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libnvdimm: fix mishandled nvdimm_clear_poison() return value

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Colin, via static analysis, reports that the length could be negative
from nvdimm_clear_poison() in the error case. There was a similar
problem with commit 0a3f27b9a6 "libnvdimm, namespace: avoid multiple
sector calculations" that I noticed when merging the for-4.10/libnvdimm
topic branch into libnvdimm-for-next, but I missed this one. Fix both of
them to the following procedure:

* if we clear a block's worth of media, clear that many blocks in
  badblocks

* if we clear less than the requested size of the transfer return an
  error

* always invalidate cache after any non-error / non-zero
  nvdimm_clear_poison result

Fixes: 82bf1037f2 ("libnvdimm: check and clear poison before writing to pmem")
Fixes: 0a3f27b9a6 ("libnvdimm, namespace: avoid multiple sector calculations")
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Dave Jiang <dave.jiang@intel.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2016-12-16 08:10:31 -08:00
parent 9cf8bd529c
commit 868f036fee
2 changed files with 19 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/nvdimm/claim.c
View File

@ -247,12 +247,13 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
long cleared;
cleared = nvdimm_clear_poison(&ndns->dev, offset, size);
if (cleared != size) {
size = cleared;
if (cleared < size)
rc = -EIO;
if (cleared > 0 && cleared / 512) {
cleared /= 512;
badblocks_clear(&nsio->bb, sector, cleared);
}
badblocks_clear(&nsio->bb, sector, cleared >> 9);
invalidate_pmem(nsio->addr + offset, size);
} else
rc = -EIO;
}

21
drivers/nvdimm/pmem.c
View File

@ -47,22 +47,29 @@ static struct nd_region *to_region(struct pmem_device *pmem)
return to_nd_region(to_dev(pmem)->parent);
}
static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
static int pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
unsigned int len)
{
struct device *dev = to_dev(pmem);
sector_t sector, cleared;
sector_t sector;
long cleared;
int rc = 0;
sector = (offset - pmem->data_offset) / 512;
cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len) / 512;
if (cleared) {
dev_dbg(dev, "%s: %#llx clear %ld sector%s\n",
__func__, (unsigned long long) sector,
cleared, cleared > 1 ? "s" : "");
cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
if (cleared < len)
rc = -EIO;
if (cleared > 0 && cleared / 512) {
cleared /= 512;
dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__,
(unsigned long long) sector, cleared,
cleared > 1 ? "s" : "");
badblocks_clear(&pmem->bb, sector, cleared);
}
invalidate_pmem(pmem->virt_addr + offset, len);
return rc;
}
static void write_pmem(void *pmem_addr, struct page *page,