[PATCH bpf-next] xsk: Simplify xp_aligned_validate_desc implementation

From: Kal Conley
Date: Mon Apr 10 2023 - 08:19:07 EST


Perform the chunk boundary check like the page boundary check in
xp_desc_crosses_non_contig_pg(). This simplifies the implementation and
reduces the number of branches.

Signed-off-by: Kal Conley <kal.conley@xxxxxxxxxxx>
---
net/xdp/xsk_queue.h | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index dea4f378327d..6d40a77fccbe 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -133,16 +133,12 @@ static inline bool xskq_cons_read_addr_unchecked(struct xsk_queue *q, u64 *addr)
static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
struct xdp_desc *desc)
{
- u64 chunk, chunk_end;
+ u64 offset = desc->addr & (pool->chunk_size - 1);

- chunk = xp_aligned_extract_addr(pool, desc->addr);
- if (likely(desc->len)) {
- chunk_end = xp_aligned_extract_addr(pool, desc->addr + desc->len - 1);
- if (chunk != chunk_end)
- return false;
- }
+ if (offset + desc->len > pool->chunk_size)
+ return false;

- if (chunk >= pool->addrs_cnt)
+ if (desc->addr >= pool->addrs_cnt)
return false;

if (desc->options)
--
2.39.2