Commit 35cdd865 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'libnvdimm-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 

Pull libnvdimm and DAX updates from Dan Williams:
 "New support for clearing memory errors when a file is in DAX mode,
  alongside with some other fixes and cleanups.

  Previously it was only possible to clear these errors using a truncate
  or hole-punch operation to trigger the filesystem to reallocate the
  block, now, any page aligned write can opportunistically clear errors
  as well.

  This change spans x86/mm, nvdimm, and fs/dax, and has received the
  appropriate sign-offs. Thanks to Jane for her work on this.

  Summary:

   - Add support for clearing memory error via pwrite(2) on DAX

   - Fix 'security overwrite' support in the presence of media errors

   - Miscellaneous cleanups and fixes for nfit_test (nvdimm unit tests)"

* tag 'libnvdimm-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  pmem: implement pmem_recovery_write()
  pmem: refactor pmem_clear_poison()
  dax: add .recovery_write dax_operation
  dax: introduce DAX_RECOVERY_WRITE dax access mode
  mce: fix set_mce_nospec to always unmap the whole page
  x86/mce: relocate set{clear}_mce_nospec() functions
  acpi/nfit: rely on mce->misc to determine poison granularity
  testing: nvdimm: asm/mce.h is not needed in nfit.c
  testing: nvdimm: iomap: make __nfit_test_ioremap a macro
  nvdimm: Allow overwrite in the presence of disabled dimms
  tools/testing/nvdimm: remove unneeded flush_workqueue
parents ea6c3bc6 f42e8e50

arch/x86/include/asm/set_memory.h

+0 −52
Original line number Diff line number Diff line
@@ -86,56 +86,4 @@ bool kernel_page_present(struct page *page); 


extern int kernel_set_to_readonly;



#ifdef CONFIG_X86_64

/*

 * Prevent speculative access to the page by either unmapping

 * it (if we do not require access to any part of the page) or

 * marking it uncacheable (if we want to try to retrieve data

 * from non-poisoned lines in the page).

 */

static inline int set_mce_nospec(unsigned long pfn, bool unmap)

{

	unsigned long decoy_addr;

	int rc;



	/* SGX pages are not in the 1:1 map */

	if (arch_is_platform_page(pfn << PAGE_SHIFT))

		return 0;

	/*

	 * We would like to just call:

	 *      set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);

	 * but doing that would radically increase the odds of a

	 * speculative access to the poison page because we'd have

	 * the virtual address of the kernel 1:1 mapping sitting

	 * around in registers.

	 * Instead we get tricky.  We create a non-canonical address

	 * that looks just like the one we want, but has bit 63 flipped.

	 * This relies on set_memory_XX() properly sanitizing any __pa()

	 * results with __PHYSICAL_MASK or PTE_PFN_MASK.

	 */

	decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));



	if (unmap)

		rc = set_memory_np(decoy_addr, 1);

	else

		rc = set_memory_uc(decoy_addr, 1);

	if (rc)

		pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);

	return rc;

}

#define set_mce_nospec set_mce_nospec



/* Restore full speculative operation to the pfn. */

static inline int clear_mce_nospec(unsigned long pfn)

{

	return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);

}

#define clear_mce_nospec clear_mce_nospec

#else

/*

 * Few people would run a 32-bit kernel on a machine that supports

 * recoverable errors because they have too much memory to boot 32-bit.

 */

#endif



#endif /* _ASM_X86_SET_MEMORY_H */

arch/x86/kernel/cpu/mce/core.c

+3 −3
Original line number Diff line number Diff line
@@ -581,7 +581,7 @@ static int uc_decode_notifier(struct notifier_block *nb, unsigned long val, 


	pfn = mce->addr >> PAGE_SHIFT;

	if (!memory_failure(pfn, 0)) {

		set_mce_nospec(pfn, whole_page(mce));

		set_mce_nospec(pfn);

		mce->kflags |= MCE_HANDLED_UC;

	}
@@ -1318,7 +1318,7 @@ static void kill_me_maybe(struct callback_head *cb) 


	ret = memory_failure(p->mce_addr >> PAGE_SHIFT, flags);

	if (!ret) {

		set_mce_nospec(p->mce_addr >> PAGE_SHIFT, p->mce_whole_page);

		set_mce_nospec(p->mce_addr >> PAGE_SHIFT);

		sync_core();

		return;

	}
@@ -1344,7 +1344,7 @@ static void kill_me_never(struct callback_head *cb) 
	p->mce_count = 0;

	pr_err("Kernel accessed poison in user space at %llx\n", p->mce_addr);

	if (!memory_failure(p->mce_addr >> PAGE_SHIFT, 0))

		set_mce_nospec(p->mce_addr >> PAGE_SHIFT, p->mce_whole_page);

		set_mce_nospec(p->mce_addr >> PAGE_SHIFT);

}



static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callback_head *))

arch/x86/mm/pat/set_memory.c

+47 −2
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/vmstat.h>

#include <linux/kernel.h>

#include <linux/cc_platform.h>

#include <linux/set_memory.h>



#include <asm/e820/api.h>

#include <asm/processor.h>
@@ -29,7 +30,6 @@ 
#include <asm/pgalloc.h>

#include <asm/proto.h>

#include <asm/memtype.h>

#include <asm/set_memory.h>

#include <asm/hyperv-tlfs.h>

#include <asm/mshyperv.h>
@@ -1805,7 +1805,7 @@ static inline int cpa_clear_pages_array(struct page **pages, int numpages, 
}



/*

 * _set_memory_prot is an internal helper for callers that have been passed

 * __set_memory_prot is an internal helper for callers that have been passed

 * a pgprot_t value from upper layers and a reservation has already been taken.

