4 files changed, 49 insertions, 28 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index db469fa11462..dff2152350a7 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -50,7 +50,8 @@ _TIF_WORK	= (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
 		   _TIF_UPROBE)
 _TIF_TRACE	= (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
 		   _TIF_SYSCALL_TRACEPOINT)
-_CIF_WORK	= (_CIF_MCCK_PENDING | _CIF_ASCE | _CIF_FPU)
+_CIF_WORK	= (_CIF_MCCK_PENDING | _CIF_ASCE_PRIMARY | \
+		   _CIF_ASCE_SECONDARY | _CIF_FPU)
 _PIF_WORK	= (_PIF_PER_TRAP)
 
 #define BASED(name) name-cleanup_critical(%r13)
@@ -339,8 +340,8 @@ ENTRY(system_call)
 	jo	.Lsysc_notify_resume
 	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
 	jo	.Lsysc_vxrs
-	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE
-	jo	.Lsysc_uaccess
+	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
+	jnz	.Lsysc_asce
 	j	.Lsysc_return		# beware of critical section cleanup
 
 #
@@ -358,12 +359,15 @@ ENTRY(system_call)
 	jg	s390_handle_mcck	# TIF bit will be cleared by handler
 
 #
-# _CIF_ASCE is set, load user space asce
+# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
 #
-.Lsysc_uaccess:
-	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE
+.Lsysc_asce:
+	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
 	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
-	j	.Lsysc_return
+	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_SECONDARY
+	jz	.Lsysc_return
+	larl	%r14,.Lsysc_return
+	jg	set_fs_fixup
 
 #
 # CIF_FPU is set, restore floating-point controls and floating-point registers.
@@ -661,8 +665,8 @@ ENTRY(io_int_handler)
 	jo	.Lio_notify_resume
 	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
 	jo	.Lio_vxrs
-	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE
-	jo	.Lio_uaccess
+	TSTMSK	__LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
+	jnz	.Lio_asce
 	j	.Lio_return		# beware of critical section cleanup
 
 #
@@ -675,12 +679,15 @@ ENTRY(io_int_handler)
 	j	.Lio_return
 
 #
-# _CIF_ASCE is set, load user space asce
+# _CIF_ASCE_PRIMARY and/or CIF_ASCE_SECONDARY set, load user space asce
 #
-.Lio_uaccess:
-	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE
+.Lio_asce:
+	ni	__LC_CPU_FLAGS+7,255-_CIF_ASCE_PRIMARY
 	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
-	j	.Lio_return
+	TSTMSK	__LC_CPU_FLAGS,_CIF_ASCE_SECONDARY
+	jz	.Lio_return
+	larl	%r14,.Lio_return
+	jg	set_fs_fixup
 
 #
 # CIF_FPU is set, restore floating-point controls and floating-point registers.
diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h
index e79f030dd276..33f901865326 100644
--- a/arch/s390/kernel/entry.h
+++ b/arch/s390/kernel/entry.h
@@ -80,5 +80,6 @@ long sys_s390_pci_mmio_read(unsigned long, void __user *, size_t);
 DECLARE_PER_CPU(u64, mt_cycles[8]);
 
 void verify_facilities(void);
+void set_fs_fixup(void);
 
 #endif /* _ENTRY_H */
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 56e14d073167..80c093e0c6f1 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -116,6 +116,19 @@ static int notrace s390_validate_registers(union mci mci, int umode)
 			s390_handle_damage();
 		kill_task = 1;
 	}
+	/* Validate control registers */
+	if (!mci.cr) {
+		/*
+		 * Control registers have unknown contents.
+		 * Can't recover and therefore stopping machine.
+		 */
+		s390_handle_damage();
+	} else {
+		asm volatile(
+			"	lctlg	0,15,0(%0)\n"
+			"	ptlb\n"
+			: : "a" (&S390_lowcore.cregs_save_area) : "memory");
+	}
 	if (!mci.fp) {
 		/*
 		 * Floating point registers can't be restored. If the
@@ -208,18 +221,6 @@ static int notrace s390_validate_registers(union mci mci, int umode)
 		 */
 		kill_task = 1;
 	}
-	/* Validate control registers */
-	if (!mci.cr) {
-		/*
-		 * Control registers have unknown contents.
-		 * Can't recover and therefore stopping machine.
-		 */
-		s390_handle_damage();
-	} else {
-		asm volatile(
-			"	lctlg	0,15,0(%0)"
-			: : "a" (&S390_lowcore.cregs_save_area) : "memory");
-	}
 	/*
 	 * We don't even try to validate the TOD register, since we simply
 	 * can't write something sensible into that register.
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index c5b86b4a1a8b..54281660582c 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -100,8 +100,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 	return 0;
 }
 
-int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
-		unsigned long arg, struct task_struct *p)
+int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp,
+		    unsigned long arg, struct task_struct *p, unsigned long tls)
 {
 	struct fake_frame
 	{
@@ -156,7 +156,6 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
 
 	/* Set a new TLS ?  */
 	if (clone_flags & CLONE_SETTLS) {
-		unsigned long tls = frame->childregs.gprs[6];
 		if (is_compat_task()) {
 			p->thread.acrs[0] = (unsigned int)tls;
 		} else {
@@ -234,3 +233,16 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
 	ret = PAGE_ALIGN(mm->brk + brk_rnd());
 	return (ret > mm->brk) ? ret : mm->brk;
 }
+
+void set_fs_fixup(void)
+{
+	struct pt_regs *regs = current_pt_regs();
+	static bool warned;
+
+	set_fs(USER_DS);
+	if (warned)
+		return;
+	WARN(1, "Unbalanced set_fs - int code: 0x%x\n", regs->int_code);
+	show_registers(regs);
+	warned = true;
+}