Re: [PATCH 12/12] tracing: Rename update the enum_map file
From: Jeremy Linton
Date: Tue Jun 13 2017 - 17:21:56 EST
Hi,
On 06/13/2017 04:12 PM, Steven Rostedt wrote:
On Wed, 31 May 2017 16:56:53 -0500
Jeremy Linton <jeremy.linton@xxxxxxx> wrote:
The enum_map file is used to display a list of symbol
to name conversions. As its now used to resolve sizeof
lets update the name and description.
Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
---
kernel/trace/Kconfig | 22 +++++++++++-----------
kernel/trace/trace.c | 20 ++++++++++----------
2 files changed, 21 insertions(+), 21 deletions(-)
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 7e06f04..434c840 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -667,30 +667,30 @@ config RING_BUFFER_STARTUP_TEST
If unsure, say N
-config TRACE_ENUM_MAP_FILE
- bool "Show enum mappings for trace events"
+config TRACE_EVAL_MAP_FILE
+ bool "Show eval mappings for trace events"
depends on TRACING
help
- The "print fmt" of the trace events will show the enum names instead
- of their values. This can cause problems for user space tools that
- use this string to parse the raw data as user space does not know
+ The "print fmt" of the trace events will show the enum/sizeof names
+ instead of their values. This can cause problems for user space tools
+ that use this string to parse the raw data as user space does not know
how to convert the string to its value.
To fix this, there's a special macro in the kernel that can be used
- to convert the enum into its value. If this macro is used, then the
- print fmt strings will have the enums converted to their values.
+ to convert an enum/sizeof into its value. If this macro is used, then
+ the print fmt strings will be converted to their values.
If something does not get converted properly, this option can be
- used to show what enums the kernel tried to convert.
+ used to show what enums/sizeof the kernel tried to convert.
- This option is for debugging the enum conversions. A file is created
- in the tracing directory called "enum_map" that will show the enum
+ This option is for debugging the conversions. A file is created
+ in the tracing directory called "eval_map" that will show the
names matched with their values and what trace event system they
belong too.
Normally, the mapping of the strings to values will be freed after
boot up or module load. With this option, they will not be freed, as
- they are needed for the "enum_map" file. Enabling this option will
+ they are needed for the "eval_map" file. Enabling this option will
increase the memory footprint of the running kernel.
If unsure, say N
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 676c808..7297e9d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -120,8 +120,8 @@ enum ftrace_dump_mode ftrace_dump_on_oops;
/* When set, tracing will stop when a WARN*() is hit */
int __disable_trace_on_warning;
-#ifdef CONFIG_TRACE_ENUM_MAP_FILE
-/* Map of enums to their values, for "enum_map" file */
+#ifdef CONFIG_TRACE_EVAL_MAP_FILE
+/* Map of enums to their values, for "eval_map" file */
struct trace_eval_map_head {
struct module *mod;
unsigned long length;
@@ -145,7 +145,7 @@ static DEFINE_MUTEX(trace_eval_mutex);
* one at the beginning, and one at the end. The beginning item contains
* the count of the saved maps (head.length), and the module they
* belong to if not built in (head.mod). The ending item contains a
- * pointer to the next array of saved enum_eval/enum_map items.
+ * pointer to the next array of saved eval_map items.
*/
union trace_eval_map_item {
struct trace_eval_map map;
@@ -154,7 +154,7 @@ union trace_eval_map_item {
};
static union trace_eval_map_item *trace_eval_maps;
-#endif /* CONFIG_TRACE_ENUM_MAP_FILE */
+#endif /* CONFIG_TRACE_EVAL_MAP_FILE */
static int tracing_set_tracer(struct trace_array *tr, const char *buf);
@@ -4717,7 +4717,7 @@ static const struct file_operations tracing_saved_cmdlines_size_fops = {
.write = tracing_saved_cmdlines_size_write,
};
-#ifdef CONFIG_TRACE_ENUM_MAP_FILE
+#ifdef CONFIG_TRACE_EVAL_MAP_FILE
static union trace_eval_map_item *
update_eval_map(union trace_eval_map_item *ptr)
{
@@ -4868,15 +4868,15 @@ trace_insert_eval_map_file(struct module *mod, struct trace_eval_map **start,
static void trace_create_eval_file(struct dentry *d_tracer)
{
- trace_create_file("enum_map", 0444, d_tracer,
+ trace_create_file("eval_map", 0444, d_tracer,
NULL, &tracing_eval_map_fops);
Hmm, I have to audit some userspace code to see if this is used. The
enum_map was a debug feature, but it could have been used by some tools.
I thought perf was using it, but I was mistaken. I didn't find anything
using it, but to be on the safe side I placed this patch last so it
could be dropped if a user was found. The CONFIG option seems to be
disabled in the couple distro's I checked, further indicating that if
someone is using it, they are seemingly obscure.
}
-#else /* CONFIG_TRACE_ENUM_MAP_FILE */
+#else /* CONFIG_TRACE_EVAL_MAP_FILE */
static inline void trace_create_eval_file(struct dentry *d_tracer) { }
static inline void trace_insert_eval_map_file(struct module *mod,
struct trace_eval_map **start, int len) { }
-#endif /* !CONFIG_TRACE_ENUM_MAP_FILE */
+#endif /* !CONFIG_TRACE_EVAL_MAP_FILE */
static void trace_insert_eval_map(struct module *mod,
struct trace_eval_map **start, int len)
@@ -7731,7 +7731,7 @@ static void trace_module_add_evals(struct module *mod)
trace_insert_eval_map(mod, mod->trace_evals, mod->num_trace_evals);
}
-#ifdef CONFIG_TRACE_ENUM_MAP_FILE
+#ifdef CONFIG_TRACE_EVAL_MAP_FILE
static void trace_module_remove_evals(struct module *mod)
{
union trace_eval_map_item *map;
@@ -7761,7 +7761,7 @@ static void trace_module_remove_evals(struct module *mod)
}
#else
static inline void trace_module_remove_evals(struct module *mod) { }
-#endif /* CONFIG_TRACE_ENUM_MAP_FILE */
+#endif /* CONFIG_TRACE_EVAL_MAP_FILE */
static int trace_module_notify(struct notifier_block *self,
unsigned long val, void *data)