xref: /openbmc/qemu/tests/tcg/multiarch/gdbstub/memory.py (revision f0007b7f03e2d7fc33e71c3a582f2364c51a226b) 
1#
2# Test some of the system debug features with the multiarch memory
3# test. It is a port of the original vmlinux focused test case but
4# using the "memory" test instead.
5#
6# This is launched via tests/guest-debug/run-test.py
7#
8
9import gdb
10import sys
11from test_gdbstub import main, report
12
13
14def check_step():
15    "Step an instruction, check it moved."
16    start_pc = gdb.parse_and_eval('$pc')
17    gdb.execute("si")
18    end_pc = gdb.parse_and_eval('$pc')
19
20    return not (start_pc == end_pc)
21
22
23#
24# Currently it's hard to create a hbreak with the pure python API and
25# manually matching PC to symbol address is a bit flaky thanks to
26# function prologues. However internally QEMU's gdbstub treats them
27# the same as normal breakpoints so it will do for now.
28#
29def check_break(sym_name):
30    "Setup breakpoint, continue and check we stopped."
31    sym, ok = gdb.lookup_symbol(sym_name)
32    bp = gdb.Breakpoint(sym_name, gdb.BP_BREAKPOINT)
33
34    gdb.execute("c")
35
36    # hopefully we came back
37    end_pc = gdb.parse_and_eval('$pc')
38    report(bp.hit_count == 1,
39           "break @ %s (%s %d hits)" % (end_pc, sym.value(), bp.hit_count))
40
41    bp.delete()
42
43
44def do_one_watch(sym, wtype, text):
45
46    wp = gdb.Breakpoint(sym, gdb.BP_WATCHPOINT, wtype)
47    gdb.execute("c")
48    report_str = "%s for %s" % (text, sym)
49
50    if wp.hit_count > 0:
51        report(True, report_str)
52        wp.delete()
53    else:
54        report(False, report_str)
55
56
57def check_watches(sym_name):
58    "Watch a symbol for any access."
59
60    # Should hit for any read
61    do_one_watch(sym_name, gdb.WP_ACCESS, "awatch")
62
63    # Again should hit for reads
64    do_one_watch(sym_name, gdb.WP_READ, "rwatch")
65
66    # Finally when it is written
67    do_one_watch(sym_name, gdb.WP_WRITE, "watch")
68
69
70def run_test():
71    "Run through the tests one by one"
72
73    print("Checking we can step the first few instructions")
74    step_ok = 0
75    for i in range(3):
76        if check_step():
77            step_ok += 1
78
79    report(step_ok == 3, "single step in boot code")
80
81    # If we get here we have missed some of the other breakpoints.
82    print("Setup catch-all for _exit")
83    cbp = gdb.Breakpoint("_exit", gdb.BP_BREAKPOINT)
84
85    check_break("main")
86    check_watches("test_data[128]")
87
88    report(cbp.hit_count == 0, "didn't reach backstop")
89
90
91main(run_test)
92