From ca7e324e8ad385a2da15049953c04ea7310687f7 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Wed, 27 Mar 2024 15:22:39 +0100 Subject: [PATCH] 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: Kees Cook Acked-by: Gustavo A. R. Silva Signed-off-by: Alexander Lobakin Reviewed-by: Przemek Kitszel Link: https://lore.kernel.org/r/20240327142241.1745989-2-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski --- Documentation/conf.py | 2 ++ include/linux/compiler_types.h | 11 +++++++++++ scripts/kernel-doc | 1 + 3 files changed, 14 insertions(+) diff --git a/Documentation/conf.py b/Documentation/conf.py index d148f3e8dd572..0c2205d536b38 100644 --- a/Documentation/conf.py +++ b/Documentation/conf.py @@ -75,6 +75,8 @@ if major >= 3: "__rcu", "__user", "__force", + "__counted_by_le", + "__counted_by_be", # include/linux/compiler_attributes.h: "__alias", diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 2abaa3a825a9e..a29ba6ef1e275 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -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"))) diff --git a/scripts/kernel-doc b/scripts/kernel-doc index 967f1abb0edbd..1474e95dbe4f0 100755 --- a/scripts/kernel-doc +++ b/scripts/kernel-doc @@ -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; -- 2.30.2