1 files changed, 25 insertions, 11 deletions

diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 089f3987e273..974b87474a99 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -30,8 +30,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	pmd_t *pmd;
 	pte_t *pte;
 	int err = -EFAULT;
-	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
-				 (is_write ? FAULT_FLAG_WRITE : 0);
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	*code_out = SEGV_MAPERR;
 
@@ -42,6 +41,8 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	if (in_atomic())
 		goto out_nosemaphore;
 
+	if (is_user)
+		flags |= FAULT_FLAG_USER;
 retry:
 	down_read(&mm->mmap_sem);
 	vma = find_vma(mm, address);
@@ -58,12 +59,15 @@ retry:
 
 good_area:
 	*code_out = SEGV_ACCERR;
-	if (is_write && !(vma->vm_flags & VM_WRITE))
-		goto out;
-
-	/* Don't require VM_READ|VM_EXEC for write faults! */
-	if (!is_write && !(vma->vm_flags & (VM_READ | VM_EXEC)))
-		goto out;
+	if (is_write) {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto out;
+		flags |= FAULT_FLAG_WRITE;
+	} else {
+		/* Don't require VM_READ|VM_EXEC for write faults! */
+		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+			goto out;
+	}
 
 	do {
 		int fault;
@@ -124,6 +128,8 @@ out_of_memory:
 	 * (which will retry the fault, or kill us if we got oom-killed).
 	 */
 	up_read(&mm->mmap_sem);
+	if (!is_user)
+		goto out_nosemaphore;
 	pagefault_out_of_memory();
 	return 0;
 }
@@ -200,9 +206,12 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 	int is_write = FAULT_WRITE(fi);
 	unsigned long address = FAULT_ADDRESS(fi);
 
+	if (regs)
+		current->thread.segv_regs = container_of(regs, struct pt_regs, regs);
+
 	if (!is_user && (address >= start_vm) && (address < end_vm)) {
 		flush_tlb_kernel_vm();
-		return 0;
+		goto out;
 	}
 	else if (current->mm == NULL) {
 		show_regs(container_of(regs, struct pt_regs, regs));
@@ -224,7 +233,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 
 	catcher = current->thread.fault_catcher;
 	if (!err)
-		return 0;
+		goto out;
 	else if (catcher != NULL) {
 		current->thread.fault_addr = (void *) address;
 		UML_LONGJMP(catcher, 1);
@@ -232,7 +241,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 	else if (current->thread.fault_addr != NULL)
 		panic("fault_addr set but no fault catcher");
 	else if (!is_user && arch_fixup(ip, regs))
-		return 0;
+		goto out;
 
 	if (!is_user) {
 		show_regs(container_of(regs, struct pt_regs, regs));
@@ -256,6 +265,11 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 		current->thread.arch.faultinfo = fi;
 		force_sig_info(SIGSEGV, &si, current);
 	}
+
+out:
+	if (regs)
+		current->thread.segv_regs = NULL;
+
 	return 0;
 }