| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * trace_events_synth - synthetic trace events |
| * |
| * Copyright (C) 2015, 2020 Tom Zanussi <tom.zanussi@linux.intel.com> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kallsyms.h> |
| #include <linux/security.h> |
| #include <linux/mutex.h> |
| #include <linux/slab.h> |
| #include <linux/stacktrace.h> |
| #include <linux/rculist.h> |
| #include <linux/tracefs.h> |
| |
| /* for gfp flag names */ |
| #include <linux/trace_events.h> |
| #include <trace/events/mmflags.h> |
| #include "trace_probe.h" |
| #include "trace_probe_kernel.h" |
| |
| #include "trace_synth.h" |
| |
| #undef ERRORS |
| #define ERRORS \ |
| C(BAD_NAME, "Illegal name"), \ |
| C(INVALID_CMD, "Command must be of the form: <name> field[;field] ..."),\ |
| C(INVALID_DYN_CMD, "Command must be of the form: s or -:[synthetic/]<name> field[;field] ..."),\ |
| C(EVENT_EXISTS, "Event already exists"), \ |
| C(TOO_MANY_FIELDS, "Too many fields"), \ |
| C(INCOMPLETE_TYPE, "Incomplete type"), \ |
| C(INVALID_TYPE, "Invalid type"), \ |
| C(INVALID_FIELD, "Invalid field"), \ |
| C(INVALID_ARRAY_SPEC, "Invalid array specification"), |
| |
| #undef C |
| #define C(a, b) SYNTH_ERR_##a |
| |
| enum { ERRORS }; |
| |
| #undef C |
| #define C(a, b) b |
| |
| static const char *err_text[] = { ERRORS }; |
| |
| static DEFINE_MUTEX(lastcmd_mutex); |
| static char *last_cmd; |
| |
| static int errpos(const char *str) |
| { |
| int ret = 0; |
| |
| mutex_lock(&lastcmd_mutex); |
| if (!str || !last_cmd) |
| goto out; |
| |
| ret = err_pos(last_cmd, str); |
| out: |
| mutex_unlock(&lastcmd_mutex); |
| return ret; |
| } |
| |
| static void last_cmd_set(const char *str) |
| { |
| if (!str) |
| return; |
| |
| mutex_lock(&lastcmd_mutex); |
| kfree(last_cmd); |
| last_cmd = kstrdup(str, GFP_KERNEL); |
| mutex_unlock(&lastcmd_mutex); |
| } |
| |
| static void synth_err(u8 err_type, u16 err_pos) |
| { |
| mutex_lock(&lastcmd_mutex); |
| if (!last_cmd) |
| goto out; |
| |
| tracing_log_err(NULL, "synthetic_events", last_cmd, err_text, |
| err_type, err_pos); |
| out: |
| mutex_unlock(&lastcmd_mutex); |
| } |
| |
| 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); |
| static bool synth_event_match(const char *system, const char *event, |
| int argc, const char **argv, struct dyn_event *ev); |
| |
| static struct dyn_event_operations synth_event_ops = { |
| .create = create_synth_event, |
| .show = synth_event_show, |
| .is_busy = synth_event_is_busy, |
| .free = synth_event_release, |
| .match = synth_event_match, |
| }; |
| |
| 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, |
| int argc, const char **argv, 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 synth_trace_event { |
| struct trace_entry ent; |
| u64 fields[]; |
| }; |
| |
| static int synth_event_define_fields(struct trace_event_call *call) |
| { |
| struct synth_trace_event trace; |
| int offset = offsetof(typeof(trace), fields); |
| struct synth_event *event = call->data; |
| unsigned int i, size, n_u64; |
| char *name, *type; |
| bool is_signed; |
| int ret = 0; |
| |
| for (i = 0, n_u64 = 0; i < event->n_fields; i++) { |
| size = event->fields[i]->size; |
| is_signed = event->fields[i]->is_signed; |
| type = event->fields[i]->type; |
| name = event->fields[i]->name; |
| ret = trace_define_field(call, type, name, offset, size, |
| is_signed, FILTER_OTHER); |
| if (ret) |
| break; |
| |
| event->fields[i]->offset = n_u64; |
| |
| if (event->fields[i]->is_string && !event->fields[i]->is_dynamic) { |
| offset += STR_VAR_LEN_MAX; |
| n_u64 += STR_VAR_LEN_MAX / sizeof(u64); |
| } else { |
| offset += sizeof(u64); |
| n_u64++; |
| } |
| } |
| |
| event->n_u64 = n_u64; |
| |
| return ret; |
| } |
| |
| static bool synth_field_signed(char *type) |
| { |
| if (str_has_prefix(type, "u")) |
| return false; |
| if (strcmp(type, "gfp_t") == 0) |
| return false; |
| |
| return true; |
| } |
| |
| static int synth_field_is_string(char *type) |
| { |
| if (strstr(type, "char[") != NULL) |
| return true; |
| |
| return false; |
| } |
| |
| static int synth_field_is_stack(char *type) |
| { |
| if (strstr(type, "long[") != NULL) |
| return true; |
| |
| return false; |
| } |
| |
| static int synth_field_string_size(char *type) |
| { |
| char buf[4], *end, *start; |
| unsigned int len; |
| int size, err; |
| |
| start = strstr(type, "char["); |
| if (start == NULL) |
| return -EINVAL; |
| start += sizeof("char[") - 1; |
| |
| end = strchr(type, ']'); |
| if (!end || end < start || type + strlen(type) > end + 1) |
| return -EINVAL; |
| |
| len = end - start; |
| if (len > 3) |
| return -EINVAL; |
| |
| if (len == 0) |
| return 0; /* variable-length string */ |
| |
| strncpy(buf, start, len); |
| buf[len] = '\0'; |
| |
| err = kstrtouint(buf, 0, &size); |
| if (err) |
| return err; |
| |
| if (size > STR_VAR_LEN_MAX) |
| return -EINVAL; |
| |
| return size; |
| } |
| |
| static int synth_field_size(char *type) |
| { |
| int size = 0; |
| |
| if (strcmp(type, "s64") == 0) |
| size = sizeof(s64); |
| else if (strcmp(type, "u64") == 0) |
| size = sizeof(u64); |
| else if (strcmp(type, "s32") == 0) |
| size = sizeof(s32); |
| else if (strcmp(type, "u32") == 0) |
| size = sizeof(u32); |
| else if (strcmp(type, "s16") == 0) |
| size = sizeof(s16); |
| else if (strcmp(type, "u16") == 0) |
| size = sizeof(u16); |
| else if (strcmp(type, "s8") == 0) |
| size = sizeof(s8); |
| else if (strcmp(type, "u8") == 0) |
| size = sizeof(u8); |
| else if (strcmp(type, "char") == 0) |
| size = sizeof(char); |
| else if (strcmp(type, "unsigned char") == 0) |
| size = sizeof(unsigned char); |
| else if (strcmp(type, "int") == 0) |
| size = sizeof(int); |
| else if (strcmp(type, "unsigned int") == 0) |
| size = sizeof(unsigned int); |
| else if (strcmp(type, "long") == 0) |
| size = sizeof(long); |
| else if (strcmp(type, "unsigned long") == 0) |
| size = sizeof(unsigned long); |
| else if (strcmp(type, "bool") == 0) |
| size = sizeof(bool); |
| else if (strcmp(type, "pid_t") == 0) |
| size = sizeof(pid_t); |
| else if (strcmp(type, "gfp_t") == 0) |
| size = sizeof(gfp_t); |
| else if (synth_field_is_string(type)) |
| size = synth_field_string_size(type); |
| else if (synth_field_is_stack(type)) |
| size = 0; |
| |
| return size; |
| } |
| |
| static const char *synth_field_fmt(char *type) |
| { |
| const char *fmt = "%llu"; |
| |
| if (strcmp(type, "s64") == 0) |
| fmt = "%lld"; |
| else if (strcmp(type, "u64") == 0) |
| fmt = "%llu"; |
| else if (strcmp(type, "s32") == 0) |
| fmt = "%d"; |
| else if (strcmp(type, "u32") == 0) |
| fmt = "%u"; |
| else if (strcmp(type, "s16") == 0) |
| fmt = "%d"; |
| else if (strcmp(type, "u16") == 0) |
| fmt = "%u"; |
| else if (strcmp(type, "s8") == 0) |
| fmt = "%d"; |
| else if (strcmp(type, "u8") == 0) |
| fmt = "%u"; |
| else if (strcmp(type, "char") == 0) |
| fmt = "%d"; |
| else if (strcmp(type, "unsigned char") == 0) |
| fmt = "%u"; |
| else if (strcmp(type, "int") == 0) |
| fmt = "%d"; |
| else if (strcmp(type, "unsigned int") == 0) |
| fmt = "%u"; |
| else if (strcmp(type, "long") == 0) |
| fmt = "%ld"; |
| else if (strcmp(type, "unsigned long") == 0) |
| fmt = "%lu"; |
| else if (strcmp(type, "bool") == 0) |
| fmt = "%d"; |
| else if (strcmp(type, "pid_t") == 0) |
| fmt = "%d"; |
| else if (strcmp(type, "gfp_t") == 0) |
| fmt = "%x"; |
| else if (synth_field_is_string(type)) |
| fmt = "%.*s"; |
| else if (synth_field_is_stack(type)) |
| fmt = "%s"; |
| |
| return fmt; |
| } |
| |
| static void print_synth_event_num_val(struct trace_seq *s, |
| char *print_fmt, char *name, |
| int size, u64 val, char *space) |
| { |
| switch (size) { |
| case 1: |
| trace_seq_printf(s, print_fmt, name, (u8)val, space); |
| break; |
| |
| case 2: |
| trace_seq_printf(s, print_fmt, name, (u16)val, space); |
| break; |
| |
| case 4: |
| trace_seq_printf(s, print_fmt, name, (u32)val, space); |
| break; |
| |
| default: |
| trace_seq_printf(s, print_fmt, name, val, space); |
| break; |
| } |
| } |
| |
| static enum print_line_t print_synth_event(struct trace_iterator *iter, |
| int flags, |
| struct trace_event *event) |
| { |
| struct trace_array *tr = iter->tr; |
| struct trace_seq *s = &iter->seq; |
| struct synth_trace_event *entry; |
| struct synth_event *se; |
| unsigned int i, n_u64; |
| char print_fmt[32]; |
| const char *fmt; |
| |
| entry = (struct synth_trace_event *)iter->ent; |
| se = container_of(event, struct synth_event, call.event); |
| |
| trace_seq_printf(s, "%s: ", se->name); |
| |
| for (i = 0, n_u64 = 0; i < se->n_fields; i++) { |
| if (trace_seq_has_overflowed(s)) |
| goto end; |
| |
| fmt = synth_field_fmt(se->fields[i]->type); |
| |
| /* parameter types */ |
| if (tr && tr->trace_flags & TRACE_ITER_VERBOSE) |
| trace_seq_printf(s, "%s ", fmt); |
| |
| snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt); |
| |
| /* parameter values */ |
| if (se->fields[i]->is_string) { |
| if (se->fields[i]->is_dynamic) { |
| u32 offset, data_offset; |
| char *str_field; |
| |
| offset = (u32)entry->fields[n_u64]; |
| data_offset = offset & 0xffff; |
| |
| str_field = (char *)entry + data_offset; |
| |
| trace_seq_printf(s, print_fmt, se->fields[i]->name, |
| STR_VAR_LEN_MAX, |
| str_field, |
| i == se->n_fields - 1 ? "" : " "); |
| n_u64++; |
| } else { |
| trace_seq_printf(s, print_fmt, se->fields[i]->name, |
| STR_VAR_LEN_MAX, |
| (char *)&entry->fields[n_u64], |
| i == se->n_fields - 1 ? "" : " "); |
| n_u64 += STR_VAR_LEN_MAX / sizeof(u64); |
| } |
| } else if (se->fields[i]->is_stack) { |
| u32 offset, data_offset, len; |
| unsigned long *p, *end; |
| |
| offset = (u32)entry->fields[n_u64]; |
| data_offset = offset & 0xffff; |
| len = offset >> 16; |
| |
| p = (void *)entry + data_offset; |
| end = (void *)p + len - (sizeof(long) - 1); |
| |
| trace_seq_printf(s, "%s=STACK:\n", se->fields[i]->name); |
| |
| for (; *p && p < end; p++) |
| trace_seq_printf(s, "=> %pS\n", (void *)*p); |
| n_u64++; |
| |
| } else { |
| struct trace_print_flags __flags[] = { |
| __def_gfpflag_names, {-1, NULL} }; |
| char *space = (i == se->n_fields - 1 ? "" : " "); |
| |
| print_synth_event_num_val(s, print_fmt, |
| se->fields[i]->name, |
| se->fields[i]->size, |
| entry->fields[n_u64], |
| space); |
| |
| if (strcmp(se->fields[i]->type, "gfp_t") == 0) { |
| trace_seq_puts(s, " ("); |
| trace_print_flags_seq(s, "|", |
| entry->fields[n_u64], |
| __flags); |
| trace_seq_putc(s, ')'); |
| } |
| n_u64++; |
| } |
| } |
| end: |
| trace_seq_putc(s, '\n'); |
| |
| return trace_handle_return(s); |
| } |
| |
| static struct trace_event_functions synth_event_funcs = { |
| .trace = print_synth_event |
| }; |
| |
| static unsigned int trace_string(struct synth_trace_event *entry, |
| struct synth_event *event, |
| char *str_val, |
| bool is_dynamic, |
| unsigned int data_size, |
| unsigned int *n_u64) |
| { |
| unsigned int len = 0; |
| char *str_field; |
| int ret; |
| |
| if (is_dynamic) { |
| u32 data_offset; |
| |
| data_offset = offsetof(typeof(*entry), fields); |
| data_offset += event->n_u64 * sizeof(u64); |
| data_offset += data_size; |
| |
| len = kern_fetch_store_strlen((unsigned long)str_val); |
| |
| data_offset |= len << 16; |
| *(u32 *)&entry->fields[*n_u64] = data_offset; |
| |
| ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry); |
| |
| (*n_u64)++; |
| } else { |
| str_field = (char *)&entry->fields[*n_u64]; |
| |
| #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
| if ((unsigned long)str_val < TASK_SIZE) |
| ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX); |
| else |
| #endif |
| ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX); |
| |
| if (ret < 0) |
| strcpy(str_field, FAULT_STRING); |
| |
| (*n_u64) += STR_VAR_LEN_MAX / sizeof(u64); |
| } |
| |
| return len; |
| } |
| |
| static unsigned int trace_stack(struct synth_trace_event *entry, |
| struct synth_event *event, |
| long *stack, |
| unsigned int data_size, |
| unsigned int *n_u64) |
| { |
| unsigned int len; |
| u32 data_offset; |
| void *data_loc; |
| |
| data_offset = struct_size(entry, fields, event->n_u64); |
| data_offset += data_size; |
| |
| for (len = 0; len < HIST_STACKTRACE_DEPTH; len++) { |
| if (!stack[len]) |
| break; |
| } |
| |
| /* Include the zero'd element if it fits */ |
| if (len < HIST_STACKTRACE_DEPTH) |
| len++; |
| |
| len *= sizeof(long); |
| |
| /* Find the dynamic section to copy the stack into. */ |
| data_loc = (void *)entry + data_offset; |
| memcpy(data_loc, stack, len); |
| |
| /* Fill in the field that holds the offset/len combo */ |
| data_offset |= len << 16; |
| *(u32 *)&entry->fields[*n_u64] = data_offset; |
| |
| (*n_u64)++; |
| |
| return len; |
| } |
| |
| static notrace void trace_event_raw_event_synth(void *__data, |
| u64 *var_ref_vals, |
| unsigned int *var_ref_idx) |
| { |
| unsigned int i, n_u64, val_idx, len, data_size = 0; |
| struct trace_event_file *trace_file = __data; |
| struct synth_trace_event *entry; |
| struct trace_event_buffer fbuffer; |
| struct trace_buffer *buffer; |
| struct synth_event *event; |
| int fields_size = 0; |
| |
| event = trace_file->event_call->data; |
| |
| if (trace_trigger_soft_disabled(trace_file)) |
| return; |
| |
| fields_size = event->n_u64 * sizeof(u64); |
| |
| for (i = 0; i < event->n_dynamic_fields; i++) { |
| unsigned int field_pos = event->dynamic_fields[i]->field_pos; |
| char *str_val; |
| |
| val_idx = var_ref_idx[field_pos]; |
| str_val = (char *)(long)var_ref_vals[val_idx]; |
| |
| len = kern_fetch_store_strlen((unsigned long)str_val); |
| |
| fields_size += len; |
| } |
| |
| /* |
| * Avoid ring buffer recursion detection, as this event |
| * is being performed within another event. |
| */ |
| buffer = trace_file->tr->array_buffer.buffer; |
| ring_buffer_nest_start(buffer); |
| |
| entry = trace_event_buffer_reserve(&fbuffer, trace_file, |
| sizeof(*entry) + fields_size); |
| if (!entry) |
| goto out; |
| |
| for (i = 0, n_u64 = 0; i < event->n_fields; i++) { |
| val_idx = var_ref_idx[i]; |
| if (event->fields[i]->is_string) { |
| char *str_val = (char *)(long)var_ref_vals[val_idx]; |
| |
| len = trace_string(entry, event, str_val, |
| event->fields[i]->is_dynamic, |
| data_size, &n_u64); |
| data_size += len; /* only dynamic string increments */ |
| } else if (event->fields[i]->is_stack) { |
| long *stack = (long *)(long)var_ref_vals[val_idx]; |
| |
| len = trace_stack(entry, event, stack, |
| data_size, &n_u64); |
| data_size += len; |
| } else { |
| struct synth_field *field = event->fields[i]; |
| u64 val = var_ref_vals[val_idx]; |
| |
| switch (field->size) { |
| case 1: |
| *(u8 *)&entry->fields[n_u64] = (u8)val; |
| break; |
| |
| case 2: |
| *(u16 *)&entry->fields[n_u64] = (u16)val; |
| break; |
| |
| case 4: |
| *(u32 *)&entry->fields[n_u64] = (u32)val; |
| break; |
| |
| default: |
| entry->fields[n_u64] = val; |
| break; |
| } |
| n_u64++; |
| } |
| } |
| |
| trace_event_buffer_commit(&fbuffer); |
| out: |
| ring_buffer_nest_end(buffer); |
| } |
| |
| static void free_synth_event_print_fmt(struct trace_event_call *call) |
| { |
| if (call) { |
| kfree(call->print_fmt); |
| call->print_fmt = NULL; |
| } |
| } |
| |
| static int __set_synth_event_print_fmt(struct synth_event *event, |
| char *buf, int len) |
| { |
| const char *fmt; |
| int pos = 0; |
| int i; |
| |
| /* When len=0, we just calculate the needed length */ |
