From b54de55990b0467538c6bb33523b28816384958a Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Wed, 7 Aug 2024 17:06:12 +0100 Subject: net: ethtool: fix off-by-one error in max RSS context IDs Both ethtool_ops.rxfh_max_context_id and the default value used when it's not specified are supposed to be exclusive maxima (the former is documented as such; the latter, U32_MAX, cannot be used as an ID since it equals ETH_RXFH_CONTEXT_ALLOC), but xa_alloc() expects an inclusive maximum. Subtract one from 'limit' to produce an inclusive maximum, and pass that to xa_alloc(). Increase bnxt's max by one to prevent a (very minor) regression, as BNXT_MAX_ETH_RSS_CTX is an inclusive max. This is safe since bnxt is not actually hard-limited; BNXT_MAX_ETH_RSS_CTX is just a leftover from old driver code that managed context IDs itself. Rename rxfh_max_context_id to rxfh_max_num_contexts to make its semantics (hopefully) more obvious. Fixes: 847a8ab18676 ("net: ethtool: let the core choose RSS context IDs") Signed-off-by: Edward Cree Link: https://patch.msgid.link/5a2d11a599aa5b0cc6141072c01accfb7758650c.1723045898.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski --- net/ethtool/ioctl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/ethtool/ioctl.c') diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index 8ca13208d240..a8e276ecf723 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -1449,12 +1449,13 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev, } if (ops->create_rxfh_context) { - u32 limit = ops->rxfh_max_context_id ?: U32_MAX; + u32 limit = ops->rxfh_max_num_contexts ?: U32_MAX; u32 ctx_id; /* driver uses new API, core allocates ID */ ret = xa_alloc(&dev->ethtool->rss_ctx, &ctx_id, ctx, - XA_LIMIT(1, limit), GFP_KERNEL_ACCOUNT); + XA_LIMIT(1, limit - 1), + GFP_KERNEL_ACCOUNT); if (ret < 0) { kfree(ctx); goto out; -- cgit v1.2.3-70-g09d2