riscv: Fix config KASAN && DEBUG_VIRTUAL

commit c648c4b upstream.

__virt_to_phys function is called very early in the boot process (ie
kasan_early_init) so it should not be instrumented by KASAN otherwise it
bugs.

Fix this by declaring phys_addr.c as non-kasan instrumentable.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Fixes: 8ad8b72 (riscv: Add KASAN support)
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/riscv/mm/Makefile

@@ -24,6 +24,9 @@ obj-$(CONFIG_KASAN)   += kasan_init.o
 ifdef CONFIG_KASAN
 KASAN_SANITIZE_kasan_init.o := n
 KASAN_SANITIZE_init.o := n
+ifdef CONFIG_DEBUG_VIRTUAL
+KASAN_SANITIZE_physaddr.o := n
+endif
 endif
 
 obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o