Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Received-SPF: Pass (protection.outlook.com: domain of nokia.com designates
 131.228.2.8 as permitted sender) receiver=protection.outlook.com;
 client-ip=131.228.2.8; helo=fihe3nok0734.emea.nsn-net.net;
From:   Alexander A Sverdlin <alexander.sverdlin@nokia.com>
To:     linux-mips@vger.kernel.org
Cc:     Alexander Sverdlin <alexander.sverdlin@nokia.com>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Paul Burton <paulburton@kernel.org>,
        Leonid Rosenboim <lrosenboim@caviumnetworks.com>,
        Corey Minyard <cminyard@mvista.com>,
        linux-kernel@vger.kernel.org,
        Serge Semin <fancer.lancer@gmail.com>,
        "Maciej W . Rozycki" <macro@linux-mips.org>,
        Jinyang He <hejinyang@loongson.cn>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>
Subject: [PATCH 1/2] MIPS: Don't round up kernel sections size for memblock_add()
Date:   Thu,  3 Dec 2020 13:36:48 +0100
Message-Id: <20201203123649.44046-1-alexander.sverdlin@nokia.com>
MIME-Version: 1.0
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Dec 2020 12:36:55.7721
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 40d0b287-4fa3-41d6-8790-08d897881ea4
X-MS-Exchange-CrossTenant-Id: 5d471751-9675-428d-917b-70f44f9630b0
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=5d471751-9675-428d-917b-70f44f9630b0;Ip=[131.228.2.8];Helo=[fihe3nok0734.emea.nsn-net.net]
X-MS-Exchange-CrossTenant-AuthSource: AM5EUR03FT038.eop-EUR03.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR07MB6495
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Alexander Sverdlin <alexander.sverdlin@nokia.com>

Linux doesn't own the memory immediately after the kernel image. On Octeon
bootloader places a shared structure right close after the kernel _end,
refer to "struct cvmx_bootinfo *octeon_bootinfo" in cavium-octeon/setup.c.

If check_kernel_sections_mem() rounds the PFNs up, first memblock_alloc()
inside early_init_dt_alloc_memory_arch() <= device_tree_init() returns
memory block overlapping with the above octeon_bootinfo structure, which
is being overwritten afterwards.

Fixes: a94e4f24ec83 ("MIPS: init: Drop boot_mem_map")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
---
 arch/mips/kernel/setup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index ca579de..9d11f68 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -498,8 +498,8 @@ static void __init request_crashkernel(struct resource *res)
 
 static void __init check_kernel_sections_mem(void)
 {
-	phys_addr_t start = PFN_PHYS(PFN_DOWN(__pa_symbol(&_text)));
-	phys_addr_t size = PFN_PHYS(PFN_UP(__pa_symbol(&_end))) - start;
+	phys_addr_t start = __pa_symbol(&_text);
+	phys_addr_t size = __pa_symbol(&_end) - start;
 
 	if (!memblock_is_region_memory(start, size)) {
 		pr_info("Kernel sections are not in the memory maps\n");
-- 
2.10.2