| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * trace_events_hist - trace event hist triggers |
| * |
| * Copyright (C) 2015 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 "tracing_map.h" |
| #include "trace_synth.h" |
| |
| #define ERRORS \ |
| C(NONE, "No error"), \ |
| C(DUPLICATE_VAR, "Variable already defined"), \ |
| C(VAR_NOT_UNIQUE, "Variable name not unique, need to use fully qualified name (subsys.event.var) for variable"), \ |
| C(TOO_MANY_VARS, "Too many variables defined"), \ |
| C(MALFORMED_ASSIGNMENT, "Malformed assignment"), \ |
| C(NAMED_MISMATCH, "Named hist trigger doesn't match existing named trigger (includes variables)"), \ |
| C(TRIGGER_EEXIST, "Hist trigger already exists"), \ |
| C(TRIGGER_ENOENT_CLEAR, "Can't clear or continue a nonexistent hist trigger"), \ |
| C(SET_CLOCK_FAIL, "Couldn't set trace_clock"), \ |
| C(BAD_FIELD_MODIFIER, "Invalid field modifier"), \ |
| C(TOO_MANY_SUBEXPR, "Too many subexpressions (3 max)"), \ |
| C(TIMESTAMP_MISMATCH, "Timestamp units in expression don't match"), \ |
| C(TOO_MANY_FIELD_VARS, "Too many field variables defined"), \ |
| C(EVENT_FILE_NOT_FOUND, "Event file not found"), \ |
| C(HIST_NOT_FOUND, "Matching event histogram not found"), \ |
| C(HIST_CREATE_FAIL, "Couldn't create histogram for field"), \ |
| C(SYNTH_VAR_NOT_FOUND, "Couldn't find synthetic variable"), \ |
| C(SYNTH_EVENT_NOT_FOUND,"Couldn't find synthetic event"), \ |
| C(SYNTH_TYPE_MISMATCH, "Param type doesn't match synthetic event field type"), \ |
| C(SYNTH_COUNT_MISMATCH, "Param count doesn't match synthetic event field count"), \ |
| C(FIELD_VAR_PARSE_FAIL, "Couldn't parse field variable"), \ |
| C(VAR_CREATE_FIND_FAIL, "Couldn't create or find variable"), \ |
| C(ONX_NOT_VAR, "For onmax(x) or onchange(x), x must be a variable"), \ |
| C(ONX_VAR_NOT_FOUND, "Couldn't find onmax or onchange variable"), \ |
| C(ONX_VAR_CREATE_FAIL, "Couldn't create onmax or onchange variable"), \ |
| C(FIELD_VAR_CREATE_FAIL,"Couldn't create field variable"), \ |
| C(TOO_MANY_PARAMS, "Too many action params"), \ |
| C(PARAM_NOT_FOUND, "Couldn't find param"), \ |
| C(INVALID_PARAM, "Invalid action param"), \ |
| C(ACTION_NOT_FOUND, "No action found"), \ |
| C(NO_SAVE_PARAMS, "No params found for save()"), \ |
| C(TOO_MANY_SAVE_ACTIONS,"Can't have more than one save() action per hist"), \ |
| C(ACTION_MISMATCH, "Handler doesn't support action"), \ |
| C(NO_CLOSING_PAREN, "No closing paren found"), \ |
| C(SUBSYS_NOT_FOUND, "Missing subsystem"), \ |
| C(INVALID_SUBSYS_EVENT, "Invalid subsystem or event name"), \ |
| C(INVALID_REF_KEY, "Using variable references in keys not supported"), \ |
| C(VAR_NOT_FOUND, "Couldn't find variable"), \ |
| C(FIELD_NOT_FOUND, "Couldn't find field"), \ |
| C(EMPTY_ASSIGNMENT, "Empty assignment"), \ |
| C(INVALID_SORT_MODIFIER,"Invalid sort modifier"), \ |
| C(EMPTY_SORT_FIELD, "Empty sort field"), \ |
| C(TOO_MANY_SORT_FIELDS, "Too many sort fields (Max = 2)"), \ |
| C(INVALID_SORT_FIELD, "Sort field must be a key or a val"), \ |
| C(INVALID_STR_OPERAND, "String type can not be an operand in expression"), \ |
| C(EXPECT_NUMBER, "Expecting numeric literal"), \ |
| C(UNARY_MINUS_SUBEXPR, "Unary minus not supported in sub-expressions"), \ |
| C(DIVISION_BY_ZERO, "Division by zero"), |
| |
| #undef C |
| #define C(a, b) HIST_ERR_##a |
| |
| enum { ERRORS }; |
| |
| #undef C |
| #define C(a, b) b |
| |
| static const char *err_text[] = { ERRORS }; |
| |
| struct hist_field; |
| |
| typedef u64 (*hist_field_fn_t) (struct hist_field *field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event); |
| |
| #define HIST_FIELD_OPERANDS_MAX 2 |
| #define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX) |
| #define HIST_ACTIONS_MAX 8 |
| #define HIST_CONST_DIGITS_MAX 21 |
| #define HIST_DIV_SHIFT 20 /* For optimizing division by constants */ |
| |
| enum field_op_id { |
| FIELD_OP_NONE, |
| FIELD_OP_PLUS, |
| FIELD_OP_MINUS, |
| FIELD_OP_UNARY_MINUS, |
| FIELD_OP_DIV, |
| FIELD_OP_MULT, |
| }; |
| |
| enum hist_field_fn { |
| HIST_FIELD_FN_NOP, |
| HIST_FIELD_FN_VAR_REF, |
| HIST_FIELD_FN_COUNTER, |
| HIST_FIELD_FN_CONST, |
| HIST_FIELD_FN_LOG2, |
| HIST_FIELD_FN_BUCKET, |
| HIST_FIELD_FN_TIMESTAMP, |
| HIST_FIELD_FN_CPU, |
| HIST_FIELD_FN_STRING, |
| HIST_FIELD_FN_DYNSTRING, |
| HIST_FIELD_FN_RELDYNSTRING, |
| HIST_FIELD_FN_PSTRING, |
| HIST_FIELD_FN_S64, |
| HIST_FIELD_FN_U64, |
| HIST_FIELD_FN_S32, |
| HIST_FIELD_FN_U32, |
| HIST_FIELD_FN_S16, |
| HIST_FIELD_FN_U16, |
| HIST_FIELD_FN_S8, |
| HIST_FIELD_FN_U8, |
| HIST_FIELD_FN_UMINUS, |
| HIST_FIELD_FN_MINUS, |
| HIST_FIELD_FN_PLUS, |
| HIST_FIELD_FN_DIV, |
| HIST_FIELD_FN_MULT, |
| HIST_FIELD_FN_DIV_POWER2, |
| HIST_FIELD_FN_DIV_NOT_POWER2, |
| HIST_FIELD_FN_DIV_MULT_SHIFT, |
| HIST_FIELD_FN_EXECNAME, |
| }; |
| |
| /* |
| * A hist_var (histogram variable) contains variable information for |
| * hist_fields having the HIST_FIELD_FL_VAR or HIST_FIELD_FL_VAR_REF |
| * flag set. A hist_var has a variable name e.g. ts0, and is |
| * associated with a given histogram trigger, as specified by |
| * hist_data. The hist_var idx is the unique index assigned to the |
| * variable by the hist trigger's tracing_map. The idx is what is |
| * used to set a variable's value and, by a variable reference, to |
| * retrieve it. |
| */ |
| struct hist_var { |
| char *name; |
| struct hist_trigger_data *hist_data; |
| unsigned int idx; |
| }; |
| |
| struct hist_field { |
| struct ftrace_event_field *field; |
| unsigned long flags; |
| unsigned long buckets; |
| const char *type; |
| struct hist_field *operands[HIST_FIELD_OPERANDS_MAX]; |
| struct hist_trigger_data *hist_data; |
| enum hist_field_fn fn_num; |
| unsigned int ref; |
| unsigned int size; |
| unsigned int offset; |
| unsigned int is_signed; |
| |
| /* |
| * Variable fields contain variable-specific info in var. |
| */ |
| struct hist_var var; |
| enum field_op_id operator; |
| char *system; |
| char *event_name; |
| |
| /* |
| * The name field is used for EXPR and VAR_REF fields. VAR |
| * fields contain the variable name in var.name. |
| */ |
| char *name; |
| |
| /* |
| * When a histogram trigger is hit, if it has any references |
| * to variables, the values of those variables are collected |
| * into a var_ref_vals array by resolve_var_refs(). The |
| * current value of each variable is read from the tracing_map |
| * using the hist field's hist_var.idx and entered into the |
| * var_ref_idx entry i.e. var_ref_vals[var_ref_idx]. |
| */ |
| unsigned int var_ref_idx; |
| bool read_once; |
| |
| unsigned int var_str_idx; |
| |
| /* Numeric literals are represented as u64 */ |
| u64 constant; |
| /* Used to optimize division by constants */ |
| u64 div_multiplier; |
| }; |
| |
| static u64 hist_fn_call(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event); |
| |
| static u64 hist_field_const(struct hist_field *field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| return field->constant; |
| } |
| |
| static u64 hist_field_counter(struct hist_field *field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| return 1; |
| } |
| |
| static u64 hist_field_string(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| char *addr = (char *)(event + hist_field->field->offset); |
| |
| return (u64)(unsigned long)addr; |
| } |
| |
| static u64 hist_field_dynstring(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| u32 str_item = *(u32 *)(event + hist_field->field->offset); |
| int str_loc = str_item & 0xffff; |
| char *addr = (char *)(event + str_loc); |
| |
| return (u64)(unsigned long)addr; |
| } |
| |
| static u64 hist_field_reldynstring(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| u32 *item = event + hist_field->field->offset; |
| u32 str_item = *item; |
| int str_loc = str_item & 0xffff; |
| char *addr = (char *)&item[1] + str_loc; |
| |
| return (u64)(unsigned long)addr; |
| } |
| |
| static u64 hist_field_pstring(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| char **addr = (char **)(event + hist_field->field->offset); |
| |
| return (u64)(unsigned long)*addr; |
| } |
| |
| static u64 hist_field_log2(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand = hist_field->operands[0]; |
| |
| u64 val = hist_fn_call(operand, elt, buffer, rbe, event); |
| |
| return (u64) ilog2(roundup_pow_of_two(val)); |
| } |
| |
| static u64 hist_field_bucket(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand = hist_field->operands[0]; |
| unsigned long buckets = hist_field->buckets; |
| |
| u64 val = hist_fn_call(operand, elt, buffer, rbe, event); |
| |
| if (WARN_ON_ONCE(!buckets)) |
| return val; |
| |
| if (val >= LONG_MAX) |
| val = div64_ul(val, buckets); |
| else |
| val = (u64)((unsigned long)val / buckets); |
| return val * buckets; |
| } |
| |
| static u64 hist_field_plus(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand1 = hist_field->operands[0]; |
| struct hist_field *operand2 = hist_field->operands[1]; |
| |
| u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event); |
| u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event); |
| |
| return val1 + val2; |
| } |
| |
| static u64 hist_field_minus(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand1 = hist_field->operands[0]; |
| struct hist_field *operand2 = hist_field->operands[1]; |
| |
| u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event); |
| u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event); |
| |
| return val1 - val2; |
| } |
| |
| static u64 hist_field_div(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand1 = hist_field->operands[0]; |
| struct hist_field *operand2 = hist_field->operands[1]; |
| |
| u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event); |
| u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event); |
| |
| /* Return -1 for the undefined case */ |
| if (!val2) |
| return -1; |
| |
| /* Use shift if the divisor is a power of 2 */ |
| if (!(val2 & (val2 - 1))) |
| return val1 >> __ffs64(val2); |
| |
| return div64_u64(val1, val2); |
| } |
| |
| static u64 div_by_power_of_two(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand1 = hist_field->operands[0]; |
