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-rw-r--r--arch/arm64/mm/fault.c31
-rw-r--r--arch/arm64/mm/hugetlbpage.c73
-rw-r--r--arch/arm64/mm/mmu.c11
-rw-r--r--arch/arm64/mm/ptdump_debugfs.c3
4 files changed, 67 insertions, 51 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 8b281cf308b3..2d1ebc0c3437 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -487,17 +487,29 @@ static void do_bad_area(unsigned long far, unsigned long esr,
}
}
-static bool fault_from_pkey(unsigned long esr, struct vm_area_struct *vma,
- unsigned int mm_flags)
+static bool fault_from_pkey(struct vm_area_struct *vma, unsigned int mm_flags)
{
- unsigned long iss2 = ESR_ELx_ISS2(esr);
-
if (!system_supports_poe())
return false;
- if (esr_fsc_is_permission_fault(esr) && (iss2 & ESR_ELx_Overlay))
- return true;
-
+ /*
+ * We do not check whether an Overlay fault has occurred because we
+ * cannot make a decision based solely on its value:
+ *
+ * - If Overlay is set, a fault did occur due to POE, but it may be
+ * spurious in those cases where we update POR_EL0 without ISB (e.g.
+ * on context-switch). We would then need to manually check POR_EL0
+ * against vma_pkey(vma), which is exactly what
+ * arch_vma_access_permitted() does.
+ *
+ * - If Overlay is not set, we may still need to report a pkey fault.
+ * This is the case if an access was made within a mapping but with no
+ * page mapped, and POR_EL0 forbids the access (according to
+ * vma_pkey()). Such access will result in a SIGSEGV regardless
+ * because core code checks arch_vma_access_permitted(), but in order
+ * to report the correct error code - SEGV_PKUERR - we must handle
+ * that case here.
+ */
return !arch_vma_access_permitted(vma,
mm_flags & FAULT_FLAG_WRITE,
mm_flags & FAULT_FLAG_INSTRUCTION,
@@ -595,7 +607,7 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
goto bad_area;
}
- if (fault_from_pkey(esr, vma, mm_flags)) {
+ if (fault_from_pkey(vma, mm_flags)) {
pkey = vma_pkey(vma);
vma_end_read(vma);
fault = 0;
@@ -639,7 +651,7 @@ retry:
goto bad_area;
}
- if (fault_from_pkey(esr, vma, mm_flags)) {
+ if (fault_from_pkey(vma, mm_flags)) {
pkey = vma_pkey(vma);
mmap_read_unlock(mm);
fault = 0;
@@ -786,6 +798,7 @@ static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs)
*/
siaddr = untagged_addr(far);
}
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_STILL_OK);
arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
return 0;
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 5f1e2103888b..fe167ce297a1 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -100,20 +100,11 @@ static int find_num_contig(struct mm_struct *mm, unsigned long addr,
static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
{
- int contig_ptes = 0;
+ int contig_ptes = 1;
*pgsize = size;
switch (size) {
-#ifndef __PAGETABLE_PMD_FOLDED
- case PUD_SIZE:
- if (pud_sect_supported())
- contig_ptes = 1;
- break;
-#endif
- case PMD_SIZE:
- contig_ptes = 1;
- break;
case CONT_PMD_SIZE:
*pgsize = PMD_SIZE;
contig_ptes = CONT_PMDS;
@@ -122,6 +113,8 @@ static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
*pgsize = PAGE_SIZE;
contig_ptes = CONT_PTES;
break;
+ default:
+ WARN_ON(!__hugetlb_valid_size(size));
}
return contig_ptes;
@@ -163,24 +156,23 @@ static pte_t get_clear_contig(struct mm_struct *mm,
unsigned long pgsize,
unsigned long ncontig)
{
- pte_t orig_pte = __ptep_get(ptep);
- unsigned long i;
-
- for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
- pte_t pte = __ptep_get_and_clear(mm, addr, ptep);
-
- /*
- * If HW_AFDBM is enabled, then the HW could turn on
- * the dirty or accessed bit for any page in the set,
- * so check them all.
