gdbstub: add support to Xfer:auxv:read: packet

This allows gdb to access the target’s auxiliary vector,
which can be helpful for telling system libraries important details
about the hardware, operating system, and process.

Signed-off-by: Lirong Yuan <yuanzi@google.com>
[AJB: minor tweaks to test case, update MAINTAINERS, restrict to Linux]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200730193932.3654677-1-yuanzi@google.com>
Message-Id: <20210108224256.2321-7-alex.bennee@linaro.org>

2 files changed, 66 insertions, 0 deletions

diff --git a/tests/tcg/multiarch/Makefile.target b/tests/tcg/multiarch/Makefile.target
index cb49cc9..1dd0f64 100644
--- a/tests/tcg/multiarch/Makefile.target
+++ b/tests/tcg/multiarch/Makefile.target
@@ -55,6 +55,15 @@ run-gdbstub-sha1: sha1
 	"basic gdbstub support")
 
 EXTRA_RUNS += run-gdbstub-sha1
+
+run-gdbstub-qxfer-auxv-read: sha1
+	$(call run-test, $@, $(GDB_SCRIPT) \
+		--gdb $(HAVE_GDB_BIN) \
+		--qemu $(QEMU) --qargs "$(QEMU_OPTS)" \
+		--bin $< --test $(MULTIARCH_SRC)/gdbstub/test-qxfer-auxv-read.py, \
+	"basic gdbstub qXfer:auxv:read support")
+
+EXTRA_RUNS += run-gdbstub-sha1 run-gdbstub-qxfer-auxv-read
 endif
 
 
diff --git a/tests/tcg/multiarch/gdbstub/test-qxfer-auxv-read.py b/tests/tcg/multiarch/gdbstub/test-qxfer-auxv-read.py
new file mode 100644
index 0000000..d91e8fd
--- /dev/null
+++ b/tests/tcg/multiarch/gdbstub/test-qxfer-auxv-read.py
@@ -0,0 +1,57 @@
+from __future__ import print_function
+#
+# Test auxiliary vector is loaded via gdbstub
+#
+# 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 run_test():
+    "Run through the tests one by one"
+
+    auxv = gdb.execute("info auxv", False, True)
+    report(isinstance(auxv, str), "Fetched auxv from inferior")
+    report(auxv.find("sha1"), "Found test binary name in auxv")
+
+#
+# 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)
+
+try:
+    # These are not very useful in scripts
+    gdb.execute("set pagination off")
+    gdb.execute("set confirm off")
+
+    # Run the actual tests
+    run_test()
+except (gdb.error):
+    print ("GDB Exception: %s" % (sys.exc_info()[0]))
+    failcount += 1
+    pass
+
+print("All tests complete: %d failures" % failcount)
+exit(failcount)