From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 6390C379EFF for ; Thu, 10 Sep 2026 14:39:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789051178; cv=none; b=IiH9tvnm11b/Nuj2bw+5686D1N3otw4ZH9clK7jEyxxCHbMGkWrpv60JAq1lepcws+BOzQCZZP7TChgM6woomhLkGgBodpjbXKOhXRETAVFfhrce0qlaU0UgKRNhNFqsOHxIRqJW3G4vLx7s+EQbHU7a92wUJDA26oZFE1DJIxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789051178; c=relaxed/simple; bh=nQqD24AcBqX87/qO9vz7xMHPW+yH8JkWx7cQ1A9H9Ns=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IOeDYGalbA5C9T4PyN4mRqqV/LTgFoDYGV/TJr6uTM/zgNn8X5LP3s8LhWut5E9A1XDw/VQNR087bWRNqb0G5xZCnVRfI4VygcUvtoS29r2MWpKa3YH7gkQiioTjlKt2pK38/+tjiwdgSCVkYX6fhvLM8v3E4TTFLZa06PooarM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MfNPYgMW; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MfNPYgMW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BCA11F00898; Thu, 10 Sep 2026 14:39:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789051176; bh=+fqCevs9JI8L0cAkSZhcUZiF/uweXIl1iADi68j65hU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MfNPYgMWSqIbJ9vx5N1g8I2Yua5I4UST8B0c9PlSlklzHGBpE4B6RmiZ5EWCGOS1w /mMQkF2AEl64JY3u+2Jf0zlSGUoxHnQVTMGaW6aHKk3FYeSpEY/GConUSZAEe7o3Qx q2u9HaZJAfSA+QFfd/HzIs/ZiHeNFvtUOqeRpRhgM+kSBJ5/KSUKXxdQspJf+E+f+c 0QLZO1vxO+pj1MUZlxtdO81jN+k91NUbBQeC21t2Lka4R9iYc0o7eaI2U/uitGRiRp h5KY5wYsBqiwnaINGjj+A7122QN++F6//u8OEY5UFLfc40yv5HdWC08dnK3N4+A31o zkvslgKQpoL0g== From: Sasha Levin To: stable@vger.kernel.org Cc: Christoph Hellwig , Robin Murphy , Sasha Levin Subject: [PATCH 5.15.y 04/10] dma-direct: warn if there is no pool for force unencrypted allocations Date: Thu, 10 Sep 2026 10:39:25 -0400 Message-ID: <20260910143932.771351-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260910143932.771351-1-sashal@kernel.org> References: <2026090811-unwound-smuggler-adf1@gregkh> <20260910143932.771351-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Christoph Hellwig [ Upstream commit 78bc72787ab9e638173aeb1f589578105d3a43c9 ] Instead of blindly running into a blocking operation for a non-blocking gfp, return NULL and spew an error. Note that Kconfig prevents this for all currently relevant platforms, and this is just a debug check. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy Stable-dep-of: 94a04ad732c9 ("dma-direct: return struct page from dma_direct_alloc_from_pool()") Signed-off-by: Sasha Levin --- kernel/dma/direct.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 0d6467b6553b7..5a71b6edfd1cd 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -162,6 +162,9 @@ static void *dma_direct_alloc_from_pool(struct device *dev, size_t size, u64 phys_mask; void *ret; + if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_DMA_COHERENT_POOL))) + return NULL; + gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask, &phys_mask); page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok); @@ -246,8 +249,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, * Decrypting memory may block, so allocate the memory from the atomic * pools if we can't block. */ - if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && - force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) && + if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) && !is_swiotlb_for_alloc(dev)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); @@ -357,8 +359,7 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, struct page *page; void *ret; - if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && - force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) && + if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) && !is_swiotlb_for_alloc(dev)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); -- 2.53.0