Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging

* Reverse debugging (Pavel)
* CFLAGS cleanup (Paolo)
* ASLR fix (Mark)
* cpus.c refactoring (Claudio)

# gpg: Signature made Tue 06 Oct 2020 07:35:09 BST
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini-gitlab/tags/for-upstream: (37 commits)
  tests/acceptance: add reverse debugging test
  replay: create temporary snapshot at debugger connection
  replay: describe reverse debugging in docs/replay.txt
  gdbstub: add reverse continue support in replay mode
  gdbstub: add reverse step support in replay mode
  replay: flush rr queue before loading the vmstate
  replay: implement replay-seek command
  replay: introduce breakpoint at the specified step
  replay: introduce info hmp/qmp command
  qapi: introduce replay.json for record/replay-related stuff
  migration: introduce icount field for snapshots
  qcow2: introduce icount field for snapshots
  replay: provide an accessor for rr filename
  replay: don't record interrupt poll
  configure: don't enable ASLR for --enable-debug Windows builds
  configure: consistently pass CFLAGS/CXXFLAGS/LDFLAGS to meson
  configure: do not clobber environment CFLAGS/CXXFLAGS/LDFLAGS
  dtc: Convert Makefile bits to meson bits
  slirp: Convert Makefile bits to meson bits
  accel/tcg: use current_machine as it is always set for softmmu
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 62 insertions, 2 deletions

diff --git a/gdbstub.c b/gdbstub.c
index 9dfb6e4142..f19f98ab1a 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -51,6 +51,7 @@
 #include "sysemu/runstate.h"
 #include "hw/semihosting/semihost.h"
 #include "exec/exec-all.h"
+#include "sysemu/replay.h"
 
 #ifdef CONFIG_USER_ONLY
 #define GDB_ATTACHED "0"
@@ -375,6 +376,20 @@ typedef struct GDBState {
  */
 static int sstep_flags = SSTEP_ENABLE|SSTEP_NOIRQ|SSTEP_NOTIMER;
 
+/* Retrieves flags for single step mode. */
+static int get_sstep_flags(void)
+{
+    /*
+     * In replay mode all events written into the log should be replayed.
+     * That is why NOIRQ flag is removed in this mode.
+     */
+    if (replay_mode != REPLAY_MODE_NONE) {
+        return SSTEP_ENABLE;
+    } else {
+        return sstep_flags;
+    }
+}
+
 static GDBState gdbserver_state;
 
 static void init_gdbserver_state(void)
@@ -501,7 +516,7 @@ static int gdb_continue_partial(char *newstates)
                 break; /* nothing to do here */
             case 's':
                 trace_gdbstub_op_stepping(cpu->cpu_index);
-                cpu_single_step(cpu, sstep_flags);
+                cpu_single_step(cpu, get_sstep_flags());
                 cpu_resume(cpu);
                 flag = 1;
                 break;
@@ -1874,10 +1889,38 @@ static void handle_step(GdbCmdContext *gdb_ctx, void *user_ctx)
         gdb_set_cpu_pc((target_ulong)gdb_ctx->params[0].val_ull);
     }
 
-    cpu_single_step(gdbserver_state.c_cpu, sstep_flags);
+    cpu_single_step(gdbserver_state.c_cpu, get_sstep_flags());
     gdb_continue();
 }
 
+static void handle_backward(GdbCmdContext *gdb_ctx, void *user_ctx)
+{
+    if (replay_mode != REPLAY_MODE_PLAY) {
+        put_packet("E22");
+    }
+    if (gdb_ctx->num_params == 1) {
+        switch (gdb_ctx->params[0].opcode) {
+        case 's':
+            if (replay_reverse_step()) {
+                gdb_continue();
+            } else {
+                put_packet("E14");
+            }
+            return;
+        case 'c':
+            if (replay_reverse_continue()) {
+                gdb_continue();
+            } else {
+                put_packet("E14");
+            }
+            return;
+        }
+    }
+
+    /* Default invalid command */
+    put_packet("");
+}
+
 static void handle_v_cont_query(GdbCmdContext *gdb_ctx, void *user_ctx)
 {
     put_packet("vCont;c;C;s;S");
@@ -2124,6 +2167,11 @@ static void handle_query_supported(GdbCmdContext *gdb_ctx, void *user_ctx)
         g_string_append(gdbserver_state.str_buf, ";qXfer:features:read+");
     }
 
+    if (replay_mode == REPLAY_MODE_PLAY) {
+        g_string_append(gdbserver_state.str_buf,
+            ";ReverseStep+;ReverseContinue+");
+    }
+
     if (gdb_ctx->num_params &&
         strstr(gdb_ctx->params[0].data, "multiprocess+")) {
         gdbserver_state.multiprocess = true;
@@ -2460,6 +2508,17 @@ static int gdb_handle_packet(const char *line_buf)
             cmd_parser = &step_cmd_desc;
         }
         break;
+    case 'b':
+        {
+            static const GdbCmdParseEntry backward_cmd_desc = {
+                .handler = handle_backward,
+                .cmd = "b",
+                .cmd_startswith = 1,
+                .schema = "o0"
+            };
+            cmd_parser = &backward_cmd_desc;
+        }
+        break;
     case 'F':
         {
             static const GdbCmdParseEntry file_io_cmd_desc = {
@@ -3262,6 +3321,7 @@ static void gdb_chr_event(void *opaque, QEMUChrEvent event)
         s->g_cpu = s->c_cpu;
 
         vm_stop(RUN_STATE_PAUSED);
+        replay_gdb_attached();
         gdb_has_xml = false;
         break;
     default: