cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

memory.py (3204B)

      1from __future__ import print_function
      2#
      3# Test some of the softmmu debug features with the multiarch memory
      4# test. It is a port of the original vmlinux focused test case but
      5# using the "memory" test instead.
      6#
      7# This is launched via tests/guest-debug/run-test.py
      8#
      9
     10import gdb
     11import sys
     12
     13failcount = 0
     14
     15
     16def report(cond, msg):
     17    "Report success/fail of test"
     18    if cond:
     19        print("PASS: %s" % (msg))
     20    else:
     21        print("FAIL: %s" % (msg))
     22        global failcount
     23        failcount += 1
     24
     25
     26def check_step():
     27    "Step an instruction, check it moved."
     28    start_pc = gdb.parse_and_eval('$pc')
     29    gdb.execute("si")
     30    end_pc = gdb.parse_and_eval('$pc')
     31
     32    return not (start_pc == end_pc)
     33
     34
     35#
     36# Currently it's hard to create a hbreak with the pure python API and
     37# manually matching PC to symbol address is a bit flaky thanks to
     38# function prologues. However internally QEMU's gdbstub treats them
     39# the same as normal breakpoints so it will do for now.
     40#
     41def check_break(sym_name):
     42    "Setup breakpoint, continue and check we stopped."
     43    sym, ok = gdb.lookup_symbol(sym_name)
     44    bp = gdb.Breakpoint(sym_name, gdb.BP_BREAKPOINT)
     45
     46    gdb.execute("c")
     47
     48    # hopefully we came back
     49    end_pc = gdb.parse_and_eval('$pc')
     50    report(bp.hit_count == 1,
     51           "break @ %s (%s %d hits)" % (end_pc, sym.value(), bp.hit_count))
     52
     53    bp.delete()
     54
     55
     56def do_one_watch(sym, wtype, text):
     57
     58    wp = gdb.Breakpoint(sym, gdb.BP_WATCHPOINT, wtype)
     59    gdb.execute("c")
     60    report_str = "%s for %s" % (text, sym)
     61
     62    if wp.hit_count > 0:
     63        report(True, report_str)
     64        wp.delete()
     65    else:
     66        report(False, report_str)
     67
     68
     69def check_watches(sym_name):
     70    "Watch a symbol for any access."
     71
     72    # Should hit for any read
     73    do_one_watch(sym_name, gdb.WP_ACCESS, "awatch")
     74
     75    # Again should hit for reads
     76    do_one_watch(sym_name, gdb.WP_READ, "rwatch")
     77
     78    # Finally when it is written
     79    do_one_watch(sym_name, gdb.WP_WRITE, "watch")
     80
     81
     82def run_test():
     83    "Run through the tests one by one"
     84
     85    print("Checking we can step the first few instructions")
     86    step_ok = 0
     87    for i in range(3):
     88        if check_step():
     89            step_ok += 1
     90
     91    report(step_ok == 3, "single step in boot code")
     92
     93    # If we get here we have missed some of the other breakpoints.
     94    print("Setup catch-all for _exit")
     95    cbp = gdb.Breakpoint("_exit", gdb.BP_BREAKPOINT)
     96
     97    check_break("main")
     98    check_watches("test_data[128]")
     99
    100    report(cbp.hit_count == 0, "didn't reach backstop")
    101
    102#
    103# This runs as the script it sourced (via -x, via run-test.py)
    104#
    105try:
    106    inferior = gdb.selected_inferior()
    107    arch = inferior.architecture()
    108    print("ATTACHED: %s" % arch.name())
    109except (gdb.error, AttributeError):
    110    print("SKIPPING (not connected)", file=sys.stderr)
    111    exit(0)
    112
    113if gdb.parse_and_eval('$pc') == 0:
    114    print("SKIP: PC not set")
    115    exit(0)
    116
    117try:
    118    # These are not very useful in scripts
    119    gdb.execute("set pagination off")
    120
    121    # Run the actual tests
    122    run_test()
    123except (gdb.error):
    124    print("GDB Exception: %s" % (sys.exc_info()[0]))
    125    failcount += 1
    126    pass
    127
    128# Finally kill the inferior and exit gdb with a count of failures
    129gdb.execute("kill")
    130exit(failcount)