Commit ca7e324e authored by Alexander Lobakin's avatar Alexander Lobakin Committed by Jakub Kicinski
Browse files

compiler_types: add Endianness-dependent __counted_by_{le,be} 



Some structures contain flexible arrays at the end and the counter for
them, but the counter has explicit Endianness and thus __counted_by()
can't be used directly.

To increase test coverage for potential problems without breaking
anything, introduce __counted_by_{le,be}() defined depending on
platform's Endianness to either __counted_by() when applicable or noop
otherwise.
Maybe it would be a good idea to introduce such attributes on compiler
level if possible, but for now let's stop on what we have.

Acked-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: default avatarAlexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: default avatarPrzemek Kitszel <przemyslaw.kitszel@intel.com>
Link: https://lore.kernel.org/r/20240327142241.1745989-2-aleksander.lobakin@intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6e9b0190

Documentation/conf.py

+2 −0
Original line number Diff line number Diff line
@@ -75,6 +75,8 @@ if major >= 3: 
            "__rcu",

            "__user",

            "__force",

            "__counted_by_le",

            "__counted_by_be",



            # include/linux/compiler_attributes.h:

            "__alias",

include/linux/compiler_types.h

+11 −0
Original line number Diff line number Diff line
@@ -282,6 +282,17 @@ struct ftrace_likely_data { 
#define __no_sanitize_or_inline __always_inline

#endif



/*

 * Apply __counted_by() when the Endianness matches to increase test coverage.

 */

#ifdef __LITTLE_ENDIAN

#define __counted_by_le(member)	__counted_by(member)

#define __counted_by_be(member)

#else

#define __counted_by_le(member)

#define __counted_by_be(member)	__counted_by(member)

#endif



/* Do not trap wrapping arithmetic within an annotated function. */

#ifdef CONFIG_UBSAN_SIGNED_WRAP

# define __signed_wrap __attribute__((no_sanitize("signed-integer-overflow")))

scripts/kernel-doc

+1 −0
Original line number Diff line number Diff line
@@ -1143,6 +1143,7 @@ sub dump_struct($$) { 
        $members =~ s/\s*$attribute/ /gi;

        $members =~ s/\s*__aligned\s*\([^;]*\)/ /gos;

        $members =~ s/\s*__counted_by\s*\([^;]*\)/ /gos;

        $members =~ s/\s*__counted_by_(le|be)\s*\([^;]*\)/ /gos;

        $members =~ s/\s*__packed\s*/ /gos;

        $members =~ s/\s*CRYPTO_MINALIGN_ATTR/ /gos;

        $members =~ s/\s*____cacheline_aligned_in_smp/ /gos;