- */
- if (pte_dirty(pte))
- orig_pte = pte_mkdirty(orig_pte);
-
- if (pte_young(pte))
- orig_pte = pte_mkyoung(orig_pte);
+ pte_t pte, tmp_pte;
+ bool present;
+
+ pte = __ptep_get_and_clear(mm, addr, ptep);
+ present = pte_present(pte);
+ while (--ncontig) {
+ ptep++;
+ addr += pgsize;
+ tmp_pte = __ptep_get_and_clear(mm, addr, ptep);
+ if (present) {
+ if (pte_dirty(tmp_pte))
+ pte = pte_mkdirty(pte);
+ if (pte_young(tmp_pte))
+ pte = pte_mkyoung(pte);
+ }
}
- return orig_pte;
+ return pte;
}
static pte_t get_clear_contig_flush(struct mm_struct *mm,
@@ -385,18 +377,13 @@ void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
__pte_clear(mm, addr, ptep);
}
-pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
- unsigned long addr, pte_t *ptep)
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, unsigned long sz)
{
int ncontig;
size_t pgsize;
- pte_t orig_pte = __ptep_get(ptep);
-
- if (!pte_cont(orig_pte))
- return __ptep_get_and_clear(mm, addr, ptep);
-
- ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+ ncontig = num_contig_ptes(sz, &pgsize);
return get_clear_contig(mm, addr, ptep, pgsize, ncontig);
}
@@ -508,6 +495,18 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
static int __init hugetlbpage_init(void)
{
+ /*
+ * HugeTLB pages are supported on maximum four page table
+ * levels (PUD, CONT PMD, PMD, CONT PTE) for a given base
+ * page size, corresponding to hugetlb_add_hstate() calls
+ * here.
+ *
+ * HUGE_MAX_HSTATE should at least match maximum supported
+ * HugeTLB page sizes on the platform. Any new addition to
+ * supported HugeTLB page sizes will also require changing
+ * HUGE_MAX_HSTATE as well.
+ */
+ BUILD_BUG_ON(HUGE_MAX_HSTATE < 4);
if (pud_sect_supported())
hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
@@ -526,6 +525,8 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
{
+ unsigned long psize = huge_page_size(hstate_vma(vma));
+
if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) {
/*
* Break-before-make (BBM) is required for all user space mappings
@@ -535,7 +536,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
if (pte_user_exec(__ptep_get(ptep)))
return huge_ptep_clear_flush(vma, addr, ptep);
}
- return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+ return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, psize);
}
void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index e55b02fbddc8..aed8d32979d9 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1176,8 +1176,11 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
struct vmem_altmap *altmap)
{
WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END));
+ /* [start, end] should be within one section */
+ WARN_ON_ONCE(end - start > PAGES_PER_SECTION * sizeof(struct page));
- if (!IS_ENABLED(CONFIG_ARM64_4K_PAGES))
+ if (!IS_ENABLED(CONFIG_ARM64_4K_PAGES) ||
+ (end - start < PAGES_PER_SECTION * sizeof(struct page)))
return vmemmap_populate_basepages(start, end, node, altmap);
else
return vmemmap_populate_hugepages(start, end, node, altmap);
@@ -1282,7 +1285,8 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
next = addr;
end = addr + PUD_SIZE;
do {
- pmd_free_pte_page(pmdp, next);
+ if (pmd_present(pmdp_get(pmdp)))
+ pmd_free_pte_page(pmdp, next);
} while (pmdp++, next += PMD_SIZE, next != end);
pud_clear(pudp);
@@ -1357,7 +1361,8 @@ int arch_add_memory(int nid, u64 start, u64 size,
__remove_pgd_mapping(swapper_pg_dir,
__phys_to_virt(start), size);
else {
- max_pfn = PFN_UP(start + size);
+ /* Address of hotplugged memory can be smaller */
+ max_pfn = max(max_pfn, PFN_UP(start + size));
max_low_pfn = max_pfn;
}
diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c
index 68bf1a125502..1e308328c079 100644
--- a/arch/arm64/mm/ptdump_debugfs.c
+++ b/arch/arm64/mm/ptdump_debugfs.c
@@ -1,6 +1,5 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/debugfs.h>
-#include <linux/memory_hotplug.h>
#include <linux/seq_file.h>
#include <asm/ptdump.h>
@@ -9,9 +8,7 @@ static int ptdump_show(struct seq_file *m, void *v)
{
struct ptdump_info *info = m->private;
- get_online_mems();
ptdump_walk(m, info);
- put_online_mems();
return 0;
}
DEFINE_SHOW_ATTRIBUTE(ptdump);
generated by cgit v1.2.3 (git 2.39.0) at 2025-08-29 13:10:29 +0300