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From:   Miguel Ojeda <ojeda@kernel.org>
To:     Linus Torvalds <torvalds@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, patches@lists.linux.dev,
        Jarkko Sakkinen <jarkko@kernel.org>,
        Miguel Ojeda <ojeda@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@google.com>,
        Joe Perches <joe@perches.com>,
        Andy Whitcroft <apw@canonical.com>,
        Dwaipayan Ray <dwaipayanray1@gmail.com>,
        Lukas Bulwahn <lukas.bulwahn@gmail.com>
Subject: [PATCH v10 15/27] scripts: checkpatch: diagnose uses of `%pA` in the C side as errors
Date:   Tue, 27 Sep 2022 15:14:46 +0200
Message-Id: <20220927131518.30000-16-ojeda@kernel.org>
In-Reply-To: <20220927131518.30000-1-ojeda@kernel.org>
References: <20220927131518.30000-1-ojeda@kernel.org>
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The `%pA` format specifier is only intended to be used from Rust.

`checkpatch.pl` already gives a warning for invalid specificers:

    WARNING: Invalid vsprintf pointer extension '%pA'

This makes it an error and introduces an explanatory message:

    ERROR: Invalid vsprintf pointer extension '%pA' - '%pA' is only intended to be used from Rust code

Suggested-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Joe Perches <joe@perches.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 scripts/checkpatch.pl | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 79e759aac543..74a769310adf 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6783,15 +6783,19 @@ sub process {
 				}
 				if ($bad_specifier ne "") {
 					my $stat_real = get_stat_real($linenr, $lc);
+					my $msg_level = \&WARN;
 					my $ext_type = "Invalid";
 					my $use = "";
 					if ($bad_specifier =~ /p[Ff]/) {
 						$use = " - use %pS instead";
 						$use =~ s/pS/ps/ if ($bad_specifier =~ /pf/);
+					} elsif ($bad_specifier =~ /pA/) {
+						$use =  " - '%pA' is only intended to be used from Rust code";
+						$msg_level = \&ERROR;
 					}
 
-					WARN("VSPRINTF_POINTER_EXTENSION",
-					     "$ext_type vsprintf pointer extension '$bad_specifier'$use\n" . "$here\n$stat_real\n");
+					&{$msg_level}("VSPRINTF_POINTER_EXTENSION",
+						      "$ext_type vsprintf pointer extension '$bad_specifier'$use\n" . "$here\n$stat_real\n");
 				}
 			}
 		}
-- 
2.37.3