From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- tools/perf/util/parse-events.l | 372 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 372 insertions(+) create mode 100644 tools/perf/util/parse-events.l (limited to 'tools/perf/util/parse-events.l') diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l new file mode 100644 index 000000000..251ce4321 --- /dev/null +++ b/tools/perf/util/parse-events.l @@ -0,0 +1,372 @@ + +%option reentrant +%option bison-bridge +%option prefix="parse_events_" +%option stack +%option bison-locations +%option yylineno +%option noyywrap + +%{ +#include +#include +#include +#include "parse-events.h" +#include "parse-events-bison.h" + +char *parse_events_get_text(yyscan_t yyscanner); +YYSTYPE *parse_events_get_lval(yyscan_t yyscanner); +int parse_events_get_column(yyscan_t yyscanner); +int parse_events_get_leng(yyscan_t yyscanner); + +static int get_column(yyscan_t scanner) +{ + return parse_events_get_column(scanner) - parse_events_get_leng(scanner); +} + +static int value(struct parse_events_state *parse_state, yyscan_t scanner, int base) +{ + YYSTYPE *yylval = parse_events_get_lval(scanner); + char *text = parse_events_get_text(scanner); + u64 num; + + errno = 0; + num = strtoull(text, NULL, base); + if (errno) { + struct parse_events_error *error = parse_state->error; + char *help = NULL; + + if (asprintf(&help, "Bad base %d number \"%s\"", base, text) > 0) + parse_events_error__handle(error, get_column(scanner), help , NULL); + + return PE_ERROR; + } + + yylval->num = num; + return PE_VALUE; +} + +static int str(yyscan_t scanner, int token) +{ + YYSTYPE *yylval = parse_events_get_lval(scanner); + char *text = parse_events_get_text(scanner); + + yylval->str = strdup(text); + return token; +} + +static int quoted_str(yyscan_t scanner, int token) +{ + YYSTYPE *yylval = parse_events_get_lval(scanner); + char *text = parse_events_get_text(scanner); + + /* + * If a text tag specified on the command line + * contains opening single quite ' then it is + * expected that the tag ends with single quote + * as well, like this: + * name=\'CPU_CLK_UNHALTED.THREAD:cmask=1\' + * quotes need to be escaped to bypass shell + * processing. + */ + yylval->str = strndup(&text[1], strlen(text) - 2); + return token; +} + +/* + * This function is called when the parser gets two kind of input: + * + * @cfg1 or @cfg2=config + * + * The leading '@' is stripped off before 'cfg1' and 'cfg2=config' are given to + * bison. In the latter case it is necessary to keep the string intact so that + * the PMU kernel driver can determine what configurable is associated to + * 'config'. + */ +static int drv_str(yyscan_t scanner, int token) +{ + YYSTYPE *yylval = parse_events_get_lval(scanner); + char *text = parse_events_get_text(scanner); + + /* Strip off the '@' */ + yylval->str = strdup(text + 1); + return token; +} + +/* + * Use yyless to return all the characaters to the input. Update the column for + * location debugging. If __alloc is non-zero set yylval to the text for the + * returned token's value. + */ +#define REWIND(__alloc) \ +do { \ + YYSTYPE *__yylval = parse_events_get_lval(yyscanner); \ + char *text = parse_events_get_text(yyscanner); \ + \ + if (__alloc) \ + __yylval->str = strdup(text); \ + \ + yycolumn -= strlen(text); \ + yyless(0); \ +} while (0) + +static int term(yyscan_t scanner, enum parse_events__term_type type) +{ + YYSTYPE *yylval = parse_events_get_lval(scanner); + + yylval->term_type = type; + return PE_TERM; +} + +static void modifiers_error(struct parse_events_state *parse_state, yyscan_t scanner, + int pos, char mod_char, const char *mod_name) +{ + struct parse_events_error *error = parse_state->error; + char *help = NULL; + + if (asprintf(&help, "Duplicate modifier '%c' (%s)", mod_char, mod_name) > 0) + parse_events_error__handle(error, get_column(scanner) + pos, help , NULL); +} + +static int modifiers(struct parse_events_state *parse_state, yyscan_t scanner) +{ + YYSTYPE *yylval = parse_events_get_lval(scanner); + char *text = parse_events_get_text(scanner); + struct parse_events_modifier mod = { .precise = 0, }; + + for (size_t i = 0, n = strlen(text); i < n; i++) { +#define CASE(c, field) \ + case c: \ + if (mod.field) { \ + modifiers_error(parse_state, scanner, i, c, #field); \ + return PE_ERROR; \ + } \ + mod.field = true; \ + break + + switch (text[i]) { + CASE('u', user); + CASE('k', kernel); + CASE('h', hypervisor); + CASE('I', non_idle); + CASE('G', guest); + CASE('H', host); + case 'p': + mod.precise++; + /* + * precise ip: + * + * 0 - SAMPLE_IP can have arbitrary skid + * 1 - SAMPLE_IP must have constant skid + * 2 - SAMPLE_IP requested to have 0 skid + * 3 - SAMPLE_IP must have 0 skid + * + * See also PERF_RECORD_MISC_EXACT_IP + */ + if (mod.precise > 3) { + struct parse_events_error *error = parse_state->error; + char *help = strdup("Maximum precise value is 3"); + + if (help) { + parse_events_error__handle(error, get_column(scanner) + i, + help , NULL); + } + return PE_ERROR; + } + break; + CASE('P', precise_max); + CASE('S', sample_read); + CASE('D', pinned); + CASE('W', weak); + CASE('e', exclusive); + CASE('b', bpf); + CASE('R', retire_lat); + CASE('X', dont_regroup); + default: + return PE_ERROR; + } +#undef CASE + } + yylval->mod = mod; + return PE_MODIFIER_EVENT; +} + +#define YY_USER_ACTION \ +do { \ + yylloc->last_column = yylloc->first_column; \ + yylloc->first_column = yycolumn; \ + yycolumn += yyleng; \ +} while (0); + +%} + +%x mem +%s config +%x event + +group [^,{}/]*[{][^}]*[}][^,{}/]* +event_pmu [^,{}/]+[/][^/]*[/][^,{}/]* +event [^,{}/]+ + +num_dec [0-9]+ +num_hex 0x[a-fA-F0-9]{1,16} +num_raw_hex [a-fA-F0-9]{1,16} +/* Regular pattern to match the token PE_NAME. */ +name_start [a-zA-Z0-9_*?\[\]] +name {name_start}[a-zA-Z0-9_*?.\[\]!\-]* +/* PE_NAME token when inside a config term list, allows ':'. */ +term_name {name_start}[a-zA-Z0-9_*?.\[\]!\-:]* +/* + * PE_NAME token when quoted, allows ':,.='. + * Matches the RHS of terms like: name='COMPLEX_CYCLES_NAME:orig=cycles,desc=chip-clock-ticks'. + */ +quoted_name [\']{name_start}[a-zA-Z0-9_*?.\[\]!\-:,\.=]*[\'] +drv_cfg_term [a-zA-Z0-9_\.]+(=[a-zA-Z0-9_*?\.:]+)? +/* + * If you add a modifier you need to update modifiers(). + * Also, the letters in modifier_event must not be in modifier_bp. + */ +modifier_event [ukhpPGHSDIWebRX]{1,17} +modifier_bp [rwx]{1,3} +digit [0-9] +non_digit [^0-9] + +%% + +%{ + struct parse_events_state *_parse_state = parse_events_get_extra(yyscanner); + { + int start_token = _parse_state->stoken; + + if (start_token == PE_START_TERMS) + BEGIN(config); + else if (start_token == PE_START_EVENTS) + BEGIN(event); + + if (start_token) { + _parse_state->stoken = 0; + /* + * The flex parser does not init locations variable + * via the scan_string interface, so we need do the + * init in here. + */ + yycolumn = 0; + return start_token; + } + } +%} + +{ + +{group} { + BEGIN(INITIAL); + REWIND(0); + } + +{event_pmu} | +{event} { + BEGIN(INITIAL); + REWIND(1); + return PE_EVENT_NAME; + } + +<> { + BEGIN(INITIAL); + REWIND(0); + } +, { + return ','; + } +} + +{ + /* + * Please update config_term_names when new static term is added. + */ +config { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG); } +config1 { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG1); } +config2 { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG2); } +config3 { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG3); } +config4 { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG4); } +name { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_NAME); } +period { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD); } +freq { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_SAMPLE_FREQ); } +branch_type { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE); } +time { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_TIME); } +call-graph { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CALLGRAPH); } +stack-size { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_STACKSIZE); } +max-stack { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_MAX_STACK); } +nr { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_MAX_EVENTS); } +inherit { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_INHERIT); } +no-inherit { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_NOINHERIT); } +overwrite { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_OVERWRITE); } +no-overwrite { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_NOOVERWRITE); } +percore { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_PERCORE); } +aux-output { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_AUX_OUTPUT); } +aux-action { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_AUX_ACTION); } +aux-sample-size { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_AUX_SAMPLE_SIZE); } +metric-id { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_METRIC_ID); } +cpu { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CPU); } +ratio-to-prev { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_RATIO_TO_PREV); } +legacy-hardware-config { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_LEGACY_HARDWARE_CONFIG); } +legacy-cache-config { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_LEGACY_CACHE_CONFIG); } +r{num_raw_hex} { return str(yyscanner, PE_RAW); } +r0x{num_raw_hex} { return str(yyscanner, PE_RAW); } +, { return ','; } +"/" { BEGIN(INITIAL); return '/'; } +{num_dec} { return value(_parse_state, yyscanner, 10); } +{num_hex} { return value(_parse_state, yyscanner, 16); } +{term_name} { return str(yyscanner, PE_NAME); } +@{drv_cfg_term} { return drv_str(yyscanner, PE_DRV_CFG_TERM); } +} + +{ +{modifier_bp} { return str(yyscanner, PE_MODIFIER_BP); } + /* + * The colon before memory access modifiers can get mixed up with the + * colon before event modifiers. Fortunately none of the option letters + * are the same, so trailing context can be used disambiguate the two + * cases. + */ +":"/{modifier_bp} { return PE_BP_COLON; } + /* + * The slash before memory length can get mixed up with the slash before + * config terms. Fortunately config terms do not start with a numeric + * digit, so trailing context can be used disambiguate the two cases. + */ +"/"/{digit} { return PE_BP_SLASH; } +"/"/{non_digit} { BEGIN(config); return '/'; } +{num_dec} { return value(_parse_state, yyscanner, 10); } +{num_hex} { return value(_parse_state, yyscanner, 16); } + /* + * We need to separate 'mem:' scanner part, in order to get specific + * modifier bits parsed out. Otherwise we would need to handle PE_NAME + * and we'd need to parse it manually. During the escape from + * state we need to put the escaping char back, so we dont miss it. + */ +. { unput(*yytext); BEGIN(INITIAL); } + /* + * We destroy the scanner after reaching EOF, + * but anyway just to be sure get back to INIT state. + */ +<> { BEGIN(INITIAL); } +} + +mem: { BEGIN(mem); return PE_PREFIX_MEM; } +r{num_raw_hex} { return str(yyscanner, PE_RAW); } +{num_dec} { return value(_parse_state, yyscanner, 10); } +{num_hex} { return value(_parse_state, yyscanner, 16); } + +{modifier_event} { return modifiers(_parse_state, yyscanner); } +{name} { return str(yyscanner, PE_NAME); } +{quoted_name} { return quoted_str(yyscanner, PE_NAME); } +"/" { BEGIN(config); return '/'; } +, { BEGIN(event); return ','; } +: { return ':'; } +"{" { BEGIN(event); return '{'; } +"}" { return '}'; } += { return '='; } +\n { } +. { } + +%% -- cgit v1.3.1