[PATCH RFC PKS/PMEM 57/58] nvdimm/pmem: Stray access protection for pmem->virt_addr
From: ira.weiny@intel.com
Date: 2020-10-09 19:55:13
Also in:
amd-gfx, bpf, ceph-devel, dri-devel, intel-gfx, intel-wired-lan, io-uring, kexec, kvm, linux-bcache, linux-block, linux-btrfs, linux-cifs, linux-doc, linux-efi, linux-ext4, linux-f2fs-devel, linux-fsdevel, linux-kselftest, linux-mm, linux-mmc, linux-nfs, linux-rdma, linux-scsi, linux-um, linuxppc-dev, lkml, nvdimm, target-devel, xen-devel
Subsystem:
libnvdimm pmem: persistent memory driver, libnvdimm: non-volatile memory device subsystem, the rest · Maintainers:
Dan Williams, Vishal Verma, Dave Jiang, Ira Weiny, Linus Torvalds
From: Ira Weiny <ira.weiny@intel.com> The pmem driver uses a cached virtual address to access its memory directly. Because the nvdimm driver is well aware of the special protections it has mapped memory with, we call dev_access_[en|dis]able() around the direct pmem->virt_addr (pmem_addr) usage instead of the unnecessary overhead of trying to get a page to kmap. Signed-off-by: Ira Weiny <ira.weiny@intel.com> --- drivers/nvdimm/pmem.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index fab29b514372..e4dc1ae990fc 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c@@ -148,7 +148,9 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem, if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) return BLK_STS_IOERR; + dev_access_enable(false); rc = read_pmem(page, page_off, pmem_addr, len); + dev_access_disable(false); flush_dcache_page(page); return rc; }
@@ -180,11 +182,13 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem, * after clear poison. */ flush_dcache_page(page); + dev_access_enable(false); write_pmem(pmem_addr, page, page_off, len); if (unlikely(bad_pmem)) { rc = pmem_clear_poison(pmem, pmem_off, len); write_pmem(pmem_addr, page, page_off, len); } + dev_access_disable(false); return rc; }
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2.28.0.rc0.12.gb6a658bd00c9