From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07E58C433DF for ; Thu, 6 Aug 2020 17:49:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DF83206B2 for ; Thu, 6 Aug 2020 17:49:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730544AbgHFRsz (ORCPT ); Thu, 6 Aug 2020 13:48:55 -0400 Received: from mga05.intel.com ([192.55.52.43]:60463 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728474AbgHFQfC (ORCPT ); Thu, 6 Aug 2020 12:35:02 -0400 IronPort-SDR: mb8azU7q6OnPasrYFMjQyzra+BPBUkyVmFji5lA2/4RKlNTbeRGFLEXVh8k5qTver1nfYW9jx4 1eRs6yuS7eFw== X-IronPort-AV: E=McAfee;i="6000,8403,9704"; a="237715846" X-IronPort-AV: E=Sophos;i="5.75,441,1589266800"; d="scan'208";a="237715846" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Aug 2020 09:34:57 -0700 IronPort-SDR: s9MnVWk0qnB+x3CrRPd9eSjg7CJ9npFh9AmIH8kbb4Yx51prYh0UhDnfZUpJrh+Bdf2gn+i8bs huYBepBTzgKg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,441,1589266800"; d="scan'208";a="276432190" Received: from lkp-server02.sh.intel.com (HELO 37a337f97289) ([10.239.97.151]) by fmsmga008.fm.intel.com with ESMTP; 06 Aug 2020 09:34:45 -0700 Received: from kbuild by 37a337f97289 with local (Exim 4.92) (envelope-from ) id 1k3iqq-0001Tw-Ae; Thu, 06 Aug 2020 16:34:44 +0000 Date: Fri, 7 Aug 2020 00:33:42 +0800 From: kernel test robot To: Daniel Borkmann Cc: kbuild-all@lists.01.org, linux-kernel@vger.kernel.org, Alexei Starovoitov Subject: arch/x86/net/bpf_jit_comp.c:342:6: warning: Variable 'ret' is reassigned a value before the old one has been used. Message-ID: <202008070037.Dz0HMdFX%lkp@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 47ec5303d73ea344e84f46660fff693c57641386 commit: 428d5df1fa4f28daf622c48dd19da35585c9053c bpf, x86: Emit patchable direct jump as tail call date: 9 months ago compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot cppcheck warnings: (new ones prefixed by >>) >> arch/x86/net/bpf_jit_comp.c:342:6: warning: Variable 'ret' is reassigned a value before the old one has been used. [redundantAssignment] ret = 0; ^ arch/x86/net/bpf_jit_comp.c:334:6: note: Variable 'ret' is reassigned a value before the old one has been used. ret = -EBUSY; ^ arch/x86/net/bpf_jit_comp.c:342:6: note: Variable 'ret' is reassigned a value before the old one has been used. ret = 0; ^ arch/x86/net/bpf_jit_comp.c:409:2: warning: Signed integer overflow for expression '72+(139<<8)+(132<<16)+(214<<24)'. [integerOverflow] EMIT4_off32(0x48, 0x8B, 0x84, 0xD6, /* mov rax, [rsi + rdx * 8 + offsetof(...)] */ ^ vim +/ret +342 arch/x86/net/bpf_jit_comp.c 267 268 static int __bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, 269 void *old_addr, void *new_addr, 270 const bool text_live) 271 { 272 int (*emit_patch_fn)(u8 **pprog, void *func, void *ip); 273 const u8 *nop_insn = ideal_nops[NOP_ATOMIC5]; 274 u8 old_insn[X86_PATCH_SIZE] = {}; 275 u8 new_insn[X86_PATCH_SIZE] = {}; 276 u8 *prog; 277 int ret; 278 279 switch (t) { 280 case BPF_MOD_NOP_TO_CALL ... BPF_MOD_CALL_TO_NOP: 281 emit_patch_fn = emit_call; 282 break; 283 case BPF_MOD_NOP_TO_JUMP ... BPF_MOD_JUMP_TO_NOP: 284 emit_patch_fn = emit_jump; 285 break; 286 default: 287 return -ENOTSUPP; 288 } 289 290 switch (t) { 291 case BPF_MOD_NOP_TO_CALL: 292 case BPF_MOD_NOP_TO_JUMP: 293 if (!old_addr && new_addr) { 294 memcpy(old_insn, nop_insn, X86_PATCH_SIZE); 295 296 prog = new_insn; 297 ret = emit_patch_fn(&prog, new_addr, ip); 298 if (ret) 299 return ret; 300 break; 301 } 302 return -ENXIO; 303 case BPF_MOD_CALL_TO_CALL: 304 case BPF_MOD_JUMP_TO_JUMP: 305 if (old_addr && new_addr) { 306 prog = old_insn; 307 ret = emit_patch_fn(&prog, old_addr, ip); 308 if (ret) 309 return ret; 310 311 prog = new_insn; 312 ret = emit_patch_fn(&prog, new_addr, ip); 313 if (ret) 314 return ret; 315 break; 316 } 317 return -ENXIO; 318 case BPF_MOD_CALL_TO_NOP: 319 case BPF_MOD_JUMP_TO_NOP: 320 if (old_addr && !new_addr) { 321 memcpy(new_insn, nop_insn, X86_PATCH_SIZE); 322 323 prog = old_insn; 324 ret = emit_patch_fn(&prog, old_addr, ip); 325 if (ret) 326 return ret; 327 break; 328 } 329 return -ENXIO; 330 default: 331 return -ENOTSUPP; 332 } 333 334 ret = -EBUSY; 335 mutex_lock(&text_mutex); 336 if (memcmp(ip, old_insn, X86_PATCH_SIZE)) 337 goto out; 338 if (text_live) 339 text_poke_bp(ip, new_insn, X86_PATCH_SIZE, NULL); 340 else 341 memcpy(ip, new_insn, X86_PATCH_SIZE); > 342 ret = 0; 343 out: 344 mutex_unlock(&text_mutex); 345 return ret; 346 } 347 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org