From f744a064041cc1d84e1ad9d6a8e571f371850648 Mon Sep 17 00:00:00 2001 From: Haiyue Wang Date: Fri, 28 Jan 2022 18:47:14 +0800 Subject: [PATCH] gve: fix the wrong AdminQ buffer queue index check commit 1f84a9450d75e08af70d9e2f2d5e1c0ac0c881d2 upstream. The 'tail' and 'head' are 'unsigned int' type free-running count, when 'head' is overflow, the 'int i (= tail) < u32 head' will be false: Only '- loop 0: idx = 63' result is shown, so it needs to use 'int' type to compare, it can handle the overflow correctly. typedef uint32_t u32; int main() { u32 tail, head; int stail, shead; int i, loop; tail = 0xffffffff; head = 0x00000000; for (i = tail, loop = 0; i < head; i++) { unsigned int idx = i & 63; printf("+ loop %d: idx = %u\n", loop++, idx); } stail = tail; shead = head; for (i = stail, loop = 0; i < shead; i++) { unsigned int idx = i & 63; printf("- loop %d: idx = %u\n", loop++, idx); } return 0; } Fixes: 5cdad90de62c ("gve: Batch AQ commands for creating and destroying queues.") Signed-off-by: Haiyue Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/google/gve/gve_adminq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c index 6009d76e41fc..67f2b9a61463 100644 --- a/drivers/net/ethernet/google/gve/gve_adminq.c +++ b/drivers/net/ethernet/google/gve/gve_adminq.c @@ -141,7 +141,7 @@ static int gve_adminq_parse_err(struct gve_priv *priv, u32 status) */ static int gve_adminq_kick_and_wait(struct gve_priv *priv) { - u32 tail, head; + int tail, head; int i; tail = ioread32be(&priv->reg_bar0->adminq_event_counter);