Messages in this thread | | | Date | Mon, 10 Nov 2014 15:32:28 -0500 (EST) | Subject | Re: [PATCH] drivers: atm: eni: Add pci_dma_mapping_error() call | From | David Miller <> |
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From: Tina Johnson <tinajohnson.1234@gmail.com> Date: Sat, 8 Nov 2014 21:48:02 +0530
> Added a pci_dma_mapping_error() call to check for mapping errors before > further using the dma handle. Unchecked dma handles were found using > Coccinelle: > > @rule1@ > expression e1; > identifier x; > @@ > > *x = pci_map_single(...); > ... when != pci_dma_mapping_error(e1,x) > > Signed-off-by: Tina Johnson <tinajohnson.1234@gmail.com> > Acked-by: Julia Lawall <julia.lawall@lip6.fr>
I really don't like quick fixes like this, exactly because of the kind of new bug this change is introducing.
The 'trouble' label assumes that it is recovering and unwinding state when an error occurs after the DMA buffer is successfully mapped.
It unconditionally does pci_unmap_single() if 'paddr' is non-zero which it might be in the error case depending upon how DMA errors are represented on a given platform.
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