| From 36e5cd6b897e17d03008f81e075625d8e43e52d0 Mon Sep 17 00:00:00 2001 |
| From: Ard Biesheuvel <ard.biesheuvel@linaro.org> |
| Date: Tue, 8 Mar 2016 21:09:29 +0700 |
| Subject: arm64: account for sparsemem section alignment when choosing vmemmap offset |
| |
| From: Ard Biesheuvel <ard.biesheuvel@linaro.org> |
| |
| commit 36e5cd6b897e17d03008f81e075625d8e43e52d0 upstream. |
| |
| Commit dfd55ad85e4a ("arm64: vmemmap: use virtual projection of linear |
| region") fixed an issue where the struct page array would overflow into the |
| adjacent virtual memory region if system RAM was placed so high up in |
| physical memory that its addresses were not representable in the build time |
| configured virtual address size. |
| |
| However, the fix failed to take into account that the vmemmap region needs |
| to be relatively aligned with respect to the sparsemem section size, so that |
| a sequence of page structs corresponding with a sparsemem section in the |
| linear region appears naturally aligned in the vmemmap region. |
| |
| So round up vmemmap to sparsemem section size. Since this essentially moves |
| the projection of the linear region up in memory, also revert the reduction |
| of the size of the vmemmap region. |
| |
| Fixes: dfd55ad85e4a ("arm64: vmemmap: use virtual projection of linear region") |
| Tested-by: Mark Langsdorf <mlangsdo@redhat.com> |
| Tested-by: David Daney <david.daney@cavium.com> |
| Tested-by: Robert Richter <rrichter@cavium.com> |
| Acked-by: Catalin Marinas <catalin.marinas@arm.com> |
| Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> |
| Signed-off-by: Will Deacon <will.deacon@arm.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/arm64/include/asm/pgtable.h | 5 +++-- |
| 1 file changed, 3 insertions(+), 2 deletions(-) |
| |
| --- a/arch/arm64/include/asm/pgtable.h |
| +++ b/arch/arm64/include/asm/pgtable.h |
| @@ -40,7 +40,7 @@ |
| * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space, |
| * fixed mappings and modules |
| */ |
| -#define VMEMMAP_SIZE ALIGN((1UL << (VA_BITS - PAGE_SHIFT - 1)) * sizeof(struct page), PUD_SIZE) |
| +#define VMEMMAP_SIZE ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) * sizeof(struct page), PUD_SIZE) |
| |
| #ifndef CONFIG_KASAN |
| #define VMALLOC_START (VA_START) |
| @@ -52,7 +52,8 @@ |
| #define VMALLOC_END (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K) |
| |
| #define VMEMMAP_START (VMALLOC_END + SZ_64K) |
| -#define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT)) |
| +#define vmemmap ((struct page *)VMEMMAP_START - \ |
| + SECTION_ALIGN_DOWN(memstart_addr >> PAGE_SHIFT)) |
| |
| #define FIRST_USER_ADDRESS 0UL |
| |