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 C2AA834DB48; Wed, 3 Dec 2025 16:13:04 +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=1764778384; cv=none; b=rgHSIorIL/XDJc+k3VI+8d/umv5clBNQR2fbQ7EAC/B2b8u35wEXgTXEiBT8ugis7Y+FS71Cf1NpRxS0D6OBoJUaYk+rQq32p16owQmDQ2OpoNQGXZfqfKgBEE8iXvPL5kNSFzjHNNX1JDsrLqId8f0VFA/1FQATsKgn1Sm8/A8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764778384; c=relaxed/simple; bh=icws8GIuwDLKahsggebXcojELyfG3xXb7ZX2015Pkec=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Bn/NPqNmrlCprnY5uqZxppKfzxjPgHsjU3XXdNB92TDUEKQ1tXPoUp/LB5gq2M6lkWHNzllbNrZCxxX2z+Kg1rzvGVLntHZfwrA3x9QNRRE/tIZQKqBtjVom4lCSzAcOliBF7IEz5Q7Ms4aMbJcexolbqmlAmzQaHE1NQcyRiiI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=T0RGL/bd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="T0RGL/bd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28587C116B1; Wed, 3 Dec 2025 16:13:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764778384; bh=icws8GIuwDLKahsggebXcojELyfG3xXb7ZX2015Pkec=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T0RGL/bd1uck+KJoKEMxNENcLU/TjY1IiOfihcn7PogsN4E8QjDKWQ6aV5vKQacuY Osaf0t7CvuNzbBPxzIsJ2aoR/maKKKMVmjs0g3FSX41Q2R0bBRHLeORjT9gwpwHg3W OWVuNKFua8sd8g/a1ii5bNJxS+luZJbx01ScE/nw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Fabio M. De Francesco" , Ira Weiny , Andrew Morton , Sasha Levin Subject: [PATCH 5.15 329/392] mm/mempool: replace kmap_atomic() with kmap_local_page() Date: Wed, 3 Dec 2025 16:27:59 +0100 Message-ID: <20251203152426.271725935@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152414.082328008@linuxfoundation.org> References: <20251203152414.082328008@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- mm/mempool.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/mm/mempool.c +++ b/mm/mempool.c @@ -63,10 +63,10 @@ static void check_element(mempool_t *poo } 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); } } @@ -86,10 +86,10 @@ static void poison_element(mempool_t *po } 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 */