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 4979F2EDD62; Mon, 27 Oct 2025 19:20:08 +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=1761592808; cv=none; b=X4gVU5trDDi23CVX3ke0D0VO/Du+fGy8E7PgDSMpN4jY/FfEK1EyGexLdaSrcePXoi2V5oduUPVHEKr1GwRfvBT4OkFjJIoqHclXDl3RjG/A8cLvSIaFYphcP+clZlZPvefj9dOCNwDmRCB3I2qeazmGeHLAKC8zIxtg1mfbJGQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761592808; c=relaxed/simple; bh=PMe4Ub8qRZgVu94FE2TkMyBn2H+PoidHQgBnu8hU5VQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mG/rHJTZl/v8ROl7lPTrKyKa282PWQ7czb85yHcLxz8rAARy7VE62Z82JNkE2kIPGQpZ2aKQgj6ILaZx+hbpwhKro6CRhyIqrcSpMB9hk/9iboOwHSBufOdL9hewS/EXQAOLU9EX2kYuMT3fV1ZXqgXBoscwGjtAUF5kz0RMits= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MpCIXU3G; 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="MpCIXU3G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5B14C4CEF1; Mon, 27 Oct 2025 19:20:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761592808; bh=PMe4Ub8qRZgVu94FE2TkMyBn2H+PoidHQgBnu8hU5VQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MpCIXU3GrUaeKjulIa7ZtJ0yh53MKAGuicGJ9iUc8Gku1Iu28eVOOhMojpBan9px7 9rwiwC0UjADwooIFtUnfS0/CeFGepCjj2EU1LFKrvmH5qnBe5D1c8+Fq4yUfsX8csQ tJMZBaayfDeTWmMrWh9dmEomy9yuiqj12isxrHuo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Simon Schuster , Andreas Oetken , Dinh Nguyen , Sasha Levin Subject: [PATCH 6.12 002/117] nios2: ensure that memblock.current_limit is set when setting pfn limits Date: Mon, 27 Oct 2025 19:35:28 +0100 Message-ID: <20251027183453.993633300@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251027183453.919157109@linuxfoundation.org> References: <20251027183453.919157109@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Simon Schuster [ Upstream commit a20b83cf45be2057f3d073506779e52c7fa17f94 ] On nios2, with CONFIG_FLATMEM set, the kernel relies on memblock_get_current_limit() to determine the limits of mem_map, in particular for max_low_pfn. Unfortunately, memblock.current_limit is only default initialized to MEMBLOCK_ALLOC_ANYWHERE at this point of the bootup, potentially leading to situations where max_low_pfn can erroneously exceed the value of max_pfn and, thus, the valid range of available DRAM. This can in turn cause kernel-level paging failures, e.g.: [ 76.900000] Unable to handle kernel paging request at virtual address 20303000 [ 76.900000] ea = c0080890, ra = c000462c, cause = 14 [ 76.900000] Kernel panic - not syncing: Oops [ 76.900000] ---[ end Kernel panic - not syncing: Oops ]--- This patch fixes this by pre-calculating memblock.current_limit based on the upper limits of the available memory ranges via adjust_lowmem_bounds, a simplified version of the equivalent implementation within the arm architecture. Signed-off-by: Simon Schuster Signed-off-by: Andreas Oetken Signed-off-by: Dinh Nguyen Signed-off-by: Sasha Levin --- arch/nios2/kernel/setup.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c index da122a5fa43b2..8528ab1f222cd 100644 --- a/arch/nios2/kernel/setup.c +++ b/arch/nios2/kernel/setup.c @@ -142,6 +142,20 @@ static void __init find_limits(unsigned long *min, unsigned long *max_low, *max_high = PFN_DOWN(memblock_end_of_DRAM()); } +static void __init adjust_lowmem_bounds(void) +{ + phys_addr_t block_start, block_end; + u64 i; + phys_addr_t memblock_limit = 0; + + for_each_mem_range(i, &block_start, &block_end) { + if (block_end > memblock_limit) + memblock_limit = block_end; + } + + memblock_set_current_limit(memblock_limit); +} + void __init setup_arch(char **cmdline_p) { console_verbose(); @@ -155,6 +169,7 @@ void __init setup_arch(char **cmdline_p) /* Keep a copy of command line */ *cmdline_p = boot_command_line; + adjust_lowmem_bounds(); find_limits(&min_low_pfn, &max_low_pfn, &max_pfn); max_mapnr = max_low_pfn; -- 2.51.0