[PATCH] xsk: Fix umem fill/completion queue mmap on 32-bit

From: Geert Uytterhoeven
Date: Thu Jun 07 2018 - 09:38:21 EST


With gcc-4.1.2 on 32-bit:

net/xdp/xsk.c:663: warning: integer constant is too large for âlongâ type
net/xdp/xsk.c:665: warning: integer constant is too large for âlongâ type

Add the missing "ULL" suffixes to the large XDP_UMEM_PGOFF_*_RING values
to fix this.

net/xdp/xsk.c:663: warning: comparison is always false due to limited range of data type
net/xdp/xsk.c:665: warning: comparison is always false due to limited range of data type

"unsigned long" is 32-bit on 32-bit systems, hence the offset is
truncated, and can never be equal to any of the XDP_UMEM_PGOFF_*_RING
values. Use loff_t (and the required cast) to fix this.

Fixes: 423f38329d267969 ("xsk: add umem fill queue support and mmap")
Fixes: fe2308328cd2f26e ("xsk: add umem completion queue support and mmap")
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
Compile-tested only.
---
include/uapi/linux/if_xdp.h | 4 ++--
net/xdp/xsk.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
index 1fa0e977ea8d0224..caed8b1614ffc0aa 100644
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -63,8 +63,8 @@ struct xdp_statistics {
/* Pgoff for mmaping the rings */
#define XDP_PGOFF_RX_RING 0
#define XDP_PGOFF_TX_RING 0x80000000
-#define XDP_UMEM_PGOFF_FILL_RING 0x100000000
-#define XDP_UMEM_PGOFF_COMPLETION_RING 0x180000000
+#define XDP_UMEM_PGOFF_FILL_RING 0x100000000ULL
+#define XDP_UMEM_PGOFF_COMPLETION_RING 0x180000000ULL

/* Rx/Tx descriptor */
struct xdp_desc {
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index c6ed2454f7ce55e8..36919a254ba370c3 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -643,7 +643,7 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
static int xsk_mmap(struct file *file, struct socket *sock,
struct vm_area_struct *vma)
{
- unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+ loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
unsigned long size = vma->vm_end - vma->vm_start;
struct xdp_sock *xs = xdp_sk(sock->sk);
struct xsk_queue *q = NULL;
--
2.7.4