Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754462AbdGCSqr (ORCPT ); Mon, 3 Jul 2017 14:46:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:37892 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752123AbdGCSqo (ORCPT ); Mon, 3 Jul 2017 14:46:44 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD73C21C98 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org Date: Mon, 3 Jul 2017 15:46:41 -0300 From: Arnaldo Carvalho de Melo To: Krister Johansen Cc: Peter Zijlstra , Ingo Molnar , Alexander Shishkin , linux-kernel@vger.kernel.org Subject: Re: [PATCH tip/perf/core 3/7] perf probe: allow placing uprobes in alternate namespaces. Message-ID: <20170703184641.GC27350@kernel.org> References: <1498875539-4200-1-git-send-email-kjlx@templeofstupid.com> <1498875539-4200-4-git-send-email-kjlx@templeofstupid.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1498875539-4200-4-git-send-email-kjlx@templeofstupid.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 16348 Lines: 469 Em Fri, Jun 30, 2017 at 07:18:55PM -0700, Krister Johansen escreveu: > Teaches perf how to place a uprobe on a file that's in a different mount > namespace. The user must add the probe using the --target-ns argument > to perf probe. Once it has been placed, it may be recorded against > without further namespace-specific commands. > > Signed-off-by: Krister Johansen > --- > tools/perf/builtin-probe.c | 44 ++++++++++++++++++++++-- > tools/perf/util/probe-event.c | 79 +++++++++++++++++++++++++++++-------------- > tools/perf/util/probe-event.h | 10 ++++-- > 3 files changed, 101 insertions(+), 32 deletions(-) > > diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c > index cf9f9e9..5ab2e00 100644 > --- a/tools/perf/builtin-probe.c > +++ b/tools/perf/builtin-probe.c > @@ -58,6 +58,7 @@ static struct { > struct line_range line_range; > char *target; > struct strfilter *filter; > + struct nsinfo *nsi; > } params; > > /* Parse an event definition. Note that any error must die. */ > @@ -80,6 +81,9 @@ static int parse_probe_event(const char *str) > params.target_used = true; > } > > + if (params.nsi) > + pev->nsi = nsinfo__get(params.nsi); > + > /* Parse a perf-probe command into event */ > ret = parse_perf_probe_command(str, pev); > pr_debug("%d arguments\n", pev->nargs); > @@ -178,6 +182,7 @@ static int opt_set_target(const struct option *opt, const char *str, > { > int ret = -ENOENT; > char *tmp; > + struct nscookie nsc; > > if (str) { > if (!strcmp(opt->long_name, "exec")) > @@ -189,7 +194,9 @@ static int opt_set_target(const struct option *opt, const char *str, > > /* Expand given path to absolute path, except for modulename */ > if (params.uprobes || strchr(str, '/')) { > + nsinfo__mountns_enter(params.nsi, &nsc); > tmp = realpath(str, NULL); > + nsinfo__mountns_exit(&nsc); Perhaps have a nsinfo__realpath()? Don't know if this will be used elsewhere, but looks shorter. > if (!tmp) { > pr_warning("Failed to get the absolute path of %s: %m\n", str); > return ret; > @@ -208,6 +215,34 @@ static int opt_set_target(const struct option *opt, const char *str, > return ret; > } > > +static int opt_set_target_ns(const struct option *opt __maybe_unused, > + const char *str, int unset __maybe_unused) > +{ > + int ret = -ENOENT; > + pid_t ns_pid; > + struct nsinfo *nsip; > + > + if (str) { > + errno = 0; > + ns_pid = (pid_t)strtol(str, NULL, 10); > + if (errno != 0) { > + ret = -errno; > + pr_warning("Failed to parse %s as a pid: %s\n", str, > + strerror(errno)); > + return ret; > + } > + nsip = nsinfo__new(ns_pid); > + if (nsip && nsip->need_setns) > + params.nsi = nsinfo__get(nsip); > + nsinfo__put(nsip); > + > + ret = 0; > + } > + > + return ret; > +} > + > + > /* Command option callbacks */ > > #ifdef HAVE_DWARF_SUPPORT > @@ -299,6 +334,7 @@ static void cleanup_params(void) > line_range__clear(¶ms.line_range); > free(params.target); > strfilter__delete(params.filter); > + nsinfo__put(params.nsi); > memset(¶ms, 0, sizeof(params)); > } > > @@ -554,6 +590,8 @@ __cmd_probe(int argc, const char **argv) > OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"), > OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory", > "Look for files with symbols relative to this directory"), > + OPT_CALLBACK(0, "target-ns", NULL, "pid", > + "target pid for namespace information", opt_set_target_ns), > OPT_END() > }; > int ret; > @@ -634,15 +672,15 @@ __cmd_probe(int argc, const char **argv) > pr_err_with_code(" Error: Failed to show event list.", ret); > return ret; > case 'F': > - ret = show_available_funcs(params.target, params.filter, > - params.uprobes); > + ret = show_available_funcs(params.target, params.nsi, > + params.filter, params.uprobes); > if (ret < 0) > pr_err_with_code(" Error: Failed to show functions.", ret); > return ret; > #ifdef HAVE_DWARF_SUPPORT > case 'L': > ret = show_line_range(¶ms.line_range, params.target, > - params.uprobes); > + params.nsi, params.uprobes); > if (ret < 0) > pr_err_with_code(" Error: Failed to show lines.", ret); > return ret; > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 84e7e69..dce4f12 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -184,13 +184,19 @@ static struct map *kernel_get_module_map(const char *module) > return NULL; > } > > -struct map *get_target_map(const char *target, bool user) > +struct map *get_target_map(const char *target, struct nsinfo *nsi, bool user) > { > /* Init maps of given executable or kernel */ > - if (user) > - return dso__new_map(target); > - else > + if (user) { > + struct map *map; > + > + map = dso__new_map(target); > + if (map && map->dso) > + map->dso->nsinfo = nsinfo__get(nsi); > + return map; > + } else { > return kernel_get_module_map(target); > + } > } > > static int convert_exec_to_group(const char *exec, char **result) > @@ -366,7 +372,8 @@ static int kernel_get_module_dso(const char *module, struct dso **pdso) > static int find_alternative_probe_point(struct debuginfo *dinfo, > struct perf_probe_point *pp, > struct perf_probe_point *result, > - const char *target, bool uprobes) > + const char *target, struct nsinfo *nsi, > + bool uprobes) > { > struct map *map = NULL; > struct symbol *sym; > @@ -377,7 +384,7 @@ static int find_alternative_probe_point(struct debuginfo *dinfo, > if (!pp->function || pp->file) > return -ENOTSUP; > > - map = get_target_map(target, uprobes); > + map = get_target_map(target, nsi, uprobes); > if (!map) > return -EINVAL; > > @@ -421,8 +428,8 @@ static int get_alternative_probe_event(struct debuginfo *dinfo, > > memcpy(tmp, &pev->point, sizeof(*tmp)); > memset(&pev->point, 0, sizeof(pev->point)); > - ret = find_alternative_probe_point(dinfo, tmp, &pev->point, > - pev->target, pev->uprobes); > + ret = find_alternative_probe_point(dinfo, tmp, &pev->point, pev->target, > + pev->nsi, pev->uprobes); > if (ret < 0) > memcpy(&pev->point, tmp, sizeof(*tmp)); > > @@ -444,7 +451,7 @@ static int get_alternative_line_range(struct debuginfo *dinfo, > if (lr->end != INT_MAX) > len = lr->end - lr->start; > ret = find_alternative_probe_point(dinfo, &pp, &result, > - target, user); > + target, NULL, user); > if (!ret) { > lr->function = result.function; > lr->file = result.file; > @@ -457,12 +464,14 @@ static int get_alternative_line_range(struct debuginfo *dinfo, > } > > /* Open new debuginfo of given module */ > -static struct debuginfo *open_debuginfo(const char *module, bool silent) > +static struct debuginfo *open_debuginfo(const char *module, struct nsinfo *nsi, > + bool silent) > { > const char *path = module; > char reason[STRERR_BUFSIZE]; > struct debuginfo *ret = NULL; > struct dso *dso = NULL; > + struct nscookie nsc; > int err; > > if (!module || !strchr(module, '/')) { > @@ -480,6 +489,7 @@ static struct debuginfo *open_debuginfo(const char *module, bool silent) > } > path = dso->long_name; > } > + nsinfo__mountns_enter(nsi, &nsc); > ret = debuginfo__new(path); > if (!ret && !silent) { > pr_warning("The %s file has no debug information.\n", path); > @@ -489,6 +499,7 @@ static struct debuginfo *open_debuginfo(const char *module, bool silent) > pr_warning("Rebuild with -g, "); > pr_warning("or install an appropriate debuginfo package.