From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6980E32E722 for ; Mon, 24 Nov 2025 21:18:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764019087; cv=none; b=jdETtzItw8iMvSLz6zTjhJOpyLRBroeIb+KqrMO7bngj6jHCgCGbPOMHbcFBdUjECb3WSgeqS40+Ma9Gd0ZXvAAJUcBnLrdAfzsd/V9iUbYIEXBMgq8EBk08NpPw0tp9AS384hvYhPwVmGgNQ2QRTR6GEQdfQ0VP1czOARqyyeg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764019087; c=relaxed/simple; bh=F3qWh8Zw1liB2/TeEmTmKFCZDs6dZJCNSAqzyC1hJWA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kbKPWHuuFFOBhpFfa4aX+q+fNlQ1m+6VBYvE78Bmq4ArEz37Yg6HMtkjL7sFIikS6btzP468PZ4RIWzGAsx9E5cLA2PDg5nJDTvEYyD66NiBd1s4kqXqiivYX6asEDT0nOiDgmQi/rupAyqGGpeU6vbfZ6bm2gHY+ku2gNgyt58= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a3AKKhjK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a3AKKhjK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E88BC4CEF1; Mon, 24 Nov 2025 21:18:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764019085; bh=F3qWh8Zw1liB2/TeEmTmKFCZDs6dZJCNSAqzyC1hJWA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a3AKKhjKZTKRVhO977/typv3rgmobgCWHTyLznnr5SJyWehjjtLYxVXIunB4Uj4O+ c+gTrmwDbitBQqaJ5B4R0uNmuYlV8XQM+VAzdpnWK3yrIJDWR+Ab3HF/7aKjsn245g 1yrgWMIBh794dRv2rfjJ8yWWgFjrw7nPpFJzarOngceCGKcrenR/7x6oHgU0cit8zP yGB7+BDkSNCswRw66/ARpQw/gaaIeZRCyZBKTwvASOqXtK96GrxE2i+d2/p5z3iG2b sKsKBYnhBz35OS7LioMYgxKI1u1OjvP21xo91+qDSfpYCe58RBbaGPfHjgz4P0nGO/ cO3fTSHe/PZJg== From: Sasha Levin To: stable@vger.kernel.org Cc: "Fabio M. De Francesco" , Ira Weiny , Andrew Morton , Sasha Levin Subject: [PATCH 6.1.y 1/2] mm/mempool: replace kmap_atomic() with kmap_local_page() Date: Mon, 24 Nov 2025 16:18:02 -0500 Message-ID: <20251124211803.34596-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025112435-agile-sprawl-f420@gregkh> References: <2025112435-agile-sprawl-f420@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Fabio M. De Francesco" [ Upstream commit f2bcc99a5e901a13b754648d1dbab60f4adf9375 ] kmap_atomic() has been deprecated in favor of kmap_local_page(). Therefore, replace kmap_atomic() with kmap_local_page(). kmap_atomic() is implemented like a kmap_local_page() which also disables page-faults and preemption (the latter only in !PREEMPT_RT kernels). The kernel virtual addresses returned by these two API are only valid in the context of the callers (i.e., they cannot be handed to other threads). With kmap_local_page() the mappings are per thread and CPU local like in kmap_atomic(); however, they can handle page-faults and can be called from any context (including interrupts). The tasks that call kmap_local_page() can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. The code blocks between the mappings and un-mappings don't rely on the above-mentioned side effects of kmap_atomic(), so that mere replacements of the old API with the new one is all that they require (i.e., there is no need to explicitly call pagefault_disable() and/or preempt_disable()). Link: https://lkml.kernel.org/r/20231120142640.7077-1-fabio.maria.de.francesco@linux.intel.com Signed-off-by: Fabio M. De Francesco Cc: Ira Weiny Signed-off-by: Andrew Morton Stable-dep-of: ec33b59542d9 ("mm/mempool: fix poisoning order>0 pages with HIGHMEM") Signed-off-by: Sasha Levin --- mm/mempool.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/mempool.c b/mm/mempool.c index 96488b13a1ef1..81f38f8c2cbbe 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -62,10 +62,10 @@ static void check_element(mempool_t *pool, void *element) } else if (pool->free == mempool_free_pages) { /* Mempools backed by page allocator */ int order = (int)(long)pool->pool_data; - void *addr = kmap_atomic((struct page *)element); + void *addr = kmap_local_page((struct page *)element); __check_element(pool, addr, 1UL << (PAGE_SHIFT + order)); - kunmap_atomic(addr); + kunmap_local(addr); } } @@ -85,10 +85,10 @@ static void poison_element(mempool_t *pool, void *element) } else if (pool->alloc == mempool_alloc_pages) { /* Mempools backed by page allocator */ int order = (int)(long)pool->pool_data; - void *addr = kmap_atomic((struct page *)element); + void *addr = kmap_local_page((struct page *)element); __poison_element(addr, 1UL << (PAGE_SHIFT + order)); - kunmap_atomic(addr); + kunmap_local(addr); } } #else /* CONFIG_DEBUG_SLAB || CONFIG_SLUB_DEBUG_ON */ -- 2.51.0