4 files changed, 43 insertions, 17 deletions

diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index 66c94417c0ba..4af60374eba0 100644
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -271,7 +271,7 @@ static int restore_sigregs_ext32(struct pt_regs *regs,
 
 	/* Restore high gprs from signal stack */
 	if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high,
-			     sizeof(&sregs_ext->gprs_high)))
+			     sizeof(sregs_ext->gprs_high)))
 		return -EFAULT;
 	for (i = 0; i < NUM_GPRS; i++)
 		*(__u32 *)&regs->gprs[i] = gprs_high[i];
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c
index cfcba2dd9bb5..0943b11a2f6e 100644
--- a/arch/s390/kernel/perf_event.c
+++ b/arch/s390/kernel/perf_event.c
@@ -260,12 +260,13 @@ static unsigned long __store_trace(struct perf_callchain_entry *entry,
 void perf_callchain_kernel(struct perf_callchain_entry *entry,
 			   struct pt_regs *regs)
 {
-	unsigned long head;
+	unsigned long head, frame_size;
 	struct stack_frame *head_sf;
 
 	if (user_mode(regs))
 		return;
 
+	frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
 	head = regs->gprs[15];
 	head_sf = (struct stack_frame *) head;
 
@@ -273,8 +274,9 @@ void perf_callchain_kernel(struct perf_callchain_entry *entry,
 		return;
 
 	head = head_sf->back_chain;
-	head = __store_trace(entry, head, S390_lowcore.async_stack - ASYNC_SIZE,
-			     S390_lowcore.async_stack);
+	head = __store_trace(entry, head,
+			     S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
+			     S390_lowcore.async_stack + frame_size);
 
 	__store_trace(entry, head, S390_lowcore.thread_info,
 		      S390_lowcore.thread_info + THREAD_SIZE);
diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index 5acba3cb7220..8f64ebd63767 100644
--- a/arch/s390/kernel/stacktrace.c
+++ b/arch/s390/kernel/stacktrace.c
@@ -59,26 +59,32 @@ static unsigned long save_context_stack(struct stack_trace *trace,
 	}
 }
 
-void save_stack_trace(struct stack_trace *trace)
+static void __save_stack_trace(struct stack_trace *trace, unsigned long sp)
 {
-	register unsigned long sp asm ("15");
-	unsigned long orig_sp, new_sp;
+	unsigned long new_sp, frame_size;
 
-	orig_sp = sp;
-	new_sp = save_context_stack(trace, orig_sp,
-				    S390_lowcore.panic_stack - PAGE_SIZE,
-				    S390_lowcore.panic_stack, 1);
-	if (new_sp != orig_sp)
-		return;
+	frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+	new_sp = save_context_stack(trace, sp,
+			S390_lowcore.panic_stack + frame_size - PAGE_SIZE,
+			S390_lowcore.panic_stack + frame_size, 1);
 	new_sp = save_context_stack(trace, new_sp,
-				    S390_lowcore.async_stack - ASYNC_SIZE,
-				    S390_lowcore.async_stack, 1);
-	if (new_sp != orig_sp)
-		return;
+			S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
+			S390_lowcore.async_stack + frame_size, 1);
 	save_context_stack(trace, new_sp,
 			   S390_lowcore.thread_info,
 			   S390_lowcore.thread_info + THREAD_SIZE, 1);
 }
+
+void save_stack_trace(struct stack_trace *trace)
+{
+	register unsigned long r15 asm ("15");
+	unsigned long sp;
+
+	sp = r15;
+	__save_stack_trace(trace, sp);
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
 EXPORT_SYMBOL_GPL(save_stack_trace);
 
 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
@@ -86,6 +92,10 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 	unsigned long sp, low, high;
 
 	sp = tsk->thread.ksp;
+	if (tsk == current) {
+		/* Get current stack pointer. */
+		asm volatile("la %0,0(15)" : "=a" (sp));
+	}
 	low = (unsigned long) task_stack_page(tsk);
 	high = (unsigned long) task_pt_regs(tsk);
 	save_context_stack(trace, sp, low, high, 0);
@@ -93,3 +103,14 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+	unsigned long sp;
+
+	sp = kernel_stack_pointer(regs);
+	__save_stack_trace(trace, sp);
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_regs);
diff --git a/arch/s390/kernel/trace.c b/arch/s390/kernel/trace.c
index 21a5df99552b..dde7654f5c68 100644
--- a/arch/s390/kernel/trace.c
+++ b/arch/s390/kernel/trace.c
@@ -18,6 +18,9 @@ void trace_s390_diagnose_norecursion(int diag_nr)
 	unsigned long flags;
 	unsigned int *depth;
 
+	/* Avoid lockdep recursion. */
+	if (IS_ENABLED(CONFIG_LOCKDEP))
+		return;
 	local_irq_save(flags);
 	depth = this_cpu_ptr(&diagnose_trace_depth);
 	if (*depth == 0) {