arm64: mte: set VM_MTE_ALLOWED for hugetlbfs at correct place

The commit 5de1950 ("mm: resolve faulty mmap_region() error path
behaviour") moved vm flags validation before fop->mmap for file
mappings.  But when commit 25c17c4 ("hugetlb: arm64: add mte support")
was rebased on top of it, the hugetlbfs part was missed.  Mmapping
hugetlbfs file may not have MAP_HUGETLB set.

Fixes: 25c17c4 ("hugetlb: arm64: add mte support")
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20241119200914.1145249-1-yang@os.amperecomputing.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: Yang Shi

arch/arm64/include/asm/mman.h

@@ -7,6 +7,7 @@
 #ifndef BUILD_VDSO
 #include <linux/compiler.h>
 #include <linux/fs.h>
+#include <linux/hugetlb.h>
 #include <linux/shmem_fs.h>
 #include <linux/types.h>
 
@@ -44,7 +45,7 @@ static inline unsigned long arch_calc_vm_flag_bits(struct file *file,
 	if (system_supports_mte()) {
 		if (flags & (MAP_ANONYMOUS | MAP_HUGETLB))
 			return VM_MTE_ALLOWED;
-		if (shmem_file(file))
+		if (shmem_file(file) || is_file_hugepages(file))
 			return VM_MTE_ALLOWED;
 	}
 

fs/hugetlbfs/inode.c

@@ -113,7 +113,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 	 * way when do_mmap unwinds (may be important on powerpc
 	 * and ia64).
 	 */
-	vm_flags_set(vma, VM_HUGETLB | VM_DONTEXPAND | VM_MTE_ALLOWED);
+	vm_flags_set(vma, VM_HUGETLB | VM_DONTEXPAND);
 	vma->vm_ops = &hugetlb_vm_ops;
 
 	ret = seal_check_write(info->seals, vma);