1 files changed, 155 insertions, 0 deletions
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
new file mode 100644
index 000000000..722fd712e
--- /dev/null
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
+ */
+#include <linux/sched/debug.h>
+#include <linux/kallsyms.h>
+#include <linux/kprobes.h>
+#include <linux/uaccess.h>
+#include <linux/hardirq.h>
+#include <linux/kdebug.h>
+#include <linux/export.h>
+#include <linux/ptrace.h>
+#include <linux/kexec.h>
+#include <linux/sysfs.h>
+#include <linux/bug.h>
+#include <linux/nmi.h>
+
+#include <asm/stacktrace.h>
+
+const char *stack_type_name(enum stack_type type)
+{
+	if (type == STACK_TYPE_IRQ)
+		return "IRQ";
+
+	if (type == STACK_TYPE_SOFTIRQ)
+		return "SOFTIRQ";
+
+	if (type == STACK_TYPE_ENTRY)
+		return "ENTRY_TRAMPOLINE";
+
+	if (type == STACK_TYPE_EXCEPTION)
+		return "#DF";
+
+	return NULL;
+}
+
+static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
+{
+	unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack_ptr);
+	unsigned long *end   = begin + (THREAD_SIZE / sizeof(long));
+
+	/*
+	 * This is a software stack, so 'end' can be a valid stack pointer.
+	 * It just means the stack is empty.
+	 */
+	if (stack < begin || stack > end)
+		return false;
+
+	info->type	= STACK_TYPE_IRQ;
+	info->begin	= begin;
+	info->end	= end;
+
+	/*
+	 * See irq_32.c -- the next stack pointer is stored at the beginning of
+	 * the stack.
+	 */
+	info->next_sp	= (unsigned long *)*begin;
+
+	return true;
+}
+
+static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
+{
+	unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack_ptr);
+	unsigned long *end   = begin + (THREAD_SIZE / sizeof(long));
+
+	/*
+	 * This is a software stack, so 'end' can be a valid stack pointer.
+	 * It just means the stack is empty.
+	 */
+	if (stack < begin || stack > end)
+		return false;
+
+	info->type	= STACK_TYPE_SOFTIRQ;
+	info->begin	= begin;
+	info->end	= end;
+
+	/*
+	 * The next stack pointer is stored at the beginning of the stack.
+	 * See irq_32.c.
+	 */
+	info->next_sp	= (unsigned long *)*begin;
+
+	return true;
+}
+
+static bool in_doublefault_stack(unsigned long *stack, struct stack_info *info)
+{
+	struct cpu_entry_area *cea = get_cpu_entry_area(raw_smp_processor_id());
+	struct doublefault_stack *ss = &cea->doublefault_stack;
+
+	void *begin = ss->stack;
+	void *end = begin + sizeof(ss->stack);
+
+	if ((void *)stack < begin || (void *)stack >= end)
+		return false;
+
+	info->type	= STACK_TYPE_EXCEPTION;
+	info->begin	= begin;
+	info->end	= end;
+	info->next_sp	= (unsigned long *)this_cpu_read(cpu_tss_rw.x86_tss.sp);
+
+	return true;
+}
+
+
+int get_stack_info(unsigned long *stack, struct task_struct *task,
+		   struct stack_info *info, unsigned long *visit_mask)
+{
+	if (!stack)
+		goto unknown;
+
+	task = task ? : current;
+
+	if (in_task_stack(stack, task, info))
+		goto recursion_check;
+
+	if (task != current)
+		goto unknown;
+
+	if (in_entry_stack(stack, info))
+		goto recursion_check;
+
+	if (in_hardirq_stack(stack, info))
+		goto recursion_check;
+
+	if (in_softirq_stack(stack, info))
+		goto recursion_check;
+
+	if (in_doublefault_stack(stack, info))
+		goto recursion_check;
+
+	goto unknown;
+
+recursion_check:
+	/*
+	 * Make sure we don't iterate through any given stack more than once.
+	 * If it comes up a second time then there's something wrong going on:
+	 * just break out and report an unknown stack type.
+	 */
+	if (visit_mask) {
+		if (*visit_mask & (1UL << info->type)) {
+			printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
+			goto unknown;
+		}
+		*visit_mask |= 1UL << info->type;
+	}
+
+	return 0;
+
+unknown:
+	info->type = STACK_TYPE_UNKNOWN;
+	return -EINVAL;
+}