On Mon, Mar 22, 2021 at 05:01:59PM +0100, David Hildenbrand wrote: > It used to be true that we can have system RAM only on the first level > in the resourc tree. However, this is no longer holds for driver-managed > system RAM (i.e., dax/kmem and virtio-mem). > > The function walk_mem_res() only consideres 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().
Here I dunno, but consider to add Fixes tag if it fixes known bad behaviour. > Let's find all busy IORESOURCE_MEM resources, making the function > behave similar to walk_system_ram_res(). > > Cc: Andrew Morton <[email protected]> > Cc: Greg Kroah-Hartman <[email protected]> > Cc: Dan Williams <[email protected]> > Cc: Daniel Vetter <[email protected]> > Cc: Andy Shevchenko <[email protected]> > Cc: Mauro Carvalho Chehab <[email protected]> > Cc: Signed-off-by: David Hildenbrand <[email protected]> > Cc: Dave Young <[email protected]> > Cc: Baoquan He <[email protected]> > Cc: Vivek Goyal <[email protected]> > Cc: Dave Hansen <[email protected]> > Cc: Keith Busch <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: Qian Cai <[email protected]> > Cc: Oscar Salvador <[email protected]> > Cc: Eric Biederman <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Borislav Petkov <[email protected]> > Cc: "H. Peter Anvin" <[email protected]> > Cc: Tom Lendacky <[email protected]> > Cc: Brijesh Singh <[email protected]> > Cc: [email protected] > Cc: [email protected] > Signed-off-by: David Hildenbrand <[email protected]> > --- > 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); > } > > -- > 2.29.2 > -- With Best Regards, Andy Shevchenko
