7 @@ prepare_resume_reply (char *buf, ptid_t ptid, case TARGET_WAITKIND_STOPPED: case TARGET_WAITKIND_FORKED: case TARGET_WAITKIND_VFORKED: + case TARGET_WAITKIND_VFORK_DONE: case TARGET_WAITKIND_EXECD: { struct thread_info *saved_thread; @@ -1135,6 +1136,12 @@ prepare_resume_reply (char *buf, ptid_t ptid, buf = write_ptid (buf, status->value.related_pid); strcat (buf, ";"); } + else if (status->kind == TARGET_WAITKIND_VFORK_DONE && report_vfork_events) + { + enum gdb_signal signal = GDB_SIGNAL_TRAP; + + sprintf (buf, "T%02xvforkdone:;", signal); + } else if (status->kind == TARGET_WAITKIND_EXECD && multi_process) { enum gdb_signal signal = GDB_SIGNAL_TRAP; @@ -1269,16 +1276,6 @@ prepare_resume_reply (char *buf, ptid_t ptid, else sprintf (buf, "X%02x", status->value.sig); break; - case TARGET_WAITKIND_VFORK_DONE: - if (report_vfork_events) - { - enum gdb_signal signal = GDB_SIGNAL_TRAP; - - sprintf (buf, "T%02xvforkdone:;", signal); - } - else - sprintf (buf, "T%02x", GDB_SIGNAL_0); - break; default: error ("unhandled waitkind"); break; -- 2.7.4