The patch titled
Subject: Documentation/checkpatch: prefer stracpy/strscpy over strcpy/strlcpy/strncpy.
has been added to the -mm tree. Its filename is
documentation-checkpatch-prefer-stracpy-strscpy-over-strcpy-strlcpy-strncpy.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/documentation-checkpatch-prefer-stracpy-strscpy-over-strcpy-strlcpy-strncpy.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/documentation-checkpatch-prefer-stracpy-strscpy-over-strcpy-strlcpy-strncpy.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Nitin Gote <nitin.r.gote@xxxxxxxxx>
Subject: Documentation/checkpatch: prefer stracpy/strscpy over strcpy/strlcpy/strncpy.
Add check in checkpatch.pl to deprecate strcpy(), strlcpy() and strncpy()
in favor of stracpy() or strscpy().
Update Documentation/process/deprecated.rst for stracpy() and strscpy().
Link: http://lkml.kernel.org/r/20190728160608.3119-1-nitin.r.gote@xxxxxxxxx
Signed-off-by: Nitin Gote <nitin.r.gote@xxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/process/deprecated.rst | 10 +++++-----
scripts/checkpatch.pl | 24 ++++++++++++++++++++++++
2 files changed, 29 insertions(+), 5 deletions(-)
--- a/Documentation/process/deprecated.rst~documentation-checkpatch-prefer-stracpy-strscpy-over-strcpy-strlcpy-strncpy
+++ a/Documentation/process/deprecated.rst
@@ -84,7 +84,7 @@ buffer. This could result in linear over
end of the buffer, leading to all kinds of misbehaviors. While
`CONFIG_FORTIFY_SOURCE=y` and various compiler flags help reduce the
risk of using this function, there is no good reason to add new uses of
-this function. The safe replacement is :c:func:`strscpy`.
+this function. The safe replacement is stracpy() or strscpy().
strncpy() on NUL-terminated strings
-----------------------------------
@@ -93,9 +93,9 @@ will be NUL terminated. This can lead to
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
+stracpy() or strscpy(). If, however, the destination buffer still needs
+NUL-padding, the safe replacement is stracpy_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
@@ -107,7 +107,7 @@ strlcpy()
:c:func:`strlcpy` reads the entire source buffer first, possibly exceeding
the given limit of bytes to copy. This is inefficient and can lead to
linear read overflows if a source string is not NUL-terminated. The
-safe replacement is :c:func:`strscpy`.
+safe replacement is stracpy() or strscpy().
Variable Length Arrays (VLAs)
-----------------------------
--- a/scripts/checkpatch.pl~documentation-checkpatch-prefer-stracpy-strscpy-over-strcpy-strlcpy-strncpy
+++ a/scripts/checkpatch.pl
@@ -605,6 +605,20 @@ foreach my $entry (keys %deprecated_apis
}
$deprecated_apis_search = "(?:${deprecated_apis_search})";
+our %deprecated_string_apis = (
+ "strcpy" => "stracpy or strscpy",
+ "strlcpy" => "stracpy or strscpy",
+ "strncpy" => "stracpy or strscpy - for non-NUL-terminated uses, strncpy dest should be __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/ &&
_
Patches currently in -mm which might be from nitin.r.gote@xxxxxxxxx are
documentation-checkpatch-prefer-stracpy-strscpy-over-strcpy-strlcpy-strncpy.patch
