diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 5f28d5cf57eee8f6f71f39a7972ab7cf9cad3f57..e7d48fa0d43084191da6247a716d1d82edb0674f 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -597,6 +597,15 @@ static int gdb_handle_vcont(const char *p)
* or incorrect parameters passed.
*/
res = 0;
+
+ /*
+ * target_count and last_target keep track of how many CPUs we are going to
+ * step or resume, and a pointer to the state structure of one of them,
+ * respectivelly
+ */
+ int target_count = 0;
+ CPUState *last_target = NULL;
+
while (*p) {
if (*p++ != ';') {
return -ENOTSUP;
@@ -637,6 +646,9 @@ static int gdb_handle_vcont(const char *p)
while (cpu) {
if (newstates[cpu->cpu_index] == 1) {
newstates[cpu->cpu_index] = cur_action;
+
+ target_count++;
+ last_target = cpu;
}
cpu = gdb_next_attached_cpu(cpu);
@@ -654,6 +666,9 @@ static int gdb_handle_vcont(const char *p)
while (cpu) {
if (newstates[cpu->cpu_index] == 1) {
newstates[cpu->cpu_index] = cur_action;
+
+ target_count++;
+ last_target = cpu;
}
cpu = gdb_next_cpu_in_process(cpu);
@@ -671,11 +686,25 @@ static int gdb_handle_vcont(const char *p)
/* only use if no previous match occourred */
if (newstates[cpu->cpu_index] == 1) {
newstates[cpu->cpu_index] = cur_action;
+
+ target_count++;
+ last_target = cpu;
}
break;
}
}
+ /*
+ * if we're about to resume a specific set of CPUs/threads, make it so that
+ * in case execution gets interrupted, we can send GDB a stop reply with a
+ * correct value. it doesn't really matter which CPU we tell GDB the signal
+ * happened in (VM pauses stop all of them anyway), so long as it is one of
+ * the ones we resumed/single stepped here.
+ */
+ if (target_count > 0) {
+ gdbserver_state.c_cpu = last_target;
+ }
+
gdbserver_state.signal = signal;
gdb_continue_partial(newstates);
return res;
diff --git a/tests/tcg/multiarch/gdbstub/interrupt.py b/tests/tcg/multiarch/gdbstub/interrupt.py
new file mode 100644
index 0000000000000000000000000000000000000000..e222ac94c5a8953f86ae1af7675b89855adbb07e
--- /dev/null
+++ b/tests/tcg/multiarch/gdbstub/interrupt.py
@@ -0,0 +1,97 @@
+from __future__ import print_function
+#
+# Test some of the softmmu debug features with the multiarch memory
+# test. It is a port of the original vmlinux focused test case but
+# using the "memory" test instead.
+#
+# This is launched via tests/guest-debug/run-test.py
+#
+
+import gdb
+import sys
+
+failcount = 0
+
+
+def report(cond, msg):
+ "Report success/fail of test"
+ if cond:
+ print("PASS: %s" % (msg))
+ else:
+ print("FAIL: %s" % (msg))
+ global failcount
+ failcount += 1
+
+
+def check_interrupt(thread):
+ """
+ Check that, if thread is resumed, we go back to the same thread when the
+ program gets interrupted.
+ """
+
+ # Switch to the thread we're going to be running the test in.
+ print("thread ", thread.num)
+ gdb.execute("thr %d" % thread.num)
+
+ # Enter the loop() function on this thread.
+ #
+ # While there are cleaner ways to do this, we want to minimize the number of
+ # side effects on the gdbstub's internal state, since those may mask bugs.
+ # Ideally, there should be no difference between what we're doing here and
+ # the program reaching the loop() function on its own.
+ #
+ # For this to be safe, we only need the prologue of loop() to not have
+ # instructions that may have problems with what we're doing here. We don't
+ # have to worry about anything else, as this function never returns.
+ gdb.execute("set $pc = loop")
+
+ # Continue and then interrupt the task.
+ gdb.post_event(lambda: gdb.execute("interrupt"))
+ gdb.execute("c")
+
+ # Check whether the thread we're in after the interruption is the same we
+ # ran continue from.
