From: ira.weiny@intel.com
To: Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Dan Williams <dan.j.williams@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
"Shankar, Ravi V" <ravi.v.shankar@intel.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH V10 35/44] nvdimm/pmem: Enable stray access protection
Date: Tue, 19 Apr 2022 10:06:40 -0700 [thread overview]
Message-ID: <20220419170649.1022246-36-ira.weiny@intel.com> (raw)
In-Reply-To: <20220419170649.1022246-1-ira.weiny@intel.com>
From: Ira Weiny <ira.weiny@intel.com>
The persistent memory (PMEM) driver uses the memremap_pages facility to
provide 'struct page' metadata (vmemmap) for PMEM. Given that PMEM
capacity maybe orders of magnitude higher capacity than System RAM it
presents a large vulnerability surface to stray writes. Unlike stray
writes to System RAM, which may result in a crash or other undesirable
behavior, stray writes to PMEM additionally are more likely to result in
permanent data loss. Reboot is not a remediation for PMEM corruption
like it is for System RAM.
Now that all valid kernel access' to PMEM have been annotated with
{__}pgmap_set_{readwrite,noaccess}() PGMAP_PROTECTION is safe to enable
in the pmem layer.
Set PGMAP_PROTECTION if pgmap protections are available and set the
pgmap property of the dax device for it's use.
Internally, the pmem driver uses a cached virtual address,
pmem->virt_addr (pmem_addr). Call __pgmap_set_{readwrite,noaccess}()
directly when PGMAP_PROTECTION is active on those mappings.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
Changes for V9
Remove the dax operations and pass the pgmap to the dax_device
for its use.
s/pgmap_mk_*/pgmap_set_*/
s/pmem_mk_*/pmem_set_*/
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 | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 58d95242a836..2c7b18da7974 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_set_readwrite(struct pmem_device *pmem)
+{
+ if (pmem->pgmap.flags & PGMAP_PROTECTION)
+ __pgmap_set_readwrite(&pmem->pgmap);
+}
+
+static void pmem_set_noaccess(struct pmem_device *pmem)
+{
+ if (pmem->pgmap.flags & PGMAP_PROTECTION)
+ __pgmap_set_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 +161,11 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem,
if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
return BLK_STS_IOERR;
+ /* Enable direct use of pmem->virt_addr */
+ pmem_set_readwrite(pmem);
rc = read_pmem(page, page_off, pmem_addr, len);
+ pmem_set_noaccess(pmem);
+
flush_dcache_page(page);
return rc;
}
@@ -181,11 +197,15 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem,
* after clear poison.
*/
flush_dcache_page(page);
+
+ /* Enable direct use of pmem->virt_addr */
+ pmem_set_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_set_noaccess(pmem);
return rc;
}
@@ -427,6 +447,8 @@ 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 +462,8 @@ 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;
@@ -481,6 +505,8 @@ static int pmem_attach_disk(struct device *dev,
}
set_dax_nocache(dax_dev);
set_dax_nomc(dax_dev);
+ if (pmem->pgmap.flags & PGMAP_PROTECTION)
+ set_dax_pgmap(dax_dev, &pmem->pgmap);
if (is_nvdimm_sync(nd_region))
set_dax_synchronous(dax_dev);
rc = dax_add_host(dax_dev, disk);
--
2.35.1
next prev parent reply other threads:[~2022-04-19 17:08 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-19 17:06 [PATCH V10 00/44] PKS/PMEM: Add Stray Write Protection ira.weiny
2022-04-19 17:06 ` [PATCH V10 01/44] Documentation/protection-keys: Clean up documentation for User Space pkeys ira.weiny
2022-06-07 23:09 ` [tip: x86/mm] " tip-bot2 for Ira Weiny
2022-04-19 17:06 ` [PATCH V10 02/44] x86/pkeys: Clarify PKRU_AD_KEY macro ira.weiny
2022-06-07 23:09 ` [tip: x86/mm] " tip-bot2 for Ira Weiny
2022-04-19 17:06 ` [PATCH V10 03/44] x86/pkeys: Make PKRU macros generic ira.weiny
2022-04-19 17:06 ` [PATCH V10 04/44] x86/fpu: Refactor arch_set_user_pkey_access() ira.weiny
2022-04-19 17:06 ` [PATCH V10 05/44] mm/pkeys: Add Kconfig options for PKS ira.weiny
