From: Nicholas Piggin npiggin@gmail.com
[ Upstream commit 8f51e3929470942e6a8744061254fdeef646cd36 ]
create_physical_mapping expects physical addresses, but creating and splitting these mappings after boot is supplying virtual (effective) addresses. This can be irritated by booting with mem= to limit memory then probing an unused physical memory range:
echo <addr> > /sys/devices/system/memory/probe
This mostly works by accident, firstly because __va(__va(x)) == __va(x) so the virtual address does not get corrupted. Secondly because pfn_pte masks out the upper bits of the pfn beyond the physical address limit, so a pfn constructed with a 0xc000000000000000 virtual linear address will be masked back to the correct physical address in the pte.
Fixes: 6cc27341b21a8 ("powerpc/mm: add radix__create_section_mapping()") Signed-off-by: Nicholas Piggin npiggin@gmail.com Reviewed-by: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20190724084638.24982-1-npiggin@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/mm/book3s64/radix_pgtable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c index 8deb432c29754..2b6cc823046a3 100644 --- a/arch/powerpc/mm/book3s64/radix_pgtable.c +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -901,7 +901,7 @@ int __meminit radix__create_section_mapping(unsigned long start, unsigned long e return -1; }
- return create_physical_mapping(start, end, nid); + return create_physical_mapping(__pa(start), __pa(end), nid); }
int __meminit radix__remove_section_mapping(unsigned long start, unsigned long end)