tracing/dynevent: Delegate parsing to create function

Delegate command parsing to each create function so that the
command syntax can be customized.

This requires changes to the kprobe/uprobe/synthetic event handling,
which are also included here.

Link: https://lkml.kernel.org/r/e488726f49cbdbc01568618f8680584306c4c79f.1612208610.git.zanussi@kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ zanussi@kernel.org: added synthetic event modifications ]
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7fd4323..b79bcac 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9412,30 +9412,11 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 }
 EXPORT_SYMBOL_GPL(ftrace_dump);
 
-int trace_run_command(const char *buf, int (*createfn)(int, char **))
-{
-       char **argv;
-       int argc, ret;
-
-       argc = 0;
-       ret = 0;
-       argv = argv_split(GFP_KERNEL, buf, &argc);
-       if (!argv)
-               return -ENOMEM;
-
-       if (argc)
-               ret = createfn(argc, argv);
-
-       argv_free(argv);
-
-       return ret;
-}
-
 #define WRITE_BUFSIZE  4096
 
 ssize_t trace_parse_run_command(struct file *file, const char __user *buffer,
                                size_t count, loff_t *ppos,
-                               int (*createfn)(int, char **))
+                               int (*createfn)(const char *))
 {
        char *kbuf, *buf, *tmp;
        int ret = 0;
@@ -9483,7 +9464,7 @@ ssize_t trace_parse_run_command(struct file *file, const char __user *buffer,
                        if (tmp)
                                *tmp = '\0';
 
-                       ret = trace_run_command(buf, createfn);
+                       ret = createfn(buf);
                        if (ret)
                                goto out;
                        buf += size;

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 93fb08a..a9e13bd 100644 (file)
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1807,10 +1807,9 @@ extern int tracing_set_cpumask(struct trace_array *tr,
 
 #define MAX_EVENT_NAME_LEN     64
 
-extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
 extern ssize_t trace_parse_run_command(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos,
-               int (*createfn)(int, char**));
+               int (*createfn)(const char *));
 
 extern unsigned int err_pos(char *cmd, const char *str);
 extern void tracing_log_err(struct trace_array *tr,

diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 4f967d5..dc971a6 100644 (file)
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -31,23 +31,31 @@ int dyn_event_register(struct dyn_event_operations *ops)
        return 0;
 }
 
-int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
+int dyn_event_release(const char *raw_command, struct dyn_event_operations *type)
 {
        struct dyn_event *pos, *n;
        char *system = NULL, *event, *p;
-       int ret = -ENOENT;
+       int argc, ret = -ENOENT;
+       char **argv;
+
+       argv = argv_split(GFP_KERNEL, raw_command, &argc);
+       if (!argv)
+               return -ENOMEM;
 
        if (argv[0][0] == '-') {
-               if (argv[0][1] != ':')
-                       return -EINVAL;
+               if (argv[0][1] != ':') {
+                       ret = -EINVAL;
+                       goto out;
+               }
                event = &argv[0][2];
        } else {
                event = strchr(argv[0], ':');
-               if (!event)
-                       return -EINVAL;
+               if (!event) {
+                       ret = -EINVAL;
+                       goto out;
+               }
                event++;
        }
-       argc--; argv++;
 
        p = strchr(event, '/');
        if (p) {
@@ -63,7 +71,7 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
                if (type && type != pos->ops)
                        continue;
                if (!pos->ops->match(system, event,
-                               argc, (const char **)argv, pos))
+                               argc - 1, (const char **)argv + 1, pos))
                        continue;
 
                ret = pos->ops->free(pos);
@@ -71,21 +79,22 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
                        break;
        }
        mutex_unlock(&event_mutex);
-
+out:
+       argv_free(argv);
        return ret;
 }
 
-static int create_dyn_event(int argc, char **argv)
+static int create_dyn_event(const char *raw_command)
 {
        struct dyn_event_operations *ops;
        int ret = -ENODEV;
 
-       if (argv[0][0] == '-' || argv[0][0] == '!')
-               return dyn_event_release(argc, argv, NULL);
+       if (raw_command[0] == '-' || raw_command[0] == '!')
+               return dyn_event_release(raw_command, NULL);
 
        mutex_lock(&dyn_event_ops_mutex);
        list_for_each_entry(ops, &dyn_event_ops_list, list) {
-               ret = ops->create(argc, (const char **)argv);
+               ret = ops->create(raw_command);
                if (!ret || ret != -ECANCELED)
                        break;
        }

diff --git a/kernel/trace/trace_dynevent.h b/kernel/trace/trace_dynevent.h
index d6f72dc..7754936 100644 (file)
--- a/kernel/trace/trace_dynevent.h
+++ b/kernel/trace/trace_dynevent.h
@@ -39,7 +39,7 @@ struct dyn_event;
  */
 struct dyn_event_operations {
        struct list_head        list;
-       int (*create)(int argc, const char *argv[]);
+       int (*create)(const char *raw_command);
        int (*show)(struct seq_file *m, struct dyn_event *ev);
        bool (*is_busy)(struct dyn_event *ev);
        int (*free)(struct dyn_event *ev);
@@ -97,7 +97,7 @@ void *dyn_event_seq_start(struct seq_file *m, loff_t *pos);
 void *dyn_event_seq_next(struct seq_file *m, void *v, loff_t *pos);
 void dyn_event_seq_stop(struct seq_file *m, void *v);
 int dyn_events_release_all(struct dyn_event_operations *type);
-int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type);
+int dyn_event_release(const char *raw_command, struct dyn_event_operations *type);
 
