[PATCH v9 15/27] scripts: checkpatch: diagnose uses of `%pA` in the C side as errors

Miguel Ojeda
2022-08-05T15:46:15Z

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 503e8abbb2c1..23799e8013b3 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6782,15 +6782,19 @@ 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");
}
}
}
--
2.37.1