Messages in this thread | | | Subject | Re: [PATCH] sh: mm: Fix unprotected access to struct device | From | Sergei Shtylyov <> | Date | Wed, 18 Apr 2018 12:13:10 +0300 |
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Hello!
On 4/17/2018 4:35 PM, Jacopo Mondi wrote:
> 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, > access 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 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 inserting a WARN_ON() check to make future > (and existing) bogus users of this function they're should 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> > --- > arch/sh/mm/consistent.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c > index 8ce9869..b257155 100644 > --- a/arch/sh/mm/consistent.c > +++ b/arch/sh/mm/consistent.c [...] > @@ -69,9 +73,14 @@ 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);
Parens no longer needed...
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MBR, Sergei
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