From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta1.migadu.com (out-170.mta1.migadu.com [95.215.58.170]) (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 A22D9325490 for ; Tue, 14 Apr 2026 07:20:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776151255; cv=none; b=lRruk2xuZTC8jwXeNCyKhQ8Sf3Um5sQdYA9sK+VTajUxIqt2fzevX65lX/R0PibJopEMDiyeTWrsbPo1EGTx9YgB4Vx2LvuGf0exsTSdWX+YuI0k0z5Lx1Y6RVj6hKqnbSke58Sf118cu0Fa1/xuyKTknxH6YVbkq3FZJv1tIIQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776151255; c=relaxed/simple; bh=TvqoUFtdRQgG8n3xt/GZMJTs4jRmjc77KYgL/IbN+O0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VQ6x+REk9Z7zhEOdE703eDgfyHuQMkbKfDg7D3x2n6mNKiAVyjIL5NBejjg3jPJAjq5X/aYNp29Jo1diNTL7H/DlsqENQ3fMc7+D7WzmoSokrDvdeKxFsvCIlYX+p5X0HomvpCVpzwsMXPL74D/Hq4CJ/NK43Qz6wMtbEXgH5pg= 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=bChfPImS; arc=none smtp.client-ip=95.215.58.170 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="bChfPImS" Date: Tue, 14 Apr 2026 15:20:33 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1776151241; 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: in-reply-to:in-reply-to:references:references; bh=JPWYjo9GhqaMpwQ+mEVfK6/tiojaazojzQ0cBIRZ8mo=; b=bChfPImSqYu4PwGtucE+CcphBwv4vWnwTUwbVosYoWuncoTp/VY/esGiJ1QDfgKqf7W9Nf EFwgQaAFmBf2MXUGOIv8/Cseejsr4ds1ljv4cITBnukmOckSCL/A7KO4D9Lp7sMuKfn1Xg OhYTLpr/s1hYd50w32rFUqv54THNMtQ= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Baoquan He To: "Uladzislau Rezki (Sony)" Cc: linux-mm@kvack.org, Andrew Morton , Baoquan He , LKML , stable@vger.kernel.org, chenyichong Subject: Re: [PATCH] mm/vmalloc: Take vmap_purge_lock in shrinker Message-ID: References: <20260413192646.14683-1-urezki@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260413192646.14683-1-urezki@gmail.com> X-Migadu-Flow: FLOW_OUT On 04/13/26 at 09:26pm, Uladzislau Rezki (Sony) wrote: > decay_va_pool_node() can be invoked concurrently from two paths: > __purge_vmap_area_lazy() when pools are being purged, and the > shrinker via vmap_node_shrink_scan(). > > However, decay_va_pool_node() is not safe to run concurrently, > and the shrinker path currently lacks serialization, leading > to races and possible leaks. > > Protect decay_va_pool_node() by taking vmap_purge_lock in the > shrinker path to ensure serialization with purge users. > > Cc: stable@vger.kernel.org > Cc: chenyichong > Fixes: 7679ba6b36db ("mm: vmalloc: add a shrinker to drain vmap pools") > Signed-off-by: Uladzislau Rezki (Sony) > --- > mm/vmalloc.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 61caa55a4402..676851d5cfe7 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -5416,6 +5416,7 @@ vmap_node_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) > { > struct vmap_node *vn; > > + guard(mutex)(&vmap_purge_lock); > for_each_vmap_node(vn) > decay_va_pool_node(vn, true); LGTM, Reviewed-by: Baoquan He