tree: https://git.kernel.org/pub/scm/linux/kernel/git/martineau/linux.git mptcp-wakeup-squash head: 6822da7f0ab8a763ae3f89326bc0210d1eaa69a7 commit: 746f3d1d594de82d7889dab9fec32727f1b739d5 [15/19] mptcp: rework mptcp_sendmsg_frag to accept optional dfrag config: sh-magicpanelr2_defconfig (attached as .config) compiler: sh4-linux-gcc (GCC) 7.4.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 746f3d1d594de82d7889dab9fec32727f1b739d5 # save the attached .config to linux build tree GCC_VERSION=7.4.0 make.cross ARCH=sh If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): net//mptcp/protocol.c: In function 'mptcp_sendmsg_frag': poffset = &pfrag->offset; ^ In file included from include/linux/kernel.h:15:0, from net//mptcp/protocol.c:9: net//mptcp/protocol.c: In function 'mptcp_recvmsg': include/linux/kern_levels.h:5:18: warning: format '%ld' expects argument of type 'long int', but argument 4 has type 'size_t {aka unsigned int}' [-Wformat=] #define KERN_SOH "\001" /* ASCII Start Of Header */ ^ include/linux/printk.h:137:10: note: in definition of macro 'no_printk' printk(fmt, ##__VA_ARGS__); \ ^~~ include/linux/kern_levels.h:15:20: note: in expansion of macro 'KERN_SOH' #define KERN_DEBUG KERN_SOH "7" /* debug-level messages */ ^~~~~~~~ include/linux/printk.h:342:12: note: in expansion of macro 'KERN_DEBUG' no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~~~ net//mptcp/protocol.c:677:4: note: in expansion of macro 'pr_debug' pr_debug("Dup data, map len=%d acked=%lld dropped=%ld", ^~~~~~~~ net//mptcp/protocol.c:677:56: note: format string is defined here pr_debug("Dup data, map len=%d acked=%lld dropped=%ld", ~~^ %d cc1: some warnings being treated as errors vim +242 net//mptcp/protocol.c 165 166 static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, 167 struct msghdr *msg, struct mptcp_data_frag *dfrag, 168 long *timeo, int *pmss_now, 169 int *ps_goal) 170 { 171 int mss_now, avail_size, size_goal, offset, ret, frag_truesize = 0; 172 bool dfrag_collapsed, collapsed, can_collapse = false; 173 struct mptcp_sock *msk = mptcp_sk(sk); 174 struct mptcp_ext *mpext = NULL; 175 bool retransmission = !!dfrag; 176 struct page_frag *pfrag; 177 struct sk_buff *skb; 178 struct page *page; 179 u64 *write_seq; 180 size_t psize; 181 int *poffset; 182 183 /* use the mptcp page cache so that we can easily move the data 184 * from one substream to another, but do per subflow memory accounting 185 * Note: pfrag is used only !retransmission, but the compiler if 186 * fooled into a warning if we don't init here 187 */ 188 pfrag = sk_page_frag(sk); 189 if (!retransmission) { 190 while (!mptcp_page_frag_refill(ssk, pfrag)) { 191 ret = sk_stream_wait_memory(ssk, timeo); 192 if (ret) 193 return ret; 194 195 /* id sk_stream_wait_memory() sleeps snd_una can change 196 * significantly, refresh the rtx queue 197 */ 198 mptcp_clean_una(sk); 199 } 200 write_seq = &msk->write_seq; 201 page = pfrag->page; 202 } else { 203 write_seq = &dfrag->data_seq; 204 page = dfrag->page; 205 } 206 207 /* compute copy limit */ 208 mss_now = tcp_send_mss(ssk, &size_goal, msg->msg_flags); 209 *pmss_now = mss_now; 210 *ps_goal = size_goal; 211 avail_size = size_goal; 212 skb = tcp_write_queue_tail(ssk); 213 if (skb) { 214 mpext = skb_ext_find(skb, SKB_EXT_MPTCP); 