Messages in this thread Patch in this message | | | From | ira.weiny@intel ... | Subject | [PATCH V8 43/44] nvdimm/pmem: Enable stray access protection | Date | Thu, 27 Jan 2022 09:55:04 -0800 |
| |
From: Ira Weiny <ira.weiny@intel.com>
Now that all valid kernel access' to PMEM have been annotated with {__}pgmap_mk_{readwrite,noaccess}() PGMAP_PROTECTION is safe to enable in the pmem layer.
Implement the pmem_map_protected() and pmem_mk_{readwrite,noaccess}() to communicate this memory has extra protection to the upper layers if PGMAP_PROTECTION is specified.
Internally, the pmem driver uses a cached virtual address, pmem->virt_addr (pmem_addr). Use __pgmap_mk_{readwrite,noaccess}() directly when PGMAP_PROTECTION is active on the device.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
--- Changes for V8 Rebase to 5.17-rc1 Remove global param Add internal structure which uses the pmem device and pgmap device directly in the *_mk_*() calls. Add pmem dax ops callbacks Use pgmap_protection_available() s/PGMAP_PKEY_PROTECT/PGMAP_PROTECTION --- drivers/nvdimm/pmem.c | 52 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-)
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 58d95242a836..2afff8157233 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -138,6 +138,18 @@ static blk_status_t read_pmem(struct page *page, unsigned int off, return BLK_STS_OK; } +static void __pmem_mk_readwrite(struct pmem_device *pmem) +{ + if (pmem->pgmap.flags & PGMAP_PROTECTION) + __pgmap_mk_readwrite(&pmem->pgmap); +} + +static void __pmem_mk_noaccess(struct pmem_device *pmem) +{ + if (pmem->pgmap.flags & PGMAP_PROTECTION) + __pgmap_mk_noaccess(&pmem->pgmap); +} + static blk_status_t pmem_do_read(struct pmem_device *pmem, struct page *page, unsigned int page_off, sector_t sector, unsigned int len) @@ -149,7 +161,10 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem, if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) return BLK_STS_IOERR; + __pmem_mk_readwrite(pmem); rc = read_pmem(page, page_off, pmem_addr, len); + __pmem_mk_noaccess(pmem); + flush_dcache_page(page); return rc; } @@ -181,11 +196,14 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem, * after clear poison. */ flush_dcache_page(page); + + __pmem_mk_readwrite(pmem); 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); } + __pmem_mk_noaccess(pmem); return rc; } @@ -301,11 +319,36 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev, return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn); } +static bool pmem_map_protected(struct dax_device *dax_dev) +{ + struct pmem_device *pmem = dax_get_private(dax_dev); + + return (pmem->pgmap.flags & PGMAP_PROTECTION); +} + +static void pmem_mk_readwrite(struct dax_device *dax_dev) +{ + __pmem_mk_readwrite(dax_get_private(dax_dev)); +} + +static void pmem_mk_noaccess(struct dax_device *dax_dev) +{ + __pmem_mk_noaccess(dax_get_private(dax_dev)); +} + static const struct dax_operations pmem_dax_ops = { .direct_access = pmem_dax_direct_access, .zero_page_range = pmem_dax_zero_page_range, }; +static const struct dax_operations pmem_protected_dax_ops = { + .direct_access = pmem_dax_direct_access, + .zero_page_range = pmem_dax_zero_page_range, + .map_protected = pmem_map_protected, + .mk_readwrite = pmem_mk_readwrite, + .mk_noaccess = pmem_mk_noaccess, +}; + static ssize_t write_cache_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -427,6 +470,8 @@ static int pmem_attach_disk(struct device *dev, pmem->pfn_flags = PFN_DEV; if (is_nd_pfn(dev)) { pmem->pgmap.type = MEMORY_DEVICE_FS_DAX; + if (pgmap_protection_available()) + pmem->pgmap.flags |= PGMAP_PROTECTION; addr = devm_memremap_pages(dev, &pmem->pgmap); pfn_sb = nd_pfn->pfn_sb; pmem->data_offset = le64_to_cpu(pfn_sb->dataoff); @@ -440,6 +485,8 @@ static int pmem_attach_disk(struct device *dev, pmem->pgmap.range.end = res->end; pmem->pgmap.nr_range = 1; pmem->pgmap.type = MEMORY_DEVICE_FS_DAX; + if (pgmap_protection_available()) + pmem->pgmap.flags |= PGMAP_PROTECTION; addr = devm_memremap_pages(dev, &pmem->pgmap); pmem->pfn_flags |= PFN_MAP; bb_range = pmem->pgmap.range; @@ -474,7 +521,10 @@ static int pmem_attach_disk(struct device *dev, nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range); disk->bb = &pmem->bb; - dax_dev = alloc_dax(pmem, &pmem_dax_ops); + if (pmem->pgmap.flags & PGMAP_PROTECTION) + dax_dev = alloc_dax(pmem, &pmem_protected_dax_ops); + else + dax_dev = alloc_dax(pmem, &pmem_dax_ops); if (IS_ERR(dax_dev)) { rc = PTR_ERR(dax_dev); goto out; -- 2.31.1
| |