v4.19.13 snapshot.
diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c
new file mode 100644
index 0000000..5b23c4f
--- /dev/null
+++ b/arch/s390/kernel/dumpstack.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Stack dumping functions
+ *
+ * Copyright IBM Corp. 1999, 2013
+ */
+
+#include <linux/kallsyms.h>
+#include <linux/hardirq.h>
+#include <linux/kprobes.h>
+#include <linux/utsname.h>
+#include <linux/export.h>
+#include <linux/kdebug.h>
+#include <linux/ptrace.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
+#include <asm/processor.h>
+#include <asm/debug.h>
+#include <asm/dis.h>
+#include <asm/ipl.h>
+
+/*
+ * For dump_trace we have tree different stack to consider:
+ * - the panic stack which is used if the kernel stack has overflown
+ * - the asynchronous interrupt stack (cpu related)
+ * - the synchronous kernel stack (process related)
+ * The stack trace can start at any of the three stacks and can potentially
+ * touch all of them. The order is: panic stack, async stack, sync stack.
+ */
+static unsigned long
+__dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
+ unsigned long low, unsigned long high)
+{
+ struct stack_frame *sf;
+ struct pt_regs *regs;
+
+ while (1) {
+ if (sp < low || sp > high - sizeof(*sf))
+ return sp;
+ sf = (struct stack_frame *) sp;
+ if (func(data, sf->gprs[8], 0))
+ return sp;
+ /* Follow the backchain. */
+ while (1) {
+ low = sp;
+ sp = sf->back_chain;
+ if (!sp)
+ break;
+ if (sp <= low || sp > high - sizeof(*sf))
+ return sp;
+ sf = (struct stack_frame *) sp;
+ if (func(data, sf->gprs[8], 1))
+ return sp;
+ }
+ /* Zero backchain detected, check for interrupt frame. */
+ sp = (unsigned long) (sf + 1);
+ if (sp <= low || sp > high - sizeof(*regs))
+ return sp;
+ regs = (struct pt_regs *) sp;
+ if (!user_mode(regs)) {
+ if (func(data, regs->psw.addr, 1))
+ return sp;
+ }
+ low = sp;
+ sp = regs->gprs[15];
+ }
+}
+
+void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
+ unsigned long sp)
+{
+ unsigned long frame_size;
+
+ frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+#ifdef CONFIG_CHECK_STACK
+ sp = __dump_trace(func, data, sp,
+ S390_lowcore.panic_stack + frame_size - PAGE_SIZE,
+ S390_lowcore.panic_stack + frame_size);
+#endif
+ sp = __dump_trace(func, data, sp,
+ S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
+ S390_lowcore.async_stack + frame_size);
+ task = task ?: current;
+ __dump_trace(func, data, sp,
+ (unsigned long)task_stack_page(task),
+ (unsigned long)task_stack_page(task) + THREAD_SIZE);
+}
+EXPORT_SYMBOL_GPL(dump_trace);
+
+static int show_address(void *data, unsigned long address, int reliable)
+{
+ if (reliable)
+ printk(" [<%016lx>] %pSR \n", address, (void *)address);
+ else
+ printk("([<%016lx>] %pSR)\n", address, (void *)address);
+ return 0;
+}
+
+void show_stack(struct task_struct *task, unsigned long *stack)
+{
+ unsigned long sp = (unsigned long) stack;
+
+ if (!sp)
+ sp = task ? task->thread.ksp : current_stack_pointer();
+ printk("Call Trace:\n");
+ dump_trace(show_address, NULL, task, sp);
+ if (!task)
+ task = current;
+ debug_show_held_locks(task);
+}
+
+static void show_last_breaking_event(struct pt_regs *regs)
+{
+ printk("Last Breaking-Event-Address:\n");
+ printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
+}
+
+void show_registers(struct pt_regs *regs)
+{
+ struct psw_bits *psw = &psw_bits(regs->psw);
+ char *mode;
+
+ mode = user_mode(regs) ? "User" : "Krnl";
+ printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
+ if (!user_mode(regs))
+ pr_cont(" (%pSR)", (void *)regs->psw.addr);
+ pr_cont("\n");
+ printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
+ "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
+ psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
+ pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
+ printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
+ regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
+ printk(" %016lx %016lx %016lx %016lx\n",
+ regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
+ printk(" %016lx %016lx %016lx %016lx\n",
+ regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
+ printk(" %016lx %016lx %016lx %016lx\n",
+ regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
+ show_code(regs);
+}
+
+void show_regs(struct pt_regs *regs)
+{
+ show_regs_print_info(KERN_DEFAULT);
+ show_registers(regs);
+ /* Show stack backtrace if pt_regs is from kernel mode */
+ if (!user_mode(regs))
+ show_stack(NULL, (unsigned long *) regs->gprs[15]);
+ show_last_breaking_event(regs);
+}
+
+static DEFINE_SPINLOCK(die_lock);
+
+void die(struct pt_regs *regs, const char *str)
+{
+ static int die_counter;
+
+ oops_enter();
+ lgr_info_log();
+ debug_stop_all();
+ console_verbose();
+ spin_lock_irq(&die_lock);
+ bust_spinlocks(1);
+ printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
+ regs->int_code >> 17, ++die_counter);
+#ifdef CONFIG_PREEMPT
+ pr_cont("PREEMPT ");
+#endif
+#ifdef CONFIG_SMP
+ pr_cont("SMP ");
+#endif
+ if (debug_pagealloc_enabled())
+ pr_cont("DEBUG_PAGEALLOC");
+ pr_cont("\n");
+ notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
+ print_modules();
+ show_regs(regs);
+ bust_spinlocks(0);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
+ spin_unlock_irq(&die_lock);
+ if (in_interrupt())
+ panic("Fatal exception in interrupt");
+ if (panic_on_oops)
+ panic("Fatal exception: panic_on_oops");
+ oops_exit();
+ do_exit(SIGSEGV);
+}