]> bbs.cooldavid.org Git - net-next-2.6.git/blobdiff - kernel/trace/trace.c
tracing: Allow events to share their print functions
[net-next-2.6.git] / kernel / trace / trace.c
index b9be232352b81c01b7905d0fb48f22cdab9dd01c..ba0ec81158b268fc1d0d0fd1314a04d796d838e1 100644 (file)
 #include <linux/kdebug.h>
 #include <linux/string.h>
 #include <linux/rwsem.h>
+#include <linux/slab.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/poll.h>
-#include <linux/gfp.h>
 #include <linux/fs.h>
 
 #include "trace.h"
@@ -117,9 +117,12 @@ static cpumask_var_t __read_mostly tracing_buffer_mask;
  *
  * It is default off, but you can enable it with either specifying
  * "ftrace_dump_on_oops" in the kernel command line, or setting
- * /proc/sys/kernel/ftrace_dump_on_oops to true.
+ * /proc/sys/kernel/ftrace_dump_on_oops
+ * Set 1 if you want to dump buffers of all CPUs
+ * Set 2 if you want to dump the buffer of the CPU that triggered oops
  */
-int ftrace_dump_on_oops;
+
+enum ftrace_dump_mode ftrace_dump_on_oops;
 
 static int tracing_set_tracer(const char *buf);
 
@@ -139,8 +142,17 @@ __setup("ftrace=", set_cmdline_ftrace);
 
 static int __init set_ftrace_dump_on_oops(char *str)
 {
-       ftrace_dump_on_oops = 1;
-       return 1;
+       if (*str++ != '=' || !*str) {
+               ftrace_dump_on_oops = DUMP_ALL;
+               return 1;
+       }
+
+       if (!strcmp("orig_cpu", str)) {
+               ftrace_dump_on_oops = DUMP_ORIG;
+                return 1;
+        }
+
+        return 0;
 }
 __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
 
@@ -1796,7 +1808,7 @@ static void print_func_help_header(struct seq_file *m)
 }
 
 
-static void
+void
 print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 {
        unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -1924,7 +1936,7 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
        }
 
        if (event)
-               return event->trace(iter, sym_flags);
+               return event->funcs->trace(iter, sym_flags, event);
 
        if (!trace_seq_printf(s, "Unknown type %d\n", entry->type))
                goto partial;
@@ -1950,7 +1962,7 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 
        event = ftrace_find_event(entry->type);
        if (event)
-               return event->raw(iter, 0);
+               return event->funcs->raw(iter, 0, event);
 
        if (!trace_seq_printf(s, "%d ?\n", entry->type))
                goto partial;
@@ -1977,7 +1989,7 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 
        event = ftrace_find_event(entry->type);
        if (event) {
-               enum print_line_t ret = event->hex(iter, 0);
+               enum print_line_t ret = event->funcs->hex(iter, 0, event);
                if (ret != TRACE_TYPE_HANDLED)
                        return ret;
        }
@@ -2002,10 +2014,11 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
        }
 
        event = ftrace_find_event(entry->type);
-       return event ? event->binary(iter, 0) : TRACE_TYPE_HANDLED;
+       return event ? event->funcs->binary(iter, 0, event) :
+               TRACE_TYPE_HANDLED;
 }
 
-static int trace_empty(struct trace_iterator *iter)
+int trace_empty(struct trace_iterator *iter)
 {
        int cpu;
 
@@ -2072,6 +2085,23 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
        return print_trace_fmt(iter);
 }
 
+void trace_default_header(struct seq_file *m)
+{
+       struct trace_iterator *iter = m->private;
+
+       if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
+               /* print nothing if the buffers are empty */
+               if (trace_empty(iter))
+                       return;
+               print_trace_header(m, iter);
+               if (!(trace_flags & TRACE_ITER_VERBOSE))
+                       print_lat_help_header(m);
+       } else {
+               if (!(trace_flags & TRACE_ITER_VERBOSE))
+                       print_func_help_header(m);
+       }
+}
+
 static int s_show(struct seq_file *m, void *v)
 {
        struct trace_iterator *iter = v;
@@ -2084,17 +2114,9 @@ static int s_show(struct seq_file *m, void *v)
                }
                if (iter->trace && iter->trace->print_header)
                        iter->trace->print_header(m);
-               else if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
-                       /* print nothing if the buffers are empty */
-                       if (trace_empty(iter))
-                               return 0;
-                       print_trace_header(m, iter);
-                       if (!(trace_flags & TRACE_ITER_VERBOSE))
-                               print_lat_help_header(m);
-               } else {
-                       if (!(trace_flags & TRACE_ITER_VERBOSE))
-                               print_func_help_header(m);
-               }
+               else
+                       trace_default_header(m);
+
        } else if (iter->leftover) {
                /*
                 * If we filled the seq_file buffer earlier, we
@@ -2180,15 +2202,20 @@ __tracing_open(struct inode *inode, struct file *file)
 
