lkml.org 
[lkml]   [2023]   [May]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] checkpatch: Warn about 0-length and 1-element arrays
Date
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>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Fixed-by: Joe Perches <joe@perches.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230517204530.never.151-kees@kernel.org
---
v2: find using "end of struct" marking instead of $context_function (joe)
v1: https://lore.kernel.org/all/20230517204530.never.151-kees@kernel.org/
---
scripts/checkpatch.pl | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 30b0b4fdb3bf..cfa19bfc857c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -7430,6 +7430,21 @@ sub process {
}
}

+# check for array definition/declarations that should use flexible arrays instead
+ if ($sline =~ /^[\+ ]\s*}\s*;\s*$/ &&
+ $prevline =~ /^\+\s*(?:(?:struct|union|enum)\s+$Ident|\}|$Type)\s*$Ident\s*\[\s*(0|1)\s*\]\s*;\s*$/) {
+ if ($1 == '0') {
+ if (WARN("ZERO_LENGTH_ARRAY",
+ "Use C99 flexible arrays instead of zero-length arrays - see https://github.com/KSPP/linux/issues/78\n" . $hereprev) &&
+ $fix) {
+ $fixed[$fixlinenr - 1] =~ s/\[0\]/[]/g;
+ }
+ } else {
+ WARN("ONE_ELEMENT_ARRAY",
+ "Use C99 flexible arrays instead of one-element arrays - see https://github.com/KSPP/linux/issues/79\n" . $hereprev);
+ }
+ }
+
# nested likely/unlikely calls
if ($line =~ /\b(?:(?:un)?likely)\s*\(\s*!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?|WARN)/) {
WARN("LIKELY_MISUSE",
--
2.34.1
\
 
 \ /
  Last update: 2023-05-26 19:41    [W:1.410 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site