2022-04-19 17:06 ` [PATCH V10 06/44] x86/pkeys: Add PKS CPU feature bit ira.weiny
2022-04-19 17:06 ` [PATCH V10 07/44] x86/fault: Adjust WARN_ON for pkey fault ira.weiny
2022-04-19 17:06 ` [PATCH V10 08/44] Documentation/pkeys: Add initial PKS documentation ira.weiny
2022-05-09 22:03 ` Kees Cook
2022-05-10 17:18 ` Ira Weiny
2022-05-10 20:17 ` Kees Cook
2022-04-19 17:06 ` [PATCH V10 09/44] mm/pkeys: Provide for PKS key allocation ira.weiny
2022-04-19 17:06 ` [PATCH V10 10/44] x86/pkeys: Enable PKS on cpus which support it ira.weiny
2022-04-19 17:06 ` [PATCH V10 11/44] mm/pkeys: Define PKS page table macros ira.weiny
2022-04-19 17:06 ` [PATCH V10 12/44] x86/pkeys: Introduce pks_write_pkrs() ira.weiny
2022-04-19 17:06 ` [PATCH V10 13/44] x86/pkeys: Preserve the PKS MSR on context switch ira.weiny
2022-04-19 17:06 ` [PATCH V10 14/44] mm/pkeys: Introduce pks_set_readwrite() ira.weiny
2022-05-09 21:38 ` Kees Cook
2022-05-10 21:33 ` Ira Weiny
2022-05-10 22:08 ` Kees Cook
2022-05-10 22:26 ` Edgecombe, Rick P
2022-05-11 3:15 ` Kees Cook
2022-05-11 17:59 ` Ira Weiny
2022-04-19 17:06 ` [PATCH V10 15/44] mm/pkeys: Introduce pks_set_noaccess() ira.weiny
2022-04-19 17:06 ` [PATCH V10 16/44] mm/pkeys: Introduce PKS fault callbacks ira.weiny
2022-04-19 17:06 ` [PATCH V10 17/44] x86/entry: Add auxiliary pt_regs space ira.weiny
2022-04-19 17:06 ` [PATCH V10 18/44] entry: Pass pt_regs to irqentry_exit_cond_resched() ira.weiny
2022-04-19 17:06 ` [PATCH V10 19/44] entry: Add calls for save/restore auxiliary pt_regs ira.weiny
2022-04-19 17:06 ` [PATCH V10 20/44] x86/entry: Define arch_{save|restore}_auxiliary_pt_regs() ira.weiny
2022-04-19 17:06 ` [PATCH V10 21/44] x86/pkeys: Preserve PKRS MSR across exceptions ira.weiny
2022-04-19 17:06 ` [PATCH V10 22/44] x86/fault: Print PKS MSR on fault ira.weiny
2022-04-19 17:06 ` [PATCH V10 23/44] mm/pkeys: Introduce pks_update_exception() ira.weiny
2022-04-19 17:06 ` [PATCH V10 24/44] mm/pkeys: Add pks_available() ira.weiny
2022-04-19 17:06 ` [PATCH V10 25/44] memremap_pages: Add Kconfig for DEVMAP_ACCESS_PROTECTION ira.weiny
2022-04-19 17:06 ` [PATCH V10 26/44] memremap_pages: Introduce pgmap_protection_available() ira.weiny
2022-04-19 17:06 ` [PATCH V10 27/44] memremap_pages: Introduce a PGMAP_PROTECTION flag ira.weiny
2022-04-19 17:06 ` [PATCH V10 28/44] memremap_pages: Introduce devmap_protected() ira.weiny
2022-04-19 17:06 ` [PATCH V10 29/44] memremap_pages: Reserve a PKS pkey for eventual use by PMEM ira.weiny
2022-04-19 17:06 ` [PATCH V10 30/44] memremap_pages: Set PKS pkey in PTEs if requested ira.weiny
2022-04-19 17:06 ` [PATCH V10 31/44] memremap_pages: Define pgmap_set_{readwrite|noaccess}() calls ira.weiny
2022-04-19 17:06 ` [PATCH V10 32/44] memremap_pages: Add memremap.pks_fault_mode ira.weiny
2022-04-19 17:06 ` [PATCH V10 33/44] kmap: Make kmap work for devmap protected pages ira.weiny
2022-04-28 15:50 ` Christoph Hellwig
2022-05-12 1:25 ` Ira Weiny
2022-05-17 22:46 ` Ira Weiny
2022-05-18 7:33 ` Christoph Hellwig
2022-05-19 20:29 ` Ira Weiny
2022-04-19 17:06 ` [PATCH V10 34/44] dax: Stray access protection for dax_direct_access() ira.weiny
2022-04-19 17:06 ` ira.weiny [this message]
2022-04-19 17:06 ` [PATCH V10 36/44] devdax: Enable stray access protection ira.weiny
2022-04-19 17:06 ` [PATCH V10 37/44] mm/pkeys: PKS testing, add initial test code ira.weiny
2022-04-19 17:06 ` [PATCH V10 38/44] x86/selftests: Add test_pks ira.weiny
2022-04-19 17:06 ` [PATCH V10 39/44] mm/pkeys: PKS testing, add a fault call back ira.weiny
2022-04-19 17:06 ` [PATCH V10 40/44] mm/pkeys: PKS testing, add pks_set_*() tests ira.weiny
2022-04-19 17:06 ` [PATCH V10 41/44] mm/pkeys: PKS testing, test context switching ira.weiny
2022-04-19 17:06 ` [PATCH V10 42/44] mm/pkeys: PKS testing, Add exception test ira.weiny
2022-04-19 17:06 ` [PATCH V10 43/44] mm/pkeys: PKS testing, test pks_update_exception() ira.weiny
2022-04-19 17:06 ` [PATCH V10 44/44] mm/pkeys: PKS testing, add test for all keys ira.weiny
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