| struct hist_field *operand2 = hist_field->operands[1]; |
| |
| u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event); |
| |
| return val1 >> __ffs64(operand2->constant); |
| } |
| |
| static u64 div_by_not_power_of_two(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand1 = hist_field->operands[0]; |
| struct hist_field *operand2 = hist_field->operands[1]; |
| |
| u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event); |
| |
| return div64_u64(val1, operand2->constant); |
| } |
| |
| static u64 div_by_mult_and_shift(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand1 = hist_field->operands[0]; |
| struct hist_field *operand2 = hist_field->operands[1]; |
| |
| u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event); |
| |
| /* |
| * If the divisor is a constant, do a multiplication and shift instead. |
| * |
| * Choose Z = some power of 2. If Y <= Z, then: |
| * X / Y = (X * (Z / Y)) / Z |
| * |
| * (Z / Y) is a constant (mult) which is calculated at parse time, so: |
| * X / Y = (X * mult) / Z |
| * |
| * The division by Z can be replaced by a shift since Z is a power of 2: |
| * X / Y = (X * mult) >> HIST_DIV_SHIFT |
| * |
| * As long, as X < Z the results will not be off by more than 1. |
| */ |
| if (val1 < (1 << HIST_DIV_SHIFT)) { |
| u64 mult = operand2->div_multiplier; |
| |
| return (val1 * mult + ((1 << HIST_DIV_SHIFT) - 1)) >> HIST_DIV_SHIFT; |
| } |
| |
| return div64_u64(val1, operand2->constant); |
| } |
| |
| static u64 hist_field_mult(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand1 = hist_field->operands[0]; |
| struct hist_field *operand2 = hist_field->operands[1]; |
| |
| u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event); |
| u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event); |
| |
| return val1 * val2; |
| } |
| |
| static u64 hist_field_unary_minus(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_field *operand = hist_field->operands[0]; |
| |
| s64 sval = (s64)hist_fn_call(operand, elt, buffer, rbe, event); |
| u64 val = (u64)-sval; |
| |
| return val; |
| } |
| |
| #define DEFINE_HIST_FIELD_FN(type) \ |
| static u64 hist_field_##type(struct hist_field *hist_field, \ |
| struct tracing_map_elt *elt, \ |
| struct trace_buffer *buffer, \ |
| struct ring_buffer_event *rbe, \ |
| void *event) \ |
| { \ |
| type *addr = (type *)(event + hist_field->field->offset); \ |
| \ |
| return (u64)(unsigned long)*addr; \ |
| } |
| |
| DEFINE_HIST_FIELD_FN(s64); |
| DEFINE_HIST_FIELD_FN(u64); |
| DEFINE_HIST_FIELD_FN(s32); |
| DEFINE_HIST_FIELD_FN(u32); |
| DEFINE_HIST_FIELD_FN(s16); |
| DEFINE_HIST_FIELD_FN(u16); |
| DEFINE_HIST_FIELD_FN(s8); |
| DEFINE_HIST_FIELD_FN(u8); |
| |
| #define for_each_hist_field(i, hist_data) \ |
| for ((i) = 0; (i) < (hist_data)->n_fields; (i)++) |
| |
| #define for_each_hist_val_field(i, hist_data) \ |
| for ((i) = 0; (i) < (hist_data)->n_vals; (i)++) |
| |
| #define for_each_hist_key_field(i, hist_data) \ |
| for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++) |
| |
| #define HITCOUNT_IDX 0 |
| #define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE) |
| |
| enum hist_field_flags { |
| HIST_FIELD_FL_HITCOUNT = 1 << 0, |
| HIST_FIELD_FL_KEY = 1 << 1, |
| HIST_FIELD_FL_STRING = 1 << 2, |
| HIST_FIELD_FL_HEX = 1 << 3, |
| HIST_FIELD_FL_SYM = 1 << 4, |
| HIST_FIELD_FL_SYM_OFFSET = 1 << 5, |
| HIST_FIELD_FL_EXECNAME = 1 << 6, |
| HIST_FIELD_FL_SYSCALL = 1 << 7, |
| HIST_FIELD_FL_STACKTRACE = 1 << 8, |
| HIST_FIELD_FL_LOG2 = 1 << 9, |
| HIST_FIELD_FL_TIMESTAMP = 1 << 10, |
| HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11, |
| HIST_FIELD_FL_VAR = 1 << 12, |
| HIST_FIELD_FL_EXPR = 1 << 13, |
| HIST_FIELD_FL_VAR_REF = 1 << 14, |
| HIST_FIELD_FL_CPU = 1 << 15, |
| HIST_FIELD_FL_ALIAS = 1 << 16, |
| HIST_FIELD_FL_BUCKET = 1 << 17, |
| HIST_FIELD_FL_CONST = 1 << 18, |
| HIST_FIELD_FL_PERCENT = 1 << 19, |
| HIST_FIELD_FL_GRAPH = 1 << 20, |
| }; |
| |
| struct var_defs { |
| unsigned int n_vars; |
| char *name[TRACING_MAP_VARS_MAX]; |
| char *expr[TRACING_MAP_VARS_MAX]; |
| }; |
| |
| struct hist_trigger_attrs { |
| char *keys_str; |
| char *vals_str; |
| char *sort_key_str; |
| char *name; |
| char *clock; |
| bool pause; |
| bool cont; |
| bool clear; |
| bool ts_in_usecs; |
| unsigned int map_bits; |
| |
| char *assignment_str[TRACING_MAP_VARS_MAX]; |
| unsigned int n_assignments; |
| |
| char *action_str[HIST_ACTIONS_MAX]; |
| unsigned int n_actions; |
| |
| struct var_defs var_defs; |
| }; |
| |
| struct field_var { |
| struct hist_field *var; |
| struct hist_field *val; |
| }; |
| |
| struct field_var_hist { |
| struct hist_trigger_data *hist_data; |
| char *cmd; |
| }; |
| |
| struct hist_trigger_data { |
| struct hist_field *fields[HIST_FIELDS_MAX]; |
| unsigned int n_vals; |
| unsigned int n_keys; |
| unsigned int n_fields; |
| unsigned int n_vars; |
| unsigned int n_var_str; |
| unsigned int key_size; |
| struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX]; |
| unsigned int n_sort_keys; |
| struct trace_event_file *event_file; |
| struct hist_trigger_attrs *attrs; |
| struct tracing_map *map; |
| bool enable_timestamps; |
| bool remove; |
| struct hist_field *var_refs[TRACING_MAP_VARS_MAX]; |
| unsigned int n_var_refs; |
| |
| struct action_data *actions[HIST_ACTIONS_MAX]; |
| unsigned int n_actions; |
| |
| struct field_var *field_vars[SYNTH_FIELDS_MAX]; |
| unsigned int n_field_vars; |
| unsigned int n_field_var_str; |
| struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX]; |
| unsigned int n_field_var_hists; |
| |
| struct field_var *save_vars[SYNTH_FIELDS_MAX]; |
| unsigned int n_save_vars; |
| unsigned int n_save_var_str; |
| }; |
| |
| struct action_data; |
| |
| typedef void (*action_fn_t) (struct hist_trigger_data *hist_data, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, void *rec, |
| struct ring_buffer_event *rbe, void *key, |
| struct action_data *data, u64 *var_ref_vals); |
| |
| typedef bool (*check_track_val_fn_t) (u64 track_val, u64 var_val); |
| |
| enum handler_id { |
| HANDLER_ONMATCH = 1, |
| HANDLER_ONMAX, |
| HANDLER_ONCHANGE, |
| }; |
| |
| enum action_id { |
| ACTION_SAVE = 1, |
| ACTION_TRACE, |
| ACTION_SNAPSHOT, |
| }; |
| |
| struct action_data { |
| enum handler_id handler; |
| enum action_id action; |
| char *action_name; |
| action_fn_t fn; |
| |
| unsigned int n_params; |
| char *params[SYNTH_FIELDS_MAX]; |
| |
| /* |
| * When a histogram trigger is hit, the values of any |
| * references to variables, including variables being passed |
| * as parameters to synthetic events, are collected into a |
| * var_ref_vals array. This var_ref_idx array is an array of |
| * indices into the var_ref_vals array, one for each synthetic |
| * event param, and is passed to the synthetic event |
| * invocation. |
| */ |
| unsigned int var_ref_idx[SYNTH_FIELDS_MAX]; |
| struct synth_event *synth_event; |
| bool use_trace_keyword; |
| char *synth_event_name; |
| |
| union { |
| struct { |
| char *event; |
| char *event_system; |
| } match_data; |
| |
| struct { |
| /* |
| * var_str contains the $-unstripped variable |
| * name referenced by var_ref, and used when |
| * printing the action. Because var_ref |
| * creation is deferred to create_actions(), |
| * we need a per-action way to save it until |
| * then, thus var_str. |
| */ |
| char *var_str; |
| |
| /* |
| * var_ref refers to the variable being |
| * tracked e.g onmax($var). |
| */ |
| struct hist_field *var_ref; |
| |
| /* |
| * track_var contains the 'invisible' tracking |
| * variable created to keep the current |
| * e.g. max value. |
| */ |
| struct hist_field *track_var; |
| |
| check_track_val_fn_t check_val; |
| action_fn_t save_data; |
| } track_data; |
| }; |
| }; |
| |
| struct track_data { |
| u64 track_val; |
| bool updated; |
| |
| unsigned int key_len; |
| void *key; |
| struct tracing_map_elt elt; |
| |
| struct action_data *action_data; |
| struct hist_trigger_data *hist_data; |
| }; |
| |
| struct hist_elt_data { |
| char *comm; |
| u64 *var_ref_vals; |
| char **field_var_str; |
| int n_field_var_str; |
| }; |
| |
| struct snapshot_context { |
| struct tracing_map_elt *elt; |
| void *key; |
| }; |
| |
| /* |
| * Returns the specific division function to use if the divisor |
| * is constant. This avoids extra branches when the trigger is hit. |
| */ |
| static enum hist_field_fn hist_field_get_div_fn(struct hist_field *divisor) |
| { |
| u64 div = divisor->constant; |
| |
| if (!(div & (div - 1))) |
| return HIST_FIELD_FN_DIV_POWER2; |
| |
| /* If the divisor is too large, do a regular division */ |
| if (div > (1 << HIST_DIV_SHIFT)) |
| return HIST_FIELD_FN_DIV_NOT_POWER2; |
| |
| divisor->div_multiplier = div64_u64((u64)(1 << HIST_DIV_SHIFT), div); |
| return HIST_FIELD_FN_DIV_MULT_SHIFT; |
| } |
| |
| static void track_data_free(struct track_data *track_data) |
| { |
| struct hist_elt_data *elt_data; |
| |
| if (!track_data) |
| return; |
| |
| kfree(track_data->key); |
| |
| elt_data = track_data->elt.private_data; |
| if (elt_data) { |
| kfree(elt_data->comm); |
| kfree(elt_data); |
| } |
| |
| kfree(track_data); |
| } |
| |
| static struct track_data *track_data_alloc(unsigned int key_len, |
| struct action_data *action_data, |
| struct hist_trigger_data *hist_data) |
| { |
| struct track_data *data = kzalloc(sizeof(*data), GFP_KERNEL); |
| struct hist_elt_data *elt_data; |
| |
| if (!data) |
| return ERR_PTR(-ENOMEM); |
| |
| data->key = kzalloc(key_len, GFP_KERNEL); |
| if (!data->key) { |
| track_data_free(data); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| data->key_len = key_len; |
| data->action_data = action_data; |
| data->hist_data = hist_data; |
| |
| elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL); |
| if (!elt_data) { |
| track_data_free(data); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| data->elt.private_data = elt_data; |
| |
| elt_data->comm = kzalloc(TASK_COMM_LEN, GFP_KERNEL); |
| if (!elt_data->comm) { |
| track_data_free(data); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| return data; |
| } |
| |
| #define HIST_PREFIX "hist:" |
| |
| static char *last_cmd; |
