From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) (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 3CA4FF9C1 for ; Tue, 23 Sep 2025 15:52:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758642774; cv=none; b=V2Uu6ctWzq65QwTV2/W/8IUPhOD8EwOdV1QWxMqsj/ZwCb6dT9lCxDXXQLl2GPVZ8itT9sRll38sZPXDp5135aSCgdyV5GR4ZL4Xd+hY+jcoCbKsazYZGpyWYLAsNIvIHWZJ+pNOxHZxYLnhnWKNaz7ZN8c5lQPg3dsOIbEZWBQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758642774; c=relaxed/simple; bh=PnpRvo09XTjbG2aAavbxTie+QSPI947MmMHhOImIDNo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=SSbYsanZrvckDus4LTAdusXOCJdagBKFY4NyTJ3rqr+t9IMEkGcH74I2sbjRrVlOmHg0zMyQ2CtQYxqpVNKKr3xK6cJL1oZe7FY3vRIWci0J2xXbxaiV/R4M8tiScokeOeiJoKfoc1bHwa8uT6npBLZn1To1n8PlHQnqt0Cayf8= 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=aZmzvq78; arc=none smtp.client-ip=91.218.175.180 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="aZmzvq78" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1758642769; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=L5q1uku/Oh2asAwKNHxn7ONSxaJvndYdtaJFhqtsfjY=; b=aZmzvq78MAfqgatem/bWdtQFYlBVVbvHcPuEkPoK7dWP3l+M/cIIV8CX1RcCnI7V5Iqhpi oW4bu4G2S7SWXis13LsJNZxdtqFk9sKMIsP0gsXgiibFvN/SD7/r75nfZiIw8m2MQpgbbl 8HLMYSEHhmqCKNzXLxphL2hOeqvmx4w= Date: Tue, 23 Sep 2025 23:52:43 +0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [RFC PATCH bpf-next v2 4/6] bpf: Add common attr support for map_create To: Alexei Starovoitov , Andrii Nakryiko Cc: bpf , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Menglong Dong References: <20250911163328.93490-1-leon.hwang@linux.dev> <20250911163328.93490-5-leon.hwang@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Leon Hwang In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 2025/9/18 05:49, Alexei Starovoitov wrote: > On Wed, Sep 17, 2025 at 2:39 PM Andrii Nakryiko > wrote: >> >> On Thu, Sep 11, 2025 at 9:33 AM Leon Hwang wrote: >>> [...] >>> >>> + if (common_attrs->log_buf) { >>> + log = kvzalloc(sizeof(*log), GFP_KERNEL); >>> + if (!log) >>> + return -ENOMEM; >>> + err = bpf_vlog_init(log, BPF_LOG_FIXED, u64_to_user_ptr(common_attrs->log_buf), >>> + common_attrs->log_size, NULL); >>> + if (err) { >>> + kvfree(log); >>> + return err; >>> + } >>> + } >> >> what if we keep bpf_verifier_log on stack? It's 1KB, should be still >> fine to be on kernel stack, no? > > 1k is a lot. I'm pretty nervous about stack usage. kmalloc is cheap. > Let's use it. I'd drop 'v' part. There is no way it will fallback > to valloc() even if we double BPF_VERIFIER_TMP_LOG_SIZE in the future. I'll drop 'v' part in the next revision. Thanks, Leon