Re: [PATCH v4 02/12] block/bdev: Annotate the blk_holder_ops callback functions

[Bart Van Assche <bvanassche@acm.org>]

On 5/11/26 3:19 PM, Marco Elver wrote:
> On Mon, 11 May 2026 at 18:31, Bart Van Assche <bvanassche@acm.org> wrote:
>>
>> The four callback functions in blk_holder_ops all release the
>> bd_holder_lock. Annotate these functions accordingly.
>>
>> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> 
> Because of this change we'll need clang 23, or you add:
> 
> CONTEXT_ANALYSIS := $(call clang-min-version, 230000)
> 
> .. although anything else that includes blkdev.h that has
> CONTEXT_ANALYSIS := y, but is compiled with clang 22 will break.
> 
> Would have been good to wait for clang 23 to be released (August this
> year) - although if we consider the next merge window + final release
> of Linux 7.2, it might get reasonably close to August.

Hi Marco,

How about detecting whether or not Clang supports context annotations
for function pointers, e.g. as follows?

diff --git a/init/Kconfig b/init/Kconfig
index 2937c4d308ae..61e592205179 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -32,6 +32,9 @@ config CLANG_VERSION
  	default $(cc-version) if CC_IS_CLANG
  	default 0

+config CC_CONTEXT_ANNOTATIONS_ON_FUNCTION_POINTERS
+	def_bool $(success, echo 'struct __attribute__((capability("m"))) m { 
}; struct a { void (*fp)(struct m* m) 
__attribute__((release_capability(m))); };' | $(CC) -x c - -c -Wall 
-Wextra -Werror -o /dev/null)
+
  config AS_IS_GNU
  	def_bool $(success,test "$(as-name)" = GNU)


Thanks,

Bart.