1 files changed, 46 insertions, 11 deletions

diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c
index 74f4555a62ba..0e6ed4413eea 100644
--- a/arch/powerpc/mm/kasan/kasan_init_32.c
+++ b/arch/powerpc/mm/kasan/kasan_init_32.c
@@ -5,12 +5,21 @@
 #include <linux/kasan.h>
 #include <linux/printk.h>
 #include <linux/memblock.h>
+#include <linux/moduleloader.h>
 #include <linux/sched/task.h>
 #include <linux/vmalloc.h>
 #include <asm/pgalloc.h>
 #include <asm/code-patching.h>
 #include <mm/mmu_decl.h>
 
+static pgprot_t kasan_prot_ro(void)
+{
+	if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
+		return PAGE_READONLY;
+
+	return PAGE_KERNEL_RO;
+}
+
 static void kasan_populate_pte(pte_t *ptep, pgprot_t prot)
 {
 	unsigned long va = (unsigned long)kasan_early_shadow_page;
@@ -25,6 +34,7 @@ static int __ref kasan_init_shadow_page_tables(unsigned long k_start, unsigned l
 {
 	pmd_t *pmd;
 	unsigned long k_cur, k_next;
+	pgprot_t prot = slab_is_available() ? kasan_prot_ro() : PAGE_KERNEL;
 
 	pmd = pmd_offset(pud_offset(pgd_offset_k(k_start), k_start), k_start);
 
@@ -42,11 +52,20 @@ static int __ref kasan_init_shadow_page_tables(unsigned long k_start, unsigned l
 
 		if (!new)
 			return -ENOMEM;
-		if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
-			kasan_populate_pte(new, PAGE_READONLY);
-		else
-			kasan_populate_pte(new, PAGE_KERNEL_RO);
-		pmd_populate_kernel(&init_mm, pmd, new);
+		kasan_populate_pte(new, prot);
+
+		smp_wmb(); /* See comment in __pte_alloc */
+
+		spin_lock(&init_mm.page_table_lock);
+			/* Has another populated it ? */
+		if (likely((void *)pmd_page_vaddr(*pmd) == kasan_early_shadow_pte)) {
+			pmd_populate_kernel(&init_mm, pmd, new);
+			new = NULL;
+		}
+		spin_unlock(&init_mm.page_table_lock);
+
+		if (new && slab_is_available())
+			pte_free_kernel(&init_mm, new);
 	}
 	return 0;
 }
@@ -74,7 +93,7 @@ static int __ref kasan_init_region(void *start, size_t size)
 	if (!slab_is_available())
 		block = memblock_alloc(k_end - k_start, PAGE_SIZE);
 
-	for (k_cur = k_start; k_cur < k_end; k_cur += PAGE_SIZE) {
+	for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
 		pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
 		void *va = block ? block + k_cur - k_start : kasan_get_one_page();
 		pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
@@ -90,11 +109,23 @@ static int __ref kasan_init_region(void *start, size_t size)
 
 static void __init kasan_remap_early_shadow_ro(void)
 {
-	if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
-		kasan_populate_pte(kasan_early_shadow_pte, PAGE_READONLY);
-	else
-		kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL_RO);
+	pgprot_t prot = kasan_prot_ro();
+	unsigned long k_start = KASAN_SHADOW_START;
+	unsigned long k_end = KASAN_SHADOW_END;
+	unsigned long k_cur;
+	phys_addr_t pa = __pa(kasan_early_shadow_page);
+
+	kasan_populate_pte(kasan_early_shadow_pte, prot);
+
+	for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
+		pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
+		pte_t *ptep = pte_offset_kernel(pmd, k_cur);
 
+		if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
+			continue;
+
+		__set_pte_at(&init_mm, k_cur, ptep, pfn_pte(PHYS_PFN(pa), prot), 0);
+	}
 	flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END);
 }
 
@@ -137,7 +168,11 @@ void __init kasan_init(void)
 #ifdef CONFIG_MODULES
 void *module_alloc(unsigned long size)
 {
-	void *base = vmalloc_exec(size);
+	void *base;
+
+	base = __vmalloc_node_range(size, MODULE_ALIGN, VMALLOC_START, VMALLOC_END,
+				    GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
+				    NUMA_NO_NODE, __builtin_return_address(0));
 
 	if (!base)
 		return NULL;