From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43857) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XUAaa-0006Ey-48 for qemu-devel@nongnu.org; Wed, 17 Sep 2014 04:27:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XUAaU-0003gD-CA for qemu-devel@nongnu.org; Wed, 17 Sep 2014 04:27:48 -0400 Received: from greensocs.com ([178.33.234.66]:58364) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XUAaU-0003fW-24 for qemu-devel@nongnu.org; Wed, 17 Sep 2014 04:27:42 -0400 From: fred.konrad@greensocs.com Date: Wed, 17 Sep 2014 10:26:47 +0200 Message-Id: <1410942410-32604-8-git-send-email-fred.konrad@greensocs.com> In-Reply-To: <1410942410-32604-1-git-send-email-fred.konrad@greensocs.com> References: <1410942410-32604-1-git-send-email-fred.konrad@greensocs.com> Subject: [Qemu-devel] [RFC V7 07/10] gdbstub: allow reverse execution in gdb stub. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, fred.konrad@greensocs.com, mark.burton@greensocs.com, Pavel.Dovgaluk@ispras.ru, peter.maydell@linaro.org From: KONRAD Frederic This allows gdb to reverse step QEMU: reverse-stepi and reverse-cont commands are allowed. When step_backward is called, QEMU restores a snapshot before the actual instruction and stops (with a debug exit) when the previous instruction is reached. Signed-off-by: KONRAD Frederic --- gdbstub.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/gdbstub.c b/gdbstub.c index 8afe0b7..4564988 100644 --- a/gdbstub.c +++ b/gdbstub.c @@ -33,6 +33,7 @@ #include "sysemu/char.h" #include "sysemu/sysemu.h" #include "exec/gdbstub.h" +#include "reverse-execution.h" #endif #define MAX_PACKET_LENGTH 4096 @@ -1113,6 +1114,17 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf) if (cc->gdb_core_xml_file != NULL) { pstrcat(buf, sizeof(buf), ";qXfer:features:read+"); } + + #ifndef CONFIG_USER_ONLY + /* + * When reverse execution is enabled those additional features must + * be set so GDB allows reverse-stepi and reverse-continue command. + */ + if (rexec_is_enabled()) { + pstrcat(buf, sizeof(buf), ";ReverseStep+;ReverseContinue+"); + } + #endif /* !CONFIG_USER_ONLY */ + put_packet(s, buf); break; } @@ -1161,7 +1173,23 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf) } /* Unrecognised 'q' command. */ goto unknown_command; - + #ifndef CONFIG_USER_ONLY + case 'b': + /* Reverse execution. */ + switch (*p) { + case 's': + rexec_step_backward(s->c_cpu, 1); + break; + case 'c': + rexec_continue_backward(s->c_cpu); + break; + default: + buf[0] = '\0'; + put_packet(s, buf); + break; + } + break; + #endif /* !CONFIG_USER_ONLY */ default: unknown_command: /* put empty packet */ @@ -1221,6 +1249,7 @@ static void gdb_vm_state_change(void *opaque, int running, RunState state) ret = GDB_SIGNAL_TRAP; break; case RUN_STATE_PAUSED: + rexec_stop_reverse_continue(); ret = GDB_SIGNAL_INT; break; case RUN_STATE_SHUTDOWN: -- 1.9.0