]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - kernel/trace/trace_printk.c
Merge branch 'linus' into core/softlockup
[linux-2.6-omap-h63xx.git] / kernel / trace / trace_printk.c
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
new file mode 100644 (file)
index 0000000..eb81556
--- /dev/null
@@ -0,0 +1,270 @@
+/*
+ * 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/marker.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;
+}
+
+static
+void 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 int
+module_trace_bprintk_format_notify(struct notifier_block *self,
+               unsigned long val, void *data)
+{
+       return 0;
+}
+#endif /* CONFIG_MODULES */
+
+
+__initdata_or_module static
+struct 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_next(struct seq_file *m, void *v, loff_t *pos)
+{
+       const char **fmt = m->private;
+       const char **next = fmt;
+
+       (*pos)++;
+
+       if ((unsigned long)fmt >= (unsigned long)__stop___trace_bprintk_fmt)
+               return NULL;
+
+       next = fmt;
+       m->private = ++next;
+
+       return fmt;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+       return t_next(m, NULL, 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 int
+ftrace_formats_open(struct inode *inode, struct file *file)
+{
+       int ret;
+
+       ret = seq_open(file, &show_format_seq_ops);
+       if (!ret) {
+               struct seq_file *m = file->private_data;
+
+               m->private = __start___trace_bprintk_fmt;
+       }
+       return ret;
+}
+
+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;
+       struct dentry *entry;
+
+       d_tracer = tracing_init_dentry();
+       if (!d_tracer)
+               return 0;
+
+       entry = debugfs_create_file("printk_formats", 0444, d_tracer,
+                                   NULL, &ftrace_formats_fops);
+       if (!entry)
+               pr_warning("Could not create debugfs "
+                          "'printk_formats' entry\n");
+
+       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);