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author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2018-10-09 08:20:38 -0700 |
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committer | GitHub <noreply@github.com> | 2018-10-09 08:20:38 -0700 |
commit | 25bfb1aa75c8358becdab11142954c8ee9c3607f (patch) | |
tree | 36b6462db6d32c95f23057b6a39118cea374f9a9 /Lib/test/test_gdb.py | |
parent | 64bcedce8d61e1daa9ff7980cc07988574049b1f (diff) | |
download | cpython-git-25bfb1aa75c8358becdab11142954c8ee9c3607f.tar.gz |
bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (GH-9656)
When Python is built with the intel control-flow protection flags,
-mcet -fcf-protection, gdb is not able to read the stack without
actually jumping inside the function. This means an extra
'next' command is required to make the $pc (program counter)
enter the function and make the stack of the function exposed to gdb.
Co-Authored-By: Marcel Plch <gmarcel.plch@gmail.com>
(cherry picked from commit 9b7c74ca32d1bec7128d550a9ab1b2ddc7046287)
(cherry picked from commit 79d21331e605fdc941f947621846b8563485aab6)
Co-authored-by: Victor Stinner <vstinner@redhat.com>
Diffstat (limited to 'Lib/test/test_gdb.py')
-rw-r--r-- | Lib/test/test_gdb.py | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/Lib/test/test_gdb.py b/Lib/test/test_gdb.py index bedec1fb49..b33d007acb 100644 --- a/Lib/test/test_gdb.py +++ b/Lib/test/test_gdb.py @@ -60,6 +60,23 @@ checkout_hook_path = os.path.join(os.path.dirname(sys.executable), PYTHONHASHSEED = '123' + +def cet_protection(): + cflags = sysconfig.get_config_var('CFLAGS') + if not cflags: + return False + flags = cflags.split() + # True if "-mcet -fcf-protection" options are found, but false + # if "-fcf-protection=none" or "-fcf-protection=return" is found. + return (('-mcet' in flags) + and any((flag.startswith('-fcf-protection') + and not flag.endswith(("=none", "=return"))) + for flag in flags)) + +# Control-flow enforcement technology +CET_PROTECTION = cet_protection() + + def run_gdb(*args, **env_vars): """Runs gdb in --batch mode with the additional arguments given by *args. @@ -168,6 +185,12 @@ class DebuggerTests(unittest.TestCase): commands += ['set print entry-values no'] if cmds_after_breakpoint: + if CET_PROTECTION: + # bpo-32962: When Python is compiled with -mcet + # -fcf-protection, function arguments are unusable before + # running the first instruction of the function entry point. + # The 'next' command makes the required first step. + commands += ['next'] commands += cmds_after_breakpoint else: commands += ['backtrace'] @@ -868,9 +891,17 @@ id(42) id("first break point") l = MyList() ''') + cmds_after_breakpoint = ['break wrapper_call', 'continue'] + if CET_PROTECTION: + # bpo-32962: same case as in get_stack_trace(): + # we need an additional 'next' command in order to read + # arguments of the innermost function of the call stack. + cmds_after_breakpoint.append('next') + cmds_after_breakpoint.append('py-bt') + # Verify with "py-bt": gdb_output = self.get_stack_trace(cmd, - cmds_after_breakpoint=['break wrapper_call', 'continue', 'py-bt']) + cmds_after_breakpoint=cmds_after_breakpoint) self.assertRegex(gdb_output, r"<method-wrapper u?'__init__' of MyList object at ") |