3 files changed, 96 insertions, 18 deletions

diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index b85e9e82f082..9c454f90fd3d 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -13,8 +13,7 @@ endif
 KCOV_INSTRUMENT_init.o := n
 
 obj-y += init.o
-obj-y += extable.o
-obj-$(CONFIG_MMU) += fault.o pageattr.o
+obj-$(CONFIG_MMU) += extable.o fault.o pageattr.o
 obj-y += cacheflush.o
 obj-y += context.o
 obj-y += pgtable.o
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 35a84ec69a9f..6ea2cce4cc17 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -247,24 +247,12 @@ void handle_page_fault(struct pt_regs *regs)
 	 * only copy the information from the master page table,
 	 * nothing more.
 	 */
-	if (unlikely((addr >= VMALLOC_START) && (addr < VMALLOC_END))) {
+	if ((!IS_ENABLED(CONFIG_MMU) || !IS_ENABLED(CONFIG_64BIT)) &&
+	    unlikely(addr >= VMALLOC_START && addr < VMALLOC_END)) {
 		vmalloc_fault(regs, code, addr);
 		return;
 	}
 
-#ifdef CONFIG_64BIT
-	/*
-	 * Modules in 64bit kernels lie in their own virtual region which is not
-	 * in the vmalloc region, but dealing with page faults in this region
-	 * or the vmalloc region amounts to doing the same thing: checking that
-	 * the mapping exists in init_mm.pgd and updating user page table, so
-	 * just use vmalloc_fault.
-	 */
-	if (unlikely(addr >= MODULES_VADDR && addr < MODULES_END)) {
-		vmalloc_fault(regs, code, addr);
-		return;
-	}
-#endif
 	/* Enable interrupts if they were enabled in the parent context. */
 	if (!regs_irqs_disabled(regs))
 		local_irq_enable();
@@ -295,6 +283,36 @@ void handle_page_fault(struct pt_regs *regs)
 		flags |= FAULT_FLAG_WRITE;
 	else if (cause == EXC_INST_PAGE_FAULT)
 		flags |= FAULT_FLAG_INSTRUCTION;
+#ifdef CONFIG_PER_VMA_LOCK
+	if (!(flags & FAULT_FLAG_USER))
+		goto lock_mmap;
+
+	vma = lock_vma_under_rcu(mm, addr);
+	if (!vma)
+		goto lock_mmap;
+
+	if (unlikely(access_error(cause, vma))) {
+		vma_end_read(vma);
+		goto lock_mmap;
+	}
+
+	fault = handle_mm_fault(vma, addr, flags | FAULT_FLAG_VMA_LOCK, regs);
+	vma_end_read(vma);
+
+	if (!(fault & VM_FAULT_RETRY)) {
+		count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+		goto done;
+	}
+	count_vm_vma_lock_event(VMA_LOCK_RETRY);
+
+	if (fault_signal_pending(fault, regs)) {
+		if (!user_mode(regs))
+			no_context(regs, addr);
+		return;
+	}
+lock_mmap:
+#endif /* CONFIG_PER_VMA_LOCK */
+
 retry:
 	vma = lock_mm_and_find_vma(mm, addr, regs);
 	if (unlikely(!vma)) {
@@ -350,6 +368,9 @@ retry:
 
 	mmap_read_unlock(mm);
 
+#ifdef CONFIG_PER_VMA_LOCK
+done:
+#endif
 	if (unlikely(fault & VM_FAULT_ERROR)) {
 		tsk->thread.bad_cause = cause;
 		mm_fault_error(regs, addr, fault);
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 4fa420faa780..4b95d8999120 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -357,7 +357,7 @@ static phys_addr_t __init alloc_pte_late(uintptr_t va)
 	unsigned long vaddr;
 
 	vaddr = __get_free_page(GFP_KERNEL);
-	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)));
+	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page((void *)vaddr)));
 
 	return __pa(vaddr);
 }
@@ -440,7 +440,7 @@ static phys_addr_t __init alloc_pmd_late(uintptr_t va)
 	unsigned long vaddr;
 
 	vaddr = __get_free_page(GFP_KERNEL);
-	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page(vaddr)));
+	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page((void *)vaddr)));
 
 	return __pa(vaddr);
 }
@@ -1389,3 +1389,61 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
 	return vmemmap_populate_basepages(start, end, node, NULL);
 }
 #endif
+
+#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
+/*
+ * Pre-allocates page-table pages for a specific area in the kernel
+ * page-table. Only the level which needs to be synchronized between
+ * all page-tables is allocated because the synchronization can be
+ * expensive.
+ */
+static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end,
+					       const char *area)
+{
+	unsigned long addr;
+	const char *lvl;
+
+	for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
+		pgd_t *pgd = pgd_offset_k(addr);
+		p4d_t *p4d;
+		pud_t *pud;
+		pmd_t *pmd;
+
+		lvl = "p4d";
+		p4d = p4d_alloc(&init_mm, pgd, addr);
+		if (!p4d)
+			goto failed;
+
+		if (pgtable_l5_enabled)
+			continue;
+
+		lvl = "pud";
+		pud = pud_alloc(&init_mm, p4d, addr);
+		if (!pud)
+			goto failed;
+
+		if (pgtable_l4_enabled)
+			continue;
+
+		lvl = "pmd";
+		pmd = pmd_alloc(&init_mm, pud, addr);
+		if (!pmd)
+			goto failed;
+	}
+	return;
+
+failed:
+	/*
+	 * The pages have to be there now or they will be missing in
+	 * process page-tables later.
+	 */
+	panic("Failed to pre-allocate %s pages for %s area\n", lvl, area);
+}
+
+void __init pgtable_cache_init(void)
+{
+	preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc");
+	if (IS_ENABLED(CONFIG_MODULES))
+		preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules");
+}
+#endif