From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) (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 4B4C6191F94 for ; Wed, 22 Apr 2026 00:29:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776817767; cv=none; b=Dcd5KSs5ndTFac9mXD911DzL9ZZy3E1Kxu1act4YIe+c6nHgJMN6E6HyT6VCa1piv8WUBTskppiF2GKBLRix1q1C/XVCQ3pxjOZnlqmgj5mGXQO6suR5JppGQat6cq7p3tX8bLaTyx9iCZc+43AdewzmxePb4wRM0qMWcCkQyzA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776817767; c=relaxed/simple; bh=zH0U4ineaEs07T53qcgS0oQ74H5dGaHaSXFnTIvWlms=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=oI1292QSzd7yG3d06lePnubRmaUo44QOMa0QHf3lTcd53E+PvMiS5TaLzfcqfX7yAC+bdIYCZSe2pQ1JXbvZy0a8+nipO2sBnz1POPLJlJ25odhhuX8vOAlsMuU26jt0aAKfp6nj3kcLCUxFY9ecOZPtJrd22/cu2mj35huT8wM= 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=nAuOLEct; arc=none smtp.client-ip=91.218.175.170 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="nAuOLEct" Message-ID: <5323628d-65d6-4fbf-a302-2f5d3e2d46e1@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1776817762; 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=qWj/5q9t4uwb3E+DgLdW4JaDawhpaJfxsxaAHuuwY1c=; b=nAuOLEctBlMxX9my98ebK/MEvDVwUVvfnVu//rjqXn5CXVIU6cBA0arRrRp1F2dx9lwUJG +RFXs3wNTZGAW2/3a9r/HsFx1ede8+OaO14y5UTCqwAklvF0LVpl5bCGT0EE6ouwb6ANnq U5YDgRIU16EeUNnNpVkLc4dtjt9Khvo= Date: Tue, 21 Apr 2026 17:29:15 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next 2/9] bpf: Fix tail_call_reachable leak Content-Language: en-GB To: bot+bpf-ci@kernel.org, bpf@vger.kernel.org Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, jose.marchesi@oracle.com, kernel-team@fb.com, martin.lau@kernel.org, eddyz87@gmail.com, clm@meta.com, ihor.solodrai@linux.dev References: <20260421171937.3508679-1-yonghong.song@linux.dev> <154d4ed659716997501257309218648961b1f25de606e411a8f84cf16b95cc5a@mail.kernel.org> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song In-Reply-To: <154d4ed659716997501257309218648961b1f25de606e411a8f84cf16b95cc5a@mail.kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 4/21/26 11:06 AM, bot+bpf-ci@kernel.org wrote: > commit 697f215251be114235dcf2ec469f425797a26a51 > Author: Yonghong Song > > bpf: Fix tail_call_reachable leak > > This commit fixes a leak of the local tail_call_reachable flag across > sibling subprogs during the DFS traversal in > check_max_stack_depth_subprog(), which caused the JIT to emit > unnecessary tail call counter preservation code for subprogs that > could not be reached via a tail call path. > > Should this commit carry a Fixes: tag? The buggy pattern (set > tail_call_reachable to true on push, never reset on pop, then mark all > currently-on-stack frames) appears to have been introduced by commit > ebf7d1f508a7 ("bpf, x64: rework pro/epilogue and tailcall handling in > JIT") which originally added tail_call_reachable tracking to the > stack-depth DFS. > > Something like: > > Fixes: ebf7d1f508a7 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT") The above fix tag is in 2020 so it has been 5+ years. BTW, this is not really a bug although in certain cases it may cause more stack space than needed. I would skip Fixes tag for this patch. > > > --- > AI reviewed your patch. Please fix the bug or email reply why it's not a bug. > See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md > > CI run summary: https://github.com/kernel-patches/bpf/actions/runs/24736686700