security_flags: Add comment about what it does and who uses it

It was pointed out that people couldn't easily see who used this or
why so add some comments about that.

(From OE-Core rev: 67f09e9086b8fb1c0c8a1dd19419afb1a5af8daf)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/meta/conf/distro/include/security_flags.inc b/meta/conf/distro/include/security_flags.inc
index 0ee38140ef..9608c7f069 100644
--- a/meta/conf/distro/include/security_flags.inc
+++ b/meta/conf/distro/include/security_flags.inc
@@ -1,3 +1,10 @@
+# Setup extra CFLAGS and LDFLAGS which have 'security' benefits. These 
+# don't work universally, there are recipes which can't use one, the other
+# or both so a blacklist is maintained here. The idea would be over
+# time to reduce this list to nothing.
+# From a Yocto Project perspective, this file is included and tested
+# in the DISTRO="poky-lsb" configuration.
+
 SECURITY_CFLAGS ?= "-fstack-protector-all -pie -fpie -D_FORTIFY_SOURCE=2"
 SECURITY_NO_PIE_CFLAGS ?= "-fstack-protector-all -D_FORTIFY_SOURCE=2"
 SECURITY_LDFLAGS ?= "-Wl,-z,relro,-z,now"