path: root/arch
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authorJacopo Mondi <jacopo+renesas@jmondi.org>2018-04-18 11:42:35 +0200
committerRich Felker <dalias@libc.org>2018-05-05 16:51:46 -0400
commitb9826a4929bbd4dcb245429fd7434145c4fcdc9b (patch)
tree8749be4653afdecc99b127e272e27118e553157e /arch
parentsh: fix build failure for J2 cpu with SMP disabled (diff)
sh: mm: Fix unprotected access to struct device
With commit ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset") the generic DMA allocation function on which the SH 'dma_alloc_coherent()' function relies on, accesses the 'dma_pfn_offset' field of struct device. Unfortunately the 'dma_generic_alloc_coherent()' function is called from several places with a NULL struct device argument, halting the CPU during the boot process. This patch fixes the issue by protecting access to dev->dma_pfn_offset, with a trivial check for validity. It also passes a valid 'struct device' in the 'platform_resource_setup_memory()' function which is the main user of 'dma_alloc_coherent()', and inserts a WARN_ON() check to remind to future (and existing) bogus users of this function to provide a valid 'struct device' whenever possible. Fixes: ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset") Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Signed-off-by: Rich Felker <dalias@libc.org>
Diffstat (limited to 'arch')
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c
index 8ce98691d822..f1b44697ad68 100644
--- a/arch/sh/mm/consistent.c
+++ b/arch/sh/mm/consistent.c
@@ -59,7 +59,9 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
- *dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset);
+ *dma_handle = virt_to_phys(ret);
+ if (!WARN_ON(!dev))
+ *dma_handle -= PFN_PHYS(dev->dma_pfn_offset);
return ret_nocache;
@@ -69,9 +71,12 @@ void dma_generic_free_coherent(struct device *dev, size_t size,
unsigned long attrs)
int order = get_order(size);
- unsigned long pfn = (dma_handle >> PAGE_SHIFT) + dev->dma_pfn_offset;
+ unsigned long pfn = dma_handle >> PAGE_SHIFT;
int k;
+ if (!WARN_ON(!dev))
+ pfn += dev->dma_pfn_offset;
for (k = 0; k < (1 << order); k++)
__free_pages(pfn_to_page(pfn + k), 0);
@@ -143,7 +148,7 @@ int __init platform_resource_setup_memory(struct platform_device *pdev,
if (!memsize)
return 0;
- buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
+ buf = dma_alloc_coherent(&pdev->dev, memsize, &dma_handle, GFP_KERNEL);
if (!buf) {
pr_warning("%s: unable to allocate memory\n", name);
return -ENOMEM;