215 216 /* Limit the write to the size available in the 217 * current skb, if any, so that we create at most a new skb. 218 * Explicitly tells TCP internals to avoid collapsing on later 219 * queue management operation, to avoid breaking the ext <-> 220 * SSN association set here 221 */ 222 can_collapse = (size_goal - skb->len > 0) && 223 mptcp_skb_can_collapse_to(*write_seq, skb, mpext); 224 if (!can_collapse) 225 TCP_SKB_CB(skb)->eor = 1; 226 else 227 avail_size = size_goal - skb->len; 228 } 229 230 if (!retransmission) { 231 /* reuse tail pfrag, if possible, or carve a new one from the 232 * page allocator 233 */ 234 dfrag = mptcp_rtx_tail(sk); 235 offset = pfrag->offset; 236 dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag); 237 if (!dfrag_collapsed) { 238 dfrag = mptcp_carve_data_frag(msk, pfrag, offset); 239 offset = dfrag->offset; 240 frag_truesize = dfrag->overhead; 241 } 243 psize = min_t(size_t, pfrag->size - offset, avail_size); 244 245 /* Copy to page */ 246 pr_debug("left=%zu", msg_data_left(msg)); 247 psize = copy_page_from_iter(pfrag->page, offset, 248 min_t(size_t, msg_data_left(msg), 249 psize), 250 &msg->msg_iter); 251 pr_debug("left=%zu", msg_data_left(msg)); 252 if (!psize) 253 return -EINVAL; 254 255 if (!sk_wmem_schedule(sk, psize + dfrag->overhead)) 256 return -ENOMEM; 257 } else { 258 offset = dfrag->offset; 259 poffset = &dfrag->offset; 260 psize = min_t(size_t, dfrag->data_len, avail_size); 261 } 262 263 /* tell the TCP stack to delay the push so that we can safely 264 * access the skb after the sendpages call 265 */ 266 ret = do_tcp_sendpages(ssk, page, offset, psize, 267 msg->msg_flags | MSG_SENDPAGE_NOTLAST); 268 if (ret <= 0) 269 return ret; 270 271 frag_truesize += ret; 272 if (!retransmission) { 273 if (unlikely(ret < psize)) 274 iov_iter_revert(&msg->msg_iter, psize - ret); 275 276 /* send successful, keep track of sent data for mptcp-level 277 * retransmission 278 */ 279 dfrag->data_len += ret; 280 if (!dfrag_collapsed) { 281 get_page(dfrag->page); 282 list_add_tail(&dfrag->list, &msk->rtx_queue); 283 } 284 285 /* charge data on mptcp rtx queue to the master socket 286 * Note: we charge such data both to sk and ssk 287 */ 288 sk->sk_forward_alloc -= frag_truesize; 289 } 290 291 collapsed = skb == tcp_write_queue_tail(ssk); 292 if (collapsed) { 293 WARN_ON_ONCE(!can_collapse); 294 /* when collapsing mpext always exists */ 295 mpext->data_len += ret; 296 goto out; 297 } 298 299 skb = tcp_write_queue_tail(ssk); 300 mpext = skb_ext_add(skb, SKB_EXT_MPTCP); 301 if (mpext) { 302 memset(mpext, 0, sizeof(*mpext)); 303 mpext->data_seq = *write_seq; 304 mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq; 305 mpext->data_len = ret; 306 mpext->use_map = 1; 307 mpext->dsn64 = 1; 308 309 pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d", 310 mpext->data_seq, mpext->subflow_seq, mpext->data_len, 311 mpext->dsn64); 312 } 313 /* TODO: else fallback; allocation can fail, but we can't easily retire 314 * skbs from the write_queue, as we need to roll-back TCP status 315 */ 316 317 out: 318 *poffset += frag_truesize; 319 *write_seq += ret; 320 mptcp_subflow_ctx(ssk)->rel_write_seq += ret; 321 322 return ret; 323 } 324 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation