On Fri, Jul 3, 2020 at 3:57 AM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx>
>
> Add tep_plugin_add_option() and tep_plugin_print_options() to lib traceevent
> library that allows plugins to have their own options. For example, the
> function plugin by default does not print the parent, as it uses the parent
> to do the indenting. The "parent" option is created by the function plugin
> that will print the parent of the function like it does in the trace file.
>
> The tep_plugin_print_options() will print out the list of options that a
> plugin has defined.
>
> Link: http://lore.kernel.org/linux-trace-devel/20190802110101.14759-3-tz.stoyanov@xxxxxxxxx
> Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-5-tz.stoyanov@xxxxxxxxx
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
> ---
> tools/lib/traceevent/event-parse.h | 2 +
> tools/lib/traceevent/event-plugin.c | 172 ++++++++++++++++++++++++++++
> 2 files changed, 174 insertions(+)
>
> diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
> index 776c7c24ee79..02c0438527de 100644
> --- a/tools/lib/traceevent/event-parse.h
> +++ b/tools/lib/traceevent/event-parse.h
> @@ -406,7 +406,9 @@ char **tep_plugin_list_options(void);
> void tep_plugin_free_options_list(char **list);
> int tep_plugin_add_options(const char *name,
> struct tep_plugin_option *options);
> +int tep_plugin_add_option(const char *name, const char *val);
> void tep_plugin_remove_options(struct tep_plugin_option *options);
> +void tep_plugin_print_options(struct trace_seq *s);
> void tep_print_plugins(struct trace_seq *s,
> const char *prefix, const char *suffix,
> const struct tep_plugin_list *list);
> diff --git a/tools/lib/traceevent/event-plugin.c b/tools/lib/traceevent/event-plugin.c
> index b53d9a53bcf9..e8f4329ba8e0 100644
> --- a/tools/lib/traceevent/event-plugin.c
> +++ b/tools/lib/traceevent/event-plugin.c
> @@ -13,6 +13,7 @@
> #include <sys/stat.h>
> #include <unistd.h>
> #include <dirent.h>
> +#include <errno.h>
> #include "event-parse.h"
> #include "event-parse-local.h"
> #include "event-utils.h"
> @@ -247,6 +248,166 @@ void tep_plugin_remove_options(struct tep_plugin_option *options)
> }
> }
>
> +static void parse_option_name(char **option, char **plugin)
> +{
> + char *p;
> +
> + *plugin = NULL;
> +
> + if ((p = strstr(*option, ":"))) {
> + *plugin = *option;
> + *p = '\0';
> + *option = strdup(p + 1);
> + if (!*option)
> + return;
It needs to pass the error somehow..
> + }
> +}
> +
> +static struct tep_plugin_option *
> +find_registered_option(const char *plugin, const char *option)
> +{
> + struct registered_plugin_options *reg;
> + struct tep_plugin_option *op;
> + const char *op_plugin;
> +
> + for (reg = registered_options; reg; reg = reg->next) {
> + for (op = reg->options; op->name; op++) {
> + if (op->plugin_alias)
> + op_plugin = op->plugin_alias;
> + else
> + op_plugin = op->file;
> +
> + if (plugin && strcmp(plugin, op_plugin) != 0)
> + continue;
> + if (strcmp(option, op->name) != 0)
> + continue;
> +
> + return op;
> + }
> + }
> +
> + return NULL;
> +}
> +
> +static int process_option(const char *plugin, const char *option, const char *val)
> +{
> + struct tep_plugin_option *op;
> +
> + op = find_registered_option(plugin, option);
> + if (!op)
> + return 0;
> +
> + return update_option_value(op, val);
> +}
> +
> +/**
> + * tep_plugin_add_option - add an option/val pair to set plugin options
> + * @name: The name of the option (format: <plugin>:<option> or just <option>)
> + * @val: (optiona) the value for the option
Typo.
> + *
> + * Modify a plugin option. If @val is given than the value of the option
> + * is set (note, some options just take a boolean, so @val must be either
> + * "1" or "0" or "true" or "false").
