[PATCH v12 07/12] static_call: Define EXPORT_STATIC_CALL_FOR_MODULES()
From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Date: 2026-06-23 17:34:26
Also in:
bpf, kvm, linux-doc, lkml
Subsystem:
static branch/call, the rest · Maintainers:
Peter Zijlstra, Josh Poimboeuf, Jason Baron, Alice Ryhl, Linus Torvalds
There is EXPORT_STATIC_CALL_TRAMP() that hides the static key from all modules. But there is no equivalent of EXPORT_SYMBOL_FOR_MODULES() to restrict symbol visibility to only certain modules. Add EXPORT_STATIC_CALL_FOR_MODULES(name, mods) that wraps both the key and the trampoline with EXPORT_SYMBOL_FOR_MODULES(), allowing only a limited set of modules to see and update the static key. The immediate user is KVM, in the following commit. checkpatch reported below warnings with this change that I believe don't apply in this case: include/linux/static_call.h:219: WARNING: Non-declarative macros with multiple statements should be enclosed in a do - while loop include/linux/static_call.h:220: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> --- include/linux/static_call.h | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/include/linux/static_call.h b/include/linux/static_call.h
index 78a77a4ae0ea..b610afd1ed55 100644
--- a/include/linux/static_call.h
+++ b/include/linux/static_call.h@@ -216,6 +216,9 @@ extern long __static_call_return0(void); #define EXPORT_STATIC_CALL_GPL(name) \ EXPORT_SYMBOL_GPL(STATIC_CALL_KEY(name)); \ EXPORT_SYMBOL_GPL(STATIC_CALL_TRAMP(name)) +#define EXPORT_STATIC_CALL_FOR_MODULES(name, mods) \ + EXPORT_SYMBOL_FOR_MODULES(STATIC_CALL_KEY(name), mods); \ + EXPORT_SYMBOL_FOR_MODULES(STATIC_CALL_TRAMP(name), mods) /* Leave the key unexported, so modules can't change static call targets: */ #define EXPORT_STATIC_CALL_TRAMP(name) \
@@ -276,6 +279,9 @@ extern long __static_call_return0(void); #define EXPORT_STATIC_CALL_GPL(name) \ EXPORT_SYMBOL_GPL(STATIC_CALL_KEY(name)); \ EXPORT_SYMBOL_GPL(STATIC_CALL_TRAMP(name)) +#define EXPORT_STATIC_CALL_FOR_MODULES(name, mods) \ + EXPORT_SYMBOL_FOR_MODULES(STATIC_CALL_KEY(name), mods); \ + EXPORT_SYMBOL_FOR_MODULES(STATIC_CALL_TRAMP(name), mods) /* Leave the key unexported, so modules can't change static call targets: */ #define EXPORT_STATIC_CALL_TRAMP(name) \
@@ -346,6 +352,8 @@ static inline int static_call_text_reserved(void *start, void *end) #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_FOR_MODULES(name, mods) \ + EXPORT_SYMBOL_FOR_MODULES(STATIC_CALL_KEY(name), mods) #endif /* CONFIG_HAVE_STATIC_CALL */
--
2.34.1