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@xxxxxxxxxx>
---
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...
[...]
MBR, Sergei
