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 4D9CE3A1685 for ; Mon, 3 Aug 2026 06:34:38 +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=1785738880; cv=none; b=tf6xrTC7Dt1wqaeXQwbFFf8XwVfiFLph/PpYB8rBJ8TBNjdpDCUCawzbGBjv/dahtvFgd9MUN66XsFUxo7z35ToTjifAWh9HDmrE9oTHgjLMGIs8WU/SiRo1SxXXb+6wfFLqqS1KMY9VKCRVgqNwsHaLbJoIAz3BdNQpd8z/Gds= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785738880; c=relaxed/simple; bh=Nc5ILKBpIxWImQ2M0yKwLU+3q1q3QiYiBz7CJt3Q8E0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LvvdLlKTBYAC6HlaM5k2636lbNktsSwwu75s+l29oVh6NgOFns5oXzUCX8/etWBews5YMYpskUEpg8DeItij9yQgqvbm7QsrSrWo8sqVTJkIm3g9S3TeFcxz8ef5hK4AWmKwT8b0AINM8T8e5yF/z8o3L0yMXXYZ+4g6QrVJXpQ= 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=GmtggV4T; 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="GmtggV4T" Date: Mon, 3 Aug 2026 14:34:12 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1785738875; 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=8F1oQGuofg8Bs6Kuu5rlugX4pqZD+nld29FuWkWFcM4=; b=GmtggV4T/zXlj/aw4XfIWtjA0VjHzg9Bguf43nZfd67JDi8aylqNjnp+M2rYrdHuLBKKg9 0wktZvSVsfALZo7igJ+ctBM3dA9lpELnSql0xS+X5fCxWslwSz4XkWHnEhp0lEGTXe5kcQ pnPpKwfJEFnGZ/7tdcsy1g55elkNP0Y= 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 , syzbot+61c997e6be1d9bb300ba@syzkaller.appspotmail.com Subject: Re: [PATCH] mm/vmalloc: Do not warn on -ENOMEM from va_alloc() Message-ID: References: <20260802104627.63892-1-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: <20260802104627.63892-1-urezki@gmail.com> X-Migadu-Flow: FLOW_OUT On 08/02/26 at 12:46pm, Uladzislau Rezki (Sony) wrote: > Since vmalloc() accepts non-blocking GFP flags, allocation > requests may fail when callers pass restrictive GFP masks. > > va_clip() may return -ENOMEM when its GFP_NOWAIT fallback > allocation fails during NE_FIT_TYPE splitting. This is an > expected failure, so va_alloc() should return the error > without triggering a kernel splat. > > Reported-by: syzbot+61c997e6be1d9bb300ba@syzkaller.appspotmail.com > Signed-off-by: Uladzislau Rezki (Sony) > --- > mm/vmalloc.c | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 1afca3568b9b..7a0cbba3d29d 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1817,8 +1817,10 @@ va_alloc(struct vmap_area *va, > > /* Update the free vmap_area. */ > ret = va_clip(root, head, va, nva_start_addr, size); > - if (WARN_ON_ONCE(ret)) > + if (ret) { > + WARN_ON_ONCE(ret != -ENOMEM); > return ret; > + } > > return nva_start_addr; > } > @@ -1891,12 +1893,9 @@ preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node) > > /* > * Preload this CPU with one extra vmap_area object. It is used > - * when fit type of free area is NE_FIT_TYPE. It guarantees that > - * a CPU that does an allocation is preloaded. > - * > - * We do it in non-atomic context, thus it allows us to use more > - * permissive allocation masks to be more stable under low memory > - * condition and high memory pressure. > + * when fit type of free area is NE_FIT_TYPE. It is best effort > + * pre-loading. If it fails va_clip() may return -ENOMEM from its > + * GFP_NOWAIT fallback. > */ > if (!this_cpu_read(ne_fit_preload_node)) > va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); LGTM, Reviewed-by: Baoquan He