[DTrace-devel] [PATCH] Fix various memory leaks related to stapsdt and usdt probes

[Kris Van Hees]

Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
---
 libdtrace/dt_pid.c         | 14 ++++++++++----
 libdtrace/dt_prov_uprobe.c | 13 +++++++++++++
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/libdtrace/dt_pid.c b/libdtrace/dt_pid.c
index 42f667fe1..4af9141aa 100644
--- a/libdtrace/dt_pid.c
+++ b/libdtrace/dt_pid.c
@@ -1282,6 +1282,7 @@ dt_stapsdt_parse(dtrace_hdl_t *dtp, dt_proc_t *dpr, dtrace_probedesc_t *pdp,
 	int i, err = 0;
 	int fd = -1;
 	char *mod;
+	char *no_fun = "";
 
 	fd = open(path, O_RDONLY);
 	if (fd < 0) {
@@ -1415,7 +1416,7 @@ dt_stapsdt_parse(dtrace_hdl_t *dtp, dt_proc_t *dpr, dtrace_probedesc_t *pdp,
 				       &fun, &sym) == 0)
 			psp.pps_fun = (char *)fun;
 		else
-			psp.pps_fun = "";
+			psp.pps_fun = no_fun;
 		psp.pps_dev = pmp->pr_dev;
 		psp.pps_inum = pmp->pr_inum;
 		psp.pps_pid = dpr->dpr_pid;
@@ -1430,6 +1431,9 @@ dt_stapsdt_parse(dtrace_hdl_t *dtp, dt_proc_t *dpr, dtrace_probedesc_t *pdp,
 		}
 		if (err == -1)
 			break;
+
+		if (psp.pps_fun != no_fun)
+			free(psp.pps_fun);
 	}
 
 out:
@@ -1513,7 +1517,6 @@ dt_pid_create_stapsdt_probes(dtrace_probedesc_t *pdp, dtrace_hdl_t *dtp, dt_pcb_
 	const dt_provider_t *pvp;
 	dt_proc_t *dpr = NULL;
 	const char *pidstr;
-	char *path = NULL;
 	pid_t pid;
 
 	assert(pcb != NULL);
@@ -1525,8 +1528,6 @@ dt_pid_create_stapsdt_probes(dtrace_probedesc_t *pdp, dtrace_hdl_t *dtp, dt_pcb_
 	if (strlen(pidstr) == 0)
 		return 0;
 
-	asprintf(&path, "/proc/%s/maps", pidstr);
-
 	pvp = dt_provider_lookup(dtp, "stapsdt");
 	assert(pvp != NULL);
 
@@ -1542,8 +1543,13 @@ dt_pid_create_stapsdt_probes(dtrace_probedesc_t *pdp, dtrace_hdl_t *dtp, dt_pcb_
 	}
 	dpr = dt_proc_lookup(dtp, pid);
 	if (dpr) {
+		char *path = NULL;
+
+		if (asprintf(&path, "/proc/%s/maps", pidstr) == -1)
+			longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
 		dt_pid_create_stapsdt_probes_proc(pdp, dtp, pcb,
 						  pvp, dpr, path);
+		free(path);
 		dt_proc_release_unlock(dtp, pid);
 	}
 
diff --git a/libdtrace/dt_prov_uprobe.c b/libdtrace/dt_prov_uprobe.c
index 8c8dcae0c..986ac0ead 100644
--- a/libdtrace/dt_prov_uprobe.c
+++ b/libdtrace/dt_prov_uprobe.c
@@ -795,6 +795,10 @@ static int populate_args(dtrace_hdl_t *dtp, const pid_probespec_t *psp,
 	char	*nptr = NULL, *xptr = NULL;
 	size_t	i;
 
+	/* Nothing to do if we already populated the arguments. */
+	if (upp->argc >= 0)
+		return 0;
+
 	upp->argc = psp->pps_xargc;
 
 	/* Copy argument value source string data (if any). */
@@ -941,6 +945,7 @@ static dt_probe_t *create_underlying(dtrace_hdl_t *dtp,
 		upp->refcntr_off = psp->pps_refcntr_off;
 		upp->fn = strdup(psp->pps_fn);
 		upp->func = NULL;
+		upp->argc = -1;			/* no argument data yet */
 		upp->tp = dt_tp_alloc(dtp);
 		if (upp->tp == NULL)
 			goto fail;
@@ -1716,6 +1721,7 @@ static char *uprobe_create(dev_t dev, ino_t ino, const char *mapping_fn,
 	rc = dprintf(fd, "%c:%s %s\n", flags & PP_IS_RETURN ? 'r' : 'p', name, spec);
 
 out:
+	free(spec);
 	if (fd != -1)
 		close(fd);
 	if (rc < 0) {
@@ -1975,6 +1981,12 @@ static void detach(dtrace_hdl_t *dtp, const dt_probe_t *uprp)
 	uprobe_delete(upp->dev, upp->inum, upp->off, upp->flags);
 }
 
+/* Clean up the private provider data. */
+static void destroy(dtrace_hdl_t *dtp, void *arg)
+{
+	dt_htab_destroy((dt_htab_t *)arg);
+}
+
 /*
  * Used for underlying probes (uprobes).
  */
@@ -2014,6 +2026,7 @@ dt_provimpl_t	dt_usdt = {
 	.probe_destroy	= &probe_destroy,
 	.discover	= &discover,
 	.add_probe	= &add_probe_usdt,
+	.destroy	= &destroy,
 };
 
 /*
-- 
2.45.2