From b308a7c5cfef6e0d15b8872982645313f415b229 Mon Sep 17 00:00:00 2001 From: Rebecca Schultz Zavin Date: Fri, 13 Dec 2013 14:24:19 -0800 Subject: [PATCH] gpu: ion: Fix bug in ion_system_heap map_user When the requested mmap length was not an integer number of chunks or the buffer, or if an offset was provided, a bug would cause extra or incorrect pages of the buffer to be mapped. Signed-off-by: Rebecca Schultz Zavin [jstultz: modified patch to apply to staging directory] Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/ion/ion_system_heap.c | 21 +++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c index 02726a9702b1..df084695221b 100644 --- a/drivers/staging/android/ion/ion_system_heap.c +++ b/drivers/staging/android/ion/ion_system_heap.c @@ -292,18 +292,27 @@ int ion_system_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer, { struct sg_table *table = buffer->priv_virt; unsigned long addr = vma->vm_start; - unsigned long offset = vma->vm_pgoff; + unsigned long offset = vma->vm_pgoff * PAGE_SIZE; struct scatterlist *sg; int i; for_each_sg(table->sgl, sg, table->nents, i) { - if (offset) { - offset--; + struct page *page = sg_page(sg); + unsigned long remainder = vma->vm_end - addr; + unsigned long len = sg_dma_len(sg); + + if (offset >= sg_dma_len(sg)) { + offset -= sg_dma_len(sg); continue; + } else if (offset) { + page += offset / PAGE_SIZE; + len = sg_dma_len(sg) - offset; + offset = 0; } - remap_pfn_range(vma, addr, page_to_pfn(sg_page(sg)), - sg_dma_len(sg), vma->vm_page_prot); - addr += sg_dma_len(sg); + len = min(len, remainder); + remap_pfn_range(vma, addr, page_to_pfn(page), len, + vma->vm_page_prot); + addr += len; if (addr >= vma->vm_end) return 0; } -- 2.20.1