fs/procfs: fix integer to pointer cast warning in do_procmap_query()

On 32-bit architectures compiler will complain about casting __u64 to void * pointer:

fs/proc/task_mmu.c: In function 'do_procmap_query':
fs/proc/task_mmu.c:598:48: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
598 | if (karg.vma_name_size && copy_to_user((void __user *)karg.vma_name_addr,
| ^
fs/proc/task_mmu.c:605:48: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
605 | if (karg.build_id_size && copy_to_user((void __user *)karg.build_id_addr,
| ^

Fix this by using u64_to_user_ptr() helper that's meant to handle this properly.

---
 fs/proc/task_mmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index d99a390a0f41..3f1d0d2f78fe 100644
@@ -595,14 +595,14 @@ static int do_procmap_query(struct proc_maps_private *priv, void __user *uarg)
 	query_vma_teardown(mm, vma);
 	mmput(mm);
 
-	if (karg.vma_name_size && copy_to_user((void __user *)karg.vma_name_addr,
+	if (karg.vma_name_size && copy_to_user(u64_to_user_ptr(karg.vma_name_addr),
 					       name, karg.vma_name_size)) {
 		kfree(name_buf);
 		return -EFAULT;
 	}
 	kfree(name_buf);
 
-	if (karg.build_id_size && copy_to_user((void __user *)karg.build_id_addr,
+	if (karg.build_id_size && copy_to_user(u64_to_user_ptr(karg.build_id_addr),
 					       build_id_buf, karg.build_id_size))
 		return -EFAULT;
 

2.43.0

Kernel provides compat_ptr_ioctl() wrapper to sanitize pointers for 32-bit processes on 64-bit host architectures. Given procfs_procmap_ioctl() always expects pointer argument, this is exactly what we need.

This has any effect only on 32-bit processes on s390 architecture.

---
 fs/proc/task_mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 3f1d0d2f78fe..b7bb4d04e962 100644
@@ -637,7 +637,7 @@ const struct file_operations proc_pid_maps_operations = {
 	.llseek		= seq_lseek,
 	.release	= proc_map_release,
 	.unlocked_ioctl = procfs_procmap_ioctl,
-	.compat_ioctl	= procfs_procmap_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
 };
 
 /*

2.43.0