| #define LEN_OR_ZERO (len ? len - pos : 0) |
| |
| pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); |
| for (i = 0; i < event->n_fields; i++) { |
| fmt = synth_field_fmt(event->fields[i]->type); |
| pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s", |
| event->fields[i]->name, fmt, |
| i == event->n_fields - 1 ? "" : ", "); |
| } |
| pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); |
| |
| for (i = 0; i < event->n_fields; i++) { |
| if (event->fields[i]->is_string && |
| event->fields[i]->is_dynamic) |
| pos += snprintf(buf + pos, LEN_OR_ZERO, |
| ", __get_str(%s)", event->fields[i]->name); |
| else if (event->fields[i]->is_stack) |
| pos += snprintf(buf + pos, LEN_OR_ZERO, |
| ", __get_stacktrace(%s)", event->fields[i]->name); |
| else |
| pos += snprintf(buf + pos, LEN_OR_ZERO, |
| ", REC->%s", event->fields[i]->name); |
| } |
| |
| #undef LEN_OR_ZERO |
| |
| /* return the length of print_fmt */ |
| return pos; |
| } |
| |
| static int set_synth_event_print_fmt(struct trace_event_call *call) |
| { |
| struct synth_event *event = call->data; |
| char *print_fmt; |
| int len; |
| |
| /* First: called with 0 length to calculate the needed length */ |
| len = __set_synth_event_print_fmt(event, NULL, 0); |
| |
| print_fmt = kmalloc(len + 1, GFP_KERNEL); |
| if (!print_fmt) |
| return -ENOMEM; |
| |
| /* Second: actually write the @print_fmt */ |
| __set_synth_event_print_fmt(event, print_fmt, len + 1); |
| call->print_fmt = print_fmt; |
| |
| return 0; |
| } |
| |
| static void free_synth_field(struct synth_field *field) |
| { |
| kfree(field->type); |
| kfree(field->name); |
| kfree(field); |
| } |
| |
| static int check_field_version(const char *prefix, const char *field_type, |
| const char *field_name) |
| { |
| /* |
| * For backward compatibility, the old synthetic event command |
| * format did not require semicolons, and in order to not |
| * break user space, that old format must still work. If a new |
| * feature is added, then the format that uses the new feature |
| * will be required to have semicolons, as nothing that uses |
| * the old format would be using the new, yet to be created, |
| * feature. When a new feature is added, this will detect it, |
| * and return a number greater than 1, and require the format |
| * to use semicolons. |
| */ |
| return 1; |
| } |
| |
| static struct synth_field *parse_synth_field(int argc, char **argv, |
| int *consumed, int *field_version) |
| { |
| const char *prefix = NULL, *field_type = argv[0], *field_name, *array; |
| struct synth_field *field; |
| int len, ret = -ENOMEM; |
| struct seq_buf s; |
| ssize_t size; |
| |
| if (!strcmp(field_type, "unsigned")) { |
| if (argc < 3) { |
| synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type)); |
| return ERR_PTR(-EINVAL); |
| } |
| prefix = "unsigned "; |
| field_type = argv[1]; |
| field_name = argv[2]; |
| *consumed += 3; |
| } else { |
| field_name = argv[1]; |
| *consumed += 2; |
| } |
| |
| if (!field_name) { |
| synth_err(SYNTH_ERR_INVALID_FIELD, errpos(field_type)); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| *field_version = check_field_version(prefix, field_type, field_name); |
| |
| field = kzalloc(sizeof(*field), GFP_KERNEL); |
| if (!field) |
| return ERR_PTR(-ENOMEM); |
| |
| len = strlen(field_name); |
| array = strchr(field_name, '['); |
| if (array) |
| len -= strlen(array); |
| |
| field->name = kmemdup_nul(field_name, len, GFP_KERNEL); |
| if (!field->name) |
| goto free; |
| |
| if (!is_good_name(field->name)) { |
| synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name)); |
| ret = -EINVAL; |
| goto free; |
| } |
| |
| len = strlen(field_type) + 1; |
| |
| if (array) |
| len += strlen(array); |
| |
| if (prefix) |
| len += strlen(prefix); |
| |
| field->type = kzalloc(len, GFP_KERNEL); |
| if (!field->type) |
| goto free; |
| |
| seq_buf_init(&s, field->type, len); |
| if (prefix) |
| seq_buf_puts(&s, prefix); |
| seq_buf_puts(&s, field_type); |
| if (array) |
| seq_buf_puts(&s, array); |
| if (WARN_ON_ONCE(!seq_buf_buffer_left(&s))) |
| goto free; |
| |
| s.buffer[s.len] = '\0'; |
| |
| size = synth_field_size(field->type); |
| if (size < 0) { |
| if (array) |
| synth_err(SYNTH_ERR_INVALID_ARRAY_SPEC, errpos(field_name)); |
| else |
| synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type)); |
| ret = -EINVAL; |
| goto free; |
| } else if (size == 0) { |
| if (synth_field_is_string(field->type) || |
| synth_field_is_stack(field->type)) { |
| char *type; |
| |
| len = sizeof("__data_loc ") + strlen(field->type) + 1; |
| type = kzalloc(len, GFP_KERNEL); |
| if (!type) |
| goto free; |
| |
| seq_buf_init(&s, type, len); |
| seq_buf_puts(&s, "__data_loc "); |
| seq_buf_puts(&s, field->type); |
| |
| if (WARN_ON_ONCE(!seq_buf_buffer_left(&s))) |
| goto free; |
| s.buffer[s.len] = '\0'; |
| |
| kfree(field->type); |
| field->type = type; |
| |
| field->is_dynamic = true; |
| size = sizeof(u64); |
| } else { |
| synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type)); |
| ret = -EINVAL; |
| goto free; |
| } |
| } |
| field->size = size; |
| |
| if (synth_field_is_string(field->type)) |
| field->is_string = true; |
| else if (synth_field_is_stack(field->type)) |
| field->is_stack = true; |
| |
| field->is_signed = synth_field_signed(field->type); |
| out: |
| return field; |
| free: |
| free_synth_field(field); |
| field = ERR_PTR(ret); |
| goto out; |
| } |
| |
| static void free_synth_tracepoint(struct tracepoint *tp) |
| { |
| if (!tp) |
| return; |
| |
| kfree(tp->name); |
| kfree(tp); |
| } |
| |
| static struct tracepoint *alloc_synth_tracepoint(char *name) |
| { |
| struct tracepoint *tp; |
| |
| tp = kzalloc(sizeof(*tp), GFP_KERNEL); |
| if (!tp) |
| return ERR_PTR(-ENOMEM); |
| |
| tp->name = kstrdup(name, GFP_KERNEL); |
| if (!tp->name) { |
| kfree(tp); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| return tp; |
| } |
| |
| struct synth_event *find_synth_event(const char *name) |
| { |
| struct dyn_event *pos; |
| struct synth_event *event; |
| |
| for_each_dyn_event(pos) { |
| if (!is_synth_event(pos)) |
| continue; |
| event = to_synth_event(pos); |
| if (strcmp(event->name, name) == 0) |
| return event; |
| } |
| |
| return NULL; |
| } |
| |
| static struct trace_event_fields synth_event_fields_array[] = { |
| { .type = TRACE_FUNCTION_TYPE, |
| .define_fields = synth_event_define_fields }, |
| {} |
| }; |
| |
| static int register_synth_event(struct synth_event *event) |
| { |
| struct trace_event_call *call = &event->call; |
| int ret = 0; |
| |
| event->call.class = &event->class; |
| event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL); |
| if (!event->class.system) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| event->tp = alloc_synth_tracepoint(event->name); |
| if (IS_ERR(event->tp)) { |
| ret = PTR_ERR(event->tp); |
| event->tp = NULL; |
| goto out; |
| } |
| |
| INIT_LIST_HEAD(&call->class->fields); |
| call->event.funcs = &synth_event_funcs; |
| call->class->fields_array = synth_event_fields_array; |
| |
| ret = register_trace_event(&call->event); |
| if (!ret) { |
| ret = -ENODEV; |
| goto out; |
| } |
| call->flags = TRACE_EVENT_FL_TRACEPOINT; |
| call->class->reg = trace_event_reg; |
| call->class->probe = trace_event_raw_event_synth; |
| call->data = event; |
| call->tp = event->tp; |
| |
| ret = trace_add_event_call(call); |
| if (ret) { |
| pr_warn("Failed to register synthetic event: %s\n", |
| trace_event_name(call)); |
| goto err; |
| } |
| |
| ret = set_synth_event_print_fmt(call); |
| /* unregister_trace_event() will be called inside */ |
| if (ret < 0) |
| trace_remove_event_call(call); |
| out: |
| return ret; |
| err: |