| static char last_cmd_loc[MAX_FILTER_STR_VAL]; |
| |
| static int errpos(char *str) |
| { |
| if (!str || !last_cmd) |
| return 0; |
| |
| return err_pos(last_cmd, str); |
| } |
| |
| static void last_cmd_set(struct trace_event_file *file, char *str) |
| { |
| const char *system = NULL, *name = NULL; |
| struct trace_event_call *call; |
| int len; |
| |
| if (!str) |
| return; |
| |
| /* sizeof() contains the nul byte */ |
| len = sizeof(HIST_PREFIX) + strlen(str); |
| kfree(last_cmd); |
| last_cmd = kzalloc(len, GFP_KERNEL); |
| if (!last_cmd) |
| return; |
| |
| strcpy(last_cmd, HIST_PREFIX); |
| /* Again, sizeof() contains the nul byte */ |
| len -= sizeof(HIST_PREFIX); |
| strncat(last_cmd, str, len); |
| |
| if (file) { |
| call = file->event_call; |
| system = call->class->system; |
| if (system) { |
| name = trace_event_name(call); |
| if (!name) |
| system = NULL; |
| } |
| } |
| |
| if (system) |
| snprintf(last_cmd_loc, MAX_FILTER_STR_VAL, HIST_PREFIX "%s:%s", system, name); |
| } |
| |
| static void hist_err(struct trace_array *tr, u8 err_type, u16 err_pos) |
| { |
| if (!last_cmd) |
| return; |
| |
| tracing_log_err(tr, last_cmd_loc, last_cmd, err_text, |
| err_type, err_pos); |
| } |
| |
| static void hist_err_clear(void) |
| { |
| if (last_cmd) |
| last_cmd[0] = '\0'; |
| last_cmd_loc[0] = '\0'; |
| } |
| |
| typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals, |
| unsigned int *var_ref_idx); |
| |
| static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals, |
| unsigned int *var_ref_idx) |
| { |
| struct tracepoint *tp = event->tp; |
| |
| if (unlikely(atomic_read(&tp->key.enabled) > 0)) { |
| struct tracepoint_func *probe_func_ptr; |
| synth_probe_func_t probe_func; |
| void *__data; |
| |
| if (!(cpu_online(raw_smp_processor_id()))) |
| return; |
| |
| probe_func_ptr = rcu_dereference_sched((tp)->funcs); |
| if (probe_func_ptr) { |
| do { |
| probe_func = probe_func_ptr->func; |
| __data = probe_func_ptr->data; |
| probe_func(__data, var_ref_vals, var_ref_idx); |
| } while ((++probe_func_ptr)->func); |
| } |
| } |
| } |
| |
| static void action_trace(struct hist_trigger_data *hist_data, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, void *rec, |
| struct ring_buffer_event *rbe, void *key, |
| struct action_data *data, u64 *var_ref_vals) |
| { |
| struct synth_event *event = data->synth_event; |
| |
| trace_synth(event, var_ref_vals, data->var_ref_idx); |
| } |
| |
| struct hist_var_data { |
| struct list_head list; |
| struct hist_trigger_data *hist_data; |
| }; |
| |
| static u64 hist_field_timestamp(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_trigger_data *hist_data = hist_field->hist_data; |
| struct trace_array *tr = hist_data->event_file->tr; |
| |
| u64 ts = ring_buffer_event_time_stamp(buffer, rbe); |
| |
| if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr)) |
| ts = ns2usecs(ts); |
| |
| return ts; |
| } |
| |
| static u64 hist_field_cpu(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| int cpu = smp_processor_id(); |
| |
| return cpu; |
| } |
| |
| /** |
| * check_field_for_var_ref - Check if a VAR_REF field references a variable |
| * @hist_field: The VAR_REF field to check |
| * @var_data: The hist trigger that owns the variable |
| * @var_idx: The trigger variable identifier |
| * |
| * Check the given VAR_REF field to see whether or not it references |
| * the given variable associated with the given trigger. |
| * |
| * Return: The VAR_REF field if it does reference the variable, NULL if not |
| */ |
| static struct hist_field * |
| check_field_for_var_ref(struct hist_field *hist_field, |
| struct hist_trigger_data *var_data, |
| unsigned int var_idx) |
| { |
| WARN_ON(!(hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF)); |
| |
| if (hist_field && hist_field->var.idx == var_idx && |
| hist_field->var.hist_data == var_data) |
| return hist_field; |
| |
| return NULL; |
| } |
| |
| /** |
| * find_var_ref - Check if a trigger has a reference to a trigger variable |
| * @hist_data: The hist trigger that might have a reference to the variable |
| * @var_data: The hist trigger that owns the variable |
| * @var_idx: The trigger variable identifier |
| * |
| * Check the list of var_refs[] on the first hist trigger to see |
| * whether any of them are references to the variable on the second |
| * trigger. |
| * |
| * Return: The VAR_REF field referencing the variable if so, NULL if not |
| */ |
| static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data, |
| struct hist_trigger_data *var_data, |
| unsigned int var_idx) |
| { |
| struct hist_field *hist_field; |
| unsigned int i; |
| |
| for (i = 0; i < hist_data->n_var_refs; i++) { |
| hist_field = hist_data->var_refs[i]; |
| if (check_field_for_var_ref(hist_field, var_data, var_idx)) |
| return hist_field; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * find_any_var_ref - Check if there is a reference to a given trigger variable |
| * @hist_data: The hist trigger |
| * @var_idx: The trigger variable identifier |
| * |
| * Check to see whether the given variable is currently referenced by |
| * any other trigger. |
| * |
| * The trigger the variable is defined on is explicitly excluded - the |
| * assumption being that a self-reference doesn't prevent a trigger |
| * from being removed. |
| * |
| * Return: The VAR_REF field referencing the variable if so, NULL if not |
| */ |
| static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data, |
| unsigned int var_idx) |
| { |
| struct trace_array *tr = hist_data->event_file->tr; |
| struct hist_field *found = NULL; |
| struct hist_var_data *var_data; |
| |
| list_for_each_entry(var_data, &tr->hist_vars, list) { |
| if (var_data->hist_data == hist_data) |
| continue; |
| found = find_var_ref(var_data->hist_data, hist_data, var_idx); |
| if (found) |
| break; |
| } |
| |
| return found; |
| } |
| |
| /** |
| * check_var_refs - Check if there is a reference to any of trigger's variables |
| * @hist_data: The hist trigger |
| * |
| * A trigger can define one or more variables. If any one of them is |
| * currently referenced by any other trigger, this function will |
| * determine that. |
| * |
| * Typically used to determine whether or not a trigger can be removed |
| * - if there are any references to a trigger's variables, it cannot. |
| * |
| * Return: True if there is a reference to any of trigger's variables |
| */ |
| static bool check_var_refs(struct hist_trigger_data *hist_data) |
| { |
| struct hist_field *field; |
| bool found = false; |
| int i; |
| |
| for_each_hist_field(i, hist_data) { |
| field = hist_data->fields[i]; |
| if (field && field->flags & HIST_FIELD_FL_VAR) { |
| if (find_any_var_ref(hist_data, field->var.idx)) { |
| found = true; |
| break; |
| } |
| } |
| } |
| |
| return found; |
| } |
| |
| static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data) |
| { |
| struct trace_array *tr = hist_data->event_file->tr; |
| struct hist_var_data *var_data, *found = NULL; |
| |
| list_for_each_entry(var_data, &tr->hist_vars, list) { |
| if (var_data->hist_data == hist_data) { |
| found = var_data; |
| break; |
| } |
| } |
| |
| return found; |
| } |
| |
| static bool field_has_hist_vars(struct hist_field *hist_field, |
| unsigned int level) |
| { |
| int i; |
| |
| if (level > 3) |
| return false; |
| |
| if (!hist_field) |
| return false; |
| |
| if (hist_field->flags & HIST_FIELD_FL_VAR || |
| hist_field->flags & HIST_FIELD_FL_VAR_REF) |
| return true; |
| |
| for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) { |
| struct hist_field *operand; |
| |
| operand = hist_field->operands[i]; |
| if (field_has_hist_vars(operand, level + 1)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static bool has_hist_vars(struct hist_trigger_data *hist_data) |
| { |
| struct hist_field *hist_field; |
| int i; |
| |
| for_each_hist_field(i, hist_data) { |
| hist_field = hist_data->fields[i]; |
| if (field_has_hist_vars(hist_field, 0)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static int save_hist_vars(struct hist_trigger_data *hist_data) |
| { |
| struct trace_array *tr = hist_data->event_file->tr; |
| struct hist_var_data *var_data; |
| |
| var_data = find_hist_vars(hist_data); |
| if (var_data) |
| return 0; |
| |
| if (tracing_check_open_get_tr(tr)) |
| return -ENODEV; |
| |
| var_data = kzalloc(sizeof(*var_data), GFP_KERNEL); |
| if (!var_data) { |
| trace_array_put(tr); |
| return -ENOMEM; |
| } |
| |
| var_data->hist_data = hist_data; |
| list_add(&var_data->list, &tr->hist_vars); |
| |
| return 0; |
| } |
| |
| static void remove_hist_vars(struct hist_trigger_data *hist_data) |
| { |
| struct trace_array *tr = hist_data->event_file->tr; |
| struct hist_var_data *var_data; |
| |
| var_data = find_hist_vars(hist_data); |
| if (!var_data) |
| return; |
| |
| if (WARN_ON(check_var_refs(hist_data))) |
| return; |
| |
| list_del(&var_data->list); |
| |
| kfree(var_data); |
| |
| trace_array_put(tr); |
| } |
| |
| static struct hist_field *find_var_field(struct hist_trigger_data *hist_data, |
| const char *var_name) |
| { |
| struct hist_field *hist_field, *found = NULL; |
| int i; |
| |
| for_each_hist_field(i, hist_data) { |
| hist_field = hist_data->fields[i]; |
| if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR && |
| strcmp(hist_field->var.name, var_name) == 0) { |
| found = hist_field; |
| break; |
| } |
| } |
| |
| return found; |
| } |
| |
| static struct hist_field *find_var(struct hist_trigger_data *hist_data, |
| struct trace_event_file *file, |
| const char *var_name) |
| { |
| struct hist_trigger_data *test_data; |
| struct event_trigger_data *test; |
| struct hist_field *hist_field; |
| |
| lockdep_assert_held(&event_mutex); |
| |
| hist_field = find_var_field(hist_data, var_name); |
| if (hist_field) |
| return hist_field; |
| |
| list_for_each_entry(test, &file->triggers, list) { |
| if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { |
| test_data = test->private_data; |
| hist_field = find_var_field(test_data, var_name); |
| if (hist_field) |
| return hist_field; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static struct trace_event_file *find_var_file(struct trace_array *tr, |
