139 lines
3.0 KiB
C
139 lines
3.0 KiB
C
/*
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* trace binary printk
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*
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* Copyright (C) 2008 Lai Jiangshan <laijs@cn.fujitsu.com>
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*
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*/
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#include <linux/kernel.h>
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#include <linux/ftrace.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/list.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <linux/fs.h>
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#include <linux/marker.h>
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#include <linux/uaccess.h>
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#include "trace.h"
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#ifdef CONFIG_MODULES
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/*
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* modules trace_printk()'s formats are autosaved in struct trace_bprintk_fmt
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* which are queued on trace_bprintk_fmt_list.
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*/
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static LIST_HEAD(trace_bprintk_fmt_list);
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/* serialize accesses to trace_bprintk_fmt_list */
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static DEFINE_MUTEX(btrace_mutex);
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struct trace_bprintk_fmt {
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struct list_head list;
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char fmt[0];
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};
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static inline struct trace_bprintk_fmt *lookup_format(const char *fmt)
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{
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struct trace_bprintk_fmt *pos;
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list_for_each_entry(pos, &trace_bprintk_fmt_list, list) {
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if (!strcmp(pos->fmt, fmt))
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return pos;
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}
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return NULL;
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}
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static
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void hold_module_trace_bprintk_format(const char **start, const char **end)
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{
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const char **iter;
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mutex_lock(&btrace_mutex);
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for (iter = start; iter < end; iter++) {
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struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter);
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if (tb_fmt) {
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*iter = tb_fmt->fmt;
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continue;
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}
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tb_fmt = kmalloc(offsetof(struct trace_bprintk_fmt, fmt)
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+ strlen(*iter) + 1, GFP_KERNEL);
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if (tb_fmt) {
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list_add_tail(&tb_fmt->list, &trace_bprintk_fmt_list);
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strcpy(tb_fmt->fmt, *iter);
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*iter = tb_fmt->fmt;
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} else
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*iter = NULL;
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}
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mutex_unlock(&btrace_mutex);
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}
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static int module_trace_bprintk_format_notify(struct notifier_block *self,
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unsigned long val, void *data)
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{
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struct module *mod = data;
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if (mod->num_trace_bprintk_fmt) {
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const char **start = mod->trace_bprintk_fmt_start;
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const char **end = start + mod->num_trace_bprintk_fmt;
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if (val == MODULE_STATE_COMING)
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hold_module_trace_bprintk_format(start, end);
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}
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return 0;
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}
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#else /* !CONFIG_MODULES */
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__init static int
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module_trace_bprintk_format_notify(struct notifier_block *self,
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unsigned long val, void *data)
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{
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return 0;
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}
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#endif /* CONFIG_MODULES */
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__initdata_or_module static
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struct notifier_block module_trace_bprintk_format_nb = {
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.notifier_call = module_trace_bprintk_format_notify,
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};
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int __trace_printk(unsigned long ip, const char *fmt, ...)
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{
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int ret;
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va_list ap;
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if (unlikely(!fmt))
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return 0;
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if (!(trace_flags & TRACE_ITER_PRINTK))
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return 0;
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va_start(ap, fmt);
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ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
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va_end(ap);
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return ret;
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}
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EXPORT_SYMBOL_GPL(__trace_printk);
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int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap)
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{
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if (unlikely(!fmt))
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return 0;
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if (!(trace_flags & TRACE_ITER_PRINTK))
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return 0;
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return trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
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}
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EXPORT_SYMBOL_GPL(__ftrace_vprintk);
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static __init int init_trace_printk(void)
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{
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return register_module_notifier(&module_trace_bprintk_format_nb);
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}
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early_initcall(init_trace_printk);
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