[Buildroot] [PATCH] busybox: disable CONFIG_FEATURE_CLEAN_UP in default configs

[Peter Korsgaard]

>>>>> "Peter" == Peter Korsgaard <peter at korsgaard.com> writes:

 > 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 at korsgaard.com>

Committed to 2017.02.x and 2017.05.x, thanks.

-- 
Bye, Peter Korsgaard