 /*
  * for_each_dyn_event  -       iterate over the dyn_event list

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 5a8bc0b..b2588a5 100644 (file)
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -62,7 +62,7 @@ static void synth_err(u8 err_type, u8 err_pos)
                        err_type, err_pos);
 }
 
-static int create_synth_event(int argc, const char **argv);
+static int create_synth_event(const char *raw_command);
 static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
 static int synth_event_release(struct dyn_event *ev);
 static bool synth_event_is_busy(struct dyn_event *ev);
@@ -1383,18 +1383,30 @@ int synth_event_delete(const char *event_name)
 }
 EXPORT_SYMBOL_GPL(synth_event_delete);
 
-static int create_or_delete_synth_event(int argc, char **argv)
+static int create_or_delete_synth_event(const char *raw_command)
 {
-       const char *name = argv[0];
-       int ret;
+       char **argv, *name = NULL;
+       int argc = 0, ret = 0;
+
+       argv = argv_split(GFP_KERNEL, raw_command, &argc);
+       if (!argv)
+               return -ENOMEM;
+
+       if (!argc)
+               goto free;
+
+       name = argv[0];
 
        /* trace_run_command() ensures argc != 0 */
        if (name[0] == '!') {
                ret = synth_event_delete(name + 1);
-               return ret;
+               goto free;
        }
 
        ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
+free:
+       argv_free(argv);
+
        return ret == -ECANCELED ? -EINVAL : ret;
 }
 
@@ -1403,7 +1415,7 @@ static int synth_event_run_command(struct dynevent_cmd *cmd)
        struct synth_event *se;
        int ret;
 
-       ret = trace_run_command(cmd->seq.buffer, create_or_delete_synth_event);
+       ret = create_or_delete_synth_event(cmd->seq.buffer);
        if (ret)
                return ret;
 
@@ -1939,23 +1951,43 @@ int synth_event_trace_end(struct synth_event_trace_state *trace_state)
 }
 EXPORT_SYMBOL_GPL(synth_event_trace_end);
 
-static int create_synth_event(int argc, const char **argv)
+static int create_synth_event(const char *raw_command)
 {
-       const char *name = argv[0];
-       int len;
+       char **argv, *name;
+       int len, argc = 0, ret = 0;
+
+       argv = argv_split(GFP_KERNEL, raw_command, &argc);
+       if (!argv) {
+               ret = -ENOMEM;
+               return ret;
+       }
 
-       if (name[0] != 's' || name[1] != ':')
-               return -ECANCELED;
+       if (!argc)
+               goto free;
+
+       name = argv[0];
+
+       if (name[0] != 's' || name[1] != ':') {
+               ret = -ECANCELED;
+               goto free;
+       }
        name += 2;
 
        /* This interface accepts group name prefix */
        if (strchr(name, '/')) {
                len = str_has_prefix(name, SYNTH_SYSTEM "/");
-               if (len == 0)
-                       return -EINVAL;
+               if (len == 0) {
+                       ret = -EINVAL;
+                       goto free;
+               }
                name += len;
        }
-       return __create_synth_event(argc - 1, name, argv + 1);
+
+       ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
+free:
+       argv_free(argv);
+
+       return ret;
 }
 
 static int synth_event_release(struct dyn_event *ev)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index f6c459a..8a1cb08 100644 (file)
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -35,7 +35,7 @@ static int __init set_kprobe_boot_events(char *str)
 }
 __setup("kprobe_event=", set_kprobe_boot_events);
 
-static int trace_kprobe_create(int argc, const char **argv);
+static int trace_kprobe_create(const char *raw_command);
 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
 static int trace_kprobe_release(struct dyn_event *ev);
 static bool trace_kprobe_is_busy(struct dyn_event *ev);
@@ -711,7 +711,7 @@ static inline void sanitize_event_name(char *name)
                        *name = '_';
 }
 
-static int trace_kprobe_create(int argc, const char *argv[])
+static int __trace_kprobe_create(int argc, const char *argv[])
 {
        /*
         * Argument syntax:
@@ -910,20 +910,25 @@ error:
        goto out;
 }
 
-static int create_or_delete_trace_kprobe(int argc, char **argv)
+static int trace_kprobe_create(const char *raw_command)
+{
+       return trace_probe_create(raw_command, __trace_kprobe_create);
+}
+
+static int create_or_delete_trace_kprobe(const char *raw_command)
 {
        int ret;
 
