[PATCH v2 6/6] dmaengine: pl330: Make sure microcode is privileged-executable
flat view
STALE3739d
From: Mitchel Humpherys <hidden>
Date: 2016-07-09 02:09:06
Also in:
linux-iommu, lkml
Subsystem:
dma generic offload engine subsystem, the rest · Maintainers:
Vinod Koul, Linus Torvalds
Revision v2 of 4 in this series.
Revisions (4)
- v2 current
- v3 [diff vs current]
- v4 [diff vs current]
- v5 [diff vs current]
The PL330 can perform privileged instruction fetches. This can result in SMMU permission faults on SMMUs that implement the ARMv8 VMSA, which specifies that mappings that are writeable at one execution level shall not be executable at any higher-privileged level. Fix this by using the DMA_ATTR_PRIVILEGED_EXECUTABLE attribute, which will ensure that the microcode IOMMU mapping is not writeable. Cc: Dan Williams <redacted> Cc: Jassi Brar <redacted> Signed-off-by: Mitchel Humpherys <redacted> --- drivers/dma/pl330.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 372b4359da97..25bc49d47c45 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c@@ -1854,14 +1854,17 @@ static int dmac_alloc_resources(struct pl330_dmac *pl330) { int chans = pl330->pcfg.num_chan; int ret; + DEFINE_DMA_ATTRS(attrs); + dma_set_attr(DMA_ATTR_PRIVILEGED_EXECUTABLE, &attrs); /* * Alloc MicroCode buffer for 'chans' Channel threads. * A channel's buffer offset is (Channel_Id * MCODE_BUFF_PERCHAN) */ - pl330->mcode_cpu = dma_alloc_coherent(pl330->ddma.dev, + pl330->mcode_cpu = dma_alloc_attrs(pl330->ddma.dev, chans * pl330->mcbufsz, - &pl330->mcode_bus, GFP_KERNEL); + &pl330->mcode_bus, GFP_KERNEL, + &attrs); if (!pl330->mcode_cpu) { dev_err(pl330->ddma.dev, "%s:%d Can't allocate memory!\n", __func__, __LINE__);
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