 * If you want to set the pgprot to a specific page protocol, use the

 * set_memory_xx() functions.
@@ -1914,6 +1914,51 @@ int set_memory_wb(unsigned long addr, int numpages) 
}

EXPORT_SYMBOL(set_memory_wb);



/* Prevent speculative access to a page by marking it not-present */

#ifdef CONFIG_X86_64

int set_mce_nospec(unsigned long pfn)

{

	unsigned long decoy_addr;

	int rc;



	/* SGX pages are not in the 1:1 map */

	if (arch_is_platform_page(pfn << PAGE_SHIFT))

		return 0;

	/*

	 * We would like to just call:

	 *      set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);

	 * but doing that would radically increase the odds of a

	 * speculative access to the poison page because we'd have

	 * the virtual address of the kernel 1:1 mapping sitting

	 * around in registers.

	 * Instead we get tricky.  We create a non-canonical address

	 * that looks just like the one we want, but has bit 63 flipped.

	 * This relies on set_memory_XX() properly sanitizing any __pa()

	 * results with __PHYSICAL_MASK or PTE_PFN_MASK.

	 */

	decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));



	rc = set_memory_np(decoy_addr, 1);

	if (rc)

		pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);

	return rc;

}



static int set_memory_present(unsigned long *addr, int numpages)

{

	return change_page_attr_set(addr, numpages, __pgprot(_PAGE_PRESENT), 0);

}



/* Restore full speculative operation to the pfn. */

int clear_mce_nospec(unsigned long pfn)

{

	unsigned long addr = (unsigned long) pfn_to_kaddr(pfn);



	return set_memory_present(&addr, 1);

}

EXPORT_SYMBOL_GPL(clear_mce_nospec);

#endif /* CONFIG_X86_64 */



int set_memory_x(unsigned long addr, int numpages)

{

	if (!(__supported_pte_mask & _PAGE_NX))

drivers/acpi/nfit/mce.c

+2 −2
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ static int nfit_handle_mce(struct notifier_block *nb, unsigned long val, 
	 */

	mutex_lock(&acpi_desc_lock);

	list_for_each_entry(acpi_desc, &acpi_descs, list) {

		unsigned int align = 1UL << MCI_MISC_ADDR_LSB(mce->misc);

		struct device *dev = acpi_desc->dev;

		int found_match = 0;
@@ -63,8 +64,7 @@ static int nfit_handle_mce(struct notifier_block *nb, unsigned long val, 


		/* If this fails due to an -ENOMEM, there is little we can do */

		nvdimm_bus_add_badrange(acpi_desc->nvdimm_bus,

				ALIGN(mce->addr, L1_CACHE_BYTES),

				L1_CACHE_BYTES);

				ALIGN_DOWN(mce->addr, align), align);

		nvdimm_region_notify(nfit_spa->nd_region,

				NVDIMM_REVALIDATE_POISON);

drivers/dax/super.c

+12 −2
Original line number Diff line number Diff line
@@ -117,6 +117,7 @@ enum dax_device_flags { 
 * @dax_dev: a dax_device instance representing the logical memory range

 * @pgoff: offset in pages from the start of the device to translate

 * @nr_pages: number of consecutive pages caller can handle relative to @pfn

 * @mode: indicator on normal access or recovery write

 * @kaddr: output parameter that returns a virtual address mapping of pfn

 * @pfn: output parameter that returns an absolute pfn translation of @pgoff

 *
@@ -124,7 +125,7 @@ enum dax_device_flags { 
 * pages accessible at the device relative @pgoff.

 */

long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,

		void **kaddr, pfn_t *pfn)

		enum dax_access_mode mode, void **kaddr, pfn_t *pfn)

{

	long avail;
@@ -138,7 +139,7 @@ long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 
		return -EINVAL;



	avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages,

			kaddr, pfn);

			mode, kaddr, pfn);

	if (!avail)

		return -ERANGE;

	return min(avail, nr_pages);
@@ -194,6 +195,15 @@ int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, 
}

EXPORT_SYMBOL_GPL(dax_zero_page_range);



size_t dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,

		void *addr, size_t bytes, struct iov_iter *iter)

{

	if (!dax_dev->ops->recovery_write)

		return 0;

	return dax_dev->ops->recovery_write(dax_dev, pgoff, addr, bytes, iter);

}

EXPORT_SYMBOL_GPL(dax_recovery_write);



#ifdef CONFIG_ARCH_HAS_PMEM_API

void arch_wb_cache_pmem(void *addr, size_t size);

void dax_flush(struct dax_device *dax_dev, void *addr, size_t size)