linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * trace binary printk

 *

 * Copyright (C) 2008 Lai Jiangshan <laijs@cn.fujitsu.com>

 *

 */

#include <linux/seq_file.h>

#include <linux/uaccess.h>

#include <linux/kernel.h>

#include <linux/ftrace.h>

#include <linux/string.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/ctype.h>

#include <linux/list.h>

#include <linux/slab.h>

​

#include "trace.h"

​

#ifdef CONFIG_MODULES

​

/*

 * modules trace_printk()'s formats are autosaved in struct trace_bprintk_fmt

 * which are queued on trace_bprintk_fmt_list.

 */

static LIST_HEAD(trace_bprintk_fmt_list);

​

/* serialize accesses to trace_bprintk_fmt_list */

static DEFINE_MUTEX(btrace_mutex);

​

struct trace_bprintk_fmt {

    struct list_head list;

    const char *fmt;

};

​

static inline struct trace_bprintk_fmt *lookup_format(const char *fmt)

{

    struct trace_bprintk_fmt *pos;

​

    if (!fmt)

        return ERR_PTR(-EINVAL);

​

    list_for_each_entry(pos, &trace_bprintk_fmt_list, list) {

        if (!strcmp(pos->fmt, fmt))

            return pos;

    }

    return NULL;

}

​

static

void hold_module_trace_bprintk_format(const char **start, const char **end)

{

    const char **iter;

    char *fmt;

​

    /* allocate the trace_printk per cpu buffers */

    if (start != end)

        trace_printk_init_buffers();

​

    mutex_lock(&btrace_mutex);

    for (iter = start; iter < end; iter++) {

        struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter);

        if (tb_fmt) {

            if (!IS_ERR(tb_fmt))

                *iter = tb_fmt->fmt;

            continue;

        }

​

        fmt = NULL;

        tb_fmt = kmalloc(sizeof(*tb_fmt), GFP_KERNEL);

        if (tb_fmt) {

            fmt = kmalloc(strlen(*iter) + 1, GFP_KERNEL);

            if (fmt) {

                list_add_tail(&tb_fmt->list, &trace_bprintk_fmt_list);

                strcpy(fmt, *iter);

                tb_fmt->fmt = fmt;

            } else

                kfree(tb_fmt);

        }

        *iter = fmt;

​

    }

    mutex_unlock(&btrace_mutex);

}

​

static int module_trace_bprintk_format_notify(struct notifier_block *self,

        unsigned long val, void *data)

{

    struct module *mod = data;

    if (mod->num_trace_bprintk_fmt) {

        const char **start = mod->trace_bprintk_fmt_start;