4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu <mhiramat@xxxxxxxxxx> commit 7bbab38d07f3185fddf6fce126e2239010efdfce upstream. Use dyn_event framework for synthetic events. This shows synthetic events on "tracing/dynamic_events" file in addition to tracing/synthetic_events interface. User can also define new events via tracing/dynamic_events with "s:" prefix. So, the new syntax is below; s:[synthetic/]EVENT_NAME TYPE ARG; [TYPE ARG;]... To remove events via tracing/dynamic_events, you can use "-:" prefix as same as other events. Link: http://lkml.kernel.org/r/154140861301.17322.15454611233735614508.stgit@devbox Reviewed-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx> Tested-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: George Guo <guodongtai@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/Kconfig | 1 kernel/trace/trace.c | 8 + kernel/trace/trace_events_hist.c | 265 ++++++++++++++++++++++++--------------- 3 files changed, 176 insertions(+), 98 deletions(-) --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -633,6 +633,7 @@ config HIST_TRIGGERS depends on ARCH_HAVE_NMI_SAFE_CMPXCHG select TRACING_MAP select TRACING + select DYNAMIC_EVENTS default n help Hist triggers allow one or more arbitrary trace event fields --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4681,6 +4681,9 @@ static const char readme_msg[] = "\t accepts: event-definitions (one definition per line)\n" "\t Format: p[:[<group>/]<event>] <place> [<args>]\n" "\t r[maxactive][:[<group>/]<event>] <place> [<args>]\n" +#ifdef CONFIG_HIST_TRIGGERS + "\t s:[synthetic/]<event> <field> [<field>]\n" +#endif "\t -:[<group>/]<event>\n" #ifdef CONFIG_KPROBE_EVENTS "\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n" @@ -4694,6 +4697,11 @@ static const char readme_msg[] = "\t $stack<index>, $stack, $retval, $comm\n" "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string,\n" "\t b<bit-width>@<bit-offset>/<container-size>\n" +#ifdef CONFIG_HIST_TRIGGERS + "\t field: <stype> <name>;\n" + "\t stype: u8/u16/u32/u64, s8/s16/s32/s64, pid_t,\n" + "\t [unsigned] char/int/long\n" +#endif #endif " events/\t\t- Directory containing all trace event subsystems:\n" " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -15,6 +15,7 @@ #include "tracing_map.h" #include "trace.h" +#include "trace_dynevent.h" #define SYNTH_SYSTEM "synthetic" #define SYNTH_FIELDS_MAX 16 @@ -291,6 +292,21 @@ struct hist_trigger_data { unsigned int n_max_var_str; }; +static int synth_event_create(int argc, const char **argv); +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); +static bool synth_event_match(const char *system, const char *event, + struct dyn_event *ev); + +static struct dyn_event_operations synth_event_ops = { + .create = synth_event_create, + .show = synth_event_show, + .is_busy = synth_event_is_busy, + .free = synth_event_release, + .match = synth_event_match, +}; + struct synth_field { char *type; char *name; @@ -300,7 +316,7 @@ struct synth_field { }; struct synth_event { - struct list_head list; + struct dyn_event devent; int ref; char *name; struct synth_field **fields; @@ -311,6 +327,32 @@ struct synth_event { struct tracepoint *tp; }; +static bool is_synth_event(struct dyn_event *ev) +{ + return ev->ops == &synth_event_ops; +} + +static struct synth_event *to_synth_event(struct dyn_event *ev) +{ + return container_of(ev, struct synth_event, devent); +} + +static bool synth_event_is_busy(struct dyn_event *ev) +{ + struct synth_event *event = to_synth_event(ev); + + return event->ref != 0; +} + +static bool synth_event_match(const char *system, const char *event, + struct dyn_event *ev) +{ + struct synth_event *sev = to_synth_event(ev); + + return strcmp(sev->name, event) == 0 && + (!system || strcmp(system, SYNTH_SYSTEM) == 0); +} + struct action_data; typedef void (*action_fn_t) (struct hist_trigger_data *hist_data, @@ -401,7 +443,6 @@ static bool have_hist_err(void) return false; } -static LIST_HEAD(synth_event_list); static DEFINE_MUTEX(synth_event_mutex); struct synth_trace_event { @@ -758,14 +799,12 @@ static void free_synth_field(struct synt kfree(field); } -static struct synth_field *parse_synth_field(int argc, char **argv, +static struct synth_field *parse_synth_field(int argc, const char **argv, int *consumed) { struct synth_field *field; - const char *prefix = NULL; - char *field_type = argv[0], *field_name; + const