Dtrace: improve handling of library paths.

Merge changes from illumos

906 dtrace depends_on pragma should search all library paths, not just the
current one

949 dtrace should only include the first instance of a library found on
its library path

Illumos Revisions:	13353:936a1e45726c
			13354:2b2c36a81512

Reference:
https://www.illumos.org/issues/906
https://www.illumos.org/issues/949

Tested by:	Fabian Keil
Obtained from:	Illumos
MFC after:	3 weeks

2 files changed, 102 insertions, 22 deletions

diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_cc.c b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_cc.c
index 6714757..d5423f6 100644
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_cc.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_cc.c
@@ -21,6 +21,7 @@
 
 /*
  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, Joyent Inc. All rights reserved.
  */
 
 /*
@@ -2150,25 +2151,23 @@ dt_lib_depend_free(dtrace_hdl_t *dtp)
 	}
 }
 
-
 /*
- * Open all of the .d library files found in the specified directory and
- * compile each one in topological order to cache its inlines and translators,
- * etc.  We silently ignore any missing directories and other files found
- * therein. We only fail (and thereby fail dt_load_libs()) if we fail to
- * compile a library and the error is something other than #pragma D depends_on.
- * Dependency errors are silently ignored to permit a library directory to
- * contain libraries which may not be accessible depending on our privileges.
+ * Open all the .d library files found in the specified directory and
+ * compile each one of them.  We silently ignore any missing directories and
+ * other files found therein.  We only fail (and thereby fail dt_load_libs()) if
+ * we fail to compile a library and the error is something other than #pragma D
+ * depends_on.  Dependency errors are silently ignored to permit a library
+ * directory to contain libraries which may not be accessible depending on our
+ * privileges.
  */
 static int
 dt_load_libs_dir(dtrace_hdl_t *dtp, const char *path)
 {
 	struct dirent *dp;
-	const char *p;
+	const char *p, *end;
 	DIR *dirp;
 
 	char fname[PATH_MAX];
-	dtrace_prog_t *pgp;
 	FILE *fp;
 	void *rv;
 	dt_lib_depend_t *dld;
@@ -2192,9 +2191,28 @@ dt_load_libs_dir(dtrace_hdl_t *dtp, const char *path)
 			continue;
 		}
 
+		/*
+		 * Skip files whose name match an already processed library
+		 */
+		for (dld = dt_list_next(&dtp->dt_lib_dep); dld != NULL;
+		    dld = dt_list_next(dld)) {
+			end = strrchr(dld->dtld_library, '/');
+			/* dt_lib_depend_add ensures this */
+			assert(end != NULL);
+			if (strcmp(end + 1, dp->d_name) == 0)
+				break;
+		}
+
+		if (dld != NULL) {
+			dt_dprintf("skipping library %s, already processed "
+			    "library with the same name: %s", dp->d_name,
+			    dld->dtld_library);
+			continue;
+		}
+
 		dtp->dt_filetag = fname;
 		if (dt_lib_depend_add(dtp, &dtp->dt_lib_dep, fname) != 0)
-			goto err;
+			return (-1); /* preserve dt_errno */
 
 		rv = dt_compile(dtp, DT_CTX_DPROG,
 		    DTRACE_PROBESPEC_NAME, NULL,
@@ -2203,7 +2221,7 @@ dt_load_libs_dir(dtrace_hdl_t *dtp, const char *path)
 		if (rv != NULL && dtp->dt_errno &&
 		    (dtp->dt_errno != EDT_COMPILER ||
 		    dtp->dt_errtag != dt_errtag(D_PRAGMA_DEPEND)))
-			goto err;
+			return (-1); /* preserve dt_errno */
 
 		if (dtp->dt_errno)
 			dt_dprintf("error parsing library %s: %s\n",
@@ -2214,6 +2232,27 @@ dt_load_libs_dir(dtrace_hdl_t *dtp, const char *path)
 	}
 
 	(void) closedir(dirp);
+
+	return (0);
+}
+
+/*
+ * Perform a topological sorting of all the libraries found across the entire
+ * dt_lib_path.  Once sorted, compile each one in topological order to cache its
+ * inlines and translators, etc.  We silently ignore any missing directories and
+ * other files found therein. We only fail (and thereby fail dt_load_libs()) if
+ * we fail to compile a library and the error is something other than #pragma D
+ * depends_on.  Dependency errors are silently ignored to permit a library
+ * directory to contain libraries which may not be accessible depending on our
+ * privileges.
+ */
+static int
+dt_load_libs_sort(dtrace_hdl_t *dtp)
+{
+	dtrace_prog_t *pgp;
+	FILE *fp;
+	dt_lib_depend_t *dld;
+
 	/*
 	 * Finish building the graph containing the library dependencies
 	 * and perform a topological sort to generate an ordered list
@@ -2274,7 +2313,14 @@ dt_load_libs(dtrace_hdl_t *dtp)
 
 	dtp->dt_cflags |= DTRACE_C_NOLIBS;
 
