[PATCH v3] checkpatch: suppress strscpy warnings for userspace tools

[Suchit Karunakaran <suchitkarunakaran@gmail.com>]

The checkpatch.pl script currently warns against the use of strcpy,
strlcpy, and strncpy, recommending strscpy as a safer alternative.
However, these warnings are also triggered for code under tools/ and
scripts/, which are userspace utilities where strscpy is not available.
This patch suppresses these warnings for files in tools/ and scripts/.

Signed-off-by: Suchit Karunakaran <suchitkarunakaran@gmail.com>
---

Changes since v1:
- Create is_userspace function to check if the file is in userspace
  directories

Changes since v2:
- Change regex pattern to match top level directories only

 scripts/checkpatch.pl | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index e722dd6fa8ef..fe580b0810f9 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2636,6 +2636,11 @@ sub exclude_global_initialisers {
 		$realfile =~ m@/bpf/.*\.bpf\.c$@;
 }
 
+sub is_userspace {
+    my ($realfile) = @_;
+    return ($realfile =~ m@^tools/@ || $realfile =~ m@^scripts/@);
+}
+
 sub process {
 	my $filename = shift;
 
@@ -7018,21 +7023,20 @@ sub process {
 #				}
 #			}
 #		}
-
 # strcpy uses that should likely be strscpy
-		if ($line =~ /\bstrcpy\s*\(/) {
+		if ($line =~ /\bstrcpy\s*\(/ && !is_userspace($realfile)) {
 			WARN("STRCPY",
 			     "Prefer strscpy over strcpy - see: https://github.com/KSPP/linux/issues/88\n" . $herecurr);
 		}
 
 # strlcpy uses that should likely be strscpy
-		if ($line =~ /\bstrlcpy\s*\(/) {
+		if ($line =~ /\bstrlcpy\s*\(/ && !is_userspace($realfile)) {
 			WARN("STRLCPY",
 			     "Prefer strscpy over strlcpy - see: https://github.com/KSPP/linux/issues/89\n" . $herecurr);
 		}
 
 # strncpy uses that should likely be strscpy or strscpy_pad
-		if ($line =~ /\bstrncpy\s*\(/) {
+		if ($line =~ /\bstrncpy\s*\(/ && !is_userspace($realfile)) {
 			WARN("STRNCPY",
 			     "Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90\n" . $herecurr);
 		}
-- 
2.50.1