From d9c305071069164feceaff3e543c61693bc2c401 Mon Sep 17 00:00:00 2001 From: Sean Anderson Date: Thu, 11 Mar 2021 00:15:45 -0500 Subject: checkpatch: Add warnings for using strn(cat|cpy) strn(cat|cpy) has a bad habit of not nul-terminating the destination, resulting in constructions like strncpy(foo, bar, sizeof(foo) - 1); foo[sizeof(foo) - 1] = '\0'; However, it is very easy to forget about this behavior and accidentally leave a string unterminated. This has shown up in some recent coverity scans [1, 2] (including code recently touched by yours truly). Fortunately, the guys at OpenBSD came up with strl(cat|cpy), which always nul-terminate strings. These functions are already in U-Boot, so we should encourage new code to use them instead of strn(cat|cpy). [1] https://lists.denx.de/pipermail/u-boot/2021-March/442888.html [2] https://lists.denx.de/pipermail/u-boot/2021-January/438073.html Signed-off-by: Sean Anderson Reviewed-by: Simon Glass --- tools/patman/test_checkpatch.py | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/patman/test_checkpatch.py b/tools/patman/test_checkpatch.py index a4fec1d..56af5265 100644 --- a/tools/patman/test_checkpatch.py +++ b/tools/patman/test_checkpatch.py @@ -353,7 +353,7 @@ index 0000000..2234c87 Args: pm: PatchMaker object to use - msg" Expected message (e.g. 'LIVETREE') + msg: Expected message (e.g. 'LIVETREE') pmtype: Type of problem ('error', 'warning') """ result = pm.run_checkpatch() @@ -439,6 +439,18 @@ index 0000000..2234c87 self.check_struct('per_device_auto', '_priv', 'DEVICE_PRIV_AUTO') self.check_struct('per_device_plat_auto', '_plat', 'DEVICE_PLAT_AUTO') + def check_strl(self, func): + """Check one of the checks for strn(cpy|cat)""" + pm = PatchMaker() + pm.add_line('common/main.c', "strn%s(foo, bar, sizeof(foo));" % func) + self.checkSingleMessage(pm, "STRL", + "strl%s is preferred over strn%s because it always produces a nul-terminated string\n" + % (func, func)) + + def testStrl(self): + """Check for uses of strn(cat|cpy)""" + self.check_strl("cat"); + self.check_strl("cpy"); if __name__ == "__main__": unittest.main() -- cgit v1.1