| unregister_trace_event(&call->event); |
| goto out; |
| } |
| |
| static int unregister_synth_event(struct synth_event *event) |
| { |
| struct trace_event_call *call = &event->call; |
| int ret; |
| |
| ret = trace_remove_event_call(call); |
| |
| return ret; |
| } |
| |
| static void free_synth_event(struct synth_event *event) |
| { |
| unsigned int i; |
| |
| if (!event) |
| return; |
| |
| for (i = 0; i < event->n_fields; i++) |
| free_synth_field(event->fields[i]); |
| |
| kfree(event->fields); |
| kfree(event->dynamic_fields); |
| kfree(event->name); |
| kfree(event->class.system); |
| free_synth_tracepoint(event->tp); |
| free_synth_event_print_fmt(&event->call); |
| kfree(event); |
| } |
| |
| static struct synth_event *alloc_synth_event(const char *name, int n_fields, |
| struct synth_field **fields) |
| { |
| unsigned int i, j, n_dynamic_fields = 0; |
| struct synth_event *event; |
| |
| event = kzalloc(sizeof(*event), GFP_KERNEL); |
| if (!event) { |
| event = ERR_PTR(-ENOMEM); |
| goto out; |
| } |
| |
| event->name = kstrdup(name, GFP_KERNEL); |
| if (!event->name) { |
| kfree(event); |
| event = ERR_PTR(-ENOMEM); |
| goto out; |
| } |
| |
| event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL); |
| if (!event->fields) { |
| free_synth_event(event); |
| event = ERR_PTR(-ENOMEM); |
| goto out; |
| } |
| |
| for (i = 0; i < n_fields; i++) |
| if (fields[i]->is_dynamic) |
| n_dynamic_fields++; |
| |
| if (n_dynamic_fields) { |
| event->dynamic_fields = kcalloc(n_dynamic_fields, |
| sizeof(*event->dynamic_fields), |
| GFP_KERNEL); |
| if (!event->dynamic_fields) { |
| free_synth_event(event); |
| event = ERR_PTR(-ENOMEM); |
| goto out; |
| } |
| } |
| |
| dyn_event_init(&event->devent, &synth_event_ops); |
| |
| for (i = 0, j = 0; i < n_fields; i++) { |
| fields[i]->field_pos = i; |
| event->fields[i] = fields[i]; |
| |
| if (fields[i]->is_dynamic) |
| event->dynamic_fields[j++] = fields[i]; |
| } |
| event->n_dynamic_fields = j; |
| event->n_fields = n_fields; |
| out: |
| return event; |
| } |
| |
| static int synth_event_check_arg_fn(void *data) |
| { |
| struct dynevent_arg_pair *arg_pair = data; |
| int size; |
| |
| size = synth_field_size((char *)arg_pair->lhs); |
| if (size == 0) { |
| if (strstr((char *)arg_pair->lhs, "[")) |
| return 0; |
| } |
| |
| return size ? 0 : -EINVAL; |
| } |
| |
| /** |
| * synth_event_add_field - Add a new field to a synthetic event cmd |
| * @cmd: A pointer to the dynevent_cmd struct representing the new event |
| * @type: The type of the new field to add |
| * @name: The name of the new field to add |
| * |
| * Add a new field to a synthetic event cmd object. Field ordering is in |
| * the same order the fields are added. |
| * |
| * See synth_field_size() for available types. If field_name contains |
| * [n] the field is considered to be an array. |
| * |
| * Return: 0 if successful, error otherwise. |
| */ |
| int synth_event_add_field(struct dynevent_cmd *cmd, const char *type, |
| const char *name) |
| { |
| struct dynevent_arg_pair arg_pair; |
| int ret; |
| |
| if (cmd->type != DYNEVENT_TYPE_SYNTH) |
| return -EINVAL; |
| |
| if (!type || !name) |
| return -EINVAL; |
| |
| dynevent_arg_pair_init(&arg_pair, 0, ';'); |
| |
| arg_pair.lhs = type; |
| arg_pair.rhs = name; |
| |
| ret = dynevent_arg_pair_add(cmd, &arg_pair, synth_event_check_arg_fn); |
| if (ret) |
| return ret; |
| |
| if (++cmd->n_fields > SYNTH_FIELDS_MAX) |
| ret = -EINVAL; |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_add_field); |
| |
| /** |
| * synth_event_add_field_str - Add a new field to a synthetic event cmd |
| * @cmd: A pointer to the dynevent_cmd struct representing the new event |
| * @type_name: The type and name of the new field to add, as a single string |
| * |
| * Add a new field to a synthetic event cmd object, as a single |
| * string. The @type_name string is expected to be of the form 'type |
| * name', which will be appended by ';'. No sanity checking is done - |
| * what's passed in is assumed to already be well-formed. Field |
| * ordering is in the same order the fields are added. |
| * |
| * See synth_field_size() for available types. If field_name contains |
| * [n] the field is considered to be an array. |
| * |
| * Return: 0 if successful, error otherwise. |
| */ |
| int synth_event_add_field_str(struct dynevent_cmd *cmd, const char *type_name) |
| { |
| struct dynevent_arg arg; |
| int ret; |
| |
| if (cmd->type != DYNEVENT_TYPE_SYNTH) |
| return -EINVAL; |
| |
| if (!type_name) |
| return -EINVAL; |
| |
| dynevent_arg_init(&arg, ';'); |
| |
| arg.str = type_name; |
| |
| ret = dynevent_arg_add(cmd, &arg, NULL); |
| if (ret) |
| return ret; |
| |
| if (++cmd->n_fields > SYNTH_FIELDS_MAX) |
| ret = -EINVAL; |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_add_field_str); |
| |
| /** |
| * synth_event_add_fields - Add multiple fields to a synthetic event cmd |
| * @cmd: A pointer to the dynevent_cmd struct representing the new event |
| * @fields: An array of type/name field descriptions |
| * @n_fields: The number of field descriptions contained in the fields array |
| * |
| * Add a new set of fields to a synthetic event cmd object. The event |
| * fields that will be defined for the event should be passed in as an |
| * array of struct synth_field_desc, and the number of elements in the |
| * array passed in as n_fields. Field ordering will retain the |
| * ordering given in the fields array. |
| * |
| * See synth_field_size() for available types. If field_name contains |
| * [n] the field is considered to be an array. |
| * |
| * Return: 0 if successful, error otherwise. |
| */ |
| int synth_event_add_fields(struct dynevent_cmd *cmd, |
| struct synth_field_desc *fields, |
| unsigned int n_fields) |
| { |
| unsigned int i; |
| int ret = 0; |
| |
| for (i = 0; i < n_fields; i++) { |
| if (fields[i].type == NULL || fields[i].name == NULL) { |
| ret = -EINVAL; |
| break; |
| } |
| |
| ret = synth_event_add_field(cmd, fields[i].type, fields[i].name); |
| if (ret) |
| break; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_add_fields); |
| |
| /** |
| * __synth_event_gen_cmd_start - Start a synthetic event command from arg list |
| * @cmd: A pointer to the dynevent_cmd struct representing the new event |
| * @name: The name of the synthetic event |
| * @mod: The module creating the event, NULL if not created from a module |
| * @args: Variable number of arg (pairs), one pair for each field |
| * |
| * NOTE: Users normally won't want to call this function directly, but |
| * rather use the synth_event_gen_cmd_start() wrapper, which |
| * automatically adds a NULL to the end of the arg list. If this |
| * function is used directly, make sure the last arg in the variable |
| * arg list is NULL. |
| * |
| * Generate a synthetic event command to be executed by |
| * synth_event_gen_cmd_end(). This function can be used to generate |
| * the complete command or only the first part of it; in the latter |
| * case, synth_event_add_field(), synth_event_add_field_str(), or |
| * synth_event_add_fields() can be used to add more fields following |
| * this. |
| * |
| * There should be an even number variable args, each pair consisting |
| * of a type followed by a field name. |
| * |
| * See synth_field_size() for available types. If field_name contains |
| * [n] the field is considered to be an array. |
| * |
| * Return: 0 if successful, error otherwise. |
| */ |
| int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd, const char *name, |
| struct module *mod, ...) |
| { |
| struct dynevent_arg arg; |
| va_list args; |
| int ret; |
| |
| cmd->event_name = name; |
| cmd->private_data = mod; |
