From 3c9c797534364593b73ba6ab060a014af8934721 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 6 May 2021 18:05:16 -0700 Subject: [PATCH] kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources It used to be true that we can have system RAM (IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY) only on the first level in the resource tree. However, this is no longer holds for driver-managed system RAM (i.e., added via dax/kmem and virtio-mem), which gets added on lower levels, for example, inside device containers. IORESOURCE_SYSTEM_RAM is defined as IORESOURCE_MEM | IORESOURCE_SYSRAM and just a special type of IORESOURCE_MEM. The function walk_mem_res() only considers the first level and is used in arch/x86/mm/ioremap.c:__ioremap_check_mem() only. We currently fail to identify System RAM added by dax/kmem and virtio-mem as "IORES_MAP_SYSTEM_RAM", for example, allowing for remapping of such "normal RAM" in __ioremap_caller(). Let's find all IORESOURCE_MEM | IORESOURCE_BUSY resources, making the function behave similar to walk_system_ram_res(). Link: https://lkml.kernel.org/r/20210325115326.7826-3-david@redhat.com Fixes: ebf71552bb0e ("virtio-mem: Add parent resource for all added "System RAM"") Fixes: c221c0b0308f ("device-dax: "Hotplug" persistent memory for use like normal RAM") Signed-off-by: David Hildenbrand Reviewed-by: Dan Williams Cc: Greg Kroah-Hartman Cc: Dan Williams Cc: Daniel Vetter Cc: Andy Shevchenko Cc: Mauro Carvalho Chehab Cc: Dave Young Cc: Baoquan He Cc: Vivek Goyal Cc: Dave Hansen Cc: Keith Busch Cc: Michal Hocko Cc: Qian Cai Cc: Oscar Salvador Cc: Eric Biederman Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Tom Lendacky Cc: Brijesh Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/resource.c b/kernel/resource.c index 4efd6e912279..16e0c7e8ed24 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -470,7 +470,7 @@ int walk_mem_res(u64 start, u64 end, void *arg, { unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; - return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true, + return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false, arg, func); } -- 2.34.1