[kbuild-all] Re: [PATCH net-next v2 09/12] gtp: support GRO

Hi Jonas, I love your patch! Perhaps something to improve: [auto build test WARNING on net-next/master] url: https://github.com/0day-ci/linux/commits/Jonas-Bonn/gtp-IPv6-support/2020... base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 91163f82143630a9629a8bf0227d49173697c69c config: mips-randconfig-r026-20201209 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 5ff35356f1af2bb92785b38c657463924d9ec386) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://github.com/0day-ci/linux/commit/de5669628a8f684dd7ed378aaf2a99722... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jonas-Bonn/gtp-IPv6-support/20201211-203639 git checkout de5669628a8f684dd7ed378aaf2a997221d243fa # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): if (!ptype) ^~~~~~~~~~~ include/linux/compiler.h:56:28: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( , ## __VA_ARGS__) ) ) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:58:30: note: expanded from macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) (cond) : __trace_if_value(cond)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/gtp.c:413:9: note: uninitialized use occurs here return err; ^~~ drivers/net/gtp.c:402:2: note: remove the 'if' if its condition is always false if (!ptype) ^~~~~~~~~~~ include/linux/compiler.h:56:23: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( , ## __VA_ARGS__) ) ) ^ default: ^~~~~~~ drivers/net/gtp.c:413:9: note: uninitialized use occurs here return err; ^~~ drivers/net/gtp.c:372:9: note: initialize the variable 'err' to silence this warning int err; ^ = 0 fatal error: error in backend: Nested variants found in inline asm string: ' .set push .set mips64r2 .if ( 0x00 ) != -1)) 0x00 ) != -1)) : ($( static struct ftrace_branch_data __attribute__((__aligned__(4))) __attribute__((__section__("_ftrace_branch"))) __if_trace = $( .func = __func__, .file = "arch/mips/include/asm/atomic.h", .line = 153, $); 0x00 ) != -1)) : $))) ) && ( 0 ); .set push; .set mips64r2; .rept 1; sync 0x00; .endr; .set pop; .else; ; .endif 1: ll $1, $2 # atomic_fetch_add addu $0, $1, $3 sc $0, $2 beqz $0, 1b .set pop move $0, $1 ' clang-12: error: clang frontend command failed with exit code 70 (use -v to see invocation) clang version 12.0.0 (git://gitmirror/llvm_project 5ff35356f1af2bb92785b38c657463924d9ec386) Target: mipsel-unknown-linux-gnu Thread model: posix InstalledDir: /opt/cross/clang-5ff35356f1/bin clang-12: note: diagnostic msg: Makefile arch drivers include kernel scripts source usr vim +402 drivers/net/gtp.c 363 364 static int gtp_gro_complete(struct sock *sk, struct sk_buff * skb, int nhoff) 365 { 366 size_t hdrlen; 367 char* gtphdr = skb->data + nhoff; 368 u8 version; 369 __be16 type; 370 struct packet_offload *ptype; 371 uint8_t ipver; 372 int err; 373 374 version = *gtphdr >> 5; 375 switch (version) { 376 case GTP_V0: 377 hdrlen = sizeof(struct gtp0_header); 378 break; 379 case GTP_V1: 380 hdrlen = sizeof(struct gtp1_header); 381 if (*gtphdr & GTP1_F_MASK) 382 hdrlen += 4; 383 break; 384 } 385 386 skb_set_inner_network_header(skb, nhoff + hdrlen); 387 388 ipver = inner_ip_hdr(skb)->version; 389 switch (ipver) { 390 case 4: 391 type = cpu_to_be16(ETH_P_IP); 392 break; 393 case 6: 394 type = cpu_to_be16(ETH_P_IPV6); 395 break; 397 goto out; 398 } 399 400 rcu_read_lock(); 401 ptype = gro_find_complete_by_type(type); 403 goto out_unlock; 404 405 err = ptype->callbacks.gro_complete(skb, nhoff + hdrlen); 406 407 skb_set_inner_mac_header(skb, nhoff + hdrlen); 408 409 out_unlock: 410 rcu_read_unlock(); 411 out: 412 413 return err; 414 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org