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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 3BF112119B X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-2.98 / 50.00]; BAYES_HAM(-3.00)[100.00%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.17)[-0.867]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; ARC_NA(0.00)[]; URIBL_BLOCKED(0.00)[suse.de:mid,suse.de:dkim,imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[vger.kernel.org,nop.hu,gmail.com,intel.com,kernel.org,fomichev.me]; DKIM_TRACE(0.00)[suse.de:+]; TO_DN_SOME(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCVD_TLS_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; RCPT_COUNT_SEVEN(0.00)[9]; RCVD_VIA_SMTP_AUTH(0.00)[]; TAGGED_RCPT(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns,suse.de:mid,suse.de:dkim] X-Rspamd-Action: no action X-Spam-Flag: NO X-Spam-Score: -2.98 X-Spam-Level: On 10/21/25 6:25 PM, Simon Horman wrote: > On Tue, Oct 21, 2025 at 05:06:56PM +0200, Fernando Fernandez Mancera wrote: > > ... > >> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c > > ... > >> @@ -774,6 +777,7 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, >> { >> struct net_device *dev = xs->dev; >> struct sk_buff *skb = xs->skb; >> + struct page *page; >> int err; >> >> if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { >> @@ -791,6 +795,8 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, >> len = desc->len; >> >> if (!skb) { >> + struct xsk_addr_node *head_addr; >> + >> hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); >> tr = dev->needed_tailroom; >> skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); >> @@ -804,7 +810,13 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, >> if (unlikely(err)) >> goto free_err; >> >> - xsk_skb_init_misc(skb, xs, desc->addr); >> + head_addr = kmem_cache_zalloc(xsk_tx_generic_cache, GFP_KERNEL); >> + if (!head_addr) { >> + __free_page(page); > > Hi Fernando, > > Perhaps the page changes to xsk_build_skb() aren't needed > because page seems to be uninitialised here. > > Flagged by W=1 builds with Clang 21.1.1, and Smatch. > Ah, I don't know know what I was thinking about.. but yes, that page handling isn't needed of course as it isn't initialized. (I even needed the page struct because it wasn't available in that context). I will send a V2 patch if the proposed solution is accepted. In additon, the performance impact isn't as bad as I thought.. just 4 bytes pero skb.. as the cache must be initialized anyway. >> + err = -ENOMEM; >> + goto free_err; >> + } >> + xsk_skb_init_misc(skb, xs, head_addr, desc->addr); >> if (desc->options & XDP_TX_METADATA) { >> err = xsk_skb_metadata(skb, buffer, desc, >> xs->pool, hr); >> @@ -814,7 +826,6 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, >> } else { >> int nr_frags = skb_shinfo(skb)->nr_frags; >> struct xsk_addr_node *xsk_addr; >> - struct page *page; >> u8 *vaddr; >> >> if (unlikely(nr_frags == (MAX_SKB_FRAGS - 1) && xp_mb_desc(desc))) { >> @@ -843,7 +854,7 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, >> refcount_add(PAGE_SIZE, &xs->sk.sk_wmem_alloc); >> >> xsk_addr->addr = desc->addr; >> - list_add_tail(&xsk_addr->addr_node, &XSKCB(skb)->addrs_list); >> + list_add_tail(&xsk_addr->addr_node, &XSK_TX_HEAD(skb)->addr_node); >> } >> } >> >> -- >> 2.51.0 >> >>