summaryrefslogtreecommitdiffstats
path: root/arch/x86
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2022-05-27 15:49:30 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-05-27 15:49:30 -0700
commit35cdd8656eac470b9abc9de8d4bd268fbc0fb34b (patch)
tree261e2d2fc3dc5059ce3ffaf9bf231109bbbd6d0e /arch/x86
parentea6c3bc6ed93dd032568427e92424f6d33deb99b (diff)
parentf42e8e5088b9e791c8f7ac661f68e29a4996a4e3 (diff)
downloadlinux-35cdd8656eac470b9abc9de8d4bd268fbc0fb34b.tar.bz2
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
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/set_memory.h52
-rw-r--r--arch/x86/kernel/cpu/mce/core.c6
-rw-r--r--arch/x86/mm/pat/set_memory.c49
3 files changed, 50 insertions, 57 deletions
diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 78ca53512486..b45c4d27fd46 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -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 */
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index d775fcd74e98..2c8ec5c71712 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -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 *))
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 0656db33574d..1abd5438f126 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -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))