arm64: Add kasan_hw_tags_enable() prototype to silence sparse

This function is only called from assembly, no need for a prototype
declaration in a header file. In addition, add #ifdef around the
function since it is only used when CONFIG_KASAN_HW_TAGS.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: kernel test robot <lkp@intel.com>

diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index 57b30bcf9f21de03bc58a6b6b133329eb8cd4c55..f6b00743c3994a19f78be4b81b52a6c570800ec3 100644 (file)
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -244,6 +244,11 @@ static void mte_update_gcr_excl(struct task_struct *task)
                SYS_GCR_EL1);
 }
 
+#ifdef CONFIG_KASAN_HW_TAGS
+/* Only called from assembly, silence sparse */
+void __init kasan_hw_tags_enable(struct alt_instr *alt, __le32 *origptr,
+                                __le32 *updptr, int nr_inst);
+
 void __init kasan_hw_tags_enable(struct alt_instr *alt, __le32 *origptr,
                                 __le32 *updptr, int nr_inst)
 {
@@ -252,6 +257,7 @@ void __init kasan_hw_tags_enable(struct alt_instr *alt, __le32 *origptr,
        if (kasan_hw_tags_enabled())
                *updptr = cpu_to_le32(aarch64_insn_gen_nop());
 }
+#endif
 
 void mte_thread_init_user(void)
 {