MIPS: init: Ensure reserved memory regions are not added to bootmem

[ Upstream commit e89ef66d7682f031f026eee6bba03c8c2248d2a9 ]

Memories managed through boot_mem_map are generally expected to define
non-crossing areas. However, if part of a larger memory block is marked
as reserved, it would still be added to bootmem allocator as an
available block and could end up being overwritten by the allocator.

Prevent this by explicitly marking the memory as reserved it if exists
in the range used by bootmem allocator.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14608/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 1acaf0939cb5b6fad383418ff0945bede5e5aae3..4f9f1ae4921383f1bd0d230fb2bb54bed1e4462f 100644 (file)
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -506,6 +506,10 @@ static void __init bootmem_init(void)
                        continue;
                default:
                        /* Not usable memory */
+                       if (start > min_low_pfn && end < max_low_pfn)
+                               reserve_bootmem(boot_mem_map.map[i].addr,
+                                               boot_mem_map.map[i].size,
+                                               BOOTMEM_DEFAULT);
                        continue;
                }