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Commit bf2e710b authored by Krister Johansen's avatar Krister Johansen Committed by Arnaldo Carvalho de Melo
Browse files

perf maps: Lookup maps in both intitial mountns and inner mountns. 



If a process is in a mountns and has symbols in /tmp/perf-<pid>.map,
look first in the namespace using the tgid for the pidns that the
process might be in.  If the map isn't found there, try looking in the
mountns where perf is running, and use the tgid that's appropriate for
perf's pid namespace.  If all else fails, use the original pid.

This allows us to locate a symbol map file in the mount namespace, if it
was generated there.  However, we also try the tool's /tmp in case it's
there instead.

Signed-off-by: default avatarKrister Johansen <kjlx@templeofstupid.com>
Tested-by: default avatarBrendan Gregg <brendan.d.gregg@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1499305693-1599-3-git-send-email-kjlx@templeofstupid.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 843ff37b

tools/perf/util/machine.c

+2 −2
Original line number Diff line number Diff line
@@ -1392,7 +1392,7 @@ int machine__process_mmap2_event(struct machine *machine, 


	map = map__new(machine, event->mmap2.start,

			event->mmap2.len, event->mmap2.pgoff,

			event->mmap2.pid, event->mmap2.maj,

			event->mmap2.maj,

			event->mmap2.min, event->mmap2.ino,

			event->mmap2.ino_generation,

			event->mmap2.prot,
@@ -1450,7 +1450,7 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event 


	map = map__new(machine, event->mmap.start,

			event->mmap.len, event->mmap.pgoff,

			event->mmap.pid, 0, 0, 0, 0, 0, 0,

			0, 0, 0, 0, 0, 0,

			event->mmap.filename,

			type, thread);

tools/perf/util/map.c

+19 −4
Original line number Diff line number Diff line
@@ -146,11 +146,13 @@ void map__init(struct map *map, enum map_type type, 
}



struct map *map__new(struct machine *machine, u64 start, u64 len,

		     u64 pgoff, u32 pid, u32 d_maj, u32 d_min, u64 ino,

		     u64 pgoff, u32 d_maj, u32 d_min, u64 ino,

		     u64 ino_gen, u32 prot, u32 flags, char *filename,

		     enum map_type type, struct thread *thread)

{

	struct map *map = malloc(sizeof(*map));

	struct nsinfo *nsi = NULL;

	struct nsinfo *nnsi;



	if (map != NULL) {

		char newfilename[PATH_MAX];
@@ -168,9 +170,11 @@ struct map *map__new(struct machine *machine, u64 start, u64 len, 
		map->ino_generation = ino_gen;

		map->prot = prot;

		map->flags = flags;

		nsi = nsinfo__get(thread->nsinfo);



		if ((anon || no_dso) && type == MAP__FUNCTION) {

			snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", pid);

		if ((anon || no_dso) && nsi && type == MAP__FUNCTION) {

			snprintf(newfilename, sizeof(newfilename),

				 "/tmp/perf-%d.map", nsi->pid);

			filename = newfilename;

		}
@@ -180,6 +184,16 @@ struct map *map__new(struct machine *machine, u64 start, u64 len, 
		}



		if (vdso) {

			/* The vdso maps are always on the host and not the

			 * container.  Ensure that we don't use setns to look

			 * them up.

			 */

			nnsi = nsinfo__copy(nsi);

			if (nnsi) {

				nsinfo__put(nsi);

				nnsi->need_setns = false;

				nsi = nnsi;

			}

			pgoff = 0;

			dso = machine__findnew_vdso(machine, thread);

		} else
@@ -201,11 +215,12 @@ struct map *map__new(struct machine *machine, u64 start, u64 len, 
			if (type != MAP__FUNCTION)

				dso__set_loaded(dso, map->type);

		}

		dso->nsinfo = nsinfo__get(thread->nsinfo);

		dso->nsinfo = nsi;

		dso__put(dso);

	}

	return map;

out_delete:

	nsinfo__put(nsi);

	free(map);

	return NULL;

}

tools/perf/util/map.h

+1 −1
Original line number Diff line number Diff line
@@ -141,7 +141,7 @@ struct thread; 
void map__init(struct map *map, enum map_type type,

	       u64 start, u64 end, u64 pgoff, struct dso *dso);

struct map *map__new(struct machine *machine, u64 start, u64 len,

		     u64 pgoff, u32 pid, u32 d_maj, u32 d_min, u64 ino,

		     u64 pgoff, u32 d_maj, u32 d_min, u64 ino,

		     u64 ino_gen, u32 prot, u32 flags,

		     char *filename, enum map_type type, struct thread *thread);

struct map *map__new2(u64 start, struct dso *dso, enum map_type type);

tools/perf/util/namespaces.c

+77 −6
Original line number Diff line number Diff line
@@ -40,18 +40,23 @@ void namespaces__free(struct namespaces *namespaces) 
	free(namespaces);

}



void nsinfo__init(struct nsinfo *nsi)

int nsinfo__init(struct nsinfo *nsi)

{

	char oldns[PATH_MAX];

	char spath[PATH_MAX];

	char *newns = NULL;

	char *statln = NULL;

	struct stat old_stat;

	struct stat new_stat;

	FILE *f = NULL;

	size_t linesz = 0;

	int rv = -1;



	if (snprintf(oldns, PATH_MAX, "/proc/self/ns/mnt") >= PATH_MAX)

		return;

		return rv;



	if (asprintf(&newns, "/proc/%d/ns/mnt", nsi->pid) == -1)

		return;

		return rv;



	if (stat(oldns, &old_stat) < 0)

		goto out;
@@ -68,24 +73,89 @@ void nsinfo__init(struct nsinfo *nsi) 
		newns = NULL;

	}



	/* If we're dealing with a process that is in a different PID namespace,

	 * attempt to work out the innermost tgid for the process.

	 */

	if (snprintf(spath, PATH_MAX, "/proc/%d/status", nsi->pid) >= PATH_MAX)

		goto out;



	f = fopen(spath, "r");

	if (f == NULL)

		goto out;



	while (getline(&statln, &linesz, f) != -1) {

		/* Use tgid if CONFIG_PID_NS is not defined. */

		if (strstr(statln, "Tgid:") != NULL) {

			nsi->tgid = (pid_t)strtol(strrchr(statln, '\t'),

						     NULL, 10);

			nsi->nstgid = nsi->tgid;

		}



		if (strstr(statln, "NStgid:") != NULL) {

			nsi->nstgid = (pid_t)strtol(strrchr(statln, '\t'),

						     NULL, 10);

			break;

		}

	}

	rv = 0;



out:

	if (f != NULL)

		(void) fclose(f);

	free(statln);

	free(newns);

	return rv;

}



struct nsinfo *nsinfo__new(pid_t pid)

{

	struct nsinfo *nsi = calloc(1, sizeof(*nsi));

	struct nsinfo *nsi;



	if (pid == 0)

		return NULL;



	nsi = calloc(1, sizeof(*nsi));

	if (nsi != NULL) {

		nsi->pid = pid;

		nsi->tgid = pid;

		nsi->nstgid = pid;

		nsi->need_setns = false;

		/* Init may fail if the process exits while we're trying to look

		 * at its proc information.  In that case, save the pid but

		 * don't try to enter the namespace.

		 */

		if (nsinfo__init(nsi) == -1)

			nsi->need_setns = false;

		nsinfo__init(nsi);



		refcount_set(&nsi->refcnt, 1);

	}



	return nsi;

}



struct nsinfo *nsinfo__copy(struct nsinfo *nsi)

{

	struct nsinfo *nnsi;



	nnsi = calloc(1, sizeof(*nnsi));

	if (nnsi != NULL) {

		nnsi->pid = nsi->pid;

		nnsi->tgid = nsi->tgid;

		nnsi->nstgid = nsi->nstgid;

		nnsi->need_setns = nsi->need_setns;

		if (nsi->mntns_path) {

			nnsi->mntns_path = strdup(nsi->mntns_path);

			if (!nnsi->mntns_path) {

				free(nnsi);

				return NULL;

			}

		}

		refcount_set(&nnsi->refcnt, 1);

	}



	return nnsi;

}



void nsinfo__delete(struct nsinfo *nsi)

{

	zfree(&nsi->mntns_path);
@@ -105,7 +175,8 @@ void nsinfo__put(struct nsinfo *nsi) 
		nsinfo__delete(nsi);

}



void nsinfo__mountns_enter(struct nsinfo *nsi, struct nscookie *nc)

void nsinfo__mountns_enter(struct nsinfo *nsi,

				  struct nscookie *nc)

{

	char curpath[PATH_MAX];

	int oldns = -1;

tools/perf/util/namespaces.h

+4 −1
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ void namespaces__free(struct namespaces *namespaces); 


struct nsinfo {

	pid_t			pid;

	pid_t			tgid;

	pid_t			nstgid;

	bool			need_setns;

	char			*mntns_path;

	refcount_t		refcnt;
@@ -36,8 +38,9 @@ struct nscookie { 
	int			newns;

};



void nsinfo__init(struct nsinfo *nsi);

int nsinfo__init(struct nsinfo *nsi);

struct nsinfo *nsinfo__new(pid_t pid);

struct nsinfo *nsinfo__copy(struct nsinfo *nsi);

void nsinfo__delete(struct nsinfo *nsi);



struct nsinfo *nsinfo__get(struct nsinfo *nsi);