        if (iter->cpu_file == TRACE_PIPE_ALL_CPU) {
                for_each_tracing_cpu(cpu) {
-
                        iter->buffer_iter[cpu] =
-                               ring_buffer_read_start(iter->tr->buffer, cpu);
+                               ring_buffer_read_prepare(iter->tr->buffer, cpu);
+               }
+               ring_buffer_read_prepare_sync();
+               for_each_tracing_cpu(cpu) {
+                       ring_buffer_read_start(iter->buffer_iter[cpu]);
                        tracing_iter_reset(iter, cpu);
                }
        } else {
                cpu = iter->cpu_file;
                iter->buffer_iter[cpu] =
-                               ring_buffer_read_start(iter->tr->buffer, cpu);
+                       ring_buffer_read_prepare(iter->tr->buffer, cpu);
+               ring_buffer_read_prepare_sync();
+               ring_buffer_read_start(iter->buffer_iter[cpu]);
                tracing_iter_reset(iter, cpu);
        }
 
@@ -4338,7 +4365,7 @@ static int trace_panic_handler(struct notifier_block *this,
                               unsigned long event, void *unused)
 {
        if (ftrace_dump_on_oops)
-               ftrace_dump();
+               ftrace_dump(ftrace_dump_on_oops);
        return NOTIFY_OK;
 }
 
@@ -4355,7 +4382,7 @@ static int trace_die_handler(struct notifier_block *self,
        switch (val) {
        case DIE_OOPS:
                if (ftrace_dump_on_oops)
-                       ftrace_dump();
+                       ftrace_dump(ftrace_dump_on_oops);
                break;
        default:
                break;
@@ -4396,7 +4423,8 @@ trace_printk_seq(struct trace_seq *s)
        trace_seq_init(s);
 }
 
-static void __ftrace_dump(bool disable_tracing)
+static void
+__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
 {
        static arch_spinlock_t ftrace_dump_lock =
                (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
@@ -4429,12 +4457,25 @@ static void __ftrace_dump(bool disable_tracing)
        /* don't look at user memory in panic mode */
        trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
 
-       printk(KERN_TRACE "Dumping ftrace buffer:\n");
-
        /* Simulate the iterator */
        iter.tr = &global_trace;
        iter.trace = current_trace;
-       iter.cpu_file = TRACE_PIPE_ALL_CPU;
+
+       switch (oops_dump_mode) {
+       case DUMP_ALL:
+               iter.cpu_file = TRACE_PIPE_ALL_CPU;
+               break;
+       case DUMP_ORIG:
+               iter.cpu_file = raw_smp_processor_id();
+               break;
+       case DUMP_NONE:
+               goto out_enable;
+       default:
+               printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
+               iter.cpu_file = TRACE_PIPE_ALL_CPU;
+       }
+
+       printk(KERN_TRACE "Dumping ftrace buffer:\n");
 
        /*
         * We need to stop all tracing on all CPUS to read the
@@ -4473,6 +4514,7 @@ static void __ftrace_dump(bool disable_tracing)
        else
                printk(KERN_TRACE "---------------------------------\n");
 
+ out_enable:
        /* Re-enable tracing if requested */
        if (!disable_tracing) {
                trace_flags |= old_userobj;
@@ -4489,9 +4531,9 @@ static void __ftrace_dump(bool disable_tracing)
 }
 
 /* By default: disable tracing after the dump */
-void ftrace_dump(void)
+void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 {
-       __ftrace_dump(true);
+       __ftrace_dump(true, oops_dump_mode);
 }
 
 __init static int tracer_alloc_buffers(void)