// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
 *  Copyright (C) 2009  Matt Fleming
 *  Copyright (C) 2002 - 2012  Paul Mundt
 */
#include <linux/kallsyms.h>
#include <linux/ftrace.h>
#include <linux/debug_locks.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/kdebug.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <asm/unwinder.h>
#include <asm/stacktrace.h>

void dump_mem(const char *str, const char *loglvl, unsigned long bottom,
              unsigned long top)
{
        unsigned long p;
        int i;

        printk("%s%s(0x%08lx to 0x%08lx)\n", loglvl, str, bottom, top);

        for (p = bottom & ~31; p < top; ) {
                printk("%s%04lx: ", loglvl,  p & 0xffff);

                for (i = 0; i < 8; i++, p += 4) {
                        unsigned int val;

                        if (p < bottom || p >= top)
                                pr_cont("         ");
                        else {
                                if (__get_user(val, (unsigned int __user *)p)) {
                                        pr_cont("\n");
                                        return;
                                }
                                pr_cont("%08x ", val);
                        }
                }
                pr_cont("\n");
        }
}

void printk_address(unsigned long address, int reliable)
{
        pr_cont(" [<%px>] %s%pS\n", (void *) address,
                reliable ? "" : "? ", (void *) address);
}

#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static void
print_ftrace_graph_addr(unsigned long addr, void *data,
                        const struct stacktrace_ops *ops,
                        struct thread_info *tinfo, int *graph)
{
        struct task_struct *task = tinfo->task;
        struct ftrace_ret_stack *ret_stack;
        unsigned long ret_addr;

        if (addr != (unsigned long)return_to_handler)
                return;

        if (!task->ret_stack)
                return;

        ret_stack = ftrace_graph_get_ret_stack(task, *graph);
        if (!ret_stack)
                return;

        ret_addr = ret_stack->ret;

        ops->address(data, ret_addr, 1);

        (*graph)++;
}
#else
static inline void
print_ftrace_graph_addr(unsigned long addr, void *data,
                        const struct stacktrace_ops *ops,
                        struct thread_info *tinfo, int *graph)
{ }
#endif

void
stack_reader_dump(struct task_struct *task, struct pt_regs *regs,
                  unsigned long *sp, const struct stacktrace_ops *ops,
                  void *data)
{
        struct thread_info *context;
        int graph = 0;

        context = (struct thread_info *)
                ((unsigned long)sp & (~(THREAD_SIZE - 1)));

        while (!kstack_end(sp)) {
                unsigned long addr = *sp++;

                if (__kernel_text_address(addr)) {
                        ops->address(data, addr, 1);

                        print_ftrace_graph_addr(addr, data, ops,
                                                context, &graph);
                }
        }
}

/*
 * Print one address/symbol entries per line.
 */
static void print_trace_address(void *data, unsigned long addr, int reliable)
{
        printk("%s", (char *)data);
        printk_address(addr, reliable);
}

static const struct stacktrace_ops print_trace_ops = {
        .address = print_trace_address,
};

void show_trace(struct task_struct *tsk, unsigned long *sp,
                struct pt_regs *regs, const char *loglvl)
{
        if (regs && user_mode(regs))
                return;

        printk("%s\nCall trace:\n", loglvl);

        unwind_stack(tsk, regs, sp, &print_trace_ops, (void *)loglvl);

        pr_cont("\n");

        if (!tsk)
                tsk = current;

        debug_show_held_locks(tsk);
}

void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
{
        unsigned long stack;

        if (!tsk)
                tsk = current;
        if (tsk == current)
                sp = (unsigned long *)current_stack_pointer;
        else
                sp = (unsigned long *)tsk->thread.sp;

        stack = (unsigned long)sp;
        dump_mem("Stack: ", loglvl, stack, THREAD_SIZE +
                 (unsigned long)task_stack_page(tsk));
        show_trace(tsk, sp, NULL, loglvl);
}