Commit 8515e4a7 authored May 17, 2023 by Kees Cook

checkpatch: Check for 0-length and 1-element arrays

Fake flexible arrays have been deprecated since last millennium. Proper
C99 flexible arrays must be used throughout the kernel so
CONFIG_FORTIFY_SOURCE and CONFIG_UBSAN_BOUNDS can provide proper array
bounds checking.

Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Fixed-by: Joe Perches <joe@perches.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/20230517204530.never.151-kees@kernel.org

parent 8762606a

scripts/checkpatch.pl

+10 −0

Original line number	Diff line number	Diff line
		@@ -7430,6 +7430,16 @@ sub process {
		}
		}

		# check for array definition/declarations that should use flexible arrays instead
		if ($sline =~ /^[\+ ]\s\}(?:\s__packed)?\s;\s$/ &&
		$prevline =~ /^\+\s(?:\}(?:\s__packed\s)?\|$Type)\s$Ident\s\[\s(0\|1)\s\]\s;\s*$/) {
		if (ERROR("FLEXIBLE_ARRAY",
		"Use C99 flexible arrays - see https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays\n" . $hereprev) &&
		$1 == '0' && $fix) {
		$fixed[$fixlinenr - 1] =~ s/\[\s0\s\]/[]/;
		}
		}

		# nested likely/unlikely calls
		if ($line =~ /\b(?:(?:un)?likely)\s\(\s!?\s*(IS_ERR(?:_OR_NULL\|_VALUE)?\|WARN)/) {
		WARN("LIKELY_MISUSE",