+ return (thread.num == gdb.selected_thread().num)
+
+
+def run_test():
+ """
+ Test if interrupting the code always lands us on the same thread when
+ running with scheduler-lock enabled.
+ """
+
+ gdb.execute("set scheduler-locking on")
+ for thread in gdb.selected_inferior().threads():
+ report(check_interrupt(thread),
+ "thread %d resumes correctly on interrupt" % thread.num)
+
+
+#
+# This runs as the script it sourced (via -x, via run-test.py)
+#
+try:
+ inferior = gdb.selected_inferior()
+ arch = inferior.architecture()
+ print("ATTACHED: %s" % arch.name())
+except (gdb.error, AttributeError):
+ print("SKIPPING (not connected)", file=sys.stderr)
+ exit(0)
+
+if gdb.parse_and_eval('$pc') == 0:
+ print("SKIP: PC not set")
+ exit(0)
+if len(gdb.selected_inferior().threads()) == 1:
+ print("SKIP: set to run on a single thread")
+ exit(0)
+
+try:
+ # Run the actual tests
+ run_test()
+except (gdb.error):
+ print("GDB Exception: %s" % (sys.exc_info()[0]))
+ failcount += 1
+ pass
+
+# Finally kill the inferior and exit gdb with a count of failures
+gdb.execute("kill")
+exit(failcount)
diff --git a/tests/tcg/multiarch/system/Makefile.softmmu-target b/tests/tcg/multiarch/system/Makefile.softmmu-target
index a051d689d7b753e1b1d8933094697257530207c1..90810a32b2f195b70a239a0242235fe096388906 100644
--- a/tests/tcg/multiarch/system/Makefile.softmmu-target
+++ b/tests/tcg/multiarch/system/Makefile.softmmu-target
@@ -27,7 +27,15 @@ run-gdbstub-memory: memory
"-monitor none -display none -chardev file$(COMMA)path=$<.out$(COMMA)id=output $(QEMU_OPTS)" \
--bin $< --test $(MULTIARCH_SRC)/gdbstub/memory.py, \
softmmu gdbstub support)
-
+run-gdbstub-interrupt: interrupt
+ $(call run-test, $@, $(GDB_SCRIPT) \
+ --gdb $(HAVE_GDB_BIN) \
+ --qemu $(QEMU) \
+ --output $<.gdb.out \
+ --qargs \
+ "-smp 2 -monitor none -display none -chardev file$(COMMA)path=$<.out$(COMMA)id=output $(QEMU_OPTS)" \
+ --bin $< --test $(MULTIARCH_SRC)/gdbstub/interrupt.py, \
+ softmmu gdbstub support)
run-gdbstub-untimely-packet: hello
$(call run-test, $@, $(GDB_SCRIPT) \
--gdb $(HAVE_GDB_BIN) \
@@ -50,4 +58,4 @@ run-gdbstub-%:
$(call skip-test, "gdbstub test $*", "need working gdb")
endif
-MULTIARCH_RUNS += run-gdbstub-memory run-gdbstub-untimely-packet
+MULTIARCH_RUNS += run-gdbstub-memory run-gdbstub-interrupt run-gdbstub-untimely-packet
diff --git a/tests/tcg/multiarch/system/interrupt.c b/tests/tcg/multiarch/system/interrupt.c
new file mode 100644
index 0000000000000000000000000000000000000000..98d4f2eff9f222001d6e7bd2b837b0e49b0710b8
--- /dev/null
+++ b/tests/tcg/multiarch/system/interrupt.c
@@ -0,0 +1,28 @@
+/*
+ * External interruption test. This test is structured in such a way that it
+ * passes the cases that require it to exit, but we can make it enter an
+ * infinite loop from GDB.
+ *
+ * We don't have the benefit of libc, just builtin C primitives and
+ * whatever is in minilib.
+ */
+
+#include <minilib.h>
+
+void loop(void)
+{
+ do {
+ /*
+ * Loop forever. Just make sure the condition is always a constant
+ * expression, so that this loop is not UB, as per the C
+ * standard.
+ */
+ } while (1);
+}
+
+int main(void)
+{
+ return 0;
+}
+
+