| |
| if (cmd->type != DYNEVENT_TYPE_SYNTH) |
| return -EINVAL; |
| |
| dynevent_arg_init(&arg, 0); |
| arg.str = name; |
| ret = dynevent_arg_add(cmd, &arg, NULL); |
| if (ret) |
| return ret; |
| |
| va_start(args, mod); |
| for (;;) { |
| const char *type, *name; |
| |
| type = va_arg(args, const char *); |
| if (!type) |
| break; |
| name = va_arg(args, const char *); |
| if (!name) |
| break; |
| |
| if (++cmd->n_fields > SYNTH_FIELDS_MAX) { |
| ret = -EINVAL; |
| break; |
| } |
| |
| ret = synth_event_add_field(cmd, type, name); |
| if (ret) |
| break; |
| } |
| va_end(args); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start); |
| |
| /** |
| * synth_event_gen_cmd_array_start - Start synthetic event command from an array |
| * @cmd: A pointer to the dynevent_cmd struct representing the new event |
| * @name: The name of the synthetic event |
| * @fields: An array of type/name field descriptions |
| * @n_fields: The number of field descriptions contained in the fields array |
| * |
| * Generate a synthetic event command to be executed by |
| * synth_event_gen_cmd_end(). This function can be used to generate |
| * the complete command or only the first part of it; in the latter |
| * case, synth_event_add_field(), synth_event_add_field_str(), or |
| * synth_event_add_fields() can be used to add more fields following |
| * this. |
| * |
| * The event fields that will be defined for the event should be |
| * passed in as an array of struct synth_field_desc, and the number of |
| * elements in the array passed in as n_fields. Field ordering will |
| * retain the ordering given in the fields array. |
| * |
| * See synth_field_size() for available types. If field_name contains |
| * [n] the field is considered to be an array. |
| * |
| * Return: 0 if successful, error otherwise. |
| */ |
| int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name, |
| struct module *mod, |
| struct synth_field_desc *fields, |
| unsigned int n_fields) |
| { |
| struct dynevent_arg arg; |
| unsigned int i; |
| int ret = 0; |
| |
| cmd->event_name = name; |
| cmd->private_data = mod; |
| |
| if (cmd->type != DYNEVENT_TYPE_SYNTH) |
| return -EINVAL; |
| |
| if (n_fields > SYNTH_FIELDS_MAX) |
| return -EINVAL; |
| |
| dynevent_arg_init(&arg, 0); |
| arg.str = name; |
| ret = dynevent_arg_add(cmd, &arg, NULL); |
| if (ret) |
| return ret; |
| |
| for (i = 0; i < n_fields; i++) { |
| if (fields[i].type == NULL || fields[i].name == NULL) |
| return -EINVAL; |
| |
| ret = synth_event_add_field(cmd, fields[i].type, fields[i].name); |
| if (ret) |
| break; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start); |
| |
| static int __create_synth_event(const char *name, const char *raw_fields) |
| { |
| char **argv, *field_str, *tmp_fields, *saved_fields = NULL; |
| struct synth_field *field, *fields[SYNTH_FIELDS_MAX]; |
| int consumed, cmd_version = 1, n_fields_this_loop; |
| int i, argc, n_fields = 0, ret = 0; |
| struct synth_event *event = NULL; |
| |
| /* |
| * Argument syntax: |
| * - Add synthetic event: <event_name> field[;field] ... |
| * - Remove synthetic event: !<event_name> field[;field] ... |
| * where 'field' = type field_name |
| */ |
| |
| if (name[0] == '\0') { |
| synth_err(SYNTH_ERR_INVALID_CMD, 0); |
| return -EINVAL; |
| } |
| |
| if (!is_good_name(name)) { |
| synth_err(SYNTH_ERR_BAD_NAME, errpos(name)); |
| return -EINVAL; |
| } |
| |
| mutex_lock(&event_mutex); |
| |
| event = find_synth_event(name); |
| if (event) { |
| synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name)); |
| ret = -EEXIST; |
| goto err; |
| } |
| |
| tmp_fields = saved_fields = kstrdup(raw_fields, GFP_KERNEL); |
| if (!tmp_fields) { |
| ret = -ENOMEM; |
| goto err; |
| } |
| |
| while ((field_str = strsep(&tmp_fields, ";")) != NULL) { |
| argv = argv_split(GFP_KERNEL, field_str, &argc); |
| if (!argv) { |
| ret = -ENOMEM; |
| goto err; |
| } |
| |
| if (!argc) { |
| argv_free(argv); |
| continue; |
| } |
| |
| n_fields_this_loop = 0; |
| consumed = 0; |
| while (argc > consumed) { |
| int field_version; |
| |
| field = parse_synth_field(argc - consumed, |
| argv + consumed, &consumed, |
| &field_version); |
| if (IS_ERR(field)) { |
| ret = PTR_ERR(field); |
| goto err_free_arg; |
| } |
| |
| /* |
| * Track the highest version of any field we |
| * found in the command. |
| */ |
| if (field_version > cmd_version) |
| cmd_version = field_version; |
| |
| /* |
| * Now sort out what is and isn't valid for |
| * each supported version. |
| * |
| * If we see more than 1 field per loop, it |
| * means we have multiple fields between |
| * semicolons, and that's something we no |
| * longer support in a version 2 or greater |
| * command. |
| */ |
| if (cmd_version > 1 && n_fields_this_loop >= 1) { |
| synth_err(SYNTH_ERR_INVALID_CMD, errpos(field_str)); |
| ret = -EINVAL; |
| goto err_free_arg; |
| } |
| |
| if (n_fields == SYNTH_FIELDS_MAX) { |
| synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0); |
| ret = -EINVAL; |
| goto err_free_arg; |
| } |
| fields[n_fields++] = field; |
| |
| n_fields_this_loop++; |
| } |
| argv_free(argv); |
| |
| if (consumed < argc) { |
| synth_err(SYNTH_ERR_INVALID_CMD, 0); |
| ret = -EINVAL; |
| goto err; |
| } |
| |
| } |
| |
| if (n_fields == 0) { |
| synth_err(SYNTH_ERR_INVALID_CMD, 0); |
| ret = -EINVAL; |
| goto err; |
| } |
| |
| event = alloc_synth_event(name, n_fields, fields); |
| if (IS_ERR(event)) { |
| ret = PTR_ERR(event); |
| event = NULL; |
| goto err; |
| } |
| ret = register_synth_event(event); |
| if (!ret) |
| dyn_event_add(&event->devent, &event->call); |
| else |
| free_synth_event(event); |
| out: |
| mutex_unlock(&event_mutex); |
| |
| kfree(saved_fields); |
| |
| return ret; |
| err_free_arg: |
| argv_free(argv); |
| err: |
| for (i = 0; i < n_fields; i++) |
| free_synth_field(fields[i]); |
| |
| goto out; |
| } |
| |
| /** |
| * synth_event_create - Create a new synthetic event |
| * @name: The name of the new synthetic event |
| * @fields: An array of type/name field descriptions |
| * @n_fields: The number of field descriptions contained in the fields array |
| * @mod: The module creating the event, NULL if not created from a module |
| * |
| * Create a new synthetic event with the given name under the |
| * trace/events/synthetic/ directory. The event fields that will be |
| * defined for the event should be passed in as an array of struct |
| * synth_field_desc, and the number elements in the array passed in as |
| * n_fields. Field ordering will retain the ordering given in the |
| * fields array. |
| * |
| * If the new synthetic event is being created from a module, the mod |
| * param must be non-NULL. This will ensure that the trace buffer |
| * won't contain unreadable events. |
| * |
| * The new synth event should be deleted using synth_event_delete() |
| * function. The new synthetic event can be generated from modules or |
| * other kernel code using trace_synth_event() and related functions. |
| * |
| * Return: 0 if successful, error otherwise. |
| */ |
| int synth_event_create(const char *name, struct synth_field_desc *fields, |
| unsigned int n_fields, struct module *mod) |
| { |
| struct dynevent_cmd cmd; |
| char *buf; |
| int ret; |
| |
| buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL); |
| if (!buf) |
| return -ENOMEM; |
| |
| synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN); |
| |
| ret = synth_event_gen_cmd_array_start(&cmd, name, mod, |
| fields, n_fields); |
| if (ret) |
| goto out; |
| |
| ret = synth_event_gen_cmd_end(&cmd); |
| out: |
| kfree(buf); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_create); |
| |
