From patchwork Fri Jul 28 05:57:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 13331220 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 922343D86 for ; Fri, 28 Jul 2023 05:57:56 +0000 (UTC) Received: from 69-171-232-180.mail-mxout.facebook.com (69-171-232-180.mail-mxout.facebook.com [69.171.232.180]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F7B226BC for ; Thu, 27 Jul 2023 22:57:54 -0700 (PDT) Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 3F7A223CA2676; Thu, 27 Jul 2023 22:57:40 -0700 (PDT) From: Yonghong Song To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@fb.com, Martin KaFai Lau , kernel test robot Subject: [PATCH bpf-next 1/2] bpf: Fix compilation warning with -Wparentheses Date: Thu, 27 Jul 2023 22:57:40 -0700 Message-Id: <20230728055740.2284534-1-yonghong.song@linux.dev> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_BLOCKED,RDNS_DYNAMIC,SPF_HELO_PASS,SPF_SOFTFAIL, TVD_RCVD_IP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net The kernel test robot reported compilation warnings when -Wparentheses is added to KBUILD_CFLAGS with gcc compiler. The following is the error message: .../bpf-next/kernel/bpf/verifier.c: In function ‘coerce_reg_to_size_sx’: .../bpf-next/kernel/bpf/verifier.c:5901:14: error: suggest parentheses around comparison in operand of ‘==’ [-Werror=parentheses] if (s64_max >= 0 == s64_min >= 0) { ~~~~~~~~^~~~ .../bpf-next/kernel/bpf/verifier.c: In function ‘coerce_subreg_to_size_sx’: .../bpf-next/kernel/bpf/verifier.c:5965:14: error: suggest parentheses around comparison in operand of ‘==’ [-Werror=parentheses] if (s32_min >= 0 == s32_max >= 0) { ~~~~~~~~^~~~ To fix the issue, add proper parentheses for the above '>=' condition to silence the warning/error. I tried a few clang compilers like clang16 and clang18 and they do not emit such warnings with -Wparentheses. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202307281133.wi0c4SqG-lkp@intel.com/ Signed-off-by: Yonghong Song Acked-by: Jiri Olsa --- kernel/bpf/core.c | 4 ++-- kernel/bpf/verifier.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index db0b631908c2..baccdec22f19 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1877,7 +1877,7 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) case 1: AX = abs((s32)DST); do_div(AX, abs((s32)SRC)); - if ((s32)DST < 0 == (s32)SRC < 0) + if (((s32)DST < 0) == ((s32)SRC < 0)) DST = (u32)AX; else DST = (u32)-AX; @@ -1904,7 +1904,7 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) case 1: AX = abs((s32)DST); do_div(AX, abs((s32)IMM)); - if ((s32)DST < 0 == (s32)IMM < 0) + if (((s32)DST < 0) == ((s32)IMM < 0)) DST = (u32)AX; else DST = (u32)-AX; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 0b1ada93582b..e7b1af016841 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5898,7 +5898,7 @@ static void coerce_reg_to_size_sx(struct bpf_reg_state *reg, int size) s64_min = min(init_s64_max, init_s64_min); /* both of s64_max/s64_min positive or negative */ - if (s64_max >= 0 == s64_min >= 0) { + if ((s64_max >= 0) == (s64_min >= 0)) { reg->smin_value = reg->s32_min_value = s64_min; reg->smax_value = reg->s32_max_value = s64_max; reg->umin_value = reg->u32_min_value = s64_min; @@ -5962,7 +5962,7 @@ static void coerce_subreg_to_size_sx(struct bpf_reg_state *reg, int size) s32_max = max(init_s32_max, init_s32_min); s32_min = min(init_s32_max, init_s32_min); - if (s32_min >= 0 == s32_max >= 0) { + if ((s32_min >= 0) == (s32_max >= 0)) { reg->s32_min_value = s32_min; reg->s32_max_value = s32_max; reg->u32_min_value = (u32)s32_min;