Date: Tue, 22 Jan 2002 23:20:01 -0800 (PST) From: "Alexey V. Neyman" <alex.neyman@auriga.ru> To: freebsd-bugs@FreeBSD.org Subject: Re: bin/12280: LD_IGNORE_MISSING_OBJECTS not honored for ELF binarie Message-ID: <200201230720.g0N7K1j67300@freefall.freebsd.org>
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The following reply was made to PR bin/12280; it has been noted by GNATS.
From: "Alexey V. Neyman" <alex.neyman@auriga.ru>
To: bug-followup@freebsd.org
Cc:
Subject: Re: bin/12280: LD_IGNORE_MISSING_OBJECTS not honored for ELF binarie
Date: Wed, 23 Jan 2002 10:13:53 +0300
FWIW, here is the patch.
(man page changes are mostly taken from rtld.1aout man page)
diff -urN /usr/src/libexec/rtld-elf/rtld.1 rtld-elf/rtld.1
--- /usr/src/libexec/rtld-elf/rtld.1 Thu Aug 16 14:44:20 2001
+++ rtld-elf/rtld.1 Wed Jan 23 09:54:07 2002
@@ -94,6 +94,33 @@
.Ev LD_BIND_NOW
increases the start-up time of a program, but it avoids run-time
surprises caused by unexpectedly undefined functions.
+.It Ev LD_IGNORE_MISSING_OBJECTS
+When set to a nonempty string, makes it a nonfatal condition if one
+or more required shared objects cannot be loaded. Loading and
+execution proceeds using the objects that are available. A warning
+is produced for each missing object, unless the environment variable
+.Ev LD_SUPPRESS_WARNINGS
+is set to a nonempty string. This is ignored for set-user-ID and
+set-group-ID programs.
+.Pp
+Missing shared objects can be ignored without errors if all the
+following conditions are met:
+.Bl -bullet
+.It
+They do not supply definitions for any required data symbols.
+.It
+No functions defined by them are called during program execution.
+.It
+The environment variable
+.Ev LD_BIND_NOW
+is unset or is set to the empty string.
+.El
+.It Ev LD_SUPPRESS_WARNINGS
+When set to a nonempty string,
+.Nm
+will not emit warning messages about missing shared objects if
+.Ev LD_IGNORE_MISSING_OBJECTS
+is also set to non-empty string.
.It Ev LD_TRACE_LOADED_OBJECTS
When set to a nonempty string, causes
.Nm
diff -urN /usr/src/libexec/rtld-elf/rtld.c rtld-elf/rtld.c
--- /usr/src/libexec/rtld-elf/rtld.c Fri May 11 04:57:20 2001
+++ rtld-elf/rtld.c Wed Jan 23 09:23:17 2002
@@ -131,6 +131,8 @@
static char *ld_preload; /* Environment variable for libraries to
load first */
static char *ld_tracing; /* Called from ldd to print libs */
+static char *ld_ignore_missing; /* Do not bail out if an object is not
found */
+static char *ld_suppress_warns; /* Do not give warnings */
static Obj_Entry *obj_list; /* Head of linked list of shared objects */
static Obj_Entry **obj_tail; /* Link field of last object in list */
static Obj_Entry *obj_main; /* The main program shared object */
@@ -287,7 +289,9 @@
ld_debug = getenv("LD_DEBUG");
ld_library_path = getenv("LD_LIBRARY_PATH");
ld_preload = getenv("LD_PRELOAD");
+ ld_ignore_missing = getenv("LD_IGNORE_MISSING_OBJECTS");
}
+ ld_suppress_warns = getenv("LD_SUPPRESS_WARNINGS");
ld_tracing = getenv("LD_TRACE_LOADED_OBJECTS");
if (ld_debug != NULL && *ld_debug != '\0')
@@ -1062,8 +1066,15 @@
char *path = find_library(name, obj);
needed->obj = NULL;
- if (path == NULL && !ld_tracing)
- return -1;
+ if (path == NULL) {
+ if (ld_ignore_missing != NULL && *ld_ignore_missing != '\0') {
+ if (ld_suppress_warns == NULL || *ld_suppress_warns == '\0')
+ warnx("warning: %s", dlerror());
+ continue;
+ }
+ if (!ld_tracing)
+ return -1;
+ }
if (path) {
needed->obj = load_object(path);
--
<------------------------->
) May the Sun and Water ( Regards, Alexey V. Neyman
) always fall upon you! ( mailto:alex.neyman@auriga.ru
<------------------------->
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