On ARM, x86_64, sparc64 platform, virt_to_page only convert a
_valid_ virtual address to struct page *, virt_addr_valid(x)
indicates whether a virtual address is valid. If ptr is point
to a static variable in module area, virt_to_page will return
a invalid value.
Signed-off-by: lijiazi <lijiazi@xxxxxxxxxx>
---
include/linux/dma-mapping.h | 10 +++++++---
mm/vmalloc.c | 1 +
2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 330ad58..37e645d 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -580,9 +580,13 @@ static inline unsigned long dma_get_merge_boundary(struct device *dev)
static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
- /* DMA must never operate on areas that might be remapped. */
- if (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr),
- "rejecting DMA map of vmalloc memory\n"))
+ /* DMA must never operate on areas that might be remapped.
+ * ARM, X86_64, sparc64 put module in a special place, if ptr
+ * point to static variable in module area, virt_to_page will
+ * return err page *.
+ */
+ if (dev_WARN_ONCE(dev, is_vmalloc_or_module_addr(ptr),
+ "rejecting DMA map of vmalloc or module memory\n"))
return DMA_MAPPING_ERROR;
debug_dma_map_single(dev, ptr, size);
return dma_map_page_attrs(dev, virt_to_page(ptr), offset_in_page(ptr),
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 588303a..71ce6dc 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -262,6 +262,7 @@ int is_vmalloc_or_module_addr(const void *x)
#endif
return is_vmalloc_addr(x);
}
+EXPORT_SYMBOL(is_vmalloc_or_module_addr);
/*
* Walk a vmap address to the struct page it maps.
--
2.7.4
