From fb8c5a56c7ddbc2b0d2ee7a8da60fe1355f75141 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 21 Oct 2010 19:13:35 +0900 Subject: perf probe: Show accessible global variables Add --externs for allowing --vars to show accessible global (externally defined) variables from a given probe point too. This will give you a hint which globals can be accessible from the probe point. Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Ingo Molnar Cc: Frederic Weisbecker LKML-Reference: <20101021101335.3542.31003.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-probe.txt | 6 +++++- tools/perf/builtin-probe.c | 8 ++++++-- tools/perf/util/probe-event.c | 8 ++++---- tools/perf/util/probe-event.h | 2 +- tools/perf/util/probe-finder.c | 26 +++++++++++++++++++++----- tools/perf/util/probe-finder.h | 5 ++++- 6 files changed, 41 insertions(+), 14 deletions(-) diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt index 72f5d9e21432..148c178a35aa 100644 --- a/tools/perf/Documentation/perf-probe.txt +++ b/tools/perf/Documentation/perf-probe.txt @@ -18,7 +18,7 @@ or or 'perf probe' --line='FUNC[:RLN[+NUM|:RLN2]]|SRC:ALN[+NUM|:ALN2]' or -'perf probe' --vars='PROBEPOINT' +'perf probe' [--externs] --vars='PROBEPOINT' DESCRIPTION ----------- @@ -64,6 +64,10 @@ OPTIONS Show available local variables at given probe point. The argument syntax is same as PROBE SYNTAX, but NO ARGs. +--externs:: + (Only for --vars) Show external defined variables in addition to local + variables. + -f:: --force:: Forcibly add events with existing name. diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c index c777bec28466..bdf60cfdf70f 100644 --- a/tools/perf/builtin-probe.c +++ b/tools/perf/builtin-probe.c @@ -51,6 +51,7 @@ static struct { bool force_add; bool show_lines; bool show_vars; + bool show_ext_vars; bool mod_events; int nevents; struct perf_probe_event events[MAX_PROBES]; @@ -162,7 +163,7 @@ static const char * const probe_usage[] = { "perf probe --list", #ifdef DWARF_SUPPORT "perf probe --line 'LINEDESC'", - "perf probe --vars 'PROBEPOINT'", + "perf probe [--externs] --vars 'PROBEPOINT'", #endif NULL }; @@ -207,6 +208,8 @@ static const struct option options[] = { OPT_CALLBACK('V', "vars", NULL, "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT", "Show accessible variables on PROBEDEF", opt_show_vars), + OPT_BOOLEAN('\0', "externs", ¶ms.show_ext_vars, + "Show external variables too (with --vars only)"), OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name, "file", "vmlinux pathname"), OPT_STRING('s', "source", &symbol_conf.source_prefix, @@ -287,7 +290,8 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) usage_with_options(probe_usage, options); } ret = show_available_vars(params.events, params.nevents, - params.max_probe_points); + params.max_probe_points, + params.show_ext_vars); if (ret < 0) pr_err(" Error: Failed to show vars. (%d)\n", ret); return ret; diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 83192a59f02a..82b0976e2053 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -379,7 +379,7 @@ end: } static int show_available_vars_at(int fd, struct perf_probe_event *pev, - int max_vls) + int max_vls, bool externs) { char *buf; int ret, i; @@ -391,7 +391,7 @@ static int show_available_vars_at(int fd, struct perf_probe_event *pev, return -EINVAL; pr_debug("Searching variables at %s\n", buf); - ret = find_available_vars_at(fd, pev, &vls, max_vls); + ret = find_available_vars_at(fd, pev, &vls, max_vls, externs); if (ret > 0) { /* Some variables were found */ fprintf(stdout, "Available variables at %s\n", buf); @@ -421,7 +421,7 @@ static int show_available_vars_at(int fd, struct perf_probe_event *pev, /* Show available variables on given probe point */ int show_available_vars(struct perf_probe_event *pevs, int npevs, - int max_vls) + int max_vls, bool externs) { int i, fd, ret = 0; @@ -438,7 +438,7 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, setup_pager(); for (i = 0; i < npevs && ret >= 0; i++) - ret = show_available_vars_at(fd, &pevs[i], max_vls); + ret = show_available_vars_at(fd, &pevs[i], max_vls, externs); close(fd); return ret; diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index 83130f634f01..c74b1fd2c1fa 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -122,7 +122,7 @@ extern int del_perf_probe_events(struct strlist *dellist); extern int show_perf_probe_events(void); extern int show_line_range(struct line_range *lr); extern int show_available_vars(struct perf_probe_event *pevs, int npevs, - int max_probe_points); + int max_probe_points, bool externs); /* Maximum index number of event-name postfix */ diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 986027fa495f..a274fd0c143e 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1312,12 +1312,13 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data) af->pf.fb_ops, NULL); if (ret == 0) { ret = die_get_varname(die_mem, buf, MAX_VAR_LEN); + pr_debug2("Add new var: %s\n", buf); if (ret > 0) strlist__add(vl->vars, buf); } } - if (dwarf_haspc(die_mem, af->pf.addr)) + if (af->child && dwarf_haspc(die_mem, af->pf.addr)) return DIE_FIND_CB_CONTINUE; else return DIE_FIND_CB_SIBLING; @@ -1329,8 +1330,8 @@ static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf) struct available_var_finder *af = container_of(pf, struct available_var_finder, pf); struct variable_list *vl; - Dwarf_Die die_mem; - int ret; + Dwarf_Die die_mem, *scopes = NULL; + int ret, nscopes; /* Check number of tevs */ if (af->nvls == af->max_vls) { @@ -1351,8 +1352,22 @@ static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf) vl->vars = strlist__new(true, NULL); if (vl->vars == NULL) return -ENOMEM; + af->child = true; die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem); + /* Find external variables */ + if (!af->externs) + goto out; + /* Don't need to search child DIE for externs. */ + af->child = false; + nscopes = dwarf_getscopes_die(sp_die, &scopes); + while (nscopes-- > 1) + die_find_child(&scopes[nscopes], collect_variables_cb, + (void *)af, &die_mem); + if (scopes) + free(scopes); + +out: if (strlist__empty(vl->vars)) { strlist__delete(vl->vars); vl->vars = NULL; @@ -1363,11 +1378,12 @@ static int add_available_vars(Dwarf_Die *sp_die, struct probe_finder *pf) /* Find available variables at given probe point */ int find_available_vars_at(int fd, struct perf_probe_event *pev, - struct variable_list **vls, int max_vls) + struct variable_list **vls, int max_vls, + bool externs) { struct available_var_finder af = { .pf = {.pev = pev, .callback = add_available_vars}, - .max_vls = max_vls}; + .max_vls = max_vls, .externs = externs}; int ret; /* Allocate result vls array */ diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h index baffd25f39c9..516912a04011 100644 --- a/tools/perf/util/probe-finder.h +++ b/tools/perf/util/probe-finder.h @@ -30,7 +30,8 @@ extern int find_line_range(int fd, struct line_range *lr); /* Find available variables */ extern int find_available_vars_at(int fd, struct perf_probe_event *pev, - struct variable_list **vls, int max_points); + struct variable_list **vls, int max_points, + bool externs); #include #include @@ -70,6 +71,8 @@ struct available_var_finder { struct variable_list *vls; /* Found variable lists */ int nvls; /* Number of variable lists */ int max_vls; /* Max no. of variable lists */ + bool externs; /* Find external vars too */ + bool child; /* Search child scopes */ }; struct line_finder { -- cgit v1.2.3-59-g8ed1b