-       if (argv[0][0] == '-')
-               return dyn_event_release(argc, argv, &trace_kprobe_ops);
+       if (raw_command[0] == '-')
+               return dyn_event_release(raw_command, &trace_kprobe_ops);
 
-       ret = trace_kprobe_create(argc, (const char **)argv);
+       ret = trace_kprobe_create(raw_command);
        return ret == -ECANCELED ? -EINVAL : ret;
 }
 
 static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
 {
-       return trace_run_command(cmd->seq.buffer, create_or_delete_trace_kprobe);
+       return create_or_delete_trace_kprobe(cmd->seq.buffer);
 }
 
 /**
@@ -1084,7 +1089,7 @@ int kprobe_event_delete(const char *name)
 
        snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
 
-       return trace_run_command(buf, create_or_delete_trace_kprobe);
+       return create_or_delete_trace_kprobe(buf);
 }
 EXPORT_SYMBOL_GPL(kprobe_event_delete);
 
@@ -1886,7 +1891,7 @@ static __init void setup_boot_kprobe_events(void)
                if (p)
                        *p++ = '\0';
 
-               ret = trace_run_command(cmd, create_or_delete_trace_kprobe);
+               ret = create_or_delete_trace_kprobe(cmd);
                if (ret)
                        pr_warn("Failed to add event(%d): %s\n", ret, cmd);
 
@@ -1980,8 +1985,7 @@ static __init int kprobe_trace_self_tests_init(void)
 
        pr_info("Testing kprobe tracing: ");
 
-       ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)",
-                               create_or_delete_trace_kprobe);
+       ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)");
        if (WARN_ON_ONCE(ret)) {
                pr_warn("error on probing function entry.\n");
                warn++;
@@ -2002,8 +2006,7 @@ static __init int kprobe_trace_self_tests_init(void)
                }
        }
 
-       ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval",
-                               create_or_delete_trace_kprobe);
+       ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval");
        if (WARN_ON_ONCE(ret)) {
                pr_warn("error on probing function return.\n");
                warn++;
@@ -2076,13 +2079,13 @@ static __init int kprobe_trace_self_tests_init(void)
                                trace_probe_event_call(&tk->tp), file);
        }
 
-       ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);
+       ret = create_or_delete_trace_kprobe("-:testprobe");
        if (WARN_ON_ONCE(ret)) {
                pr_warn("error on deleting a probe.\n");
                warn++;
        }
 
-       ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe);
+       ret = create_or_delete_trace_kprobe("-:testprobe2");
        if (WARN_ON_ONCE(ret)) {
                pr_warn("error on deleting a probe.\n");
                warn++;

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index d2867cc..ec589a4 100644 (file)
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1134,3 +1134,20 @@ bool trace_probe_match_command_args(struct trace_probe *tp,
        }
        return true;
 }
+
+int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
+{
+       int argc = 0, ret = 0;
+       char **argv;
+
+       argv = argv_split(GFP_KERNEL, raw_command, &argc);
+       if (!argv)
+               return -ENOMEM;
+
+       if (argc)
+               ret = createfn(argc, (const char **)argv);
+
+       argv_free(argv);
+
+       return ret;
+}

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 2f703a2..7ce4027 100644 (file)
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -341,6 +341,7 @@ struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
 bool trace_probe_match_command_args(struct trace_probe *tp,
                                    int argc, const char **argv);
+int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **));
 
 #define trace_probe_for_each_link(pos, tp)     \
        list_for_each_entry(pos, &(tp)->event->files, list)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 9d94403..9b50869 100644 (file)
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -34,7 +34,7 @@ struct uprobe_trace_entry_head {
 #define DATAOF_TRACE_ENTRY(entry, is_return)           \
        ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
 
-static int trace_uprobe_create(int argc, const char **argv);
+static int trace_uprobe_create(const char *raw_command);
 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
 static int trace_uprobe_release(struct dyn_event *ev);
 static bool trace_uprobe_is_busy(struct dyn_event *ev);
@@ -530,7 +530,7 @@ end:
  * Argument syntax:
  *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS]
  */
-static int trace_uprobe_create(int argc, const char **argv)
+static int __trace_uprobe_create(int argc, const char **argv)
 {
        struct trace_uprobe *tu;
        const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
@@ -716,14 +716,19 @@ fail_address_parse:
        return ret;
 }
 
-static int create_or_delete_trace_uprobe(int argc, char **argv)
+int trace_uprobe_create(const char *raw_command)
+{
+       return trace_probe_create(raw_command, __trace_uprobe_create);
+}
+
+static int create_or_delete_trace_uprobe(const char *raw_command)
 {
        int ret;
 
-       if (argv[0][0] == '-')
-               return dyn_event_release(argc, argv, &trace_uprobe_ops);
+       if (raw_command[0] == '-')
+               return dyn_event_release(raw_command, &trace_uprobe_ops);
 
-       ret = trace_uprobe_create(argc, (const char **)argv);
+       ret = trace_uprobe_create(raw_command);
        return ret == -ECANCELED ? -EINVAL : ret;
 }