| static int destroy_synth_event(struct synth_event *se) |
| { |
| int ret; |
| |
| if (se->ref) |
| return -EBUSY; |
| |
| if (trace_event_dyn_busy(&se->call)) |
| return -EBUSY; |
| |
| ret = unregister_synth_event(se); |
| if (!ret) { |
| dyn_event_remove(&se->devent); |
| free_synth_event(se); |
| } |
| |
| return ret; |
| } |
| |
| /** |
| * synth_event_delete - Delete a synthetic event |
| * @event_name: The name of the new synthetic event |
| * |
| * Delete a synthetic event that was created with synth_event_create(). |
| * |
| * Return: 0 if successful, error otherwise. |
| */ |
| int synth_event_delete(const char *event_name) |
| { |
| struct synth_event *se = NULL; |
| struct module *mod = NULL; |
| int ret = -ENOENT; |
| |
| mutex_lock(&event_mutex); |
| se = find_synth_event(event_name); |
| if (se) { |
| mod = se->mod; |
| ret = destroy_synth_event(se); |
| } |
| mutex_unlock(&event_mutex); |
| |
| if (mod) { |
| /* |
| * It is safest to reset the ring buffer if the module |
| * being unloaded registered any events that were |
| * used. The only worry is if a new module gets |
| * loaded, and takes on the same id as the events of |
| * this module. When printing out the buffer, traced |
| * events left over from this module may be passed to |
| * the new module events and unexpected results may |
| * occur. |
| */ |
| tracing_reset_all_online_cpus(); |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_delete); |
| |
| static int check_command(const char *raw_command) |
| { |
| char **argv = NULL, *cmd, *saved_cmd, *name_and_field; |
| int argc, ret = 0; |
| |
| cmd = saved_cmd = kstrdup(raw_command, GFP_KERNEL); |
| if (!cmd) |
| return -ENOMEM; |
| |
| name_and_field = strsep(&cmd, ";"); |
| if (!name_and_field) { |
| ret = -EINVAL; |
| goto free; |
| } |
| |
| if (name_and_field[0] == '!') |
| goto free; |
| |
| argv = argv_split(GFP_KERNEL, name_and_field, &argc); |
| if (!argv) { |
| ret = -ENOMEM; |
| goto free; |
| } |
| argv_free(argv); |
| |
| if (argc < 3) |
| ret = -EINVAL; |
| free: |
| kfree(saved_cmd); |
| |
| return ret; |
| } |
| |
| static int create_or_delete_synth_event(const char *raw_command) |
| { |
| char *name = NULL, *fields, *p; |
| int ret = 0; |
| |
| raw_command = skip_spaces(raw_command); |
| if (raw_command[0] == '\0') |
| return ret; |
| |
| last_cmd_set(raw_command); |
| |
| ret = check_command(raw_command); |
| if (ret) { |
| synth_err(SYNTH_ERR_INVALID_CMD, 0); |
| return ret; |
| } |
| |
| p = strpbrk(raw_command, " \t"); |
| if (!p && raw_command[0] != '!') { |
| synth_err(SYNTH_ERR_INVALID_CMD, 0); |
| ret = -EINVAL; |
| goto free; |
| } |
| |
| name = kmemdup_nul(raw_command, p ? p - raw_command : strlen(raw_command), GFP_KERNEL); |
| if (!name) |
| return -ENOMEM; |
| |
| if (name[0] == '!') { |
| ret = synth_event_delete(name + 1); |
| goto free; |
| } |
| |
| fields = skip_spaces(p); |
| |
| ret = __create_synth_event(name, fields); |
| free: |
| kfree(name); |
| |
| return ret; |
| } |
| |
| static int synth_event_run_command(struct dynevent_cmd *cmd) |
| { |
| struct synth_event *se; |
| int ret; |
| |
| ret = create_or_delete_synth_event(cmd->seq.buffer); |
| if (ret) |
| return ret; |
| |
| se = find_synth_event(cmd->event_name); |
| if (WARN_ON(!se)) |
| return -ENOENT; |
| |
| se->mod = cmd->private_data; |
| |
| return ret; |
| } |
| |
| /** |
| * synth_event_cmd_init - Initialize a synthetic event command object |
| * @cmd: A pointer to the dynevent_cmd struct representing the new event |
| * @buf: A pointer to the buffer used to build the command |
| * @maxlen: The length of the buffer passed in @buf |
| * |
| * Initialize a synthetic event command object. Use this before |
| * calling any of the other dyenvent_cmd functions. |
| */ |
| void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen) |
| { |
| dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH, |
| synth_event_run_command); |
| } |
| EXPORT_SYMBOL_GPL(synth_event_cmd_init); |
| |
| static inline int |
| __synth_event_trace_init(struct trace_event_file *file, |
| struct synth_event_trace_state *trace_state) |
| { |
| int ret = 0; |
| |
| memset(trace_state, '\0', sizeof(*trace_state)); |
| |
| /* |
| * Normal event tracing doesn't get called at all unless the |
| * ENABLED bit is set (which attaches the probe thus allowing |
| * this code to be called, etc). Because this is called |
| * directly by the user, we don't have that but we still need |
| * to honor not logging when disabled. For the iterated |
| * trace case, we save the enabled state upon start and just |
| * ignore the following data calls. |
| */ |
| if (!(file->flags & EVENT_FILE_FL_ENABLED) || |
| trace_trigger_soft_disabled(file)) { |
| trace_state->disabled = true; |
| ret = -ENOENT; |
| goto out; |
| } |
| |
| trace_state->event = file->event_call->data; |
| out: |
| return ret; |
| } |
| |
| static inline int |
| __synth_event_trace_start(struct trace_event_file *file, |
| struct synth_event_trace_state *trace_state, |
| int dynamic_fields_size) |
| { |
| int entry_size, fields_size = 0; |
| int ret = 0; |
| |
| fields_size = trace_state->event->n_u64 * sizeof(u64); |
| fields_size += dynamic_fields_size; |
| |
| /* |
| * Avoid ring buffer recursion detection, as this event |
| * is being performed within another event. |
| */ |
| trace_state->buffer = file->tr->array_buffer.buffer; |
| ring_buffer_nest_start(trace_state->buffer); |
| |
| entry_size = sizeof(*trace_state->entry) + fields_size; |
| trace_state->entry = trace_event_buffer_reserve(&trace_state->fbuffer, |
| file, |
| entry_size); |
| if (!trace_state->entry) { |
| ring_buffer_nest_end(trace_state->buffer); |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| |
| static inline void |
| __synth_event_trace_end(struct synth_event_trace_state *trace_state) |
| { |
| trace_event_buffer_commit(&trace_state->fbuffer); |
| |
| ring_buffer_nest_end(trace_state->buffer); |
| } |
| |
| /** |
| * synth_event_trace - Trace a synthetic event |
| * @file: The trace_event_file representing the synthetic event |
| * @n_vals: The number of values in vals |
| * @args: Variable number of args containing the event values |
| * |
| * Trace a synthetic event using the values passed in the variable |
| * argument list. |
| * |
| * The argument list should be a list 'n_vals' u64 values. The number |
| * of vals must match the number of field in the synthetic event, and |
| * must be in the same order as the synthetic event fields. |
| * |
| * All vals should be cast to u64, and string vals are just pointers |
| * to strings, cast to u64. Strings will be copied into space |
| * reserved in the event for the string, using these pointers. |
| * |
| * Return: 0 on success, err otherwise. |
| */ |
| int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...) |
| { |
| unsigned int i, n_u64, len, data_size = 0; |
| struct synth_event_trace_state state; |
| va_list args; |
| int ret; |
| |
| ret = __synth_event_trace_init(file, &state); |
| if (ret) { |
| if (ret == -ENOENT) |
| ret = 0; /* just disabled, not really an error */ |
| return ret; |
| } |
| |
| if (state.event->n_dynamic_fields) { |
| va_start(args, n_vals); |
| |
| for (i = 0; i < state.event->n_fields; i++) { |
| u64 val = va_arg(args, u64); |
| |
| if (state.event->fields[i]->is_string && |
| state.event->fields[i]->is_dynamic) { |
| char *str_val = (char *)(long)val; |
| |
| data_size += strlen(str_val) + 1; |
| } |
| } |
| |
| va_end(args); |
| } |
| |
| ret = __synth_event_trace_start(file, &state, data_size); |
| if (ret) |
| return ret; |
| |
| if (n_vals != state.event->n_fields) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| data_size = 0; |
| |
