[PATCH 4/5] powerpc/spufs: consider vm_pgoff in spufs_mem_mmap_access()

["David Hildenbrand (Arm)" <david@kernel.org>]

spufs_mem_mmap_access() calculates the local store offset relative to the
start of the VMA and ignores vm_pgoff. After VMA splits, debugger reads and
writes access the wrong part of the local store. Mappings created with a
nonzero file offset have the same problem.

Properly take the vm_pgoff into account, just like spufs_mem_mmap_fault()
already does.

Fixes: a352894d0705 ("spufs: use new vm_ops->access to allow local state access from gdb")
Cc: stable@vger.kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
---
 arch/powerpc/platforms/cell/spufs/file.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index 98c47bafaf678..0a46d6f7178ab 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -248,7 +248,8 @@ static int spufs_mem_mmap_access(struct vm_area_struct *vma,
 				void *buf, int len, int write)
 {
 	struct spu_context *ctx = vma->vm_file->private_data;
-	unsigned long offset = address - vma->vm_start;
+	unsigned long offset = address - vma->vm_start +
+			       (vma->vm_pgoff << PAGE_SHIFT);
 	char *local_store;
 
 	if (write && !(vma->vm_flags & VM_WRITE))

-- 
2.43.0