busybox: disable CONFIG_FEATURE_CLEAN_UP in default configs

FEATURE_CLEAN_UP is a configuration feature to get busybox to explicitly
call free() on dynamic allocated memory just before exiting so memory leak
detectors like valgrind don't get confused.  Upstream explicitly recommends
to NOT enable this option:

config FEATURE_CLEAN_UP
	bool "Clean up all memory before exiting (usually not needed)"
	default n
	help
	  As a size optimization, busybox normally exits without explicitly
	  freeing dynamically allocated memory or closing files. This saves
	  space since the OS will clean up for us, but it can confuse debuggers
	  like valgrind, which report tons of memory and resource leaks.

	  Don't enable this unless you have a really good reason to clean
	  things up manually.

Having this option enabled adds a bit of bloat, but more significantly these
cleanup code paths don't get tested very often so some times get out of sync
with the allocation code which can lead to crashes (or security issues from
double frees), so it is safer to disable the option.

For people wanting to debug memory leak issues with busybox, the option can
still be enabled with a configuration fragment (or a custom config).

The size difference isn't huge (br-arm-full-static):

-rwxr-xr-x 1 peko peko 886K Jul  5 10:56 output-busybox1/target/bin/busybox
-rwxr-xr-x 1 peko peko 882K Jul  5 10:53 output-busybox2/target/bin/busybox

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

diff --git a/package/busybox/busybox-minimal.config b/package/busybox/busybox-minimal.config
index 2abf458b78f469d37ead39bfec4334ef6efdc82d..0c8e63e627530837c8834bf518eec6dae2dad5e5 100644 (file)
--- a/package/busybox/busybox-minimal.config
+++ b/package/busybox/busybox-minimal.config
@@ -22,7 +22,7 @@ CONFIG_FEATURE_INSTALLER=y
 # CONFIG_PAM is not set
 CONFIG_LONG_OPTS=y
 CONFIG_FEATURE_DEVPTS=y
-CONFIG_FEATURE_CLEAN_UP=y
+# CONFIG_FEATURE_CLEAN_UP is not set
 CONFIG_FEATURE_UTMP=y
 CONFIG_FEATURE_WTMP=y
 # CONFIG_FEATURE_PIDFILE is not set

diff --git a/package/busybox/busybox.config b/package/busybox/busybox.config
index c45de218081022942d36683d04e0a7f95aec703e..508128d5e3e8e9b4a2eecf433541efafff0e19b9 100644 (file)
--- a/package/busybox/busybox.config
+++ b/package/busybox/busybox.config
@@ -22,7 +22,7 @@ CONFIG_FEATURE_INSTALLER=y
 # CONFIG_PAM is not set
 CONFIG_LONG_OPTS=y
 CONFIG_FEATURE_DEVPTS=y
-CONFIG_FEATURE_CLEAN_UP=y
+# CONFIG_FEATURE_CLEAN_UP is not set
 CONFIG_FEATURE_UTMP=y
 CONFIG_FEATURE_WTMP=y
 # CONFIG_FEATURE_PIDFILE is not set