v4.19.13 snapshot.
diff --git a/arch/sparc/kernel/kstack.h b/arch/sparc/kernel/kstack.h
new file mode 100644
index 0000000..b3c5e8f
--- /dev/null
+++ b/arch/sparc/kernel/kstack.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _KSTACK_H
+#define _KSTACK_H
+
+#include <linux/thread_info.h>
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+#include <asm/irq.h>
+
+/* SP must be STACK_BIAS adjusted already. */
+static inline bool kstack_valid(struct thread_info *tp, unsigned long sp)
+{
+ unsigned long base = (unsigned long) tp;
+
+ /* Stack pointer must be 16-byte aligned. */
+ if (sp & (16UL - 1))
+ return false;
+
+ if (sp >= (base + sizeof(struct thread_info)) &&
+ sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
+ return true;
+
+ if (hardirq_stack[tp->cpu]) {
+ base = (unsigned long) hardirq_stack[tp->cpu];
+ if (sp >= base &&
+ sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
+ return true;
+ base = (unsigned long) softirq_stack[tp->cpu];
+ if (sp >= base &&
+ sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
+ return true;
+ }
+ return false;
+}
+
+/* Does "regs" point to a valid pt_regs trap frame? */
+static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs *regs)
+{
+ unsigned long base = (unsigned long) tp;
+ unsigned long addr = (unsigned long) regs;
+
+ if (addr >= base &&
+ addr <= (base + THREAD_SIZE - sizeof(*regs)))
+ goto check_magic;
+
+ if (hardirq_stack[tp->cpu]) {
+ base = (unsigned long) hardirq_stack[tp->cpu];
+ if (addr >= base &&
+ addr <= (base + THREAD_SIZE - sizeof(*regs)))
+ goto check_magic;
+ base = (unsigned long) softirq_stack[tp->cpu];
+ if (addr >= base &&
+ addr <= (base + THREAD_SIZE - sizeof(*regs)))
+ goto check_magic;
+ }
+ return false;
+
+check_magic:
+ if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC)
+ return true;
+ return false;
+
+}
+
+static inline __attribute__((always_inline)) void *set_hardirq_stack(void)
+{
+ void *orig_sp, *sp = hardirq_stack[smp_processor_id()];
+
+ __asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
+ if (orig_sp < sp ||
+ orig_sp > (sp + THREAD_SIZE)) {
+ sp += THREAD_SIZE - 192 - STACK_BIAS;
+ __asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
+ }
+
+ return orig_sp;
+}
+
+static inline __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
+{
+ __asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
+}
+
+#endif /* _KSTACK_H */