/* * trace binary printk * * Copyright (C) 2008 Lai Jiangshan <laijs@cn.fujitsu.com> * */#include <linux/seq_file.h>#include <linux/debugfs.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 <linux/fs.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;	char fmt[0];}; static inline struct trace_bprintk_fmt *lookup_format(const char *fmt){	struct trace_bprintk_fmt *pos;	list_for_each_entry(pos, &trace_bprintk_fmt_list, list) {		if (!strcmp(pos->fmt, fmt))			return pos;	}	return NULL;} staticvoid hold_module_trace_bprintk_format(const char **start, const char **end){	const char **iter; 	mutex_lock(&btrace_mutex);	for (iter = start; iter < end; iter++) {		struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter);		if (tb_fmt) {			*iter = tb_fmt->fmt;			continue;		} 		tb_fmt = kmalloc(offsetof(struct trace_bprintk_fmt, fmt)				+ strlen(*iter) + 1, GFP_KERNEL);		if (tb_fmt) {			list_add_tail(&tb_fmt->list, &trace_bprintk_fmt_list);			strcpy(tb_fmt->fmt, *iter);			*iter = tb_fmt->fmt;		} else			*iter = NULL;	}	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;		const char **end = start + mod->num_trace_bprintk_fmt; 		if (val == MODULE_STATE_COMING)			hold_module_trace_bprintk_format(start, end);	}	return 0;} #else /* !CONFIG_MODULES */__init static intmodule_trace_bprintk_format_notify(struct notifier_block *self,		unsigned long val, void *data){	return 0;}#endif /* CONFIG_MODULES */  __initdata_or_module staticstruct notifier_block module_trace_bprintk_format_nb = {	.notifier_call = module_trace_bprintk_format_notify,}; int __trace_bprintk(unsigned long ip, const char *fmt, ...) {	int ret;	va_list ap; 	if (unlikely(!fmt))		return 0; 	if (!(trace_flags & TRACE_ITER_PRINTK))		return 0; 	va_start(ap, fmt);	ret = trace_vbprintk(ip, fmt, ap);	va_end(ap);	return ret;}EXPORT_SYMBOL_GPL(__trace_bprintk); int __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap) {	if (unlikely(!fmt))		return 0; 	if (!(trace_flags & TRACE_ITER_PRINTK))		return 0; 	return trace_vbprintk(ip, fmt, ap);}EXPORT_SYMBOL_GPL(__ftrace_vbprintk); int __trace_printk(unsigned long ip, const char *fmt, ...){	int ret;	va_list ap; 	if (!(trace_flags & TRACE_ITER_PRINTK))		return 0; 	va_start(ap, fmt);	ret = trace_vprintk(ip, fmt, ap);	va_end(ap);	return ret;}EXPORT_SYMBOL_GPL(__trace_printk); int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap){	if (!(trace_flags & TRACE_ITER_PRINTK))		return 0; 	return trace_vprintk(ip, fmt, ap);}EXPORT_SYMBOL_GPL(__ftrace_vprintk); static void *t_start(struct seq_file *m, loff_t *pos){	const char **fmt = __start___trace_bprintk_fmt + *pos; 	if ((unsigned long)fmt >= (unsigned long)__stop___trace_bprintk_fmt)		return NULL;	return fmt;} static void *t_next(struct seq_file *m, void * v, loff_t *pos){	(*pos)++;	return t_start(m, pos);} static int t_show(struct seq_file *m, void *v){	const char **fmt = v;	const char *str = *fmt;	int i; 	seq_printf(m, "0x%lx : \"", *(unsigned long *)fmt); 	/*	 * Tabs and new lines need to be converted.	 */	for (i = 0; str[i]; i++) {		switch (str[i]) {		case '\n':			seq_puts(m, "\\n");			break;		case '\t':			seq_puts(m, "\\t");			break;		case '\\':			seq_puts(m, "\\");			break;		case '"':			seq_puts(m, "\\\"");			break;		default:			seq_putc(m, str[i]);		}	}	seq_puts(m, "\"\n"); 	return 0;} static void t_stop(struct seq_file *m, void *p){} static const struct seq_operations show_format_seq_ops = {	.start = t_start,	.next = t_next,	.show = t_show,	.stop = t_stop,}; static intftrace_formats_open(struct inode *inode, struct file *file){	return seq_open(file, &show_format_seq_ops);} static const struct file_operations ftrace_formats_fops = {	.open = ftrace_formats_open,	.read = seq_read,	.llseek = seq_lseek,	.release = seq_release,}; static __init int init_trace_printk_function_export(void){	struct dentry *d_tracer; 	d_tracer = tracing_init_dentry();	if (!d_tracer)		return 0; 	trace_create_file("printk_formats", 0444, d_tracer,				    NULL, &ftrace_formats_fops); 	return 0;} fs_initcall(init_trace_printk_function_export); static __init int init_trace_printk(void){	return register_module_notifier(&module_trace_bprintk_format_nb);} early_initcall(init_trace_printk);