Messages in this thread Patch in this message | | | From | Ard Biesheuvel <> | Subject | [RFC PATCH 7/7] static_call: add generic support for non-exported keys | Date | Tue, 9 Nov 2021 17:45:49 +0100 |
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The static_call feature where only the static call target is exposed to modules while access to the key is withheld is only implemented for the inline and out-of-line varieties, but not for the generic indirect call based variety.
Let's use static_call_query() to obtain the call target address if the key is not exported. Note that this means we can do the converse as well, i.e., implement static_call_query() in terms of the key struct if the key is exported, so we only need to export one of the two.
Note that this adds an additional load and potentially a direct call to the instantiations of static_call residing in module code.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- include/linux/static_call.h | 4 ++-- include/linux/static_call_types.h | 3 +-- tools/include/linux/static_call_types.h | 3 +-- 3 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/include/linux/static_call.h b/include/linux/static_call.h index 21929147879a..d88fd613f06d 100644 --- a/include/linux/static_call.h +++ b/include/linux/static_call.h @@ -302,8 +302,8 @@ static inline int static_call_text_reserved(void *start, void *end) return 0; } -#define EXPORT_STATIC_CALL(name) EXPORT_SYMBOL(STATIC_CALL_KEY(name)) -#define EXPORT_STATIC_CALL_GPL(name) EXPORT_SYMBOL_GPL(STATIC_CALL_KEY(name)) +#define EXPORT_STATIC_CALL(name) EXPORT_STATIC_CALL_QUERY(name,) +#define EXPORT_STATIC_CALL_GPL(name) EXPORT_STATIC_CALL_QUERY(name, _GPL) #define EXPORT_STATIC_CALL_FOR_UPDATE(name) EXPORT_SYMBOL(STATIC_CALL_KEY(name)) #define EXPORT_STATIC_CALL_FOR_UPDATE_GPL(name) EXPORT_SYMBOL_GPL(STATIC_CALL_KEY(name)) diff --git a/include/linux/static_call_types.h b/include/linux/static_call_types.h index eae11c5b015d..920828ad1d69 100644 --- a/include/linux/static_call_types.h +++ b/include/linux/static_call_types.h @@ -106,8 +106,7 @@ struct static_call_key { void *func; }; -#define static_call(name) \ - ((typeof(STATIC_CALL_QUERY(name)()))(STATIC_CALL_KEY(name).func)) +#define static_call(name) static_call_query(name) #endif /* CONFIG_HAVE_STATIC_CALL */ diff --git a/tools/include/linux/static_call_types.h b/tools/include/linux/static_call_types.h index eae11c5b015d..920828ad1d69 100644 --- a/tools/include/linux/static_call_types.h +++ b/tools/include/linux/static_call_types.h @@ -106,8 +106,7 @@ struct static_call_key { void *func; }; -#define static_call(name) \ - ((typeof(STATIC_CALL_QUERY(name)()))(STATIC_CALL_KEY(name).func)) +#define static_call(name) static_call_query(name) #endif /* CONFIG_HAVE_STATIC_CALL */ -- 2.30.2
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