char *prefix = NULL, *field_type = argv[0], *field_name, *array; int len, ret = 0; - char *array; if (field_type[0] == ';') field_type++; @@ -782,20 +821,31 @@ static struct synth_field *parse_synth_f *consumed = 2; } - len = strlen(field_name); - if (field_name[len - 1] == ';') - field_name[len - 1] = '\0'; - field = kzalloc(sizeof(*field), GFP_KERNEL); if (!field) return ERR_PTR(-ENOMEM); - len = strlen(field_type) + 1; + len = strlen(field_name); array = strchr(field_name, '['); if (array) + len -= strlen(array); + else if (field_name[len - 1] == ';') + len--; + + field->name = kmemdup_nul(field_name, len, GFP_KERNEL); + if (!field->name) { + ret = -ENOMEM; + goto free; + } + + if (field_type[0] == ';') + field_type++; + len = strlen(field_type) + 1; + if (array) len += strlen(array); if (prefix) len += strlen(prefix); + field->type = kzalloc(len, GFP_KERNEL); if (!field->type) { ret = -ENOMEM; @@ -806,7 +856,8 @@ static struct synth_field *parse_synth_f strcat(field->type, field_type); if (array) { strcat(field->type, array); - *array = '\0'; + if (field->type[len - 1] == ';') + field->type[len - 1] = '\0'; } field->size = synth_field_size(field->type); @@ -820,11 +871,6 @@ static struct synth_field *parse_synth_f field->is_signed = synth_field_signed(field->type); - field->name = kstrdup(field_name, GFP_KERNEL); - if (!field->name) { - ret = -ENOMEM; - goto free; - } out: return field; free: @@ -888,9 +934,13 @@ static inline void trace_synth(struct sy static struct synth_event *find_synth_event(const char *name) { + struct dyn_event *pos; struct synth_event *event; - list_for_each_entry(event, &synth_event_list, list) { + for_each_dyn_event(pos) { + if (!is_synth_event(pos)) + continue; + event = to_synth_event(pos); if (strcmp(event->name, name) == 0) return event; } @@ -941,7 +991,7 @@ static int register_synth_event(struct s ret = set_synth_event_print_fmt(call); if (ret < 0) { - trace_remove_event_call(call); + trace_remove_event_call_nolock(call); goto err; } out: @@ -979,7 +1029,7 @@ static void free_synth_event(struct synt kfree(event); } -static struct synth_event *alloc_synth_event(char *event_name, int n_fields, +static struct synth_event *alloc_synth_event(const char *name, int n_fields, struct synth_field **fields) { struct synth_event *event; @@ -991,7 +1041,7 @@ static struct synth_event *alloc_synth_e goto out; } - event->name = kstrdup(event_name, GFP_KERNEL); + event->name = kstrdup(name, GFP_KERNEL); if (!event->name) { kfree(event); event = ERR_PTR(-ENOMEM); @@ -1005,6 +1055,8 @@ static struct synth_event *alloc_synth_e goto out; } + dyn_event_init(&event->devent, &synth_event_ops); + for (i = 0; i < n_fields; i++) event->fields[i] = fields[i]; @@ -1028,16 +1080,11 @@ struct hist_var_data { struct hist_trigger_data *hist_data; }; -static int create_synth_event(int argc, char **argv) +static int __create_synth_event(int argc, const char *name, const char **argv) { struct synth_field *field, *fields[SYNTH_FIELDS_MAX]; struct synth_event *event = NULL; - bool delete_event = false; int i, consumed = 0, n_fields = 0, ret = 0; - char *name; - - mutex_lock(&event_mutex); - mutex_lock(&synth_event_mutex); /* * Argument syntax: @@ -1045,43 +1092,20 @@ static int create_synth_event(int argc, * - Remove synthetic event: !<event_name> field[;field] ... * where 'field' = type field_name */ - if (argc < 1) { - ret = -EINVAL; - goto out; - } - name = argv[0]; - if (name[0] == '!') { - delete_event = true; - name++; - } + if (name[0] == '\0' || argc < 1) + return -EINVAL; + + mutex_lock(&event_mutex); + mutex_lock(&synth_event_mutex); event = find_synth_event(name); if (event) { - if (delete_event) { - if (event->ref) { - ret = -EBUSY; - goto out; - } - ret = unregister_synth_event(event); - if (!ret) { - list_del(&event->list); - free_synth_event(event); - } - } else - ret = -EEXIST; - goto out; - } else if (delete_event) { - ret = -ENOENT; + ret = -EEXIST; goto out; } - if (argc < 2) { - ret = -EINVAL; - goto out; - } - - for (i = 1; i < argc - 1; i++) { + for (i = 0; i < argc - 1; i++) { if (strcmp(argv[i], ";") == 0) continue; if (n_fields == SYNTH_FIELDS_MAX) { @@ -1111,7 +1135,7 @@ static int create_synth_event(int argc, } ret = register_synth_event(event); if (!ret) - list_add(&event->list, &synth_event_list); + dyn_event_add(&event->devent); else free_synth_event(event); out: @@ -1126,57 +1150,77 @@ static int create_synth_event(int argc, goto out; } -static int release_all_synth_events(void) +static int create_or_delete_synth_event(int argc, char **argv) { - struct synth_event *event, *e; - int ret = 0; - - mutex_lock(&event_mutex); - mutex_lock(&synth_event_mutex); - - list_for_each_entry(event, &synth_event_list, list) { - if (event->ref) { - mutex_unlock(&synth_event_mutex); - return -EBUSY; - } - } + const char *name = argv[0]; + struct synth_event *event = NULL; + int ret; - list_for_each_entry_safe(event, e, &synth_event_list, list) { - ret = unregister_synth_event(event); - if (!ret) { - list_del(&event->list); - free_synth_event(event); + /* trace_run_command() ensures argc != 0 */ + if (name[0] == '!') { + mutex_lock(&event_mutex); + mutex_lock(&synth_event_mutex); + event = find_synth_event(name + 1); + if (event) { + if (event->ref) + ret = -EBUSY; + else { + ret = unregister_synth_event(event); + if (!ret) { + dyn_event_remove(&event->devent); + free_synth_event(event); + } + } } else - break; + ret = -ENOENT; + mutex_unlock(&synth_event_mutex); + mutex_unlock(&event_mutex); + return ret; } - mutex_unlock(&synth_event_mutex); - mutex_unlock(&event_mutex); - return ret; + ret = __create_synth_event(argc - 1, name, (const char **)argv + 1); + return ret == -ECANCELED ? -EINVAL : ret; } - -static void *synth_events_seq_start(struct seq_file *m, loff_t *pos) +static int synth_event_create(int argc, const char **argv) { - mutex_lock(&synth_event_mutex); + const char *name = argv[0]; + int len; - return seq_list_start(&synth_event_list, *pos); + if (name[0] != 's' || name[1] != ':') + return -ECANCELED; + name += 2; + + /* This interface accepts group name prefix */ + if (strchr(name, '/')) { + len = sizeof(SYNTH_SYSTEM "/") - 1; + if (strncmp(name, SYNTH_SYSTEM "/", len)) + return -EINVAL; + name += len; + } + return __create_synth_event(argc - 1, name, argv + 1); } -static void *synth_events_seq_next(struct seq_file *m, void *v, loff_t *pos) +static int synth_event_release(struct dyn_event *ev) { - return seq_list_next(v, &synth_event_list, pos); -} + struct synth_event *event = to_synth_event(ev); + int ret; -static void synth_events_seq_stop(struct seq_file *m, void *v) -{ - mutex_unlock(&synth_event_mutex); + if (event->ref) + return -EBUSY; + + ret = unregister_synth_event(event); + if (ret) + return ret; + + dyn_event_remove(ev); + free_synth_event(event); + return 0; } -static int synth_events_seq_show(struct seq_file *m, void *v) +static int __synth_event_show(struct seq_file *m, struct synth_event *event) { struct synth_field *field; - struct synth_event *event = v; unsigned int i; seq_printf(m, "%s\t", event->name); @@ -1194,11 +1238,30 @@ static int synth_events_seq_show(struct return 0; } +static int synth_event_show(struct seq_file *m, struct dyn_event *ev) +{ + struct synth_event *event = to_synth_event(ev); + + seq_printf(m, "s:%s/", event->class.system); + + return __synth_event_show(m, event); +} + +static int synth_events_seq_show(struct seq_file *m, void *v) +{ + struct dyn_event *ev = v; + + if (!is_synth_event(ev)) + return 0; + + return __synth_event_show(m, to_synth_event(ev)); +} + static const struct seq_operations synth_events_seq_op = { - .start = synth_events_seq_start, - .next = synth_events_seq_next, - .stop = synth_events_seq_stop, - .show = synth_events_seq_show + .start = dyn_event_seq_start, + .next = dyn_event_seq_next, + .stop = dyn_event_seq_stop, + .show = synth_events_seq_show, }; static int synth_events_open(struct inode *inode, struct file *file) @@ -1206,7 +1269,7 @@ static int synth_events_open(struct inod int ret; if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { - ret = release_all_synth_events(); + ret = dyn_events_release_all(&synth_event_ops); if (ret < 0) return ret; } @@ -1219,7 +1282,7 @@ static ssize_t synth_events_write(struct size_t count, loff_t *ppos) { return trace_parse_run_command(file, buffer, count, ppos, - create_synth_event); + create_or_delete_synth_event); } static const struct file_operations synth_events_fops = { @@ -5913,6 +5976,12 @@ static __init int trace_events_hist_init struct dentry *d_tracer; int err = 0; + err = dyn_event_register(&synth_event_ops); + if (err) { + pr_warn("Could not register synth_event_ops\n"); + return err; + } + d_tracer = tracing_init_dentry(); if (IS_ERR(d_tracer)) { err = PTR_ERR(d_tracer);
