4 files changed, 33 insertions, 7 deletions

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 331c4ca6205c..a6e757cbab77 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -933,6 +933,10 @@ static int __init __iommu_dma_init(void)
 		ret = register_iommu_dma_ops_notifier(&platform_bus_type);
 	if (!ret)
 		ret = register_iommu_dma_ops_notifier(&amba_bustype);
+
+	/* handle devices queued before this arch_initcall */
+	if (!ret)
+		__iommu_attach_notifier(NULL, BUS_NOTIFY_ADD_DEVICE, NULL);
 	return ret;
 }
 arch_initcall(__iommu_dma_init);
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 92ddac1e8ca2..abe2a9542b3a 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -371,6 +371,13 @@ static int __kprobes do_translation_fault(unsigned long addr,
 	return 0;
 }
 
+static int do_alignment_fault(unsigned long addr, unsigned int esr,
+			      struct pt_regs *regs)
+{
+	do_bad_area(addr, esr, regs);
+	return 0;
+}
+
 /*
  * This abort handler always returns "fault".
  */
@@ -418,7 +425,7 @@ static struct fault_info {
 	{ do_bad,		SIGBUS,  0,		"synchronous parity error (translation table walk)" },
 	{ do_bad,		SIGBUS,  0,		"synchronous parity error (translation table walk)" },
 	{ do_bad,		SIGBUS,  0,		"unknown 32"			},
-	{ do_bad,		SIGBUS,  BUS_ADRALN,	"alignment fault"		},
+	{ do_alignment_fault,	SIGBUS,  BUS_ADRALN,	"alignment fault"		},
 	{ do_bad,		SIGBUS,  0,		"unknown 34"			},
 	{ do_bad,		SIGBUS,  0,		"unknown 35"			},
 	{ do_bad,		SIGBUS,  0,		"unknown 36"			},
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
index 4c893b5189dd..232f787a088a 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -53,10 +53,10 @@ unsigned long arch_mmap_rnd(void)
 
 #ifdef CONFIG_COMPAT
 	if (test_thread_flag(TIF_32BIT))
-		rnd = (unsigned long)get_random_int() & ((1 << mmap_rnd_compat_bits) - 1);
+		rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1);
 	else
 #endif
-		rnd = (unsigned long)get_random_int() & ((1 << mmap_rnd_bits) - 1);
+		rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1);
 	return rnd << PAGE_SHIFT;
 }
 
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index cf6240741134..0795c3a36d8f 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -14,6 +14,7 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/sched.h>
+#include <linux/vmalloc.h>
 
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
@@ -44,6 +45,7 @@ static int change_memory_common(unsigned long addr, int numpages,
 	unsigned long end = start + size;
 	int ret;
 	struct page_change_data data;
+	struct vm_struct *area;
 
 	if (!PAGE_ALIGNED(addr)) {
 		start &= PAGE_MASK;
@@ -51,10 +53,23 @@ static int change_memory_common(unsigned long addr, int numpages,
 		WARN_ON_ONCE(1);
 	}
 
-	if (start < MODULES_VADDR || start >= MODULES_END)
-		return -EINVAL;
-
-	if (end < MODULES_VADDR || end >= MODULES_END)
+	/*
+	 * Kernel VA mappings are always live, and splitting live section
+	 * mappings into page mappings may cause TLB conflicts. This means
+	 * we have to ensure that changing the permission bits of the range
+	 * we are operating on does not result in such splitting.
+	 *
+	 * Let's restrict ourselves to mappings created by vmalloc (or vmap).
+	 * Those are guaranteed to consist entirely of page mappings, and
+	 * splitting is never needed.
+	 *
+	 * So check whether the [addr, addr + size) interval is entirely
+	 * covered by precisely one VM area that has the VM_ALLOC flag set.
+	 */
+	area = find_vm_area((void *)addr);
+	if (!area ||
+	    end > (unsigned long)area->addr + area->size ||
+	    !(area->flags & VM_ALLOC))
 		return -EINVAL;
 
 	if (!numpages)