From fd615c4e671979e3e362df537d6be38f8d27aa80 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko <grygorii.strashko@ti.com> Date: Tue, 21 Jan 2014 15:50:05 -0800 Subject: mm/memblock: debug: don't free reserved array if !ARCH_DISCARD_MEMBLOCK Now the Nobootmem allocator will always try to free memory allocated for reserved memory regions (free_low_memory_core_early()) without taking into to account current memblock debugging configuration (CONFIG_ARCH_DISCARD_MEMBLOCK and CONFIG_DEBUG_FS state). As result if: - CONFIG_DEBUG_FS defined - CONFIG_ARCH_DISCARD_MEMBLOCK not defined; - reserved memory regions array have been resized during boot then: - memory allocated for reserved memory regions array will be freed to buddy allocator; - debug_fs entry "sys/kernel/debug/memblock/reserved" will show garbage instead of state of memory reservations. like: 0: 0x98393bc0..0x9a393bbf 1: 0xff120000..0xff11ffff 2: 0x00000000..0xffffffff Hence, do not free memory allocated for reserved memory regions if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK). Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Paul Walmsley <paul@pwsan.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- mm/memblock.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mm/memblock.c b/mm/memblock.c index 6a2a48a122a9..de4d9c352fd6 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -269,6 +269,19 @@ phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info( if (memblock.reserved.regions == memblock_reserved_init_regions) return 0; + /* + * Don't allow nobootmem allocator to free reserved memory regions + * array if + * - CONFIG_DEBUG_FS is enabled; + * - CONFIG_ARCH_DISCARD_MEMBLOCK is not enabled; + * - reserved memory regions array have been resized during boot. + * Otherwise debug_fs entry "sys/kernel/debug/memblock/reserved" + * will show garbage instead of state of memory reservations. + */ + if (IS_ENABLED(CONFIG_DEBUG_FS) && + !IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK)) + return 0; + *addr = __pa(memblock.reserved.regions); return PAGE_ALIGN(sizeof(struct memblock_region) * -- cgit v1.2.3