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.
We have two users of walk_system_ram_res(), which currently only
consideres the first level:
a) kernel/kexec_file.c:kexec_walk_resources() -- We properly skip
IORESOURCE_SYSRAM_DRIVER_MANAGED resources via
locate_mem_hole_callback(), so even after this change, we won't be
placing kexec images onto dax/kmem and virtio-mem added memory. No
change.
b) arch/x86/kernel/crash.c:fill_up_crash_elf_data() -- we're currently
not adding relevant ranges to the crash elf header, resulting in them
not getting dumped via kdump.
This change fixes loading a crashkernel via kexec_file_load() and including
dax/kmem and virtio-mem added System RAM in the crashdump on x86-64. Note
that e.g,, arm64 relies on memblock data and, therefore, always considers
all added System RAM already.
Let's find all IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY resources, making
the function behave like walk_system_ram_range().
Fixes: ebf71552bb0e ("virtio-mem: Add parent resource for all added "System
RAM"")
Fixes: c221c0b0308f ("device-dax: "Hotplug" persistent memory for use like
normal RAM")
Reviewed-by: Dan Williams <[email protected]>
Acked-by: Baoquan He <[email protected]>
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: 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 627e61b0c124..4efd6e912279 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -457,7 +457,7 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
{
unsigned long flags = IORESOURCE_SYSTEM_RAM | 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