| va_start(args, n_vals); |
| for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) { |
| u64 val; |
| |
| val = va_arg(args, u64); |
| |
| if (state.event->fields[i]->is_string) { |
| char *str_val = (char *)(long)val; |
| |
| len = trace_string(state.entry, state.event, str_val, |
| state.event->fields[i]->is_dynamic, |
| data_size, &n_u64); |
| data_size += len; /* only dynamic string increments */ |
| } else { |
| struct synth_field *field = state.event->fields[i]; |
| |
| switch (field->size) { |
| case 1: |
| *(u8 *)&state.entry->fields[n_u64] = (u8)val; |
| break; |
| |
| case 2: |
| *(u16 *)&state.entry->fields[n_u64] = (u16)val; |
| break; |
| |
| case 4: |
| *(u32 *)&state.entry->fields[n_u64] = (u32)val; |
| break; |
| |
| default: |
| state.entry->fields[n_u64] = val; |
| break; |
| } |
| n_u64++; |
| } |
| } |
| va_end(args); |
| out: |
| __synth_event_trace_end(&state); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_trace); |
| |
| /** |
| * synth_event_trace_array - Trace a synthetic event from an array |
| * @file: The trace_event_file representing the synthetic event |
| * @vals: Array of values |
| * @n_vals: The number of values in vals |
| * |
| * Trace a synthetic event using the values passed in as 'vals'. |
| * |
| * The 'vals' array is just an array of 'n_vals' u64. The number of |
| * vals must match the number of field in the synthetic event, and |
| * must be in the same order as the synthetic event fields. |
| * |
| * All vals should be cast to u64, and string vals are just pointers |
| * to strings, cast to u64. Strings will be copied into space |
| * reserved in the event for the string, using these pointers. |
| * |
| * Return: 0 on success, err otherwise. |
| */ |
| int synth_event_trace_array(struct trace_event_file *file, u64 *vals, |
| unsigned int n_vals) |
| { |
| unsigned int i, n_u64, field_pos, len, data_size = 0; |
| struct synth_event_trace_state state; |
| char *str_val; |
| int ret; |
| |
| ret = __synth_event_trace_init(file, &state); |
| if (ret) { |
| if (ret == -ENOENT) |
| ret = 0; /* just disabled, not really an error */ |
| return ret; |
| } |
| |
| if (state.event->n_dynamic_fields) { |
| for (i = 0; i < state.event->n_dynamic_fields; i++) { |
| field_pos = state.event->dynamic_fields[i]->field_pos; |
| str_val = (char *)(long)vals[field_pos]; |
| len = strlen(str_val) + 1; |
| data_size += len; |
| } |
| } |
| |
| ret = __synth_event_trace_start(file, &state, data_size); |
| if (ret) |
| return ret; |
| |
| if (n_vals != state.event->n_fields) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| data_size = 0; |
| |
| for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) { |
| if (state.event->fields[i]->is_string) { |
| char *str_val = (char *)(long)vals[i]; |
| |
| len = trace_string(state.entry, state.event, str_val, |
| state.event->fields[i]->is_dynamic, |
| data_size, &n_u64); |
| data_size += len; /* only dynamic string increments */ |
| } else { |
| struct synth_field *field = state.event->fields[i]; |
| u64 val = vals[i]; |
| |
| switch (field->size) { |
| case 1: |
| *(u8 *)&state.entry->fields[n_u64] = (u8)val; |
| break; |
| |
| case 2: |
| *(u16 *)&state.entry->fields[n_u64] = (u16)val; |
| break; |
| |
| case 4: |
| *(u32 *)&state.entry->fields[n_u64] = (u32)val; |
| break; |
| |
| default: |
| state.entry->fields[n_u64] = val; |
| break; |
| } |
| n_u64++; |
| } |
| } |
| out: |
| __synth_event_trace_end(&state); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_trace_array); |
| |
| /** |
| * synth_event_trace_start - Start piecewise synthetic event trace |
| * @file: The trace_event_file representing the synthetic event |
| * @trace_state: A pointer to object tracking the piecewise trace state |
| * |
| * Start the trace of a synthetic event field-by-field rather than all |
| * at once. |
| * |
| * This function 'opens' an event trace, which means space is reserved |
| * for the event in the trace buffer, after which the event's |
| * individual field values can be set through either |
| * synth_event_add_next_val() or synth_event_add_val(). |
| * |
| * A pointer to a trace_state object is passed in, which will keep |
| * track of the current event trace state until the event trace is |
| * closed (and the event finally traced) using |
| * synth_event_trace_end(). |
| * |
| * Note that synth_event_trace_end() must be called after all values |
| * have been added for each event trace, regardless of whether adding |
| * all field values succeeded or not. |
| * |
| * Note also that for a given event trace, all fields must be added |
| * using either synth_event_add_next_val() or synth_event_add_val() |
| * but not both together or interleaved. |
| * |
| * Return: 0 on success, err otherwise. |
| */ |
| int synth_event_trace_start(struct trace_event_file *file, |
| struct synth_event_trace_state *trace_state) |
| { |
| int ret; |
| |
| if (!trace_state) |
| return -EINVAL; |
| |
| ret = __synth_event_trace_init(file, trace_state); |
| if (ret) { |
| if (ret == -ENOENT) |
| ret = 0; /* just disabled, not really an error */ |
| return ret; |
| } |
| |
| if (trace_state->event->n_dynamic_fields) |
| return -ENOTSUPP; |
| |
| ret = __synth_event_trace_start(file, trace_state, 0); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_trace_start); |
| |
| static int __synth_event_add_val(const char *field_name, u64 val, |
| struct synth_event_trace_state *trace_state) |
| { |
| struct synth_field *field = NULL; |
| struct synth_trace_event *entry; |
| struct synth_event *event; |
| int i, ret = 0; |
| |
| if (!trace_state) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| /* can't mix add_next_synth_val() with add_synth_val() */ |
| if (field_name) { |
| if (trace_state->add_next) { |
| ret = -EINVAL; |
| goto out; |
| } |
| trace_state->add_name = true; |
| } else { |
| if (trace_state->add_name) { |
| ret = -EINVAL; |
| goto out; |
| } |
| trace_state->add_next = true; |
| } |
| |
| if (trace_state->disabled) |
| goto out; |
| |
| event = trace_state->event; |
| if (trace_state->add_name) { |
| for (i = 0; i < event->n_fields; i++) { |
| field = event->fields[i]; |
| if (strcmp(field->name, field_name) == 0) |
| break; |
| } |
| if (!field) { |
| ret = -EINVAL; |
| goto out; |
| } |
| } else { |
| if (trace_state->cur_field >= event->n_fields) { |
| ret = -EINVAL; |
| goto out; |
| } |
| field = event->fields[trace_state->cur_field++]; |
| } |
| |
| entry = trace_state->entry; |
| if (field->is_string) { |
| char *str_val = (char *)(long)val; |
| char *str_field; |
| |
| if (field->is_dynamic) { /* add_val can't do dynamic strings */ |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| if (!str_val) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| str_field = (char *)&entry->fields[field->offset]; |
| strscpy(str_field, str_val, STR_VAR_LEN_MAX); |
| } else { |
| switch (field->size) { |
| case 1: |
| *(u8 *)&trace_state->entry->fields[field->offset] = (u8)val; |
| break; |
| |
| case 2: |
| *(u16 *)&trace_state->entry->fields[field->offset] = (u16)val; |
| break; |
| |
| case 4: |
| *(u32 *)&trace_state->entry->fields[field->offset] = (u32)val; |
| break; |
| |
| default: |
| trace_state->entry->fields[field->offset] = val; |
| break; |
| } |
| } |
| out: |
| return ret; |
| } |
| |
| /** |
| * synth_event_add_next_val - Add the next field's value to an open synth trace |
| * @val: The value to set the next field to |
| * @trace_state: A pointer to object tracking the piecewise trace state |
| * |
| * Set the value of the next field in an event that's been opened by |
| * synth_event_trace_start(). |
| * |
| * The val param should be the value cast to u64. If the value points |