| char *system, |
| char *event_name, |
| char *var_name) |
| { |
| struct hist_trigger_data *var_hist_data; |
| struct hist_var_data *var_data; |
| struct trace_event_file *file, *found = NULL; |
| |
| if (system) |
| return find_event_file(tr, system, event_name); |
| |
| list_for_each_entry(var_data, &tr->hist_vars, list) { |
| var_hist_data = var_data->hist_data; |
| file = var_hist_data->event_file; |
| if (file == found) |
| continue; |
| |
| if (find_var_field(var_hist_data, var_name)) { |
| if (found) { |
| hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE, errpos(var_name)); |
| return NULL; |
| } |
| |
| found = file; |
| } |
| } |
| |
| return found; |
| } |
| |
| static struct hist_field *find_file_var(struct trace_event_file *file, |
| const char *var_name) |
| { |
| struct hist_trigger_data *test_data; |
| struct event_trigger_data *test; |
| struct hist_field *hist_field; |
| |
| lockdep_assert_held(&event_mutex); |
| |
| list_for_each_entry(test, &file->triggers, list) { |
| if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { |
| test_data = test->private_data; |
| hist_field = find_var_field(test_data, var_name); |
| if (hist_field) |
| return hist_field; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static struct hist_field * |
| find_match_var(struct hist_trigger_data *hist_data, char *var_name) |
| { |
| struct trace_array *tr = hist_data->event_file->tr; |
| struct hist_field *hist_field, *found = NULL; |
| struct trace_event_file *file; |
| unsigned int i; |
| |
| for (i = 0; i < hist_data->n_actions; i++) { |
| struct action_data *data = hist_data->actions[i]; |
| |
| if (data->handler == HANDLER_ONMATCH) { |
| char *system = data->match_data.event_system; |
| char *event_name = data->match_data.event; |
| |
| file = find_var_file(tr, system, event_name, var_name); |
| if (!file) |
| continue; |
| hist_field = find_file_var(file, var_name); |
| if (hist_field) { |
| if (found) { |
| hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE, |
| errpos(var_name)); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| found = hist_field; |
| } |
| } |
| } |
| return found; |
| } |
| |
| static struct hist_field *find_event_var(struct hist_trigger_data *hist_data, |
| char *system, |
| char *event_name, |
| char *var_name) |
| { |
| struct trace_array *tr = hist_data->event_file->tr; |
| struct hist_field *hist_field = NULL; |
| struct trace_event_file *file; |
| |
| if (!system || !event_name) { |
| hist_field = find_match_var(hist_data, var_name); |
| if (IS_ERR(hist_field)) |
| return NULL; |
| if (hist_field) |
| return hist_field; |
| } |
| |
| file = find_var_file(tr, system, event_name, var_name); |
| if (!file) |
| return NULL; |
| |
| hist_field = find_file_var(file, var_name); |
| |
| return hist_field; |
| } |
| |
| static u64 hist_field_var_ref(struct hist_field *hist_field, |
| struct tracing_map_elt *elt, |
| struct trace_buffer *buffer, |
| struct ring_buffer_event *rbe, |
| void *event) |
| { |
| struct hist_elt_data *elt_data; |
| u64 var_val = 0; |
| |
| if (WARN_ON_ONCE(!elt)) |
| return var_val; |
| |
| elt_data = elt->private_data; |
| var_val = elt_data->var_ref_vals[hist_field->var_ref_idx]; |
| |
| return var_val; |
| } |
| |
| static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key, |
| u64 *var_ref_vals, bool self) |
| { |
| struct hist_trigger_data *var_data; |
| struct tracing_map_elt *var_elt; |
| struct hist_field *hist_field; |
| unsigned int i, var_idx; |
| bool resolved = true; |
| u64 var_val = 0; |
| |
| for (i = 0; i < hist_data->n_var_refs; i++) { |
| hist_field = hist_data->var_refs[i]; |
| var_idx = hist_field->var.idx; |
| var_data = hist_field->var.hist_data; |
| |
| if (var_data == NULL) { |
| resolved = false; |
| break; |
| } |
| |
| if ((self && var_data != hist_data) || |
| (!self && var_data == hist_data)) |
| continue; |
| |
| var_elt = tracing_map_lookup(var_data->map, key); |
| if (!var_elt) { |
| resolved = false; |
| break; |
| } |
| |
| if (!tracing_map_var_set(var_elt, var_idx)) { |
| resolved = false; |
| break; |
| } |
| |
| if (self || !hist_field->read_once) |
| var_val = tracing_map_read_var(var_elt, var_idx); |
| else |
| var_val = tracing_map_read_var_once(var_elt, var_idx); |
| |
| var_ref_vals[i] = var_val; |
| } |
| |
| return resolved; |
| } |
| |
| static const char *hist_field_name(struct hist_field *field, |
| unsigned int level) |
| { |
| const char *field_name = ""; |
| |
| if (WARN_ON_ONCE(!field)) |
| return field_name; |
| |
| if (level > 1) |
| return field_name; |
| |
| if (field->field) |
| field_name = field->field->name; |
| else if (field->flags & HIST_FIELD_FL_LOG2 || |
| field->flags & HIST_FIELD_FL_ALIAS || |
| field->flags & HIST_FIELD_FL_BUCKET) |
| field_name = hist_field_name(field->operands[0], ++level); |
| else if (field->flags & HIST_FIELD_FL_CPU) |
| field_name = "common_cpu"; |
| else if (field->flags & HIST_FIELD_FL_EXPR || |
| field->flags & HIST_FIELD_FL_VAR_REF) { |
| if (field->system) { |
| static char full_name[MAX_FILTER_STR_VAL]; |
| |
| strcat(full_name, field->system); |
| strcat(full_name, "."); |
| strcat(full_name, field->event_name); |
| strcat(full_name, "."); |
| strcat(full_name, field->name); |
| field_name = full_name; |
| } else |
| field_name = field->name; |
| } else if (field->flags & HIST_FIELD_FL_TIMESTAMP) |
| field_name = "common_timestamp"; |
| |
| if (field_name == NULL) |
| field_name = ""; |
| |
| return field_name; |
| } |
| |
| static enum hist_field_fn select_value_fn(int field_size, int field_is_signed) |
| { |
| switch (field_size) { |
| case 8: |
| if (field_is_signed) |
| return HIST_FIELD_FN_S64; |
| else |
| return HIST_FIELD_FN_U64; |
| case 4: |
| if (field_is_signed) |
| return HIST_FIELD_FN_S32; |
| else |
| return HIST_FIELD_FN_U32; |
| case 2: |
| if (field_is_signed) |
| return HIST_FIELD_FN_S16; |
| else |
| return HIST_FIELD_FN_U16; |
| case 1: |
| if (field_is_signed) |
| return HIST_FIELD_FN_S8; |
| else |
| return HIST_FIELD_FN_U8; |
| } |
| |
| return HIST_FIELD_FN_NOP; |
| } |
| |
| static int parse_map_size(char *str) |
| { |
| unsigned long size, map_bits; |
| int ret; |
| |
| ret = kstrtoul(str, 0, &size); |
| if (ret) |
| goto out; |
| |
| map_bits = ilog2(roundup_pow_of_two(size)); |
| if (map_bits < TRACING_MAP_BITS_MIN || |
| map_bits > TRACING_MAP_BITS_MAX) |
| ret = -EINVAL; |
| else |
| ret = map_bits; |
| out: |
| return ret; |
| } |
| |
| static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) |
| { |
| unsigned int i; |
| |
| if (!attrs) |
| return; |
| |
| for (i = 0; i < attrs->n_assignments; i++) |
| kfree(attrs->assignment_str[i]); |
| |
| for (i = 0; i < attrs->n_actions; i++) |
| kfree(attrs->action_str[i]); |
| |
| kfree(attrs->name); |
| kfree(attrs->sort_key_str); |
| kfree(attrs->keys_str); |
| kfree(attrs->vals_str); |
| kfree(attrs->clock); |
| kfree(attrs); |
| } |
| |
| static int parse_action(char *str, struct hist_trigger_attrs *attrs) |
| { |
| int ret = -EINVAL; |
| |
| if (attrs->n_actions >= HIST_ACTIONS_MAX) |
| return ret; |
| |
| if ((str_has_prefix(str, "onmatch(")) || |
| (str_has_prefix(str, "onmax(")) || |
| (str_has_prefix(str, "onchange("))) { |
| attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL); |
| if (!attrs->action_str[attrs->n_actions]) { |
| ret = -ENOMEM; |
| return ret; |
| } |
| attrs->n_actions++; |
| ret = 0; |
| } |
| return ret; |
| } |
| |
| static int parse_assignment(struct trace_array *tr, |
| char *str, struct hist_trigger_attrs *attrs) |
| { |
| int len, ret = 0; |
| |
| if ((len = str_has_prefix(str, "key=")) || |
| (len = str_has_prefix(str, "keys="))) { |
| attrs->keys_str = kstrdup(str + len, GFP_KERNEL); |
| if (!attrs->keys_str) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } else if ((len = str_has_prefix(str, "val=")) || |
| (len = str_has_prefix(str, "vals=")) || |
| (len = str_has_prefix(str, "values="))) { |
| attrs->vals_str = kstrdup(str + len, GFP_KERNEL); |
| if (!attrs->vals_str) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } else if ((len = str_has_prefix(str, "sort="))) { |
| attrs->sort_key_str = kstrdup(str + len, GFP_KERNEL); |
| if (!attrs->sort_key_str) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } else if (str_has_prefix(str, "name=")) { |
| attrs->name = kstrdup(str, GFP_KERNEL); |
| if (!attrs->name) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } else if ((len = str_has_prefix(str, "clock="))) { |
| str += len; |
| |
| str = strstrip(str); |
| attrs->clock = kstrdup(str, GFP_KERNEL); |
| if (!attrs->clock) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } else if ((len = str_has_prefix(str, "size="))) { |
| int map_bits = parse_map_size(str + len); |
| |
| if (map_bits < 0) { |
| ret = map_bits; |
| goto out; |
| } |
| attrs->map_bits = map_bits; |
| } else { |
| char *assignment; |
| |
| if (attrs->n_assignments == TRACING_MAP_VARS_MAX) { |
| hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(str)); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| assignment = kstrdup(str, GFP_KERNEL); |
| if (!assignment) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| attrs->assignment_str[attrs->n_assignments++] = assignment; |
| } |
| out: |
| return ret; |
| } |
| |
| static struct hist_trigger_attrs * |
| parse_hist_trigger_attrs(struct trace_array *tr, char *trigger_str) |
| { |
| struct hist_trigger_attrs *attrs; |
| int ret = 0; |
| |
| attrs = kzalloc(sizeof(*attrs), GFP_KERNEL); |
| if (!attrs) |
| return ERR_PTR(-ENOMEM); |
| |
| while (trigger_str) { |
| char *str = strsep(&trigger_str, ":"); |
| char *rhs; |
| |
| rhs = strchr(str, '='); |
| if (rhs) { |
| if (!strlen(++rhs)) { |
| ret = -EINVAL; |
| hist_err(tr, HIST_ERR_EMPTY_ASSIGNMENT, errpos(str)); |
| goto free; |
| } |
| ret = parse_assignment(tr, str, attrs); |
| if (ret) |
| goto free; |
| } else if (strcmp(str, "pause") == 0) |
| attrs->pause = true; |
| else if ((strcmp(str, "cont") == 0) || |
| (strcmp(str, "continue") == 0)) |
| attrs->cont = true; |
| else if (strcmp(str, "clear") == 0) |
| attrs->clear = true; |
| else { |
| ret = parse_action(str, attrs); |
| if (ret) |
| goto free; |
| } |
| } |
| |
| if (!attrs->keys_str) { |
| ret = -EINVAL; |
| goto free; |
| } |
| |
| if (!attrs->clock) { |
| attrs->clock = kstrdup("global", GFP_KERNEL); |
| if (!attrs->clock) { |
| ret = -ENOMEM; |
| goto free; |
| } |
| } |
| |
| return attrs; |
| free: |
| destroy_hist_trigger_attrs(attrs); |
| |
| return ERR_PTR(ret); |
| } |
| |
| static inline void save_comm(char *comm, struct task_struct *task) |
| { |
| if (!task->pid) { |
| strcpy(comm, "<idle>"); |
| return; |
| } |
| |
| if (WARN_ON_ONCE(task->pid < 0)) { |
| strcpy(comm, "<XXX>"); |
| return; |
| } |
| |
| strncpy(comm, task->comm, TASK_COMM_LEN); |
| } |
| |
| static void hist_elt_data_free(struct hist_elt_data *elt_data) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < elt_data->n_field_var_str; i++) |
| kfree(elt_data->field_var_str[i]); |
| |
| kfree(elt_data->field_var_str); |
| |
| kfree(elt_data->comm); |
| kfree(elt_data); |
| } |
| |
| static void hist_trigger_elt_data_free(struct tracing_map_elt *elt) |
| { |
| struct hist_elt_data *elt_data = elt->private_data; |
| |
| hist_elt_data_free(elt_data); |
| } |
| |
| static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt) |
| { |
| struct hist_trigger_data *hist_data = elt->map->private_data; |
| unsigned int size = TASK_COMM_LEN; |
| struct hist_elt_data *elt_data; |
| struct hist_field *hist_field; |
| unsigned int i, n_str; |
| |
| elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL); |
| if (!elt_data) |
| return -ENOMEM; |
| |
| for_each_hist_field(i, hist_data) { |
| hist_field = hist_data->fields[i]; |
| |
| if (hist_field->flags & HIST_FIELD_FL_EXECNAME) { |
| elt_data->comm = kzalloc(size, GFP_KERNEL); |
| if (!elt_data->comm) { |
| kfree(elt_data); |
| return -ENOMEM; |
| } |
| break; |
| } |
| } |
| |
| n_str = hist_data->n_field_var_str + hist_data->n_save_var_str + |
| hist_data->n_var_str; |
| if (n_str > SYNTH_FIELDS_MAX) { |
| hist_elt_data_free(elt_data); |
| return -EINVAL; |
| } |
| |
| BUILD_BUG_ON(STR_VAR_LEN_MAX & (sizeof(u64) - 1)); |
| |
| size = STR_VAR_LEN_MAX; |
| |
| elt_data->field_var_str = kcalloc(n_str, sizeof(char *), GFP_KERNEL); |
| if (!elt_data->field_var_str) { |
| hist_elt_data_free(elt_data); |
| return -EINVAL; |
| } |
| elt_data->n_field_var_str = n_str; |
| |
| for (i = 0; i < n_str; i++) { |
| elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL); |
| if (!elt_data->field_var_str[i]) { |
| hist_elt_data_free(elt_data); |
| return -ENOMEM; |
| } |
| } |
| |
| elt->private_data = elt_data; |
| |
| return 0; |
| } |
| |
| static void hist_trigger_elt_data_init(struct tracing_map_elt *elt) |
| { |
| struct hist_elt_data *elt_data = elt->private_data; |
| |
| if (elt_data->comm) |
| save_comm(elt_data->comm, current); |
| } |
| |
| static const struct tracing_map_ops hist_trigger_elt_data_ops = { |
| .elt_alloc = hist_trigger_elt_data_alloc, |
| .elt_free = hist_trigger_elt_data_free, |
| .elt_init = hist_trigger_elt_data_init, |
| }; |
| |
| static const char *get_hist_field_flags(struct hist_field *hist_field) |
| { |
| const char *flags_str = NULL; |
| |
| if (hist_field->flags & HIST_FIELD_FL_HEX) |
| flags_str = "hex"; |
| else if (hist_field->flags & HIST_FIELD_FL_SYM) |
| flags_str = "sym"; |
| else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET) |
| flags_str = "sym-offset"; |
| else if (hist_field->flags & HIST_FIELD_FL_EXECNAME) |
| flags_str = "execname"; |
| else if (hist_field->flags & HIST_FIELD_FL_SYSCALL) |
| flags_str = "syscall"; |
| else if (hist_field->flags & HIST_FIELD_FL_LOG2) |
| flags_str = "log2"; |
| else if (hist_field->flags & HIST_FIELD_FL_BUCKET) |
| flags_str = "buckets"; |
| else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS) |
| flags_str = "usecs"; |
| else if (hist_field->flags & HIST_FIELD_FL_PERCENT) |
| flags_str = "percent"; |
| else if (hist_field->flags & HIST_FIELD_FL_GRAPH) |
| flags_str = "graph"; |
| |
| return flags_str; |
| } |
| |
| static void expr_field_str(struct hist_field *field, char *expr) |
| { |
| if (field->flags & HIST_FIELD_FL_VAR_REF) |
| strcat(expr, "$"); |
| else if (field->flags & HIST_FIELD_FL_CONST) { |
| char str[HIST_CONST_DIGITS_MAX]; |
| |
| snprintf(str, HIST_CONST_DIGITS_MAX, "%llu", field->constant); |
| strcat(expr, str); |
| } |
| |
| strcat(expr, hist_field_name(field, 0)); |
| |
| if (field->flags && !(field->flags & HIST_FIELD_FL_VAR_REF)) { |
| const char *flags_str = get_hist_field_flags(field); |
| |
| if (flags_str) { |
| strcat(expr, "."); |
| strcat(expr, flags_str); |
| } |
| } |
| } |
| |
| static char *expr_str(struct hist_field *field, unsigned int level) |
| { |
| char *expr; |
| |
| if (level > 1) |
| return NULL; |
| |
| expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); |
| if (!expr) |
| return NULL; |
| |
| if (!field->operands[0]) { |
| expr_field_str(field, expr); |
| return expr; |
| } |
| |
| if (field->operator == FIELD_OP_UNARY_MINUS) { |
| char *subexpr; |
| |
| strcat(expr, "-("); |
| subexpr = expr_str(field->operands[0], ++level); |
| if (!subexpr) { |
| kfree(expr); |
| return NULL; |
| } |
| strcat(expr, subexpr); |
| strcat(expr, ")"); |
| |
| kfree(subexpr); |
| |
| return expr; |
| } |
| |
| expr_field_str(field->operands[0], expr); |
| |
| switch (field->operator) { |
| case FIELD_OP_MINUS: |
| strcat(expr, "-"); |
| break; |
| case FIELD_OP_PLUS: |
| strcat(expr, "+"); |
| break; |
| case FIELD_OP_DIV: |
| strcat(expr, "/"); |
| break; |
| case FIELD_OP_MULT: |
| strcat(expr, "*"); |
| break; |
| default: |
| kfree(expr); |
| return NULL; |
| } |
| |
| expr_field_str(field->operands[1], expr); |
| |
| return expr; |
| } |
| |
| /* |
| * If field_op != FIELD_OP_NONE, *sep points to the root operator |
| * of the expression tree to be evaluated. |
| */ |
| static int contains_operator(char *str, char **sep) |
| { |
| enum field_op_id field_op = FIELD_OP_NONE; |
| char *minus_op, *plus_op, *div_op, *mult_op; |
| |
| |
| /* |
| * Report the last occurrence of the operators first, so that the |
| * expression is evaluated left to right. This is important since |
| * subtraction and division are not associative. |
| * |
| * e.g |
| * 64/8/4/2 is 1, i.e 64/8/4/2 = ((64/8)/4)/2 |
| * 14-7-5-2 is 0, i.e 14-7-5-2 = ((14-7)-5)-2 |
| */ |
| |
| /* |
| * First, find lower precedence addition and subtraction |
| * since the expression will be evaluated recursively. |
| */ |
| minus_op = strrchr(str, '-'); |
| if (minus_op) { |
| /* |
| * Unary minus is not supported in sub-expressions. If |
| * present, it is always the next root operator. |
| */ |
| if (minus_op == str) { |
| field_op = FIELD_OP_UNARY_MINUS; |
| goto out; |
| } |
| |
| field_op = FIELD_OP_MINUS; |
| } |
| |
| plus_op = strrchr(str, '+'); |
| if (plus_op || minus_op) { |
| /* |
| * For operators of the same precedence use to rightmost as the |
| * root, so that the expression is evaluated left to right. |
| */ |
| if (plus_op > minus_op) |
| field_op = FIELD_OP_PLUS; |
| goto out; |
| } |
| |
| /* |
| * Multiplication and division have higher precedence than addition and |
| * subtraction. |
| */ |
| div_op = strrchr(str, '/'); |
| if (div_op) |
| field_op = FIELD_OP_DIV; |
| |
| mult_op = strrchr(str, '*'); |
| /* |
| * For operators of the same precedence use to rightmost as the |
| * root, so that the expression is evaluated left to right. |
| */ |
| if (mult_op > div_op) |
| field_op = FIELD_OP_MULT; |
| |
| out: |
| if (sep) { |
| switch (field_op) { |
| case FIELD_OP_UNARY_MINUS: |
| case FIELD_OP_MINUS: |
| *sep = minus_op; |
| break; |
| case FIELD_OP_PLUS: |
| *sep = plus_op; |
| break; |
| case FIELD_OP_DIV: |
| *sep = div_op; |
| break; |
| case FIELD_OP_MULT: |
| *sep = mult_op; |
| break; |
| case FIELD_OP_NONE: |
| default: |
| *sep = NULL; |
| break; |
| } |
| } |
| |
| return field_op; |
| } |
| |
| static void get_hist_field(struct hist_field *hist_field) |
| { |
| hist_field->ref++; |
| } |
| |
| static void __destroy_hist_field(struct hist_field *hist_field) |
| { |
| if (--hist_field->ref > 1) |
| return; |
| |
| kfree(hist_field->var.name); |
| kfree(hist_field->name); |
| |
| /* Can likely be a const */ |
| kfree_const(hist_field->type); |
| |
| kfree(hist_field->system); |
| kfree(hist_field->event_name); |
| |
| kfree(hist_field); |
| } |
| |
| static void destroy_hist_field(struct hist_field *hist_field, |
| unsigned int level) |
| { |
| unsigned int i; |
| |
| if (level > 3) |
| return; |
| |
| if (!hist_field) |
| return; |
| |
| if (hist_field->flags & HIST_FIELD_FL_VAR_REF) |
| return; /* var refs will be destroyed separately */ |
| |
| for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) |
| destroy_hist_field(hist_field->operands[i], level + 1); |
| |
| __destroy_hist_field(hist_field); |
| } |
| |
| static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, |
| struct ftrace_event_field *field, |
| unsigned long flags, |
| char *var_name) |
| { |
| struct hist_field *hist_field; |
| |
| if (field && is_function_field(field)) |
| return NULL; |
| |
| hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL); |
| if (!hist_field) |
| return NULL; |
| |
| hist_field->ref = 1; |
| |
| hist_field->hist_data = hist_data; |
| |
| if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS) |
| goto out; /* caller will populate */ |
| |
| if (flags & HIST_FIELD_FL_VAR_REF) { |
| hist_field->fn_num = HIST_FIELD_FN_VAR_REF; |
| goto out; |
| } |
| |
| if (flags & HIST_FIELD_FL_HITCOUNT) { |
| hist_field->fn_num = HIST_FIELD_FN_COUNTER; |
| hist_field->size = sizeof(u64); |
| hist_field->type = "u64"; |
| goto out; |
| } |
| |
| if (flags & HIST_FIELD_FL_CONST) { |
| hist_field->fn_num = HIST_FIELD_FN_CONST; |
| hist_field->size = sizeof(u64); |
| hist_field->type = kstrdup("u64", GFP_KERNEL); |
| if (!hist_field->type) |
| goto free; |
| goto out; |
| } |
| |
| if (flags & HIST_FIELD_FL_STACKTRACE) { |
| hist_field->fn_num = HIST_FIELD_FN_NOP; |
| goto out; |
| } |
| |
| if (flags & (HIST_FIELD_FL_LOG2 | HIST_FIELD_FL_BUCKET)) { |
| unsigned long fl = flags & ~(HIST_FIELD_FL_LOG2 | HIST_FIELD_FL_BUCKET); |
| hist_field->fn_num = flags & HIST_FIELD_FL_LOG2 ? HIST_FIELD_FN_LOG2 : |
| HIST_FIELD_FN_BUCKET; |
| hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL); |
| if (!hist_field->operands[0]) |
| goto free; |
| hist_field->size = hist_field->operands[0]->size; |
| hist_field->type = kstrdup_const(hist_field->operands[0]->type, GFP_KERNEL); |
| if (!hist_field->type) |
| goto free; |
| goto out; |
| } |
| |
| if (flags & HIST_FIELD_FL_TIMESTAMP) { |
| hist_field->fn_num = HIST_FIELD_FN_TIMESTAMP; |
| hist_field->size = sizeof(u64); |
| hist_field->type = "u64"; |
| goto out; |
| } |
| |
| if (flags & HIST_FIELD_FL_CPU) { |
| hist_field->fn_num = HIST_FIELD_FN_CPU; |
| hist_field->size = sizeof(int); |
| hist_field->type = "unsigned int"; |
| goto out; |
| } |
| |
| if (WARN_ON_ONCE(!field)) |
| goto out; |
| |
| /* Pointers to strings are just pointers and dangerous to dereference */ |
| if (is_string_field(field) && |
| (field->filter_type != FILTER_PTR_STRING)) { |
| flags |= HIST_FIELD_FL_STRING; |
| |
| hist_field->size = MAX_FILTER_STR_VAL; |
| hist_field->type = kstrdup_const(field->type, GFP_KERNEL); |
| if (!hist_field->type) |
| goto free; |
| |
| if (field->filter_type == FILTER_STATIC_STRING) { |
| hist_field->fn_num = HIST_FIELD_FN_STRING; |
| hist_field->size = field->size; |
| } else if (field->filter_type == FILTER_DYN_STRING) { |
| hist_field->fn_num = HIST_FIELD_FN_DYNSTRING; |
| } else if (field->filter_type == FILTER_RDYN_STRING) |
| hist_field->fn_num = HIST_FIELD_FN_RELDYNSTRING; |
| else |
| hist_field->fn_num = HIST_FIELD_FN_PSTRING; |
| } else { |
| hist_field->size = field->size; |
| hist_field->is_signed = field->is_signed; |
| hist_field->type = kstrdup_const(field->type, GFP_KERNEL); |
| if (!hist_field->type) |
| goto free; |
| |
| hist_field->fn_num = select_value_fn(field->size, |
| field->is_signed); |
| if (hist_field->fn_num == HIST_FIELD_FN_NOP) { |
| destroy_hist_field(hist_field, 0); |
| return NULL; |
| } |
| } |
| out: |
| hist_field->field = field; |
| hist_field->flags = flags; |
| |
| if (var_name) { |
| hist_field->var.name = kstrdup(var_name, GFP_KERNEL); |
| if (!hist_field->var.name) |
| goto free; |
| } |
| |
| return hist_field; |
| free: |
| destroy_hist_field(hist_field, 0); |
| return NULL; |
| } |
| |
| static void destroy_hist_fields(struct hist_trigger_data *hist_data) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < HIST_FIELDS_MAX; i++) { |
| if (hist_data->fields[i]) { |
| destroy_hist_field(hist_data->fields[i], 0); |
| hist_data->fields[i] = NULL; |
| } |
| } |
| |
| for (i = 0; i < hist_data->n_var_refs; i++) { |
| WARN_ON(!(hist_data->var_refs[i]->flags & HIST_FIELD_FL_VAR_REF)); |
| __destroy_hist_field(hist_data->var_refs[i]); |
| hist_data->var_refs[i] = NULL; |
| } |
| } |
| |
| static int init_var_ref(struct hist_field *ref_field, |
| struct hist_field *var_field, |
| char *system, char *event_name) |
| { |
| int err = 0; |
| |
| ref_field->var.idx = var_field->var.idx; |
| ref_field->var.hist_data = var_field->hist_data; |
| ref_field->size = var_field->size; |
| ref_field->is_signed = var_field->is_signed; |
| ref_field->flags |= var_field->flags & |
| (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); |
| |
| if (system) { |
| ref_field->system = kstrdup(system, GFP_KERNEL); |
| if (!ref_field->system) |
| return -ENOMEM; |
| } |
| |
| if (event_name) { |
| ref_field->event_name = kstrdup(event_name, GFP_KERNEL); |
| if (!ref_field->event_name) { |
| err = -ENOMEM; |
| goto free; |
| } |
| } |
| |
| if (var_field->var.name) { |
| ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL); |
| if (!ref_field->name) { |
| err = -ENOMEM; |
| goto free; |
| } |
| } else if (var_field->name) { |
| ref_field->name = kstrdup(var_field->name, GFP_KERNEL); |
| if (!ref_field->name) { |
| err = -ENOMEM; |
| goto free; |
| } |
| } |
| |
| ref_field->type = kstrdup_const(var_field->type, GFP_KERNEL); |
| if (!ref_field->type) { |
| err = -ENOMEM; |
| goto free; |
| } |
| out: |
| return err; |
| free: |
| kfree(ref_field->system); |
| ref_field->system = NULL; |
| kfree(ref_field->event_name); |
| ref_field->event_name = NULL; |
| kfree(ref_field->name); |
| ref_field->name = NULL; |
| |
| goto out; |
| } |
| |
| static int find_var_ref_idx(struct hist_trigger_data *hist_data, |
| struct hist_field *var_field) |
| { |
| struct hist_field *ref_field; |
| int i; |
| |
| for (i = 0; i < hist_data->n_var_refs; i++) { |
| ref_field = hist_data->var_refs[i]; |
| if (ref_field->var.idx == var_field->var.idx && |
| ref_field->var.hist_data == var_field->hist_data) |
| return i; |
| } |
| |
| return -ENOENT; |
| } |
| |
| /** |
| * create_var_ref - Create a variable reference and attach it to trigger |
| * @hist_data: The trigger that will be referencing the variable |
| * @var_field: The VAR field to create a reference to |
| * @system: The optional system string |
| * @event_name: The optional event_name string |
| * |
| * Given a variable hist_field, create a VAR_REF hist_field that |
| * represents a reference to it. |
| * |
| * This function also adds the reference to the trigger that |
| * now references the variable. |
| * |
| * Return: The VAR_REF field if successful, NULL if not |
| */ |
| static struct hist_field *create_var_ref(struct hist_trigger_data *hist_data, |
| struct hist_field *var_field, |
| char *system, char *event_name) |
| { |
| unsigned long flags = HIST_FIELD_FL_VAR_REF; |
| struct hist_field *ref_field; |
| int i; |
| |
| /* Check if the variable already exists */ |
| for (i = 0; i < hist_data->n_var_refs; i++) { |
| ref_field = hist_data->var_refs[i]; |
| if (ref_field->var.idx == var_field->var.idx && |
| ref_field->var.hist_data == var_field->hist_data) { |
| get_hist_field(ref_field); |
| return ref_field; |
| } |
| } |
| /* Sanity check to avoid out-of-bound write on 'hist_data->var_refs' */ |
| if (hist_data->n_var_refs >= TRACING_MAP_VARS_MAX) |
| return NULL; |
| ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL); |
| if (ref_field) { |
| if (init_var_ref(ref_field, var_field, system, event_name)) { |
| destroy_hist_field(ref_field, 0); |
| return NULL; |
| } |
| |
| hist_data->var_refs[hist_data->n_var_refs] = ref_field; |
| ref_field->var_ref_idx = hist_data->n_var_refs++; |
| } |
| |
| return ref_field; |
| } |
| |
| static bool is_var_ref(char *var_name) |
| { |
| if (!var_name || strlen(var_name) < 2 || var_name[0] != '$') |
| return false; |
| |
| return true; |
| } |
| |
| static char *field_name_from_var(struct hist_trigger_data *hist_data, |
| char *var_name) |
| { |
| char *name, *field; |
| unsigned int i; |
| |
| for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) { |
| name = hist_data->attrs->var_defs.name[i]; |
| |
| if (strcmp(var_name, name) == 0) { |
| field = hist_data->attrs->var_defs.expr[i]; |
| if (contains_operator(field, NULL) || is_var_ref(field)) |
| continue; |
| return field; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static char *local_field_var_ref(struct hist_trigger_data *hist_data, |
| char *system, char *event_name, |
| char *var_name) |
| { |
| struct trace_event_call *call; |
| |
| if (system && event_name) { |
| call = hist_data->event_file->event_call; |
| |
| if (strcmp(system, call->class->system) != 0) |
| return NULL; |
| |
| if (strcmp(event_name, trace_event_name(call)) != 0) |
| return NULL; |
| } |
| |
| if (!!system != !!event_name) |
| return NULL; |
| |
| if (!is_var_ref(var_name)) |
| return NULL; |
| |
| var_name++; |
| |
| return field_name_from_var(hist_data, var_name); |
| } |
| |
| static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data, |
| char *system, char *event_name, |
| char *var_name) |
| { |
| struct hist_field *var_field = NULL, *ref_field = NULL; |
| struct trace_array *tr = hist_data->event_file->tr; |
| |
| if (!is_var_ref(var_name)) |
| return NULL; |
| |
| var_name++; |
| |
| var_field = find_event_var(hist_data, system, event_name, var_name); |
| if (var_field) |
| ref_field = create_var_ref(hist_data, var_field, |
| system, event_name); |
| |
| if (!ref_field) |
| hist_err(tr, HIST_ERR_VAR_NOT_FOUND, errpos(var_name)); |
| |
| return ref_field; |
| } |
| |
| static struct ftrace_event_field * |
| parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file, |
| char *field_str, unsigned long *flags, unsigned long *buckets) |
| { |
| struct ftrace_event_field *field = NULL; |
| char *field_name, *modifier, *str; |
| struct trace_array *tr = file->tr; |
| |
| modifier = str = kstrdup(field_str, GFP_KERNEL); |
| if (!modifier) |
| return ERR_PTR(-ENOMEM); |
| |
| field_name = strsep(&modifier, "."); |
| if (modifier) { |
| if (strcmp(modifier, "hex") == 0) |
| *flags |= HIST_FIELD_FL_HEX; |
| else if (strcmp(modifier, "sym") == 0) |
| *flags |= HIST_FIELD_FL_SYM; |
| /* |
| * 'sym-offset' occurrences in the trigger string are modified |
| * to 'symXoffset' to simplify arithmetic expression parsing. |
| */ |
| else if (strcmp(modifier, "symXoffset") == 0) |
| *flags |= HIST_FIELD_FL_SYM_OFFSET; |
| else if ((strcmp(modifier, "execname") == 0) && |
| (strcmp(field_name, "common_pid") == 0)) |
| *flags |= HIST_FIELD_FL_EXECNAME; |
| else if (strcmp(modifier, "syscall") == 0) |
| *flags |= HIST_FIELD_FL_SYSCALL; |
| else if (strcmp(modifier, "log2") == 0) |
| *flags |= HIST_FIELD_FL_LOG2; |
| else if (strcmp(modifier, "usecs") == 0) |
| *flags |= HIST_FIELD_FL_TIMESTAMP_USECS; |
| else if (strncmp(modifier, "bucket", 6) == 0) { |
| int ret; |
| |
| modifier += 6; |
| |
| if (*modifier == 's') |
| modifier++; |
| if (*modifier != '=') |
| goto error; |
| modifier++; |
| ret = kstrtoul(modifier, 0, buckets); |
| if (ret || !(*buckets)) |
| goto error; |
| *flags |= HIST_FIELD_FL_BUCKET; |
| } else if (strncmp(modifier, "percent", 7) == 0) { |
| if (*flags & (HIST_FIELD_FL_VAR | HIST_FIELD_FL_KEY)) |
| goto error; |
| *flags |= HIST_FIELD_FL_PERCENT; |
| } else if (strncmp(modifier, "graph", 5) == 0) { |
| if (*flags & (HIST_FIELD_FL_VAR | HIST_FIELD_FL_KEY)) |
| goto error; |
| *flags |= HIST_FIELD_FL_GRAPH; |
| } else { |
| error: |
| hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier)); |
| field = ERR_PTR(-EINVAL); |
| goto out; |
| } |
| } |
| |
| if (strcmp(field_name, "common_timestamp") == 0) { |
| *flags |= HIST_FIELD_FL_TIMESTAMP; |
| hist_data->enable_timestamps = true; |
| if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS) |
| hist_data->attrs->ts_in_usecs = true; |
| } else if (strcmp(field_name, "common_cpu") == 0) |
| *flags |= HIST_FIELD_FL_CPU; |
| else { |
| field = trace_find_event_field(file->event_call, field_name); |
| if (!field || !field->size) { |
| /* |
| * For backward compatibility, if field_name |
| * was "cpu", then we treat this the same as |
| * common_cpu. This also works for "CPU". |
| */ |
| if (field && field->filter_type == FILTER_CPU) { |
| *flags |= HIST_FIELD_FL_CPU; |
| } else { |
| hist_err(tr, HIST_ERR_FIELD_NOT_FOUND, |
| errpos(field_name)); |
| field = ERR_PTR(-EINVAL); |
| goto out; |
| } |
| } |
| } |
| out: |
| kfree(str); |
| |
| return field; |
| } |
| |
| static struct hist_field *create_alias(struct hist_trigger_data *hist_data, |
| struct hist_field *var_ref, |
| char *var_name) |
| { |
| struct hist_field *alias = NULL; |
| unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR; |
| |
| alias = create_hist_field(hist_data, NULL, flags, var_name); |
| if (!alias) |
| return NULL; |
| |
| alias->fn_num = var_ref->fn_num; |
| alias->operands[0] = var_ref; |
| |
| if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) { |
| destroy_hist_field(alias, 0); |
| return NULL; |
| } |
| |
| alias->var_ref_idx = var_ref->var_ref_idx; |
| |
| return alias; |
| } |
| |
| static struct hist_field *parse_const(struct hist_trigger_data *hist_data, |
| char *str, char *var_name, |
| unsigned long *flags) |
| { |
| struct trace_array *tr = hist_data->event_file->tr; |
| struct hist_field *field = NULL; |
| u64 constant; |
| |
| if (kstrtoull(str, 0, &constant)) { |
| hist_err(tr, HIST_ERR_EXPECT_NUMBER, errpos(str)); |
| return NULL; |
| } |
| |
| *flags |= HIST_FIELD_FL_CONST; |
| field = create_hist_field(hist_data, NULL, *flags, var_name); |
| if (!field) |
| return NULL; |
| |
| field->constant = constant; |
| |
| return field; |
| } |
| |
| static struct hist_field *parse_atom(struct hist_trigger_data *hist_data, |
| struct trace_event_file *file, char *str, |
| unsigned long *flags, char *var_name) |
| { |
| char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str; |
| struct ftrace_event_field *field = NULL; |
| struct hist_field *hist_field = NULL; |
| unsigned long buckets = 0; |
| int ret = 0; |
| |
| if (isdigit(str[0])) { |
| hist_field = parse_const(hist_data, str, var_name, flags); |
| if (!hist_field) { |
| ret = -EINVAL; |
| goto out; |
| } |
| return hist_field; |
| } |
| |
| s = strchr(str, '.'); |
| if (s) { |
| s = strchr(++s, '.'); |
| if (s) { |
| ref_system = strsep(&str, "."); |
| if (!str) { |
| ret = -EINVAL; |
| goto out; |
| } |
| ref_event = strsep(&str, "."); |
| if (!str) { |
| ret = -EINVAL; |
| goto out; |
| } |
| ref_var = str; |
| } |
| } |
| |
| s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var); |
| if (!s) { |
| hist_field = parse_var_ref(hist_data, ref_system, |
| ref_event, ref_var); |
| if (hist_field) { |
| if (var_name) { |
| hist_field = create_alias(hist_data, hist_field, var_name); |
| if (!hist_field) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| return hist_field; |
| } |
| } else |
| str = s; |
| |
| field = parse_field(hist_data, file, str, flags, &buckets); |
| if (IS_ERR(field)) { |
| ret = PTR_ERR(field); |
| goto out; |
| } |
| |
| hist_field = create_hist_field(hist_data, field, *flags, var_name); |
| if (!hist_field) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| hist_field->buckets = buckets; |
| |
| return hist_field; |
| out: |
| return ERR_PTR(ret); |
| } |
| |
| static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, |
| struct trace_event_file *file, |
| char *str, unsigned long flags, |
| char *var_name, unsigned int *n_subexprs); |
| |
| static struct hist_field *parse_unary(struct hist_trigger_data *hist_data, |
| struct trace_event_file *file, |
| char *str, unsigned long flags, |
| char *var_name, unsigned int *n_subexprs) |
| { |
| struct hist_field *operand1, *expr = NULL; |
| unsigned long operand_flags; |
| int ret = 0; |
| char *s; |
| |
| /* Unary minus operator, increment n_subexprs */ |
| ++*n_subexprs; |
| |
| /* we support only -(xxx) i.e. explicit parens required */ |
| |
| if (*n_subexprs > 3) { |
| hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str)); |
| ret = -EINVAL; |
| goto free; |
| } |
| |
| str++; /* skip leading '-' */ |
| |
| s = strchr(str, '('); |
| if (s) |
| str++; |
| else { |
| ret = -EINVAL; |
| goto free; |
| } |
| |
| s = strrchr(str, ')'); |
| if (s) { |
| /* unary minus not supported in sub-expressions */ |
| if (*(s+1) != '\0') { |
| hist_err(file->tr, HIST_ERR_UNARY_MINUS_SUBEXPR, |
| errpos(str)); |
| ret = -EINVAL; |
| goto free; |
| } |
| *s = '\0'; |
| } |
| else { |
| ret = -EINVAL; /* no closing ')' */ |
| goto free; |
| } |
| |
| flags |= HIST_FIELD_FL_EXPR; |
| expr = create_hist_field(hist_data, NULL, flags, var_name); |
| if (!expr) { |
| ret = -ENOMEM; |
| goto free; |
| } |
| |
| operand_flags = 0; |
| operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, n_subexprs); |
| if (IS_ERR(operand1)) { |
| ret = PTR_ERR(operand1); |
| goto free; |
| } |
| if (operand1->flags & HIST_FIELD_FL_STRING) { |
| /* String type can not be the operand of unary operator. */ |
| hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str)); |
| destroy_hist_field(operand1, 0); |
| ret = -EINVAL; |
| goto free; |
| } |
| |
| expr->flags |= operand1->flags & |
| (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); |
| expr->fn_num = HIST_FIELD_FN_UMINUS; |
| expr->operands[0] = operand1; |
| expr->size = operand1->size; |
| expr->is_signed = operand1->is_signed; |
| expr->operator = FIELD_OP_UNARY_MINUS; |
| expr->name = expr_str(expr, 0); |
| expr->type = kstrdup_const(operand1->type, GFP_KERNEL); |
| if (!expr->type) { |
| ret = -ENOMEM; |
| goto free; |
| } |
| |
| return expr; |
| free: |
| destroy_hist_field(expr, 0); |
| return ERR_PTR(ret); |
| } |
| |
| /* |
| * If the operands are var refs, return pointers the |
| * variable(s) referenced in var1 and var2, else NULL. |
| */ |
| static int check_expr_operands(struct trace_array *tr, |
| struct hist_field *operand1, |
| struct hist_field *operand2, |
| struct hist_field **var1, |
| struct hist_field **var2) |
| { |
| unsigned long operand1_flags = operand1->flags; |
| unsigned long operand2_flags = operand2->flags; |
| |
| if ((operand1_flags & HIST_FIELD_FL_VAR_REF) || |
| (operand1_flags & HIST_FIELD_FL_ALIAS)) { |
| struct hist_field *var; |
| |
| var = find_var_field(operand1->var.hist_data, operand1->name); |
| if (!var) |
| return -EINVAL; |
| operand1_flags = var->flags; |
| *var1 = var; |
| } |
| |
| if ((operand2_flags & HIST_FIELD_FL_VAR_REF) || |
| (operand2_flags & HIST_FIELD_FL_ALIAS)) { |
| struct hist_field *var; |
| |
| var = find_var_field(operand2->var.hist_data, operand2->name); |
| if (!var) |
| return -EINVAL; |
| operand2_flags = var->flags; |
| *var2 = var; |
| } |
| |
| if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) != |
| (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) { |
| hist_err(tr, HIST_ERR_TIMESTAMP_MISMATCH, 0); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, |
| struct trace_event_file *file, |
| char *str, unsigned long flags, |
| char *var_name, unsigned int *n_subexprs) |
| { |
| struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL; |
| struct hist_field *var1 = NULL, *var2 = NULL; |
| unsigned long operand_flags, operand2_flags; |
| int field_op, ret = -EINVAL; |
| char *sep, *operand1_str; |
| enum hist_field_fn op_fn; |
| bool combine_consts; |
| |
| if (*n_subexprs > 3) { |
| hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str)); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| field_op = contains_operator(str, &sep); |
| |
| if (field_op == FIELD_OP_NONE) |
| return parse_atom(hist_data, file, str, &flags, var_name); |
| |
| if (field_op == FIELD_OP_UNARY_MINUS) |
| return parse_unary(hist_data, file, str, flags, var_name, n_subexprs); |
| |
| /* Binary operator found, increment n_subexprs */ |
| ++*n_subexprs; |
| |
| /* Split the expression string at the root operator */ |
| if (!sep) |
| return ERR_PTR(-EINVAL); |
| |
| *sep = '\0'; |
| operand1_str = str; |
| str = sep+1; |
| |
| /* Binary operator requires both operands */ |
| if (*operand1_str == '\0' || *str == '\0') |
| return ERR_PTR(-EINVAL); |
| |
| operand_flags = 0; |
| |
| /* LHS of string is an expression e.g. a+b in a+b+c */ |
| operand1 = parse_expr(hist_data, file, operand1_str, operand_flags, NULL, n_subexprs); |
| if (IS_ERR(operand1)) |
| return ERR_CAST(operand1); |
| |
| if (operand1->flags & HIST_FIELD_FL_STRING) { |
| hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(operand1_str)); |
| ret = -EINVAL; |
| goto free_op1; |
| } |
| |
| /* RHS of string is another expression e.g. c in a+b+c */ |
| operand_flags = 0; |
| operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, n_subexprs); |
| if (IS_ERR(operand2)) { |
| ret = PTR_ERR(operand2); |
| goto free_op1; |
| } |
| if (operand2->flags & HIST_FIELD_FL_STRING) { |
| hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str)); |
| ret = -EINVAL; |
| goto free_operands; |
| } |
| |
| switch (field_op) { |
| case FIELD_OP_MINUS: |
| op_fn = HIST_FIELD_FN_MINUS; |
| break; |
| case FIELD_OP_PLUS: |
| op_fn = HIST_FIELD_FN_PLUS; |
| break; |
| case FIELD_OP_DIV: |
| op_fn = HIST_FIELD_FN_DIV; |
| break; |
| case FIELD_OP_MULT: |
| op_fn = HIST_FIELD_FN_MULT; |
| break; |
| default: |
| ret = -EINVAL; |
| goto free_operands; |
| } |
| |
| ret = check_expr_operands(file->tr, operand1, operand2, &var1, &var2); |
| if (ret) |
| goto free_operands; |
| |
| operand_flags = var1 ? var1->flags : operand1->flags; |
| operand2_flags = var2 ? var2->flags : operand2->flags; |
| |
| /* |
| * If both operands are constant, the expression can be |
| * collapsed to a single constant. |
