From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-173.mta1.migadu.com (out-173.mta1.migadu.com [95.215.58.173]) (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 905EC1F4634 for ; Thu, 12 Feb 2026 01:14:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770858889; cv=none; b=n5T0cY3WAR73coqkKnQCX4ud7Y2fWe9pAzDx1QKbZgKtvEQ+3kput1J+FHnp5KwUiwbJRDIcseg1VE74GTWzPmmBgNawOL8t757c6IdgC0UO/sd0ePNOHP8bjqKXxdY0qCVTw270MoUUxomRrplh5np3NsRhLrjLVDtl7jlmX7I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770858889; c=relaxed/simple; bh=yM1ccGWJitx0+WTiHAo7F0fQXHUFWHzBwuaDPI2/4Uc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N/LzNY/2zmnKMd59LqThFY9qs/YYFNWMayiwWHIg21VK1BS4zdnAGmymz89KEBueUHRDRHk85RP54u7Vv+0I4M49YN1SBod+6Vz0sR1kNh34n6JgHY9nRt9AA3mtbp+KOzdz3p/ZyWLB3h5gWn7s/TkKSSP82tFBxqAGZ9lXOFc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=vaGWQ4DE; arc=none smtp.client-ip=95.215.58.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="vaGWQ4DE" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1770858886; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DjCyTymnNRA4SVevlIpD5/RjOO+nGAgUAHsQw7CcXlU=; b=vaGWQ4DExg+LUePrT8qQxbh97itOtPlQIEK/mZ7vexfo+q7x/Zz454twvGLr/+jFKzGdx7 j7RnHemQr0mWxCuApGG5f5bqqxTT4ie9jiNMi7U6J19k/Jo8q1EE/KOVoH2sW+CtXB8CYq Rdarec4AucK9xqXi7Rgo/LQDgFoZWrw= From: Ihor Solodrai To: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Eduard Zingerman Cc: Amery Hung , Mykyta Yatsenko , =?UTF-8?q?Alexis=20Lothor=C3=A9?= , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: [PATCH bpf-next v1 12/14] selftests/bpf: Fix array bounds warning in jit_disasm_helpers Date: Wed, 11 Feb 2026 17:13:54 -0800 Message-ID: <20260212011356.3266753-13-ihor.solodrai@linux.dev> In-Reply-To: <20260212011356.3266753-1-ihor.solodrai@linux.dev> References: <20260212011356.3266753-1-ihor.solodrai@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Compiler cannot infer upper bound for labels.cnt and warns about potential buffer overflow in snprintf. Add an explicit bounds check (... && i < MAX_LOCAL_LABELS) in the loop condition to fix the warning. Signed-off-by: Ihor Solodrai --- .../testing/selftests/bpf/jit_disasm_helpers.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/tools/testing/selftests/bpf/jit_disasm_helpers.c b/tools/testing/selftests/bpf/jit_disasm_helpers.c index febd6b12e372..364c557c5115 100644 --- a/tools/testing/selftests/bpf/jit_disasm_helpers.c +++ b/tools/testing/selftests/bpf/jit_disasm_helpers.c @@ -122,15 +122,15 @@ static int disasm_one_func(FILE *text_out, uint8_t *image, __u32 len) pc += cnt; } qsort(labels.pcs, labels.cnt, sizeof(*labels.pcs), cmp_u32); - for (i = 0; i < labels.cnt; ++i) - /* gcc is unable to infer upper bound for labels.cnt and assumes - * it to be U32_MAX. U32_MAX takes 10 decimal digits. - * snprintf below prints into labels.names[*], - * which has space only for two digits and a letter. - * To avoid truncation warning use (i % MAX_LOCAL_LABELS), - * which informs gcc about printed value upper bound. - */ - snprintf(labels.names[i], sizeof(labels.names[i]), "L%d", i % MAX_LOCAL_LABELS); + /* gcc is unable to infer upper bound for labels.cnt and + * assumes it to be U32_MAX. U32_MAX takes 10 decimal digits. + * snprintf below prints into labels.names[*], which has space + * only for two digits and a letter. To avoid truncation + * warning use (i < MAX_LOCAL_LABELS), which informs gcc about + * printed value upper bound. + */ + for (i = 0; i < labels.cnt && i < MAX_LOCAL_LABELS; ++i) + snprintf(labels.names[i], sizeof(labels.names[i]), "L%d", i); /* now print with labels */ labels.print_phase = true; -- 2.53.0