| * to a string, the val param should be a char * cast to u64. |
| * |
| * This function assumes all the fields in an event are to be set one |
| * after another - successive calls to this function are made, one for |
| * each field, in the order of the fields in the event, until all |
| * fields have been set. If you'd rather set each field individually |
| * without regard to ordering, synth_event_add_val() can be used |
| * instead. |
| * |
| * Note however that synth_event_add_next_val() and |
| * synth_event_add_val() can't be intermixed for a given event trace - |
| * one or the other but not both can be used at the same time. |
| * |
| * Note also that synth_event_trace_end() must be called after all |
| * values have been added for each event trace, regardless of whether |
| * adding all field values succeeded or not. |
| * |
| * Return: 0 on success, err otherwise. |
| */ |
| int synth_event_add_next_val(u64 val, |
| struct synth_event_trace_state *trace_state) |
| { |
| return __synth_event_add_val(NULL, val, trace_state); |
| } |
| EXPORT_SYMBOL_GPL(synth_event_add_next_val); |
| |
| /** |
| * synth_event_add_val - Add a named field's value to an open synth trace |
| * @field_name: The name of the synthetic event field value to set |
| * @val: The value to set the named field to |
| * @trace_state: A pointer to object tracking the piecewise trace state |
| * |
| * Set the value of the named field in an event that's been opened by |
| * synth_event_trace_start(). |
| * |
| * The val param should be the value cast to u64. If the value points |
| * to a string, the val param should be a char * cast to u64. |
| * |
| * This function looks up the field name, and if found, sets the field |
| * to the specified value. This lookup makes this function more |
| * expensive than synth_event_add_next_val(), so use that or the |
| * none-piecewise synth_event_trace() instead if efficiency is more |
| * important. |
| * |
| * Note however that synth_event_add_next_val() and |
| * synth_event_add_val() can't be intermixed for a given event trace - |
| * one or the other but not both can be used at the same time. |
| * |
| * Note also that synth_event_trace_end() must be called after all |
| * values have been added for each event trace, regardless of whether |
| * adding all field values succeeded or not. |
| * |
| * Return: 0 on success, err otherwise. |
| */ |
| int synth_event_add_val(const char *field_name, u64 val, |
| struct synth_event_trace_state *trace_state) |
| { |
| return __synth_event_add_val(field_name, val, trace_state); |
| } |
| EXPORT_SYMBOL_GPL(synth_event_add_val); |
| |
| /** |
| * synth_event_trace_end - End piecewise synthetic event trace |
| * @trace_state: A pointer to object tracking the piecewise trace state |
| * |
| * End the trace of a synthetic event opened by |
| * synth_event_trace__start(). |
| * |
| * This function 'closes' an event trace, which basically means that |
| * it commits the reserved event and cleans up other loose ends. |
| * |
| * A pointer to a trace_state object is passed in, which will keep |
| * track of the current event trace state opened with |
| * synth_event_trace_start(). |
| * |
| * Note that this function must be called after all values have been |
| * added for each event trace, regardless of whether adding all field |
| * values succeeded or not. |
| * |
| * Return: 0 on success, err otherwise. |
| */ |
| int synth_event_trace_end(struct synth_event_trace_state *trace_state) |
| { |
| if (!trace_state) |
| return -EINVAL; |
| |
| __synth_event_trace_end(trace_state); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(synth_event_trace_end); |
| |
| static int create_synth_event(const char *raw_command) |
| { |
| char *fields, *p; |
| const char *name; |
| int len, ret = 0; |
| |
| raw_command = skip_spaces(raw_command); |
| if (raw_command[0] == '\0') |
| return ret; |
| |
| last_cmd_set(raw_command); |
| |
| name = raw_command; |
| |
| /* Don't try to process if not our system */ |
| if (name[0] != 's' || name[1] != ':') |
| return -ECANCELED; |
| name += 2; |
| |
| p = strpbrk(raw_command, " \t"); |
| if (!p) { |
| synth_err(SYNTH_ERR_INVALID_CMD, 0); |
| return -EINVAL; |
| } |
| |
| fields = skip_spaces(p); |
| |
| /* This interface accepts group name prefix */ |
| if (strchr(name, '/')) { |
| len = str_has_prefix(name, SYNTH_SYSTEM "/"); |
| if (len == 0) { |
| synth_err(SYNTH_ERR_INVALID_DYN_CMD, 0); |
| return -EINVAL; |
| } |
| name += len; |
| } |
| |
| len = name - raw_command; |
| |
| ret = check_command(raw_command + len); |
| if (ret) { |
| synth_err(SYNTH_ERR_INVALID_CMD, 0); |
| return ret; |
| } |
| |
| name = kmemdup_nul(raw_command + len, p - raw_command - len, GFP_KERNEL); |
| if (!name) |
| return -ENOMEM; |
| |
| ret = __create_synth_event(name, fields); |
| |
| kfree(name); |
| |
| return ret; |
| } |
| |
| static int synth_event_release(struct dyn_event *ev) |
| { |
| struct synth_event *event = to_synth_event(ev); |
| int ret; |
| |
| if (event->ref) |
| return -EBUSY; |
| |
| if (trace_event_dyn_busy(&event->call)) |
| return -EBUSY; |
| |
| ret = unregister_synth_event(event); |
| if (ret) |
| return ret; |
| |
| dyn_event_remove(ev); |
| free_synth_event(event); |
| return 0; |
| } |
| |
| static int __synth_event_show(struct seq_file *m, struct synth_event *event) |
| { |
| struct synth_field *field; |
| unsigned int i; |
| char *type, *t; |
| |
| seq_printf(m, "%s\t", event->name); |
| |
| for (i = 0; i < event->n_fields; i++) { |
| field = event->fields[i]; |
| |
| type = field->type; |
| t = strstr(type, "__data_loc"); |
| if (t) { /* __data_loc belongs in format but not event desc */ |
| t += sizeof("__data_loc"); |
| type = t; |
| } |
| |
| /* parameter values */ |
| seq_printf(m, "%s %s%s", type, field->name, |
| i == event->n_fields - 1 ? "" : "; "); |
| } |
| |
| seq_putc(m, '\n'); |
| |
| 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 = 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) |
| { |
| int ret; |
| |
| ret = security_locked_down(LOCKDOWN_TRACEFS); |
| if (ret) |
| return ret; |
| |
| if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { |
| ret = dyn_events_release_all(&synth_event_ops); |
| if (ret < 0) |
| return ret; |
| } |
| |
| return seq_open(file, &synth_events_seq_op); |
| } |
| |
| static ssize_t synth_events_write(struct file *file, |
| const char __user *buffer, |
| size_t count, loff_t *ppos) |
| { |
| return trace_parse_run_command(file, buffer, count, ppos, |
| create_or_delete_synth_event); |
| } |
| |
| static const struct file_operations synth_events_fops = { |
| .open = synth_events_open, |
| .write = synth_events_write, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| /* |
| * Register dynevent at core_initcall. This allows kernel to setup kprobe |
| * events in postcore_initcall without tracefs. |
| */ |
| static __init int trace_events_synth_init_early(void) |
| { |
| int err = 0; |
| |
| err = dyn_event_register(&synth_event_ops); |
| if (err) |
| pr_warn("Could not register synth_event_ops\n"); |
| |
| return err; |
| } |
| core_initcall(trace_events_synth_init_early); |
| |
| static __init int trace_events_synth_init(void) |
| { |
| struct dentry *entry = NULL; |
| int err = 0; |
| err = tracing_init_dentry(); |
| if (err) |
| goto err; |
| |
| entry = tracefs_create_file("synthetic_events", TRACE_MODE_WRITE, |
| NULL, NULL, &synth_events_fops); |
| if (!entry) { |
| err = -ENODEV; |
| goto err; |
| } |
| |
| return err; |
| err: |
| pr_warn("Could not create tracefs 'synthetic_events' entry\n"); |
| |
| return err; |
| } |
| |
| fs_initcall(trace_events_synth_init); |