On Wed, Apr 10, 2019 at 10:44:03AM +0100, Robin Murphy wrote: > Hi Dan, > > On 10/04/2019 10:34, Dan Carpenter wrote: > > Hello Jean-Philippe Brucker, > > > > This is a semi-automatic email about new static checker warnings. > > > > The patch fac83d29d954: "iommu/io-pgtable-arm: Fix pgtable allocation > > in selftest" from Jun 18, 2018, leads to the following Smatch > > complaint: > > > > drivers/iommu/io-pgtable-arm.c:246 __arm_lpae_alloc_pages() > > error: we previously assumed 'dev' could be null (see line 239) > > > > drivers/iommu/io-pgtable-arm.c > > 238 VM_BUG_ON((gfp & __GFP_HIGHMEM)); > > 239 p = alloc_pages_node(dev ? dev_to_node(dev) : > > NUMA_NO_NODE, > > ^^^ > > We added a NULL check here > > > > 240 gfp | __GFP_ZERO, order); > > 241 if (!p) > > 242 return NULL; > > 243 > > 244 pages = page_address(p); > > 245 if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)) { > > The selftests *should* always set this quirk such that they never get to the > DMA mapping calls (that was one of the reasons for implementing things that > way) - I guess that might be a bit too sneaky for Smatch, but I can take a > look to double-check that the flow is working correctly such that this > really is a false-positive.
Ah, thanks. I have a plan for fixing these false positives caused by not tracking bit masks. It's not that complicated to fix, it just takes time to write the code. regards, dan carpenter _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu