From: "Steven Rostedt (Red Hat)" <[email protected]> Add a enum_map file in the tracing directory to see what enums have been saved to convert in the print fmt files.
Signed-off-by: Steven Rostedt <[email protected]> --- kernel/trace/trace.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 107 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c9a714a42b7b..f2e63d0bf45e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -123,7 +123,7 @@ enum ftrace_dump_mode ftrace_dump_on_oops; /* When set, tracing will stop when a WARN*() is hit */ int __disable_trace_on_warning; -/* Map of enums to their values */ +/* Map of enums to their values, for "enum_map" file */ struct trace_enum_map_head { struct module *mod; unsigned long length; @@ -136,10 +136,12 @@ struct trace_enum_map_tail { * "end" is first and points to NULL as it must be different * than "mod" or "enum_string" */ - const char *end; /* points to NULL */ union trace_enum_map_item *next; + const char *end; /* points to NULL */ }; +static DEFINE_MUTEX(trace_enum_mutex); + /* * The trace_enum_maps are saved in an array with two extra elements, * one at the beginning, and one at the end. The beginning item contains @@ -3940,6 +3942,97 @@ static const struct file_operations tracing_saved_cmdlines_size_fops = { .write = tracing_saved_cmdlines_size_write, }; +static union trace_enum_map_item * +update_enum_map(union trace_enum_map_item *ptr) +{ + if (!ptr->map.enum_string) { + if (ptr->tail.next) { + ptr = ptr->tail.next; + /* Set ptr to the next real item (skip head) */ + ptr++; + } else + return NULL; + } + return ptr; +} + +static void *enum_map_next(struct seq_file *m, void *v, loff_t *pos) +{ + union trace_enum_map_item *ptr = v; + + /* + * Paranoid! If ptr points to end, we don't want to increment past it. + * This really should never happen. + */ + ptr = update_enum_map(ptr); + if (WARN_ON_ONCE(!ptr)) + return NULL; + + ptr++; + + (*pos)++; + + ptr = update_enum_map(ptr); + + return ptr; +} + +static void *enum_map_start(struct seq_file *m, loff_t *pos) +{ + union trace_enum_map_item *v; + loff_t l = 0; + + mutex_lock(&trace_enum_mutex); + + v = trace_enum_maps; + if (v) + v++; + + while (v && l < *pos) { + v = enum_map_next(m, v, &l); + } + + return v; +} + +static void enum_map_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&trace_enum_mutex); +} + +static int enum_map_show(struct seq_file *m, void *v) +{ + union trace_enum_map_item *ptr = v; + + seq_printf(m, "%s %ld (%s)\n", + ptr->map.enum_string, ptr->map.enum_value, + ptr->map.system); + + return 0; +} + +static const struct seq_operations tracing_enum_map_seq_ops = { + .start = enum_map_start, + .next = enum_map_next, + .stop = enum_map_stop, + .show = enum_map_show, +}; + +static int tracing_enum_map_open(struct inode *inode, struct file *filp) +{ + if (tracing_disabled) + return -ENODEV; + + return seq_open(filp, &tracing_enum_map_seq_ops); +} + +static const struct file_operations tracing_enum_map_fops = { + .open = tracing_enum_map_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + static inline union trace_enum_map_item * trace_enum_jmp_to_tail(union trace_enum_map_item *ptr) { @@ -3971,6 +4064,8 @@ static void trace_insert_enum_map(struct module *mod, return; } + mutex_lock(&trace_enum_mutex); + if (!trace_enum_maps) trace_enum_maps = map_array; else { @@ -3996,6 +4091,8 @@ static void trace_insert_enum_map(struct module *mod, /* Pass in the start of the array (-len) */ trace_event_enum_update(&map_array[-len].map, len); + + mutex_unlock(&trace_enum_mutex); } static ssize_t @@ -6667,6 +6764,8 @@ static void trace_module_remove_enums(struct module *mod) if (!mod->num_trace_enums) return; + mutex_lock(&trace_enum_mutex); + map = trace_enum_maps; while (map) { @@ -6677,10 +6776,12 @@ static void trace_module_remove_enums(struct module *mod) map = map->tail.next; } if (!map) - return; + goto out; *last = trace_enum_jmp_to_tail(map)->tail.next; kfree(map); + out: + mutex_unlock(&trace_enum_mutex); } static int trace_module_notify(struct notifier_block *self, @@ -6732,6 +6833,9 @@ static __init int tracer_init_debugfs(void) trace_enum_init(); + trace_create_file("enum_map", 0444, d_tracer, + NULL, &tracing_enum_map_fops); + #ifdef CONFIG_MODULES register_module_notifier(&trace_module_nb); #endif -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
