1 files changed, 151 insertions, 0 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
new file mode 100644
index 000000000..5cdb9e84d
--- /dev/null
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -0,0 +1,151 @@
+// 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>
+
+static char *exception_stack_names[N_EXCEPTION_STACKS] = {
+		[ DOUBLEFAULT_STACK-1	]	= "#DF",
+		[ NMI_STACK-1		]	= "NMI",
+		[ DEBUG_STACK-1		]	= "#DB",
+		[ MCE_STACK-1		]	= "#MC",
+};
+
+static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {
+	[0 ... N_EXCEPTION_STACKS - 1]		= EXCEPTION_STKSZ,
+	[DEBUG_STACK - 1]			= DEBUG_STKSZ
+};
+
+const char *stack_type_name(enum stack_type type)
+{
+	BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
+
+	if (type == STACK_TYPE_IRQ)
+		return "IRQ";
+
+	if (type == STACK_TYPE_ENTRY) {
+		/*
+		 * On 64-bit, we have a generic entry stack that we
+		 * use for all the kernel entry points, including
+		 * SYSENTER.
+		 */
+		return "ENTRY_TRAMPOLINE";
+	}
+
+	if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST)
+		return exception_stack_names[type - STACK_TYPE_EXCEPTION];
+
+	return NULL;
+}
+
+static bool in_exception_stack(unsigned long *stack, struct stack_info *info)
+{
+	unsigned long *begin, *end;
+	struct pt_regs *regs;
+	unsigned k;
+
+	BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
+
+	for (k = 0; k < N_EXCEPTION_STACKS; k++) {
+		end   = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k];
+		begin = end - (exception_stack_sizes[k] / sizeof(long));
+		regs  = (struct pt_regs *)end - 1;
+
+		if (stack <= begin || stack >= end)
+			continue;
+
+		info->type	= STACK_TYPE_EXCEPTION + k;
+		info->begin	= begin;
+		info->end	= end;
+		info->next_sp	= (unsigned long *)regs->sp;
+
+		return true;
+	}
+
+	return false;
+}
+
+static bool in_irq_stack(unsigned long *stack, struct stack_info *info)
+{
+	unsigned long *end   = (unsigned long *)this_cpu_read(irq_stack_ptr);
+	unsigned long *begin = end - (IRQ_STACK_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;
+
+	/*
+	 * The next stack pointer is the first thing pushed by the entry code
+	 * after switching to the irq stack.
+	 */
+	info->next_sp = (unsigned long *)*(end - 1);
+
+	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_exception_stack(stack, info))
+		goto recursion_check;
+
+	if (in_irq_stack(stack, info))
+		goto recursion_check;
+
+	if (in_entry_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;
+}