xsk: Remove unnecessary member in xdp_umem

Remove the unnecessary member of address in struct xdp_umem as it is
only used during the umem registration. No need to carry this around
as it is not used during run-time nor when unregistering the umem.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1588599232-24897-3-git-send-email-magnus.karlsson@intel.com

include/net/xdp_sock.h

@@ -50,7 +50,6 @@ struct xdp_umem {
 	u32 headroom;
 	u32 chunk_size_nohr;
 	struct user_struct *user;
-	unsigned long address;
 	refcount_t users;
 	struct work_struct work;
 	struct page **pgs;

net/xdp/xdp_umem.c

@@ -279,7 +279,7 @@ void xdp_put_umem(struct xdp_umem *umem)
 	}
 }
 
-static int xdp_umem_pin_pages(struct xdp_umem *umem)
+static int xdp_umem_pin_pages(struct xdp_umem *umem, unsigned long address)
 {
 	unsigned int gup_flags = FOLL_WRITE;
 	long npgs;
@@ -291,7 +291,7 @@ static int xdp_umem_pin_pages(struct xdp_umem *umem)
 		return -ENOMEM;
 
 	down_read(&current->mm->mmap_sem);
-	npgs = pin_user_pages(umem->address, umem->npgs,
+	npgs = pin_user_pages(address, umem->npgs,
 			      gup_flags | FOLL_LONGTERM, &umem->pgs[0], NULL);
 	up_read(&current->mm->mmap_sem);
 
@@ -385,7 +385,6 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 	if (headroom >= chunk_size - XDP_PACKET_HEADROOM)
 		return -EINVAL;
 
-	umem->address = (unsigned long)addr;
 	umem->chunk_mask = unaligned_chunks ? XSK_UNALIGNED_BUF_ADDR_MASK
 					    : ~((u64)chunk_size - 1);
 	umem->size = size;
@@ -404,7 +403,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 	if (err)
 		return err;
 
-	err = xdp_umem_pin_pages(umem);
+	err = xdp_umem_pin_pages(umem, (unsigned long)addr);
 	if (err)
 		goto out_account;