diff options
| author | Borislav Petkov <bp@suse.de> | 2016-11-14 19:41:31 +0100 |
|---|---|---|
| committer | Michal Marek <mmarek@suse.com> | 2016-11-15 17:08:14 +0100 |
| commit | c6a385539175ebc603da53aafb7753d39089f32e (patch) | |
| tree | 7719bd0abb47d7f3bf6fe9ecbdaa50c58b01e005 | |
| parent | cc6acc11cad1eb1ae39707a3a6e4a97fafbeeabd (diff) | |
kbuild: Steal gcc's pie from the very beginning
So Sebastian turned off the PIE for kernel builds but that was too late
- Kbuild.include already uses KBUILD_CFLAGS and trying to disable gcc
options with, say cc-disable-warning, fails:
gcc -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
...
-Wno-sign-compare -fno-asynchronous-unwind-tables -Wframe-address -c -x c /dev/null -o .31392.tmp
/dev/null:1:0: error: code model kernel does not support PIC mode
because that returns an error and we can't disable the warning. For
example in this case:
KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
which leads to gcc issuing all those warnings again.
So let's turn off PIE/PIC at the earliest possible moment, when we
declare KBUILD_CFLAGS so that cc-disable-warning picks it up too.
Also, we need the $(call cc-option ...) because -fno-PIE is supported
since gcc v3.4 and our lowest supported gcc version is 3.2 right now.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.com>