arm64: Treat handle_arch_irq as a function pointer

handle_arch_irq isn't actually text, it's just a function pointer.
It doesn't need to be stored in the text section and doing so
causes problesm if we ever want to make the kernel text read only.
Declare handle_arch_irq as a proper function pointer stored in
the data section.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 622a409916f3..99c8d13fc00d 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -167,7 +167,8 @@ tsk	.req	x28		// current thread_info
  * Interrupt handling.
  */
         .macro  irq_handler
-        ldr     x1, handle_arch_irq
+        adrp    x1, handle_arch_irq
+        ldr     x1, [x1, #:lo12:handle_arch_irq]
         mov     x0, sp
         blr     x1
         .endm
@@ -699,6 +700,3 @@ ENTRY(sys_rt_sigreturn_wrapper)
         mov     x0, sp
         b       sys_rt_sigreturn
 ENDPROC(sys_rt_sigreturn_wrapper)
-
-ENTRY(handle_arch_irq)
-        .quad   0