> + */
> +int tep_plugin_add_option(const char *name, const char *val)
> +{
> + struct trace_plugin_options *op;
> + char *option_str;
> + char *plugin;
> +
> + option_str = strdup(name);
> + if (!option_str)
> + return -ENOMEM;
> +
> + parse_option_name(&option_str, &plugin);
> +
> + /* If the option exists, update the val */
> + for (op = trace_plugin_options; op; op = op->next) {
> + /* Both must be NULL or not NULL */
> + if ((!plugin || !op->plugin) && plugin != op->plugin)
> + continue;
> + if (plugin && strcmp(plugin, op->plugin) != 0)
> + continue;
> + if (strcmp(op->option, option_str) != 0)
> + continue;
> +
> + /* update option */
> + free(op->value);
> + if (val) {
> + op->value = strdup(val);
> + if (!op->value)
> + goto out_free;
> + } else
> + op->value = NULL;
> +
> + /* plugin and option_str don't get freed at the end */
> + free(plugin);
> + free(option_str);
> +
> + plugin = op->plugin;
> + option_str = op->option;
> + break;
> + }
> +
> + /* If not found, create */
> + if (!op) {
> + op = malloc(sizeof(*op));
> + if (!op)
> + return -ENOMEM;
goto out_free ?
> + memset(op, 0, sizeof(*op));
> + op->next = trace_plugin_options;
> + trace_plugin_options = op;
I think it's better doing this after setting the value below..
> +
> + op->plugin = plugin;
> + op->option = option_str;
> +
> + if (val) {
> + op->value = strdup(val);
> + if (!op->value)
> + goto out_free;
The option_str will be freed and op will have a dangling pointer..
> + }
> + }
> +
> + return process_option(plugin, option_str, val);
> + out_free:
> + free(option_str);
Why not free plugin too?
Thanks
Namhyung
> + return -ENOMEM;
> +}
> +
> +static void print_op_data(struct trace_seq *s, const char *name,
> + const char *op)
> +{
> + if (op)
> + trace_seq_printf(s, "%8s:\t%s\n", name, op);
> +}
> +
> +/**
> + * tep_plugin_print_options - print out the registered plugin options
> + * @s: The trace_seq descriptor to write the plugin options into
> + *
> + * Writes a list of options into trace_seq @s.
> + */
> +void tep_plugin_print_options(struct trace_seq *s)
> +{
> + struct registered_plugin_options *reg;
> + struct tep_plugin_option *op;
> +
> + for (reg = registered_options; reg; reg = reg->next) {
> + if (reg != registered_options)
> + trace_seq_printf(s, "============\n");
> + for (op = reg->options; op->name; op++) {
> + if (op != reg->options)
> + trace_seq_printf(s, "------------\n");
> + print_op_data(s, "file", op->file);
> + print_op_data(s, "plugin", op->plugin_alias);
> + print_op_data(s, "option", op->name);
> + print_op_data(s, "desc", op->description);
> + print_op_data(s, "value", op->value);
> + trace_seq_printf(s, "%8s:\t%d\n", "set", op->set);
> + }
> + }
> +}
> +
> /**
> * tep_print_plugins - print out the list of plugins loaded
> * @s: the trace_seq descripter to write to
> @@ -273,6 +434,7 @@ load_plugin(struct tep_handle *tep, const char *path,
> const char *file, void *data)
> {
> struct tep_plugin_list **plugin_list = data;
> + struct tep_plugin_option *options;
> tep_plugin_load_func func;
> struct tep_plugin_list *list;
> const char *alias;
> @@ -297,6 +459,16 @@ load_plugin(struct tep_handle *tep, const char *path,
> if (!alias)
> alias = file;
>
> + options = dlsym(handle, TEP_PLUGIN_OPTIONS_NAME);
> + if (options) {
> + while (options->name) {
> + ret = update_option(alias, options);
> + if (ret < 0)
> + goto out_free;
> + options++;
> + }
> + }
> +
> func = dlsym(handle, TEP_PLUGIN_LOADER_NAME);
> if (!func) {
> warning("could not find func '%s' in plugin '%s'\n%s\n",
> --
> 2.26.2
>
>
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