dereference_symbol_descriptor() needs to obtain the module pointer
belonging to pointer in order to resolve that pointer.
The returned mod pointer is obtained under RCU-sched/ preempt_disable()
guarantees and needs to be used within this section to ensure that the
module is not removed in the meantime.
Extend the preempt_disable() section to also cover
dereference_module_function_descriptor().
Fixes: 04b8eb7a4ccd9 ("symbol lookup: introduce
dereference_symbol_descriptor()")
Cc: James E.J. Bottomley <james.bottom...@hansenpartnership.com>
Cc: Christophe Leroy <christophe.le...@csgroup.eu>
Cc: Helge Deller <del...@gmx.de>
Cc: Madhavan Srinivasan <ma...@linux.ibm.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Naveen N Rao <nav...@kernel.org>
Cc: Nicholas Piggin <npig...@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.w...@gmail.com>
Cc: linux-par...@vger.kernel.org
Cc: linuxppc-...@lists.ozlabs.org
Reviewed-by: Sergey Senozhatsky <senozhat...@chromium.org>
Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
include/linux/kallsyms.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index c3f075e8f60cb..1c6a6c1704d8d 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -57,10 +57,10 @@ static inline void *dereference_symbol_descriptor(void *ptr)
preempt_disable();
mod = __module_address((unsigned long)ptr);
- preempt_enable();
if (mod)
ptr = dereference_module_function_descriptor(mod, ptr);
+ preempt_enable();
#endif
return ptr;
}
--
2.47.1