| */ |
| combine_consts = operand_flags & operand2_flags & HIST_FIELD_FL_CONST; |
| |
| flags |= combine_consts ? HIST_FIELD_FL_CONST : HIST_FIELD_FL_EXPR; |
| |
| flags |= operand1->flags & |
| (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); |
| |
| expr = create_hist_field(hist_data, NULL, flags, var_name); |
| if (!expr) { |
| ret = -ENOMEM; |
| goto free_operands; |
| } |
| |
| operand1->read_once = true; |
| operand2->read_once = true; |
| |
| /* The operands are now owned and free'd by 'expr' */ |
| expr->operands[0] = operand1; |
| expr->operands[1] = operand2; |
| |
| if (field_op == FIELD_OP_DIV && |
| operand2_flags & HIST_FIELD_FL_CONST) { |
| u64 divisor = var2 ? var2->constant : operand2->constant; |
| |
| if (!divisor) { |
| hist_err(file->tr, HIST_ERR_DIVISION_BY_ZERO, errpos(str)); |
| ret = -EDOM; |
| goto free_expr; |
| } |
| |
| /* |
| * Copy the divisor here so we don't have to look it up |
| * later if this is a var ref |
| */ |
| operand2->constant = divisor; |
| op_fn = hist_field_get_div_fn(operand2); |
| } |
| |
| expr->fn_num = op_fn; |
| |
| if (combine_consts) { |
| if (var1) |
| expr->operands[0] = var1; |
| if (var2) |
| expr->operands[1] = var2; |
| |
| expr->constant = hist_fn_call(expr, NULL, NULL, NULL, NULL); |
| expr->fn_num = HIST_FIELD_FN_CONST; |
| |
| expr->operands[0] = NULL; |
| expr->operands[1] = NULL; |
| |
| /* |
| * var refs won't be destroyed immediately |
| * See: destroy_hist_field() |
| */ |
| destroy_hist_field(operand2, 0); |
| destroy_hist_field(operand1, 0); |
| |
| expr->name = expr_str(expr, 0); |
| } else { |
| /* The operand sizes should be the same, so just pick one */ |
| expr->size = operand1->size; |
| expr->is_signed = operand1->is_signed; |
| |
| expr->operator = field_op; |
| expr->type = kstrdup_const(operand1->type, GFP_KERNEL); |
| if (!expr->type) { |
| ret = -ENOMEM; |
| goto free_expr; |
| } |
| |
| expr->name = expr_str(expr, 0); |
| } |
| |
| return expr; |
| |
| free_operands: |
| destroy_hist_field(operand2, 0); |
| free_op1: |
| destroy_hist_field(operand1, 0); |
| return ERR_PTR(ret); |
| |
| free_expr: |
| destroy_hist_field(expr, 0); |
| return ERR_PTR(ret); |
| } |
| |
| static char *find_trigger_filter(struct hist_trigger_data *hist_data, |
| struct trace_event_file *file) |
| { |
| struct event_trigger_data *test; |
| |
| lockdep_assert_held(&event_mutex); |
| |
| list_for_each_entry(test, &file->triggers, list) { |
| if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { |
| if (test->private_data == hist_data) |
| return test->filter_str; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static struct event_command trigger_hist_cmd; |
| static int event_hist_trigger_parse(struct event_command *cmd_ops, |
| struct trace_event_file *file, |
| char *glob, char *cmd, |
| char *param_and_filter); |
| |
| static bool compatible_keys(struct hist_trigger_data *target_hist_data, |
| struct hist_trigger_data *hist_data, |
| unsigned int n_keys) |
| { |
| struct hist_field *target_hist_field, *hist_field; |
| unsigned int n, i, j; |
| |
| if (hist_data->n_fields - hist_data->n_vals != n_keys) |
| return false; |
| |
| i = hist_data->n_vals; |
| j = target_hist_data->n_vals; |
| |
| for (n = 0; n < n_keys; n++) { |
| hist_field = hist_data->fields[i + n]; |
| target_hist_field = target_hist_data->fields[j + n]; |
| |
| if (strcmp(hist_field->type, target_hist_field->type) != 0) |
| return false; |
| if (hist_field->size != target_hist_field->size) |
| return false; |
| if (hist_field->is_signed != target_hist_field->is_signed) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static struct hist_trigger_data * |
| find_compatible_hist(struct hist_trigger_data *target_hist_data, |
| struct trace_event_file *file) |
| { |
| struct hist_trigger_data *hist_data; |
| struct event_trigger_data *test; |
| unsigned int n_keys; |
| |
| lockdep_assert_held(&event_mutex); |
| |
| n_keys = target_hist_data->n_fields - target_hist_data->n_vals; |
| |
| list_for_each_entry(test, &file->triggers, list) { |
| if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { |
| hist_data = test->private_data; |
| |
| if (compatible_keys(target_hist_data, hist_data, n_keys)) |
| return hist_data; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static struct trace_event_file *event_file(struct trace_array *tr, |
| char *system, char *event_name) |
| { |
| struct trace_event_file *file; |
| |
| file = __find_event_file(tr, system, event_name); |
| if (!file) |
| return ERR_PTR(-EINVAL); |
| |
| return file; |
| } |
| |
| static struct hist_field * |
| find_synthetic_field_var(struct hist_trigger_data *target_hist_data, |
| char *system, char *event_name, char *field_name) |
| { |
| struct hist_field *event_var; |
| char *synthetic_name; |
| |
| synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); |
| if (!synthetic_name) |
| return ERR_PTR(-ENOMEM); |
| |
| strcpy(synthetic_name, "synthetic_"); |
| strcat(synthetic_name, field_name); |
| |
| event_var = find_event_var(target_hist_data, system, event_name, synthetic_name); |
| |
| kfree(synthetic_name); |
| |
| return event_var; |
| } |
| |
| /** |
| * create_field_var_hist - Automatically create a histogram and var for a field |
| * @target_hist_data: The target hist trigger |
| * @subsys_name: Optional subsystem name |
| * @event_name: Optional event name |
| * @field_name: The name of the field (and the resulting variable) |
| * |
| * Hist trigger actions fetch data from variables, not directly from |
| * events. However, for convenience, users are allowed to directly |
| * specify an event field in an action, which will be automatically |
| * converted into a variable on their behalf. |
| * |
| * If a user specifies a field on an event that isn't the event the |
| * histogram currently being defined (the target event histogram), the |
| * only way that can be accomplished is if a new hist trigger is |
| * created and the field variable defined on that. |
| * |
| * This function creates a new histogram compatible with the target |
| * event (meaning a histogram with the same key as the target |
| * histogram), and creates a variable for the specified field, but |
| * with 'synthetic_' prepended to the variable name in order to avoid |
| * collision with normal field variables. |
| * |
| * Return: The variable created for the field. |
| */ |
| static struct hist_field * |
| create_field_var_hist(struct hist_trigger_data *target_hist_data, |
| char *subsys_name, char *event_name, char *field_name) |
| { |
| struct trace_array *tr = target_hist_data->event_file->tr; |
| struct hist_trigger_data *hist_data; |
| unsigned int i, n, first = true; |
| struct field_var_hist *var_hist; |
| struct trace_event_file *file; |
| struct hist_field *key_field; |
| struct hist_field *event_var; |
| char *saved_filter; |
| char *cmd; |
| int ret; |
| |
| if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) { |
| hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name)); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| file = event_file(tr, subsys_name, event_name); |
| |
| if (IS_ERR(file)) { |
| hist_err(tr, HIST_ERR_EVENT_FILE_NOT_FOUND, errpos(field_name)); |
| ret = PTR_ERR(file); |
| return ERR_PTR(ret); |
| } |
| |
| /* |
| * Look for a histogram compatible with target. We'll use the |
| * found histogram specification to create a new matching |
| * histogram with our variable on it. target_hist_data is not |
| * yet a registered histogram so we can't use that. |
| */ |
| hist_data = find_compatible_hist(target_hist_data, file); |
| if (!hist_data) { |
| hist_err(tr, HIST_ERR_HIST_NOT_FOUND, errpos(field_name)); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| /* See if a synthetic field variable has already been created */ |
| event_var = find_synthetic_field_var(target_hist_data, subsys_name, |
| event_name, field_name); |
| if (!IS_ERR_OR_NULL(event_var)) |
| return event_var; |
| |
| var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL); |
| if (!var_hist) |
| return ERR_PTR(-ENOMEM); |
| |
| cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); |
| if (!cmd) { |
| kfree(var_hist); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| /* Use the same keys as the compatible histogram */ |
| strcat(cmd, "keys="); |
| |
| for_each_hist_key_field(i, hist_data) { |
| key_field = hist_data->fields[i]; |
| if (!first) |
| strcat(cmd, ","); |
| strcat(cmd, key_field->field->name); |
| first = false; |
| } |
| |
| /* Create the synthetic field variable specification */ |
| strcat(cmd, ":synthetic_"); |
| strcat(cmd, field_name); |
| strcat(cmd, "="); |
| strcat(cmd, field_name); |
| |
| /* Use the same filter as the compatible histogram */ |
| saved_filter = find_trigger_filter(hist_data, file); |
| if (saved_filter) { |
| strcat(cmd, " if "); |
| strcat(cmd, saved_filter); |
| } |
| |
| var_hist->cmd = kstrdup(cmd, GFP_KERNEL); |
| if (!var_hist->cmd) { |
| kfree(cmd); |
| kfree(var_hist); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| /* Save the compatible histogram information */ |
| var_hist->hist_data = hist_data; |
| |
| /* Create the new histogram with our variable */ |
| ret = event_hist_trigger_parse(&trigger_hist_cmd, file, |
| "", "hist", cmd); |
| if (ret) { |
| kfree(cmd); |
| kfree(var_hist->cmd); |
| kfree(var_hist); |
| hist_err(tr, HIST_ERR_HIST_CREATE_FAIL, errpos(field_name)); |
| return ERR_PTR(ret); |
| } |
| |
| kfree(cmd); |
| |
| /* If we can't find the variable, something went wrong */ |
| event_var = find_synthetic_field_var(target_hist_data, subsys_name, |
| event_name, field_name); |
| if (IS_ERR_OR_NULL(event_var)) { |
| kfree(var_hist->cmd); |
| kfree(var_hist); |
| hist_err(tr, HIST_ERR_SYNTH_VAR_NOT_FOUND, errpos(field_name)); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| n = target_hist_data->n_field_var_hists; |
| target_hist_data->field_var_hists[n] = var_hist; |
| target_hist_data->n_field_var_hists++; |
| |
| return event_var; |
| } |
| |
| static struct hist_field * |
| find_target_event_var(struct hist_trigger_data *hist_data, |
| char *subsys_name, char *event_name, char *var_name) |
|