diff options
Diffstat (limited to 'target/linux/generic')
| -rw-r--r-- | target/linux/generic/patches-4.4/103-Fix-alloc_node_mem_map-with-ARCH_PFN_OFFSET-calcu.patch | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.4/103-Fix-alloc_node_mem_map-with-ARCH_PFN_OFFSET-calcu.patch b/target/linux/generic/patches-4.4/103-Fix-alloc_node_mem_map-with-ARCH_PFN_OFFSET-calcu.patch new file mode 100644 index 0000000000..b2daa17d9a --- /dev/null +++ b/target/linux/generic/patches-4.4/103-Fix-alloc_node_mem_map-with-ARCH_PFN_OFFSET-calcu.patch @@ -0,0 +1,86 @@ +From: Tobias Wolf <dev-NTEO@vplace.de> +Date: Wed, 30 Nov 2016 09:16:41 +0100 +Subject: [PATCH] mm: Fix alloc_node_mem_map with ARCH_PFN_OFFSET + calculation + +Dear folks, + +An rt288x (ralink) based router (Belkin F5D8235 v1) does not boot with any +kernel beyond version 4.3 resulting in: + +BUG: Bad page state in process swapper pfn:086ac + +bisect resulted in: + +a1c34a3bf00af2cede839879502e12dc68491ad5 is the first bad commit +commit a1c34a3bf00af2cede839879502e12dc68491ad5 +Author: Laura Abbott <laura@labbott.name> +Date: Thu Nov 5 18:48:46 2015 -0800 + + mm: Don't offset memmap for flatmem + + Srinivas Kandagatla reported bad page messages when trying to remove the + bottom 2MB on an ARM based IFC6410 board + + BUG: Bad page state in process swapper pfn:fffa8 + page:ef7fb500 count:0 mapcount:0 mapping: (null) index:0x0 + flags: 0x96640253(locked|error|dirty|active|arch_1|reclaim|mlocked) + page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set + bad because of flags: + flags: 0x200041(locked|active|mlocked) + Modules linked in: + CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.0-rc3-00007-g412f9ba-dirty +#816 + Hardware name: Qualcomm (Flattened Device Tree) + unwind_backtrace + show_stack + dump_stack + bad_page + free_pages_prepare + free_hot_cold_page + __free_pages + free_highmem_page + mem_init + start_kernel + Disabling lock debugging due to kernel taint + [...] +:040000 040000 2de013c372345fd471cd58f0553c9b38b0ef1cc4 +0a8156f848733dfa21e16c196dfb6c0a76290709 M mm + +This fix for ARM does not account ARCH_PFN_OFFSET for mem_map as later used by +page_to_pfn anymore. + +The following output was generated with two hacked in printk statements: + +printk("before %p vs. %p or %p\n", mem_map, mem_map - offset, mem_map - +(pgdat->node_start_pfn - ARCH_PFN_OFFSET)); + if (page_to_pfn(mem_map) != pgdat->node_start_pfn) + mem_map -= offset + (pgdat->node_start_pfn - ARCH_PFN_OFFSET); +printk("after %p\n", mem_map); + +Output: + +[ 0.000000] before 8861b280 vs. 8861b280 or 8851b280 +[ 0.000000] after 8851b280 + +As seen in the first line mem_map with subtraction of offset does not equal the +mem_map after subtraction of ARCH_PFN_OFFSET. + +After adding the offset of ARCH_PFN_OFFSET as well to mem_map as the +previously calculated offset is zero for the named platform it is able to boot +4.4 and 4.9-rc7 again. + +Signed-off-by: Tobias Wolf <dev-NTEO@vplace.de> +--- + +--- a/mm/page_alloc.c ++++ b/mm/page_alloc.c +@@ -5326,7 +5326,7 @@ static void __init_refok alloc_node_mem_ + mem_map = NODE_DATA(0)->node_mem_map; + #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM) + if (page_to_pfn(mem_map) != pgdat->node_start_pfn) +- mem_map -= offset; ++ mem_map -= offset + (pgdat->node_start_pfn - ARCH_PFN_OFFSET); + #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ + } + #endif |