libdtrace: allow D libraries to declare dependencies on kernel modules

The "depends_on module" pragma can be used to declare a dependency on a
DTrace module, which for kernel probes corresponds to a KLD. Such
dependencies cannot be checked if the KLD is compiled into the kernel.
Therefore, allow a module dependency to be satisfied if either a kernel
module or a KLD with the specified name is loaded.

Differential Revision:	https://reviews.freebsd.org/D2653
Reviewed by:	gnn, rpaulo
Reported by:	gnn

1 files changed, 20 insertions, 0 deletions

diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c
index 80e4be9..ac0524b 100644
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c
@@ -1178,6 +1178,9 @@ alloc:
 #endif
 	dtp->dt_modbuckets = _dtrace_strbuckets;
 	dtp->dt_mods = calloc(dtp->dt_modbuckets, sizeof (dt_module_t *));
+#ifdef __FreeBSD__
+	dtp->dt_kmods = calloc(dtp->dt_modbuckets, sizeof (dt_module_t *));
+#endif
 	dtp->dt_provbuckets = _dtrace_strbuckets;
 	dtp->dt_provs = calloc(dtp->dt_provbuckets, sizeof (dt_provider_t *));
 	dt_proc_hash_create(dtp);
@@ -1199,6 +1202,7 @@ alloc:
 	if (dtp->dt_mods == NULL || dtp->dt_provs == NULL ||
 	    dtp->dt_procs == NULL || dtp->dt_ld_path == NULL ||
 #ifdef __FreeBSD__
+	    dtp->dt_kmods == NULL ||
 	    dtp->dt_objcopy_path == NULL ||
 #endif
 	    dtp->dt_cpp_path == NULL || dtp->dt_cpp_argv == NULL)
@@ -1621,6 +1625,10 @@ dtrace_close(dtrace_hdl_t *dtp)
 	dtrace_prog_t *pgp;
 	dt_xlator_t *dxp;
 	dt_dirpath_t *dirp;
+#ifdef __FreeBSD__
+	dt_kmodule_t *dkm;
+	uint_t h;
+#endif
 	int i;
 
 	if (dtp->dt_procs != NULL)
@@ -1648,6 +1656,15 @@ dtrace_close(dtrace_hdl_t *dtp)
 	if (dtp->dt_tls != NULL)
 		dt_idhash_destroy(dtp->dt_tls);
 
+#ifdef __FreeBSD__
+	for (h = 0; h < dtp->dt_modbuckets; h++)
+		while ((dkm = dtp->dt_kmods[h]) != NULL) {
+			dtp->dt_kmods[h] = dkm->dkm_next;
+			free(dkm->dkm_name);
+			free(dkm);
+		}
+#endif
+
 	while ((dmp = dt_list_next(&dtp->dt_modlist)) != NULL)
 		dt_module_destroy(dtp, dmp);
 
@@ -1697,6 +1714,9 @@ dtrace_close(dtrace_hdl_t *dtp)
 #endif
 
 	free(dtp->dt_mods);
+#ifdef __FreeBSD__
+	free(dtp->dt_kmods);
+#endif
 	free(dtp->dt_provs);
 	free(dtp);
 }