diff mbox series

[net-next,v2,1/3] compiler_types: add Endianness-dependent __counted_by_{le,be}

Message ID 20240327142241.1745989-2-aleksander.lobakin@intel.com (mailing list archive)
State Accepted
Commit ca7e324e8ad385a2da15049953c04ea7310687f7
Delegated to: Netdev Maintainers
Headers show
Series compiler_types: add Endianness-dependent __counted_by_{le,be} | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 15406 this patch: 15406
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 3 maintainers not CCed: linux-doc@vger.kernel.org corbet@lwn.net przemyslaw.kitszel@intel.com
netdev/build_clang success Errors and warnings before: 2143 this patch: 2143
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 16565 this patch: 16565
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 32 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-03-28--03-00 (tests: 949)

Commit Message

Alexander Lobakin March 27, 2024, 2:22 p.m. UTC
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 <keescook@chromium.org>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 Documentation/conf.py          |  2 ++
 scripts/kernel-doc             |  1 +
 include/linux/compiler_types.h | 11 +++++++++++
 3 files changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/Documentation/conf.py b/Documentation/conf.py
index d148f3e8dd57..0c2205d536b3 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/scripts/kernel-doc b/scripts/kernel-doc
index 967f1abb0edb..1474e95dbe4f 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;
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 2abaa3a825a9..a29ba6ef1e27 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")))