\n"); > } > + nsinfo__mountns_exit(&nsc); > return ret; > } > > @@ -516,7 +527,7 @@ static struct debuginfo *debuginfo_cache__open(const char *module, bool silent) > goto out; > } > > - debuginfo_cache = open_debuginfo(module, silent); > + debuginfo_cache = open_debuginfo(module, NULL, silent); > if (!debuginfo_cache) > zfree(&debuginfo_cache_path); > out: > @@ -531,14 +542,18 @@ static void debuginfo_cache__exit(void) > } > > > -static int get_text_start_address(const char *exec, unsigned long *address) > +static int get_text_start_address(const char *exec, unsigned long *address, > + struct nsinfo *nsi) > { > Elf *elf; > GElf_Ehdr ehdr; > GElf_Shdr shdr; > int fd, ret = -ENOENT; > + struct nscookie nsc; > > + nsinfo__mountns_enter(nsi, &nsc); > fd = open(exec, O_RDONLY); > + nsinfo__mountns_exit(&nsc); > if (fd < 0) > return -errno; > > @@ -582,7 +597,7 @@ static int find_perf_probe_point_from_dwarf(struct probe_trace_point *tp, > ret = -EINVAL; > goto error; > } > - ret = get_text_start_address(tp->module, &stext); > + ret = get_text_start_address(tp->module, &stext, NULL); > if (ret < 0) > goto error; > addr += stext; > @@ -659,7 +674,7 @@ post_process_offline_probe_trace_events(struct probe_trace_event *tevs, > > /* Prepare a map for offline binary */ > map = dso__new_map(pathname); > - if (!map || get_text_start_address(pathname, &stext) < 0) { > + if (!map || get_text_start_address(pathname, &stext, NULL) < 0) { > pr_warning("Failed to get ELF symbols for %s\n", pathname); > return -EINVAL; > } > @@ -676,7 +691,8 @@ post_process_offline_probe_trace_events(struct probe_trace_event *tevs, > } > > static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs, > - int ntevs, const char *exec) > + int ntevs, const char *exec, > + struct nsinfo *nsi) > { > int i, ret = 0; > unsigned long stext = 0; > @@ -684,7 +700,7 @@ static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs, > if (!exec) > return 0; > > - ret = get_text_start_address(exec, &stext); > + ret = get_text_start_address(exec, &stext, nsi); > if (ret < 0) > return ret; > > @@ -715,7 +731,7 @@ post_process_module_probe_trace_events(struct probe_trace_event *tevs, > if (!module) > return 0; > > - map = get_target_map(module, false); > + map = get_target_map(module, NULL, false); > if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) { > pr_warning("Failed to get ELF symbols for %s\n", module); > return -EINVAL; > @@ -802,7 +818,8 @@ static int post_process_probe_trace_events(struct perf_probe_event *pev, > int ret; > > if (uprobe) > - ret = add_exec_to_probe_trace_events(tevs, ntevs, module); > + ret = add_exec_to_probe_trace_events(tevs, ntevs, module, > + pev->nsi); > else if (module) > /* Currently ref_reloc_sym based probe is not for drivers */ > ret = post_process_module_probe_trace_events(tevs, ntevs, > @@ -825,7 +842,7 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, > struct debuginfo *dinfo; > int ntevs, ret = 0; > > - dinfo = open_debuginfo(pev->target, !need_dwarf); > + dinfo = open_debuginfo(pev->target, pev->nsi, !need_dwarf); > if (!dinfo) { > if (need_dwarf) > return -ENOENT; > @@ -945,7 +962,7 @@ static int __show_line_range(struct line_range *lr, const char *module, > char sbuf[STRERR_BUFSIZE]; > > /* Search a line range */ > - dinfo = open_debuginfo(module, false); > + dinfo = open_debuginfo(module, NULL, false); > if (!dinfo) > return -ENOENT; > > @@ -1021,14 +1038,18 @@ static int __show_line_range(struct line_range *lr, const char *module, > return ret; > } > > -int show_line_range(struct line_range *lr, const char *module, bool user) > +int show_line_range(struct line_range *lr, const char *module, > + struct nsinfo *nsi, bool user) > { > int ret; > + struct nscookie nsc; > > ret = init_probe_symbol_maps(user); > if (ret < 0) > return ret; > + nsinfo__mountns_enter(nsi, &nsc); > ret = __show_line_range(lr, module, user); > + nsinfo__mountns_exit(&nsc); > exit_probe_symbol_maps(); > > return ret; > @@ -1111,7 +1132,7 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, > if (ret < 0) > return ret; > > - dinfo = open_debuginfo(pevs->target, false); > + dinfo = open_debuginfo(pevs->target, pevs->nsi, false); > if (!dinfo) { > ret = -ENOENT; > goto out; > @@ -2703,6 +2724,7 @@ static int __add_probe_trace_events(struct perf_probe_event *pev, > struct probe_trace_event *tev = NULL; > struct probe_cache *cache = NULL; > struct strlist *namelist[2] = {NULL, NULL}; > + struct nscookie nsc; > > up = pev->uprobes ? 1 : 0; > fd[up] = __open_probe_file_and_namelist(up, &namelist[up]); > @@ -2729,7 +2751,9 @@ static int __add_probe_trace_events(struct perf_probe_event *pev, > if (ret < 0) > break; > > + nsinfo__mountns_enter(pev->nsi, &nsc); > ret = probe_file__add_event(fd[up], tev); > + nsinfo__mountns_exit(&nsc); > if (ret < 0) > break; > > @@ -2805,7 +2829,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, > int ret, i, j, skipped = 0; > char *mod_name; > > - map = get_target_map(pev->target, pev->uprobes); > + map = get_target_map(pev->target, pev->nsi, pev->uprobes); > if (!map) { > ret = -EINVAL; > goto out; > @@ -3345,13 +3369,16 @@ int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs) > void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs) > { > int i, j; > + struct perf_probe_event *pev; > > /* Loop 3: cleanup and free trace events */ > for (i = 0; i < npevs; i++) { > + pev = &pevs[i]; > for (j = 0; j < pevs[i].ntevs; j++) > clear_probe_trace_event(&pevs[i].tevs[j]); > zfree(&pevs[i].tevs); > pevs[i].ntevs = 0; > + nsinfo__zput(pev->nsi); > clear_perf_probe_event(&pevs[i]); > } > } > @@ -3409,8 +3436,8 @@ int del_perf_probe_events(struct strfilter *filter) > return ret; > } > > -int show_available_funcs(const char *target, struct strfilter *_filter, > - bool user) > +int show_available_funcs(const char *target, struct nsinfo *nsi, > + struct strfilter *_filter, bool user) > { > struct rb_node *nd; > struct map *map; > @@ -3421,7 +3448,7 @@ int show_available_funcs(const char *target, struct strfilter *_filter, > return ret; > > /* Get a symbol map */ > - map = get_target_map(target, user); > + map = get_target_map(target, nsi, user); > if (!map) { > pr_err("Failed to get a map for %s\n", (target) ? : "kernel"); > return -EINVAL; > diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h > index 5812947..078681d 100644 > --- a/tools/perf/util/probe-event.h > +++ b/tools/perf/util/probe-event.h > @@ -4,6 +4,7 @@ > #include > #include > #include "intlist.h" > +#include "namespaces.h" > > /* Probe related configurations */ > struct probe_conf { > @@ -92,6 +93,7 @@ struct perf_probe_event { > struct perf_probe_arg *args; /* Arguments */ > struct probe_trace_event *tevs; > int ntevs; > + struct nsinfo *nsi; /* Target namespace */ > }; > > /* Line range */ > @@ -163,10 +165,12 @@ int show_perf_probe_event(const char *group, const char *event, > struct perf_probe_event *pev, > const char *module, bool use_stdout); > int show_perf_probe_events(struct strfilter *filter); > -int show_line_range(struct line_range *lr, const char *module, bool user); > +int show_line_range(struct line_range *lr, const char *module, > + struct nsinfo *nsi, bool user); > int show_available_vars(struct perf_probe_event *pevs, int npevs, > struct strfilter *filter); > -int show_available_funcs(const char *module, struct strfilter *filter, bool user); > +int show_available_funcs(const char *module, struct nsinfo *nsi, > + struct strfilter *filter, bool user); > void arch__fix_tev_from_maps(struct perf_probe_event *pev, > struct probe_trace_event *tev, struct map *map, > struct symbol *sym); > @@ -180,7 +184,7 @@ int e_snprintf(char *str, size_t size, const char *format, ...) __printf(3, 4); > int copy_to_probe_trace_arg(struct probe_trace_arg *tvar, > struct perf_probe_arg *pvar); > > -struct map *get_target_map(const char *target, bool user); > +struct map *get_target_map(const char *target, struct nsinfo *nsi, bool user); > > void arch__post_process_probe_trace_events(struct perf_probe_event *pev, > int ntevs); > -- > 2.7.4