Unverified Commit 827a4381 authored Oct 02, 2018 by Vincent Chen Committed by Palmer Dabbelt Oct 22, 2018

RISC-V: Avoid corrupting the upper 32-bit of phys_addr_t in ioremap



For 32bit, the upper 32-bit of phys_addr_t will be flushed to zero
after AND with PAGE_MASK because the data type of PAGE_MASK is
unsigned long. To fix this problem, the page alignment is done by
subtracting the page offset instead of AND with PAGE_MASK.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

parent 757331db

arch/riscv/mm/ioremap.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -42,7 +42,7 @@ static void __iomem *__ioremap_caller(phys_addr_t addr, size_t size,

		/* Page-align mappings */
		offset = addr & (~PAGE_MASK);
		addr &= PAGE_MASK;
		addr -= offset;
		size = PAGE_ALIGN(size + offset);

		area = get_vm_area_caller(size, VM_IOREMAP, caller);