[PATCH v2 01/12] x86/ioremap: Fix page aligned size calculation in __ioremap_caller()

Michael Kelley
2022-11-11T06:22:34Z

If applying the PHYSICAL_PAGE_MASK to the phys_addr argument causes
upper bits to be masked out, the re-calculation of size to account for
page alignment is incorrect because the same bits are not masked out
in last_addr.

Fix this by masking the page aligned last_addr as well.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
arch/x86/mm/ioremap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 78c5bc6..0343de4 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -218,7 +218,7 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
*/
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PHYSICAL_PAGE_MASK;
- size = PAGE_ALIGN(last_addr+1) - phys_addr;
+ size = (PAGE_ALIGN(last_addr+1) & PHYSICAL_PAGE_MASK) - phys_addr;

retval = memtype_reserve(phys_addr, (u64)phys_addr + size,
pcm, &new_pcm);
--
1.8.3.1