On Tue, 9 Nov 2021 at 19:53, Peter Zijlstra [off-list ref] wrote:
On Tue, Nov 09, 2021 at 05:45:45PM +0100, Ard Biesheuvel wrote:
quoted
@@ -196,13 +190,21 @@ extern long __static_call_return0(void);
EXPORT_SYMBOL_GPL(STATIC_CALL_KEY(name)); \
EXPORT_SYMBOL_GPL(STATIC_CALL_TRAMP(name))
+#define EXPORT_STATIC_CALL_GETKEY_HELPER(name) \
+ struct static_call_key *STATIC_CALL_GETKEY(name)(void) { \
+ BUG_ON(!core_kernel_text( \
+ (unsigned long)__builtin_return_address(0))); \
+ return &STATIC_CALL_KEY(name); \
+ } \
+ EXPORT_SYMBOL_GPL(STATIC_CALL_GETKEY(name))
So if I were a nevarious module, I would look up the above symbol from
kallsyms (it is exported and easily obtainable) and then simply
read the text to discover the key address and we're in business.
Yeah I realised that. So would you prefer to have a
.static_call_tramp_key section in each module and look up the keys in
the module loader?
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel