diff options
Diffstat (limited to 'tools/perf/util/probe-event.c')
| -rw-r--r-- | tools/perf/util/probe-event.c | 425 |
1 files changed, 326 insertions, 99 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 919937eb0be2..d8bb616ff57c 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -41,6 +41,7 @@ #include "symbol.h" #include "thread.h" #include <api/fs/debugfs.h> +#include <api/fs/tracefs.h> #include "trace-event.h" /* For __maybe_unused */ #include "probe-event.h" #include "probe-finder.h" @@ -79,6 +80,7 @@ static int init_symbol_maps(bool user_only) int ret; symbol_conf.sort_by_name = true; + symbol_conf.allow_aliases = true; ret = symbol__init(NULL); if (ret < 0) { pr_debug("Failed to init symbol map.\n"); @@ -133,6 +135,8 @@ static struct ref_reloc_sym *kernel_get_ref_reloc_sym(void) return NULL; kmap = map__kmap(host_machine->vmlinux_maps[MAP__FUNCTION]); + if (!kmap) + return NULL; return kmap->ref_reloc_sym; } @@ -150,7 +154,7 @@ static u64 kernel_get_symbol_address_by_name(const char *name, bool reloc) sym = __find_kernel_function_by_name(name, &map); if (sym) return map->unmap_ip(map, sym->start) - - (reloc) ? 0 : map->reloc; + ((reloc) ? 0 : map->reloc); } return 0; } @@ -177,6 +181,25 @@ static struct map *kernel_get_module_map(const char *module) return NULL; } +static struct map *get_target_map(const char *target, bool user) +{ + /* Init maps of given executable or kernel */ + if (user) + return dso__new_map(target); + else + return kernel_get_module_map(target); +} + +static void put_target_map(struct map *map, bool user) +{ + if (map && user) { + /* Only the user map needs to be released */ + dso__delete(map->dso); + map__delete(map); + } +} + + static struct dso *kernel_get_module_dso(const char *module) { struct dso *dso; @@ -248,6 +271,13 @@ out: return ret; } +static void clear_perf_probe_point(struct perf_probe_point *pp) +{ + free(pp->file); + free(pp->function); + free(pp->lazy_line); +} + static void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs) { int i; @@ -257,6 +287,104 @@ static void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs) } #ifdef HAVE_DWARF_SUPPORT +/* + * Some binaries like glibc have special symbols which are on the symbol + * table, but not in the debuginfo. If we can find the address of the + * symbol from map, we can translate the address back to the probe point. + */ +static int find_alternative_probe_point(struct debuginfo *dinfo, + struct perf_probe_point *pp, + struct perf_probe_point *result, + const char *target, bool uprobes) +{ + struct map *map = NULL; + struct symbol *sym; + u64 address = 0; + int ret = -ENOENT; + + /* This can work only for function-name based one */ + if (!pp->function || pp->file) + return -ENOTSUP; + + map = get_target_map(target, uprobes); + if (!map) + return -EINVAL; + + /* Find the address of given function */ + map__for_each_symbol_by_name(map, pp->function, sym) { + if (uprobes) + address = sym->start; + else + address = map->unmap_ip(map, sym->start); + break; + } + if (!address) { + ret = -ENOENT; + goto out; + } + pr_debug("Symbol %s address found : %" PRIx64 "\n", + pp->function, address); + + ret = debuginfo__find_probe_point(dinfo, (unsigned long)address, + result); + if (ret <= 0) + ret = (!ret) ? -ENOENT : ret; + else { + result->offset += pp->offset; + result->line += pp->line; + result->retprobe = pp->retprobe; + ret = 0; + } + +out: + put_target_map(map, uprobes); + return ret; + +} + +static int get_alternative_probe_event(struct debuginfo *dinfo, + struct perf_probe_event *pev, + struct perf_probe_point *tmp, + const char *target) +{ + int ret; + + memcpy(tmp, &pev->point, sizeof(*tmp)); + memset(&pev->point, 0, sizeof(pev->point)); + ret = find_alternative_probe_point(dinfo, tmp, &pev->point, + target, pev->uprobes); + if (ret < 0) + memcpy(&pev->point, tmp, sizeof(*tmp)); + + return ret; +} + +static int get_alternative_line_range(struct debuginfo *dinfo, + struct line_range *lr, + const char *target, bool user) +{ + struct perf_probe_point pp = { .function = lr->function, + .file = lr->file, + .line = lr->start }; + struct perf_probe_point result; + int ret, len = 0; + + memset(&result, 0, sizeof(result)); + + if (lr->end != INT_MAX) + len = lr->end - lr->start; + ret = find_alternative_probe_point(dinfo, &pp, &result, + target, user); + if (!ret) { + lr->function = result.function; + lr->file = result.file; + lr->start = result.line; + if (lr->end != INT_MAX) + lr->end = lr->start + len; + clear_perf_probe_point(&pp); + } + return ret; +} /* Open new debuginfo of given module */ static struct debuginfo *open_debuginfo(const char *module, bool silent) @@ -465,6 +593,7 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, int max_tevs, const char *target) { bool need_dwarf = perf_probe_event_need_dwarf(pev); + struct perf_probe_point tmp; struct debuginfo *dinfo; int ntevs, ret = 0; @@ -481,6 +610,20 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, /* Searching trace events corresponding to a probe event */ ntevs = debuginfo__find_trace_events(dinfo, pev, tevs, max_tevs); + if (ntevs == 0) { /* Not found, retry with an alternative */ + ret = get_alternative_probe_event(dinfo, pev, &tmp, target); + if (!ret) { + ntevs = debuginfo__find_trace_events(dinfo, pev, + tevs, max_tevs); + /* + * Write back to the original probe_event for + * setting appropriate (user given) event name + */ + clear_perf_probe_point(&pev->point); + memcpy(&pev->point, &tmp, sizeof(tmp)); + } + } + debuginfo__delete(dinfo); if (ntevs > 0) { /* Succeeded to find trace events */ @@ -495,11 +638,9 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, } if (ntevs == 0) { /* No error but failed to find probe point. */ - pr_warning("Probe point '%s' not found in debuginfo.\n", + pr_warning("Probe point '%s' not found.\n", synthesize_perf_probe_point(&pev->point)); - if (need_dwarf) - return -ENOENT; - return 0; + return -ENOENT; } /* Error path : ntevs < 0 */ pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs); @@ -514,63 +655,6 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, return ntevs; } -/* - * Find a src file from a DWARF tag path. Prepend optional source path prefix - * and chop off leading directories that do not exist. Result is passed back as - * a newly allocated path on success. - * Return 0 if file was found and readable, -errno otherwise. - */ -static int get_real_path(const char *raw_path, const char *comp_dir, - char **new_path) -{ - const char *prefix = symbol_conf.source_prefix; - - if (!prefix) { - if (raw_path[0] != '/' && comp_dir) - /* If not an absolute path, try to use comp_dir */ - prefix = comp_dir; - else { - if (access(raw_path, R_OK) == 0) { - *new_path = strdup(raw_path); - return 0; - } else - return -errno; - } - } - - *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2)); - if (!*new_path) - return -ENOMEM; - - for (;;) { - sprintf(*new_path, "%s/%s", prefix, raw_path); - - if (access(*new_path, R_OK) == 0) - return 0; - - if (!symbol_conf.source_prefix) - /* In case of searching comp_dir, don't retry */ - return -errno; - - switch (errno) { - case ENAMETOOLONG: - case ENOENT: - case EROFS: - case EFAULT: - raw_path = strchr(++raw_path, '/'); - if (!raw_path) { - zfree(new_path); - return -ENOENT; - } - continue; - - default: - zfree(new_path); - return -errno; - } - } -} - #define LINEBUF_SIZE 256 #define NR_ADDITIONAL_LINES 2 @@ -622,7 +706,8 @@ static int _show_one_line(FILE *fp, int l, bool skip, bool show_num) * Show line-range always requires debuginfo to find source file and * line number. */ -static int __show_line_range(struct line_range *lr, const char *module) +static int __show_line_range(struct line_range *lr, const char *module, + bool user) { int l = 1; struct int_node *ln; @@ -638,6 +723,11 @@ static int __show_line_range(struct line_range *lr, const char *module) return -ENOENT; ret = debuginfo__find_line_range(dinfo, lr); + if (!ret) { /* Not found, retry with an alternative */ + ret = get_alternative_line_range(dinfo, lr, module, user); + if (!ret) + ret = debuginfo__find_line_range(dinfo, lr); + } debuginfo__delete(dinfo); if (ret == 0 || ret == -ENOENT) { pr_warning("Specified source line is not found.\n"); @@ -650,7 +740,11 @@ static int __show_line_range(struct line_range *lr, const char *module) /* Convert source file path */ tmp = lr->path; ret = get_real_path(tmp, lr->comp_dir, &lr->path); - free(tmp); /* Free old path */ + + /* Free old path when new path is assigned */ + if (tmp != lr->path) + free(tmp); + if (ret < 0) { pr_warning("Failed to find source file path.\n"); return ret; @@ -707,7 +801,7 @@ int show_line_range(struct line_range *lr, const char *module, bool user) ret = init_symbol_maps(user); if (ret < 0) return ret; - ret = __show_line_range(lr, module); + ret = __show_line_range(lr, module, user); exit_symbol_maps(); return ret; @@ -716,12 +810,13 @@ int show_line_range(struct line_range *lr, const char *module, bool user) static int show_available_vars_at(struct debuginfo *dinfo, struct perf_probe_event *pev, int max_vls, struct strfilter *_filter, - bool externs) + bool externs, const char *target) { char *buf; int ret, i, nvars; struct str_node *node; struct variable_list *vls = NULL, *vl; + struct perf_probe_point tmp; const char *var; buf = synthesize_perf_probe_point(&pev->point); @@ -731,6 +826,15 @@ static int show_available_vars_at(struct debuginfo *dinfo, ret = debuginfo__find_available_vars_at(dinfo, pev, &vls, max_vls, externs); + if (!ret) { /* Not found, retry with an alternative */ + ret = get_alternative_probe_event(dinfo, pev, &tmp, target); + if (!ret) { + ret = debuginfo__find_available_vars_at(dinfo, pev, + &vls, max_vls, externs); + /* Release the old probe_point */ + clear_perf_probe_point(&tmp); + } + } if (ret <= 0) { if (ret == 0 || ret == -ENOENT) { pr_err("Failed to find the address of %s\n", buf); @@ -793,7 +897,7 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, for (i = 0; i < npevs && ret >= 0; i++) ret = show_available_vars_at(dinfo, &pevs[i], max_vls, _filter, - externs); + externs, module); debuginfo__delete(dinfo); out: @@ -1739,15 +1843,13 @@ static int convert_to_perf_probe_event(struct probe_trace_event *tev, void clear_perf_probe_event(struct perf_probe_event *pev) { - struct perf_probe_point *pp = &pev->point; struct perf_probe_arg_field *field, *next; int i; free(pev->event); free(pev->group); - free(pp->file); - free(pp->function); - free(pp->lazy_line); + free(pev->target); + clear_perf_probe_point(&pev->point); for (i = 0; i < pev->nargs; i++) { free(pev->args[i].name); @@ -1805,7 +1907,7 @@ static void print_open_warning(int err, bool is_kprobe) " - please rebuild kernel with %s.\n", is_kprobe ? 'k' : 'u', config); } else if (err == -ENOTSUP) - pr_warning("Debugfs is not mounted.\n"); + pr_warning("Tracefs or debugfs is not mounted.\n"); else pr_warning("Failed to open %cprobe_events: %s\n", is_kprobe ? 'k' : 'u', @@ -1816,7 +1918,7 @@ static void print_both_open_warning(int kerr, int uerr) { /* Both kprobes and uprobes are disabled, warn it. */ if (kerr == -ENOTSUP && uerr == -ENOTSUP) - pr_warning("Debugfs is not mounted.\n"); + pr_warning("Tracefs or debugfs is not mounted.\n"); else if (kerr == -ENOENT && uerr == -ENOENT) pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS " "or/and CONFIG_UPROBE_EVENTS.\n"); @@ -1833,13 +1935,20 @@ static int open_probe_events(const char *trace_file, bool readwrite) { char buf[PATH_MAX]; const char *__debugfs; + const char *tracing_dir = ""; int ret; - __debugfs = debugfs_find_mountpoint(); - if (__debugfs == NULL) - return -ENOTSUP; + __debugfs = tracefs_find_mountpoint(); + if (__debugfs == NULL) { + tracing_dir = "tracing/"; + + __debugfs = debugfs_find_mountpoint(); + if (__debugfs == NULL) + return -ENOTSUP; + } - ret = e_snprintf(buf, PATH_MAX, "%s/%s", __debugfs, trace_file); + ret = e_snprintf(buf, PATH_MAX, "%s/%s%s", + __debugfs, tracing_dir, trace_file); if (ret >= 0) { pr_debug("Opening %s write=%d\n", buf, readwrite); if (readwrite && !probe_event_dry_run) @@ -1855,12 +1964,12 @@ static int open_probe_events(const char *trace_file, bool readwrite) static int open_kprobe_events(bool readwrite) { - return open_probe_events("tracing/kprobe_events", readwrite); + return open_probe_events("kprobe_events", readwrite); } static int open_uprobe_events(bool readwrite) { - return open_probe_events("tracing/uprobe_events", readwrite); + return open_probe_events("uprobe_events", readwrite); } /* Get raw string list of current kprobe_events or uprobe_events */ @@ -1895,6 +2004,95 @@ static struct strlist *get_probe_trace_command_rawlist(int fd) return sl; } +struct kprobe_blacklist_node { + struct list_head list; + unsigned long start; + unsigned long end; + char *symbol; +}; + +static void kprobe_blacklist__delete(struct list_head *blacklist) +{ + struct kprobe_blacklist_node *node; + + while (!list_empty(blacklist)) { + node = list_first_entry(blacklist, + struct kprobe_blacklist_node, list); + list_del(&node->list); + free(node->symbol); + free(node); + } +} + +static int kprobe_blacklist__load(struct list_head *blacklist) +{ + struct kprobe_blacklist_node *node; + const char *__debugfs = debugfs_find_mountpoint(); + char buf[PATH_MAX], *p; + FILE *fp; + int ret; + + if (__debugfs == NULL) + return -ENOTSUP; + + ret = e_snprintf(buf, PATH_MAX, "%s/kprobes/blacklist", __debugfs); + if (ret < 0) + return ret; + + fp = fopen(buf, "r"); + if (!fp) + return -errno; + + ret = 0; + while (fgets(buf, PATH_MAX, fp)) { + node = zalloc(sizeof(*node)); + if (!node) { + ret = -ENOMEM; + break; + } + INIT_LIST_HEAD(&node->list); + list_add_tail(&node->list, blacklist); + if (sscanf(buf, "0x%lx-0x%lx", &node->start, &node->end) != 2) { + ret = -EINVAL; + break; + } + p = strchr(buf, '\t'); + if (p) { + p++; + if (p[strlen(p) - 1] == '\n') + p[strlen(p) - 1] = '\0'; + } else + p = (char *)"unknown"; + node->symbol = strdup(p); + if (!node->symbol) { + ret = -ENOMEM; + break; + } + pr_debug2("Blacklist: 0x%lx-0x%lx, %s\n", + node->start, node->end, node->symbol); + ret++; + } + if (ret < 0) + kprobe_blacklist__delete(blacklist); + fclose(fp); + + return ret; +} + +static struct kprobe_blacklist_node * +kprobe_blacklist__find_by_address(struct list_head *blacklist, + unsigned long address) +{ + struct kprobe_blacklist_node *node; + + list_for_each_entry(node, blacklist, list) { + if (node->start <= address && address <= node->end) + return node; + } + + return NULL; +} + /* Show an event */ static int show_perf_probe_event(struct perf_probe_event *pev, const char *module) @@ -2100,6 +2298,27 @@ static int get_new_event_name(char *buf, size_t len, const char *base, return ret; } +/* Warn if the current kernel's uprobe implementation is old */ +static void warn_uprobe_event_compat(struct probe_trace_event *tev) +{ + int i; + char *buf = synthesize_probe_trace_command(tev); + + /* Old uprobe event doesn't support memory dereference */ + if (!tev->uprobes || tev->nargs == 0 || !buf) + goto out; + + for (i = 0; i < tev->nargs; i++) + if (strglobmatch(tev->args[i].value, "[$@+-]*")) { + pr_warning("Please upgrade your kernel to at least " + "3.14 to have access to feature %s\n", + tev->args[i].value); + break; + } +out: + free(buf); +} + static int __add_probe_trace_events(struct perf_probe_event *pev, struct probe_trace_event *tevs, int ntevs, bool allow_suffix) @@ -2109,6 +2328,8 @@ static int __add_probe_trace_events(struct perf_probe_event *pev, char buf[64]; const char *event, *group; struct strlist *namelist; + LIST_HEAD(blacklist); + struct kprobe_blacklist_node *node; if (pev->uprobes) fd = open_uprobe_events(true); @@ -2126,11 +2347,25 @@ static int __add_probe_trace_events(struct perf_probe_event *pev, pr_debug("Failed to get current event list.\n"); return -EIO; } + /* Get kprobe blacklist if exists */ + if (!pev->uprobes) { + ret = kprobe_blacklist__load(&blacklist); + if (ret < 0) + pr_debug("No kprobe blacklist support, ignored\n"); + } ret = 0; pr_info("Added new event%s\n", (ntevs > 1) ? "s:" : ":"); for (i = 0; i < ntevs; i++) { tev = &tevs[i]; + /* Ensure that the address is NOT blacklisted */ + node = kprobe_blacklist__find_by_address(&blacklist, + tev->point.address); + if (node) { + pr_warning("Warning: Skipped probing on blacklisted function: %s\n", node->symbol); + continue; + } + if (pev->event) event = pev->event; else @@ -2180,14 +2415,18 @@ static int __add_probe_trace_events(struct perf_probe_event *pev, */ allow_suffix = true; } + if (ret == -EINVAL && pev->uprobes) + warn_uprobe_event_compat(tev); - if (ret >= 0) { + /* Note that it is possible to skip all events because of blacklist */ + if (ret >= 0 && tev->event) { /* Show how to use the event. */ pr_info("\nYou can now use it in all perf tools, such as:\n\n"); pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", tev->group, tev->event); } + kprobe_blacklist__delete(&blacklist); strlist__delete(namelist); close(fd); return ret; @@ -2199,8 +2438,7 @@ static int find_probe_functions(struct map *map, char *name) struct symbol *sym; map__for_each_symbol_by_name(map, name, sym) { - if (sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL) - found++; + found++; } return found; @@ -2218,7 +2456,6 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, int max_tevs, const char *target) { struct map *map = NULL; - struct kmap *kmap = NULL; struct ref_reloc_sym *reloc_sym = NULL; struct symbol *sym; struct probe_trace_event *tev; @@ -2227,11 +2464,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, int num_matched_functions; int ret, i; - /* Init maps of given executable or kernel */ - if (pev->uprobes) - map = dso__new_map(target); - else - map = kernel_get_module_map(target); + map = get_target_map(target, pev->uprobes); if (!map) { ret = -EINVAL; goto out; @@ -2255,8 +2488,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, } if (!pev->uprobes && !pp->retprobe) { - kmap = map__kmap(map); - reloc_sym = kmap->ref_reloc_sym; + reloc_sym = kernel_get_ref_reloc_sym(); if (!reloc_sym) { pr_warning("Relocated base symbol is not found!\n"); ret = -EINVAL; @@ -2324,11 +2556,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, } out: - if (map && pev->uprobes) { - /* Only when using uprobe(exec) map needs to be released */ - dso__delete(map->dso); - map__delete(map); - } + put_target_map(map, pev->uprobes); return ret; nomem_out: @@ -2369,7 +2597,7 @@ struct __event_package { }; int add_perf_probe_events(struct perf_probe_event *pevs, int npevs, - int max_tevs, const char *target, bool force_add) + int max_tevs, bool force_add) { int i, j, ret; struct __event_package *pkgs; @@ -2393,7 +2621,7 @@ int add_perf_probe_events(struct perf_probe_event *pevs, int npevs, ret = convert_to_probe_trace_events(pkgs[i].pev, &pkgs[i].tevs, max_tevs, - target); + pkgs[i].pev->target); if (ret < 0) goto end; pkgs[i].ntevs = ret; @@ -2568,8 +2796,7 @@ static struct strfilter *available_func_filter; static int filter_available_functions(struct map *map __maybe_unused, struct symbol *sym) { - if ((sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL) && - strfilter__compare(available_func_filter, sym->name)) + if (strfilter__compare(available_func_filter, sym->name)) return 0; return 1; } |