xtensa: use MEMBLOCK_ALLOC_ANYWHERE for KASAN shadow map

commit e64681b487c897ec871465083bf0874087d47b66 upstream.

KASAN shadow map doesn't need to be accessible through the linear kernel
mapping, allocate its pages with MEMBLOCK_ALLOC_ANYWHERE so that high
memory can be used. This frees up to ~100MB of low memory on xtensa
configurations with KASAN and high memory.

Cc: stable@vger.kernel.org # v5.1+
Fixes: f240ec09bb8a ("memblock: replace memblock_alloc_base(ANYWHERE) with memblock_phys_alloc")
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/xtensa/mm/kasan_init.c b/arch/xtensa/mm/kasan_init.c
index af71525..b771459 100644 (file)
--- a/arch/xtensa/mm/kasan_init.c
+++ b/arch/xtensa/mm/kasan_init.c
@@ -56,7 +56,9 @@ static void __init populate(void *start, void *end)
 
                for (k = 0; k < PTRS_PER_PTE; ++k, ++j) {
                        phys_addr_t phys =
-                               memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+                               memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE,
+                                                         0,
+                                                         MEMBLOCK_ALLOC_ANYWHERE);
 
                        if (!phys)
                                panic("Failed to allocate page table page\n");