-	for (dirp = dt_list_next(&dtp->dt_lib_path);
+	/*
+	 * /usr/lib/dtrace is always at the head of the list. The rest of the
+	 * list is specified in the precedence order the user requested. Process
+	 * everything other than the head first. DTRACE_C_NOLIBS has already
+	 * been spcified so dt_vopen will ensure that there is always one entry
+	 * in dt_lib_path.
+	 */
+	for (dirp = dt_list_next(dt_list_next(&dtp->dt_lib_path));
 	    dirp != NULL; dirp = dt_list_next(dirp)) {
 		if (dt_load_libs_dir(dtp, dirp->dir_path) != 0) {
 			dtp->dt_cflags &= ~DTRACE_C_NOLIBS;
@@ -2282,6 +2328,16 @@ dt_load_libs(dtrace_hdl_t *dtp)
 		}
 	}
 
+	/* Handle /usr/lib/dtrace */
+	dirp = dt_list_next(&dtp->dt_lib_path);
+	if (dt_load_libs_dir(dtp, dirp->dir_path) != 0) {
+		dtp->dt_cflags &= ~DTRACE_C_NOLIBS;
+		return (-1); /* errno is set for us */
+	}
+
+	if (dt_load_libs_sort(dtp) < 0)
+		return (-1); /* errno is set for us */
+
 	return (0);
 }
 
diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_pragma.c b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_pragma.c
index a9328ab..00578f4 100644
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_pragma.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_pragma.c
@@ -21,7 +21,7 @@
 
 /*
  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
+ * Copyright (c) 2011, Joyent Inc. All rights reserved.
  */
 
 #pragma ident	"%Z%%M%	%I%	%E% SMI"
@@ -31,9 +31,13 @@
 #if defined(sun)
 #include <alloca.h>
 #endif
+#include <fcntl.h>
 #include <stdlib.h>
 #include <stdio.h>
 
+#include <sys/types.h>
+#include <sys/stat.h>
+
 #include <dt_parser.h>
 #include <dt_impl.h>
 #include <dt_provider.h>
@@ -201,6 +205,29 @@ dt_pragma_binding(const char *prname, dt_node_t *dnp)
 		dtp->dt_globals->dh_defer = &dt_pragma_apply;
 }
 
+static void 
+dt_pragma_depends_finddep(dtrace_hdl_t *dtp, const char *lname, char *lib,
+    size_t len)
+{
+	dt_dirpath_t *dirp;
+	struct stat sbuf;
+	int found = 0;
+
+	for (dirp = dt_list_next(&dtp->dt_lib_path); dirp != NULL;
+	    dirp = dt_list_next(dirp)) {
+		(void) snprintf(lib, len, "%s/%s", dirp->dir_path, lname);
+
+		if (stat(lib, &sbuf) == 0) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found)
+		xyerror(D_PRAGMA_DEPEND,
+		    "failed to find dependency in libpath: %s", lname);
+}
+
 /*
  * The #pragma depends_on directive can be used to express a dependency on a
  * module, provider or library which if not present will cause processing to
@@ -230,16 +257,13 @@ dt_pragma_depends(const char *prname, dt_node_t *cnp)
 		if (yypcb->pcb_cflags & DTRACE_C_CTL) {
 			assert(dtp->dt_filetag != NULL);
 
-			/*
-			 * We have the file we are working on in dtp->dt_filetag
-			 * so find that node and add the dependency in.
-			 */
+			dt_pragma_depends_finddep(dtp, nnp->dn_string, lib,
+			    sizeof (lib));
+
 			dld = dt_lib_depend_lookup(&dtp->dt_lib_dep,
 			    dtp->dt_filetag);
 			assert(dld != NULL);
 
-			(void) snprintf(lib, sizeof (lib), "%s%s",
-			    dld->dtld_libpath, nnp->dn_string);
 			if ((dt_lib_depend_add(dtp, &dld->dtld_dependencies,
 			    lib)) != 0) {
 				xyerror(D_PRAGMA_DEPEND,
@@ -261,8 +285,8 @@ dt_pragma_depends(const char *prname, dt_node_t *cnp)
 			    dtp->dt_filetag);
 			assert(dld != NULL);
 
-			(void) snprintf(lib, sizeof (lib), "%s%s",
-			    dld->dtld_libpath, nnp->dn_string);
+			dt_pragma_depends_finddep(dtp, nnp->dn_string, lib,
+			    sizeof (lib));
 			dld = dt_lib_depend_lookup(&dtp->dt_lib_dep_sorted,
 			    lib);
 			assert(dld != NULL);