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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-26 01:43:59 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-26 01:43:59 (GMT)
commit2923b27e54242acf27fd16b299e102117c82f52f (patch)
tree86b3e27575814dab74307a7928bf579455b70e24 /drivers/nvdimm
parent828bf6e904eb8fc8969333568802689fbbf07a40 (diff)
parentc953cc987ab87d180e1d5de2f1c217abe33aac77 (diff)
Merge tag 'libnvdimm-for-4.19_dax-memory-failure' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm memory-failure update from Dave Jiang: "As it stands, memory_failure() gets thoroughly confused by dev_pagemap backed mappings. The recovery code has specific enabling for several possible page states and needs new enabling to handle poison in dax mappings. In order to support reliable reverse mapping of user space addresses: 1/ Add new locking in the memory_failure() rmap path to prevent races that would typically be handled by the page lock. 2/ Since dev_pagemap pages are hidden from the page allocator and the "compound page" accounting machinery, add a mechanism to determine the size of the mapping that encompasses a given poisoned pfn. 3/ Given pmem errors can be repaired, change the speculatively accessed poison protection, mce_unmap_kpfn(), to be reversible and otherwise allow ongoing access from the kernel. A side effect of this enabling is that MADV_HWPOISON becomes usable for dax mappings, however the primary motivation is to allow the system to survive userspace consumption of hardware-poison via dax. Specifically the current behavior is: mce: Uncorrected hardware memory error in user-access at af34214200 {1}[Hardware Error]: It has been corrected by h/w and requires no further action mce: [Hardware Error]: Machine check events logged {1}[Hardware Error]: event severity: corrected Memory failure: 0xaf34214: reserved kernel page still referenced by 1 users [..] Memory failure: 0xaf34214: recovery action for reserved kernel page: Failed mce: Memory error not recovered <reboot> ...and with these changes: Injecting memory failure for pfn 0x20cb00 at process virtual address 0x7f763dd00000 Memory failure: 0x20cb00: Killing dax-pmd:5421 due to hardware memory corruption Memory failure: 0x20cb00: recovery action for dax page: Recovered Given all the cross dependencies I propose taking this through nvdimm.git with acks from Naoya, x86/core, x86/RAS, and of course dax folks" * tag 'libnvdimm-for-4.19_dax-memory-failure' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm, pmem: Restore page attributes when clearing errors x86/memory_failure: Introduce {set, clear}_mce_nospec() x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses mm, memory_failure: Teach memory_failure() about dev_pagemap pages filesystem-dax: Introduce dax_lock_mapping_entry() mm, memory_failure: Collect mapping size in collect_procs() mm, madvise_inject_error: Let memory_failure() optionally take a page reference mm, dev_pagemap: Do not clear ->mapping on final put mm, madvise_inject_error: Disable MADV_SOFT_OFFLINE for ZONE_DEVICE pages filesystem-dax: Set page->index device-dax: Set page->index device-dax: Enable page_mapping() device-dax: Convert to vmf_insert_mixed and vm_fault_t
Diffstat (limited to 'drivers/nvdimm')
-rw-r--r--drivers/nvdimm/pmem.c26
-rw-r--r--drivers/nvdimm/pmem.h13
2 files changed, 39 insertions, 0 deletions
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index c236498..6071e29 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -20,6 +20,7 @@
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/platform_device.h>
+#include <linux/set_memory.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/badblocks.h>
@@ -51,6 +52,30 @@ static struct nd_region *to_region(struct pmem_device *pmem)
return to_nd_region(to_dev(pmem)->parent);
}
+static void hwpoison_clear(struct pmem_device *pmem,
+ phys_addr_t phys, unsigned int len)
+{
+ unsigned long pfn_start, pfn_end, pfn;
+
+ /* only pmem in the linear map supports HWPoison */
+ if (is_vmalloc_addr(pmem->virt_addr))
+ return;
+
+ pfn_start = PHYS_PFN(phys);
+ pfn_end = pfn_start + PHYS_PFN(len);
+ for (pfn = pfn_start; pfn < pfn_end; pfn++) {
+ struct page *page = pfn_to_page(pfn);
+
+ /*
+ * Note, no need to hold a get_dev_pagemap() reference
+ * here since we're in the driver I/O path and
+ * outstanding I/O requests pin the dev_pagemap.
+ */
+ if (test_and_clear_pmem_poison(page))
+ clear_mce_nospec(pfn);
+ }
+}
+
static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
phys_addr_t offset, unsigned int len)
{
@@ -65,6 +90,7 @@ static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
if (cleared < len)
rc = BLK_STS_IOERR;
if (cleared > 0 && cleared / 512) {
+ hwpoison_clear(pmem, pmem->phys_addr + offset, cleared);
cleared /= 512;
dev_dbg(dev, "%#llx clear %ld sector%s\n",
(unsigned long long) sector, cleared,
diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h
index a64ebc7..59cfe13 100644
--- a/drivers/nvdimm/pmem.h
+++ b/drivers/nvdimm/pmem.h
@@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NVDIMM_PMEM_H__
#define __NVDIMM_PMEM_H__
+#include <linux/page-flags.h>
#include <linux/badblocks.h>
#include <linux/types.h>
#include <linux/pfn_t.h>
@@ -27,4 +28,16 @@ struct pmem_device {
long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
long nr_pages, void **kaddr, pfn_t *pfn);
+
+#ifdef CONFIG_MEMORY_FAILURE
+static inline bool test_and_clear_pmem_poison(struct page *page)
+{
+ return TestClearPageHWPoison(page);
+}
+#else
+static inline bool test_and_clear_pmem_poison(struct page *page)
+{
+ return false;
+}
+#endif
#endif /* __NVDIMM_PMEM_H__ */

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