[v3] Added warnings in checkpatch.pl script to :
diff mbox series

Message ID 20190709122417.25778-1-nitin.r.gote@intel.com
State Superseded
Headers show
Series
  • [v3] Added warnings in checkpatch.pl script to :
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Commit Message

Gote, Nitin R July 9, 2019, 12:24 p.m. UTC
From: Nitin Gote <nitin.r.gote@intel.com>

1. Deprecate strcpy() in favor of strscpy().
2. Deprecate strlcpy() in favor of strscpy().
3. Deprecate strncpy() in favor of strscpy() or strscpy_pad().

Updated strncpy() section in Documentation/process/deprecated.rst
to cover strscpy_pad() case.

Signed-off-by: Nitin Gote <nitin.r.gote@intel.com>
---
 Change log:
 v1->v2
 - For string related apis, created different %deprecated_string_api
   and these will get emitted at CHECK Level using command line option
   -f/--file to avoid bad patched from novice script users.

 v2->v3
 - Avoided use of $check in implementation.
 - Incorporated trivial comments.

 Documentation/process/deprecated.rst |  6 +++---
 scripts/checkpatch.pl                | 24 ++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)

--
2.17.1

Comments

Jonathan Corbet July 9, 2019, 1:40 p.m. UTC | #1
On Tue,  9 Jul 2019 17:54:17 +0530
NitinGote <nitin.r.gote@intel.com> wrote:

> From: Nitin Gote <nitin.r.gote@intel.com>

The patch needs a proper subject line.

> 1. Deprecate strcpy() in favor of strscpy().
> 2. Deprecate strlcpy() in favor of strscpy().
> 3. Deprecate strncpy() in favor of strscpy() or strscpy_pad().
> 
> Updated strncpy() section in Documentation/process/deprecated.rst
> to cover strscpy_pad() case.
> 
> Signed-off-by: Nitin Gote <nitin.r.gote@intel.com>
> ---
>  Change log:
>  v1->v2
>  - For string related apis, created different %deprecated_string_api
>    and these will get emitted at CHECK Level using command line option
>    -f/--file to avoid bad patched from novice script users.
> 
>  v2->v3
>  - Avoided use of $check in implementation.
>  - Incorporated trivial comments.
> 
>  Documentation/process/deprecated.rst |  6 +++---
>  scripts/checkpatch.pl                | 24 ++++++++++++++++++++++++
>  2 files changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/process/deprecated.rst b/Documentation/process/deprecated.rst
> index 49e0f64a3427..f564de3caf76 100644
> --- a/Documentation/process/deprecated.rst
> +++ b/Documentation/process/deprecated.rst
> @@ -93,9 +93,9 @@ will be NUL terminated. This can lead to various linear read overflows
>  and other misbehavior due to the missing termination. It also NUL-pads the
>  destination buffer if the source contents are shorter than the destination
>  buffer size, which may be a needless performance penalty for callers using
> -only NUL-terminated strings. The safe replacement is :c:func:`strscpy`.
> -(Users of :c:func:`strscpy` still needing NUL-padding will need an
> -explicit :c:func:`memset` added.)
> +only NUL-terminated strings. In this case, the safe replacement is
> +:c:func:`strscpy`. If, however, the destination buffer still needs
> +NUL-padding, the safe replacement is :c:func:`strscpy_pad`.

Please don't use :c:func: in anything new; just write that as strscpy()
(or whatever) and The Right Thing will happen.

(Maybe we need a checkpatch rule for that :)

Thanks,

jon

Patch
diff mbox series

diff --git a/Documentation/process/deprecated.rst b/Documentation/process/deprecated.rst
index 49e0f64a3427..f564de3caf76 100644
--- a/Documentation/process/deprecated.rst
+++ b/Documentation/process/deprecated.rst
@@ -93,9 +93,9 @@  will be NUL terminated. This can lead to various linear read overflows
 and other misbehavior due to the missing termination. It also NUL-pads the
 destination buffer if the source contents are shorter than the destination
 buffer size, which may be a needless performance penalty for callers using
-only NUL-terminated strings. The safe replacement is :c:func:`strscpy`.
-(Users of :c:func:`strscpy` still needing NUL-padding will need an
-explicit :c:func:`memset` added.)
+only NUL-terminated strings. In this case, the safe replacement is
+:c:func:`strscpy`. If, however, the destination buffer still needs
+NUL-padding, the safe replacement is :c:func:`strscpy_pad`.

 If a caller is using non-NUL-terminated strings, :c:func:`strncpy()` can
 still be used, but destinations should be marked with the `__nonstring
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index bb28b178d929..e6fbf4cf4be4 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -605,6 +605,20 @@  foreach my $entry (keys %deprecated_apis) {
 }
 $deprecated_apis_search = "(?:${deprecated_apis_search})";

+our %deprecated_string_apis = (
+        "strcpy"				=> "strscpy",
+        "strlcpy"				=> "strscpy",
+        "strncpy"				=> "strscpy, strscpy_pad or for non-NUL-terminated strings, strncpy() can still be used, but destinations should be marked with the __nonstring",
+);
+
+#Create a search pattern for all these strings apis to speed up a loop below
+our $deprecated_string_apis_search = "";
+foreach my $entry (keys %deprecated_string_apis) {
+        $deprecated_string_apis_search .= '|' if ($deprecated_string_apis_search ne "");
+        $deprecated_string_apis_search .= $entry;
+}
+$deprecated_string_apis_search = "(?:${deprecated_string_apis_search})";
+
 our $mode_perms_world_writable = qr{
 	S_IWUGO		|
 	S_IWOTH		|
@@ -6446,6 +6460,16 @@  sub process {
 			     "Deprecated use of '$deprecated_api', prefer '$new_api' instead\n" . $herecurr);
 		}

+# check for string deprecated apis
+		if ($line =~ /\b($deprecated_string_apis_search)\b\s*\(/) {
+			my $deprecated_string_api = $1;
+			my $new_api = $deprecated_string_apis{$deprecated_string_api};
+			my $msg_level = \&WARN;
+			$msg_level = \&CHK if ($file);
+			&{$msg_level}("DEPRECATED_API",
+				      "Deprecated use of '$deprecated_string_api', prefer '$new_api' instead\n" . $herecurr);
+		}
+
 # check for various structs that are normally const (ops, kgdb, device_tree)
 # and avoid what seem like struct definitions 'struct foo {'
 		if ($line !~ /\bconst\b/ &&