diff options
| -rw-r--r-- | tools/perf/Documentation/perf-record.txt | 55 | ||||
| -rw-r--r-- | tools/perf/builtin-record.c | 14 | ||||
| -rw-r--r-- | tools/perf/util/auxtrace.c | 737 | ||||
| -rw-r--r-- | tools/perf/util/auxtrace.h | 54 |
4 files changed, 857 insertions, 3 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index babbb63..9233519 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -89,9 +89,62 @@ OPTIONS --filter=<filter>:: Event filter. This option should follow a event selector (-e) which - selects tracepoint event(s). Multiple '--filter' options are combined + selects either tracepoint event(s) or a hardware trace PMU + (e.g. Intel PT or CoreSight). + + - tracepoint filters + + In the case of tracepoints, multiple '--filter' options are combined using '&&'. + - address filters + + A hardware trace PMU advertises its ability to accept a number of + address filters by specifying a non-zero value in + /sys/bus/event_source/devices/<pmu>/nr_addr_filters. + + Address filters have the format: + + filter|start|stop|tracestop <start> [/ <size>] [@<file name>] + + Where: + - 'filter': defines a region that will be traced. + - 'start': defines an address at which tracing will begin. + - 'stop': defines an address at which tracing will stop. + - 'tracestop': defines a region in which tracing will stop. + + <file name> is the name of the object file, <start> is the offset to the + code to trace in that file, and <size> is the size of the region to + trace. 'start' and 'stop' filters need not specify a <size>. + + If no object file is specified then the kernel is assumed, in which case + the start address must be a current kernel memory address. + + <start> can also be specified by providing the name of a symbol. If the + symbol name is not unique, it can be disambiguated by inserting #n where + 'n' selects the n'th symbol in address order. Alternately #0, #g or #G + select only a global symbol. <size> can also be specified by providing + the name of a symbol, in which case the size is calculated to the end + of that symbol. For 'filter' and 'tracestop' filters, if <size> is + omitted and <start> is a symbol, then the size is calculated to the end + of that symbol. + + If <size> is omitted and <start> is '*', then the start and size will + be calculated from the first and last symbols, i.e. to trace the whole + file. + + If symbol names (or '*') are provided, they must be surrounded by white + space. + + The filter passed to the kernel is not necessarily the same as entered. + To see the filter that is passed, use the -v option. + + The kernel may not be able to configure a trace region if it is not + within a single mapping. MMAP events (or /proc/<pid>/maps) can be + examined to determine if that is a possibility. + + Multiple filters can be separated with space or comma. + --exclude-perf:: Don't record events issued by perf itself. This option should follow a event selector (-e) which selects tracepoint event(s). It adds a diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 962adcf..67d2a90 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1581,6 +1581,18 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused) if (err) goto out; + /* + * Allow aliases to facilitate the lookup of symbols for address + * filters. Refer to auxtrace_parse_filters(). + */ + symbol_conf.allow_aliases = true; + + symbol__init(NULL); + + err = auxtrace_parse_filters(rec->evlist); + if (err) + goto out; + if (dry_run) goto out; @@ -1594,8 +1606,6 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused) err = -ENOMEM; - symbol__init(NULL); - if (symbol_conf.kptr_restrict) pr_warning( "WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,\n" diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c index c0aba8e..c5a6e0b1 100644 --- a/tools/perf/util/auxtrace.c +++ b/tools/perf/util/auxtrace.c @@ -16,6 +16,10 @@ #include <sys/types.h> #include <sys/mman.h> #include <stdbool.h> +#include <ctype.h> +#include <string.h> +#include <limits.h> +#include <errno.h> #include <linux/kernel.h> #include <linux/perf_event.h> @@ -35,9 +39,14 @@ #include "../perf.h" #include "util.h" #include "evlist.h" +#include "dso.h" +#include "map.h" +#include "pmu.h" +#include "evsel.h" #include "cpumap.h" #include "thread_map.h" #include "asm/bug.h" +#include "symbol/kallsyms.h" #include "auxtrace.h" #include <linux/hash.h> @@ -1399,3 +1408,731 @@ void *auxtrace_cache__lookup(struct auxtrace_cache *c, u32 key) return NULL; } + +static void addr_filter__free_str(struct addr_filter *filt) +{ + free(filt->str); + filt->action = NULL; + filt->sym_from = NULL; + filt->sym_to = NULL; + filt->filename = NULL; + filt->str = NULL; +} + +static struct addr_filter *addr_filter__new(void) +{ + struct addr_filter *filt = zalloc(sizeof(*filt)); + + if (filt) + INIT_LIST_HEAD(&filt->list); + + return filt; +} + +static void addr_filter__free(struct addr_filter *filt) +{ + if (filt) + addr_filter__free_str(filt); + free(filt); +} + +static void addr_filters__add(struct addr_filters *filts, + struct addr_filter *filt) +{ + list_add_tail(&filt->list, &filts->head); + filts->cnt += 1; +} + +static void addr_filters__del(struct addr_filters *filts, + struct addr_filter *filt) +{ + list_del_init(&filt->list); + filts->cnt -= 1; +} + +void addr_filters__init(struct addr_filters *filts) +{ + INIT_LIST_HEAD(&filts->head); + filts->cnt = 0; +} + +void addr_filters__exit(struct addr_filters *filts) +{ + struct addr_filter *filt, *n; + + list_for_each_entry_safe(filt, n, &filts->head, list) { + addr_filters__del(filts, filt); + addr_filter__free(filt); + } +} + +static int parse_num_or_str(char **inp, u64 *num, const char **str, + const char *str_delim) +{ + *inp += strspn(*inp, " "); + + if (isdigit(**inp)) { + char *endptr; + + if (!num) + return -EINVAL; + errno = 0; + *num = strtoull(*inp, &endptr, 0); + if (errno) + return -errno; + if (endptr == *inp) + return -EINVAL; + *inp = endptr; + } else { + size_t n; + + if (!str) + return -EINVAL; + *inp += strspn(*inp, " "); + *str = *inp; + n = strcspn(*inp, str_delim); + if (!n) + return -EINVAL; + *inp += n; + if (**inp) { + **inp = '\0'; + *inp += 1; + } + } + return 0; +} + +static int parse_action(struct addr_filter *filt) +{ + if (!strcmp(filt->action, "filter")) { + filt->start = true; + filt->range = true; + } else if (!strcmp(filt->action, "start")) { + filt->start = true; + } else if (!strcmp(filt->action, "stop")) { + filt->start = false; + } else if (!strcmp(filt->action, "tracestop")) { + filt->start = false; + filt->range = true; + filt->action += 5; /* Change 'tracestop' to 'stop' */ + } else { + return -EINVAL; + } + return 0; +} + +static int parse_sym_idx(char **inp, int *idx) +{ + *idx = -1; + + *inp += strspn(*inp, " "); + + if (**inp != '#') + return 0; + + *inp += 1; + + if (**inp == 'g' || **inp == 'G') { + *inp += 1; + *idx = 0; + } else { + unsigned long num; + char *endptr; + + errno = 0; + num = strtoul(*inp, &endptr, 0); + if (errno) + return -errno; + if (endptr == *inp || num > INT_MAX) + return -EINVAL; + *inp = endptr; + *idx = num; + } + + return 0; +} + +static int parse_addr_size(char **inp, u64 *num, const char **str, int *idx) +{ + int err = parse_num_or_str(inp, num, str, " "); + + if (!err && *str) + err = parse_sym_idx(inp, idx); + + return err; +} + +static int parse_one_filter(struct addr_filter *filt, const char **filter_inp) +{ + char *fstr; + int err; + + filt->str = fstr = strdup(*filter_inp); + if (!fstr) + return -ENOMEM; + + err = parse_num_or_str(&fstr, NULL, &filt->action, " "); + if (err) + goto out_err; + + err = parse_action(filt); + if (err) + goto out_err; + + err = parse_addr_size(&fstr, &filt->addr, &filt->sym_from, + &filt->sym_from_idx); + if (err) + goto out_err; + + fstr += strspn(fstr, " "); + + if (*fstr == '/') { + fstr += 1; + err = parse_addr_size(&fstr, &filt->size, &filt->sym_to, + &filt->sym_to_idx); + if (err) + goto out_err; + filt->range = true; + } + + fstr += strspn(fstr, " "); + + if (*fstr == '@') { + fstr += 1; + err = parse_num_or_str(&fstr, NULL, &filt->filename, " ,"); + if (err) + goto out_err; + } + + fstr += strspn(fstr, " ,"); + + *filter_inp += fstr - filt->str; + + return 0; + +out_err: + addr_filter__free_str(filt); + + return err; +} + +int addr_filters__parse_bare_filter(struct addr_filters *filts, + const char *filter) +{ + struct addr_filter *filt; + const char *fstr = filter; + int err; + + while (*fstr) { + filt = addr_filter__new(); + err = parse_one_filter(filt, &fstr); + if (err) { + addr_filter__free(filt); + addr_filters__exit(filts); + return err; + } + addr_filters__add(filts, filt); + } + + return 0; +} + +struct sym_args { + const char *name; + u64 start; + u64 size; + int idx; + int cnt; + bool started; + bool global; + bool selected; + bool duplicate; + bool near; +}; + +static bool kern_sym_match(struct sym_args *args, const char *name, char type) +{ + /* A function with the same name, and global or the n'th found or any */ + return symbol_type__is_a(type, MAP__FUNCTION) && + !strcmp(name, args->name) && + ((args->global && isupper(type)) || + (args->selected && ++(args->cnt) == args->idx) || + (!args->global && !args->selected)); +} + +static int find_kern_sym_cb(void *arg, const char *name, char type, u64 start) +{ + struct sym_args *args = arg; + + if (args->started) { + if (!args->size) + args->size = start - args->start; + if (args->selected) { + if (args->size) + return 1; + } else if (kern_sym_match(args, name, type)) { + args->duplicate = true; + return 1; + } + } else if (kern_sym_match(args, name, type)) { + args->started = true; + args->start = start; + } + + return 0; +} + +static int print_kern_sym_cb(void *arg, const char *name, char type, u64 start) +{ + struct sym_args *args = arg; + + if (kern_sym_match(args, name, type)) { + pr_err("#%d\t0x%"PRIx64"\t%c\t%s\n", + ++args->cnt, start, type, name); + args->near = true; + } else if (args->near) { + args->near = false; + pr_err("\t\twhich is near\t\t%s\n", name); + } + + return 0; +} + +static int sym_not_found_error(const char *sym_name, int idx) +{ + if (idx > 0) { + pr_err("N'th occurrence (N=%d) of symbol '%s' not found.\n", + idx, sym_name); + } else if (!idx) { + pr_err("Global symbol '%s' not found.\n", sym_name); + } else { + pr_err("Symbol '%s' not found.\n", sym_name); + } + pr_err("Note that symbols must be functions.\n"); + + return -EINVAL; +} + +static int find_kern_sym(const char *sym_name, u64 *start, u64 *size, int idx) +{ + struct sym_args args = { + .name = sym_name, + .idx = idx, + .global = !idx, + .selected = idx > 0, + }; + int err; + + *start = 0; + *size = 0; + + err = kallsyms__parse("/proc/kallsyms", &args, find_kern_sym_cb); + if (err < 0) { + pr_err("Failed to parse /proc/kallsyms\n"); + return err; + } + + if (args.duplicate) { + pr_err("Multiple kernel symbols with name '%s'\n", sym_name); + args.cnt = 0; + kallsyms__parse("/proc/kallsyms", &args, print_kern_sym_cb); + pr_err("Disambiguate symbol name by inserting #n after the name e.g. %s #2\n", + sym_name); + pr_err("Or select a global symbol by inserting #0 or #g or #G\n"); + return -EINVAL; + } + + if (!args.started) { + pr_err("Kernel symbol lookup: "); + return sym_not_found_error(sym_name, idx); + } + + *start = args.start; + *size = args.size; + + return 0; +} + +static int find_entire_kern_cb(void *arg, const char *name __maybe_unused, + char type, u64 start) +{ + struct sym_args *args = arg; + + if (!symbol_type__is_a(type, MAP__FUNCTION)) + return 0; + + if (!args->started) { + args->started = true; + args->start = start; + } + /* Don't know exactly where the kernel ends, so we add a page */ + args->size = round_up(start, page_size) + page_size - args->start; + + return 0; +} + +static int addr_filter__entire_kernel(struct addr_filter *filt) +{ + struct sym_args args = { .started = false }; + int err; + + err = kallsyms__parse("/proc/kallsyms", &args, find_entire_kern_cb); + if (err < 0 || !args.started) { + pr_err("Failed to parse /proc/kallsyms\n"); + return err; + } + + filt->addr = args.start; + filt->size = args.size; + + return 0; +} + +static int check_end_after_start(struct addr_filter *filt, u64 start, u64 size) +{ + if (start + size >= filt->addr) + return 0; + + if (filt->sym_from) { + pr_err("Symbol '%s' (0x%"PRIx64") comes before '%s' (0x%"PRIx64")\n", + filt->sym_to, start, filt->sym_from, filt->addr); + } else { + pr_err("Symbol '%s' (0x%"PRIx64") comes before address 0x%"PRIx64")\n", + filt->sym_to, start, filt->addr); + } + + return -EINVAL; +} + +static int addr_filter__resolve_kernel_syms(struct addr_filter *filt) +{ + bool no_size = false; + u64 start, size; + int err; + + if (symbol_conf.kptr_restrict) { + pr_err("Kernel addresses are restricted. Unable to resolve kernel symbols.\n"); + return -EINVAL; + } + + if (filt->sym_from && !strcmp(filt->sym_from, "*")) + return addr_filter__entire_kernel(filt); + + if (filt->sym_from) { + err = find_kern_sym(filt->sym_from, &start, &size, + filt->sym_from_idx); + if (err) + return err; + filt->addr = start; + if (filt->range && !filt->size && !filt->sym_to) { + filt->size = size; + no_size = !!size; + } + } + + if (filt->sym_to) { + err = find_kern_sym(filt->sym_to, &start, &size, + filt->sym_to_idx); + if (err) + return err; + + err = check_end_after_start(filt, start, size); + if (err) + return err; + filt->size = start + size - filt->addr; + no_size = !!size; + } + + /* The very last symbol in kallsyms does not imply a particular size */ + if (no_size) { + pr_err("Cannot determine size of symbol '%s'\n", + filt->sym_to ? filt->sym_to : filt->sym_from); + return -EINVAL; + } + + return 0; +} + +static struct dso *load_dso(const char *name) +{ + struct map *map; + struct dso *dso; + + map = dso__new_map(name); + if (!map) + return NULL; + + map__load(map); + + dso = dso__get(map->dso); + + map__put(map); + + return dso; +} + +static bool dso_sym_match(struct symbol *sym, const char *name, int *cnt, + int idx) +{ + /* Same name, and global or the n'th found or any */ + return !arch__compare_symbol_names(name, sym->name) && + ((!idx && sym->binding == STB_GLOBAL) || + (idx > 0 && ++*cnt == idx) || + idx < 0); +} + +static void print_duplicate_syms(struct dso *dso, const char *sym_name) +{ + struct symbol *sym; + bool near = false; + int cnt = 0; + + pr_err("Multiple symbols with name '%s'\n", sym_name); + + sym = dso__first_symbol(dso, MAP__FUNCTION); + while (sym) { + if (dso_sym_match(sym, sym_name, &cnt, -1)) { + pr_err("#%d\t0x%"PRIx64"\t%c\t%s\n", + ++cnt, sym->start, + sym->binding == STB_GLOBAL ? 'g' : + sym->binding == STB_LOCAL ? 'l' : 'w', + sym->name); + near = true; + } else if (near) { + near = false; + pr_err("\t\twhich is near\t\t%s\n", sym->name); + } + sym = dso__next_symbol(sym); + } + + pr_err("Disambiguate symbol name by inserting #n after the name e.g. %s #2\n", + sym_name); + pr_err("Or select a global symbol by inserting #0 or #g or #G\n"); +} + +static int find_dso_sym(struct dso *dso, const char *sym_name, u64 *start, + u64 *size, int idx) +{ + struct symbol *sym; + int cnt = 0; + + *start = 0; + *size = 0; + + sym = dso__first_symbol(dso, MAP__FUNCTION); + while (sym) { + if (*start) { + if (!*size) + *size = sym->start - *start; + if (idx > 0) { + if (*size) + return 1; + } else if (dso_sym_match(sym, sym_name, &cnt, idx)) { + print_duplicate_syms(dso, sym_name); + return -EINVAL; + } + } else if (dso_sym_match(sym, sym_name, &cnt, idx)) { + *start = sym->start; + *size = sym->end - sym->start; + } + sym = dso__next_symbol(sym); + } + + if (!*start) + return sym_not_found_error(sym_name, idx); + + return 0; +} + +static int addr_filter__entire_dso(struct addr_filter *filt, struct dso *dso) +{ + struct symbol *first_sym = dso__first_symbol(dso, MAP__FUNCTION); + struct symbol *last_sym = dso__last_symbol(dso, MAP__FUNCTION); + + if (!first_sym || !last_sym) { + pr_err("Failed to determine filter for %s\nNo symbols found.\n", + filt->filename); + return -EINVAL; + } + + filt->addr = first_sym->start; + filt->size = last_sym->end - first_sym->start; + + return 0; +} + +static int addr_filter__resolve_syms(struct addr_filter *filt) +{ + u64 start, size; + struct dso *dso; + int err = 0; + + if (!filt->sym_from && !filt->sym_to) + return 0; + + if (!filt->filename) + return addr_filter__resolve_kernel_syms(filt); + + dso = load_dso(filt->filename); + if (!dso) { + pr_err("Failed to load symbols from: %s\n", filt->filename); + return -EINVAL; + } + + if (filt->sym_from && !strcmp(filt->sym_from, "*")) { + err = addr_filter__entire_dso(filt, dso); + goto put_dso; + } + + if (filt->sym_from) { + err = find_dso_sym(dso, filt->sym_from, &start, &size, + filt->sym_from_idx); + if (err) + goto put_dso; + filt->addr = start; + if (filt->range && !filt->size && !filt->sym_to) + filt->size = size; + } + + if (filt->sym_to) { + err = find_dso_sym(dso, filt->sym_to, &start, &size, + filt->sym_to_idx); + if (err) + goto put_dso; + + err = check_end_after_start(filt, start, size); + if (err) + return err; + + filt->size = start + size - filt->addr; + } + +put_dso: + dso__put(dso); + + return err; +} + +static char *addr_filter__to_str(struct addr_filter *filt) +{ + char filename_buf[PATH_MAX]; + const char *at = ""; + const char *fn = ""; + char *filter; + int err; + + if (filt->filename) { + at = "@"; + fn = realpath(filt->filename, filename_buf); + if (!fn) + return NULL; + } + + if (filt->range) { + err = asprintf(&filter, "%s 0x%"PRIx64"/0x%"PRIx64"%s%s", + filt->action, filt->addr, filt->size, at, fn); + } else { + err = asprintf(&filter, "%s 0x%"PRIx64"%s%s", + filt->action, filt->addr, at, fn); + } + + return err < 0 ? NULL : filter; +} + +static int parse_addr_filter(struct perf_evsel *evsel, const char *filter, + int max_nr) +{ + struct addr_filters filts; + struct addr_filter *filt; + int err; + + addr_filters__init(&filts); + + err = addr_filters__parse_bare_filter(&filts, filter); + if (err) + goto out_exit; + + if (filts.cnt > max_nr) { + pr_err("Error: number of address filters (%d) exceeds maximum (%d)\n", + filts.cnt, max_nr); + err = -EINVAL; + goto out_exit; + } + + list_for_each_entry(filt, &filts.head, list) { + char *new_filter; + + err = addr_filter__resolve_syms(filt); + if (err) + goto out_exit; + + new_filter = addr_filter__to_str(filt); + if (!new_filter) { + err = -ENOMEM; + goto out_exit; + } + + if (perf_evsel__append_addr_filter(evsel, new_filter)) { + err = -ENOMEM; + goto out_exit; + } + } + +out_exit: + addr_filters__exit(&filts); + + if (err) { + pr_err("Failed to parse address filter: '%s'\n", filter); + pr_err("Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]\n"); + pr_err("Where multiple filters are separated by space or comma.\n"); + } + + return err; +} + +static struct perf_pmu *perf_evsel__find_pmu(struct perf_evsel *evsel) +{ + struct perf_pmu *pmu = NULL; + + while ((pmu = perf_pmu__scan(pmu)) != NULL) { + if (pmu->type == evsel->attr.type) + break; + } + + return pmu; +} + +static int perf_evsel__nr_addr_filter(struct perf_evsel *evsel) +{ + struct perf_pmu *pmu = perf_evsel__find_pmu(evsel); + int nr_addr_filters = 0; + + if (!pmu) + return 0; + + perf_pmu__scan_file(pmu, "nr_addr_filters", "%d", &nr_addr_filters); + + return nr_addr_filters; +} + +int auxtrace_parse_filters(struct perf_evlist *evlist) +{ + struct perf_evsel *evsel; + char *filter; + int err, max_nr; + + evlist__for_each_entry(evlist, evsel) { + filter = evsel->filter; + max_nr = perf_evsel__nr_addr_filter(evsel); + if (!filter || !max_nr) + continue; + evsel->filter = NULL; + err = parse_addr_filter(evsel, filter, max_nr); + free(filter); + if (err) + return err; + pr_debug("Address filter: %s\n", evsel->filter); + } + + return 0; +} diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h index 09286f1..26fb1ee 100644 --- a/tools/perf/util/auxtrace.h +++ b/tools/perf/util/auxtrace.h @@ -318,6 +318,48 @@ struct auxtrace_record { unsigned int alignment; }; +/** + * struct addr_filter - address filter. + * @list: list node + * @range: true if it is a range filter + * @start: true if action is 'filter' or 'start' + * @action: 'filter', 'start' or 'stop' ('tracestop' is accepted but converted + * to 'stop') + * @sym_from: symbol name for the filter address + * @sym_to: symbol name that determines the filter size + * @sym_from_idx: selects n'th from symbols with the same name (0 means global + * and less than 0 means symbol must be unique) + * @sym_to_idx: same as @sym_from_idx but for @sym_to + * @addr: filter address + * @size: filter region size (for range filters) + * @filename: DSO file name or NULL for the kernel + * @str: allocated string that contains the other string members + */ +struct addr_filter { + struct list_head list; + bool range; + bool start; + const char *action; + const char *sym_from; + const char *sym_to; + int sym_from_idx; + int sym_to_idx; + u64 addr; + u64 size; + const char *filename; + char *str; +}; + +/** + * struct addr_filters - list of address filters. + * @head: list of address filters + * @cnt: number of address filters + */ +struct addr_filters { + struct list_head head; + int cnt; +}; + #ifdef HAVE_AUXTRACE_SUPPORT /* @@ -482,6 +524,12 @@ void perf_session__auxtrace_error_inc(struct perf_session *session, union perf_event *event); void events_stats__auxtrace_error_warn(const struct events_stats *stats); +void addr_filters__init(struct addr_filters *filts); +void addr_filters__exit(struct addr_filters *filts); +int addr_filters__parse_bare_filter(struct addr_filters *filts, + const char *filter); +int auxtrace_parse_filters(struct perf_evlist *evlist); + static inline int auxtrace__process_event(struct perf_session *session, union perf_event *event, struct perf_sample *sample, @@ -640,6 +688,12 @@ void auxtrace_index__free(struct list_head *head __maybe_unused) { } +static inline +int auxtrace_parse_filters(struct perf_evlist *evlist __maybe_unused) +{ + return 0; +} + int auxtrace_mmap__mmap(struct auxtrace_mmap *mm, struct auxtrace_mmap_params *mp, void *userpg, int fd); |
