From: David Hildenbrand <david@xxxxxxxxxx> Subject: 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@xxxxxxxxxx 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 <david@xxxxxxxxxx> Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> Cc: Dave Young <dyoung@xxxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Keith Busch <keith.busch@xxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Qian Cai <cai@xxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx> Cc: Brijesh Singh <brijesh.singh@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/resource.c~kernel-resource-make-walk_mem_res-find-all-busy-ioresource_mem-resources +++ a/kernel/resource.c @@ -470,7 +470,7 @@ int walk_mem_res(u64 start, u64 end, voi { 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); } _
