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| author | Matt Weber <matthew.weber@rockwellcollins.com> | 2018-09-17 16:21:51 -0500 |
|---|---|---|
| committer | Peter Korsgaard <peter@korsgaard.com> | 2018-10-20 12:53:03 +0200 |
| commit | 394bdd11fc1f741c88c89f0e71571d87a29ab627 (patch) | |
| tree | ae9c2ee26a4809b1846959abccad6f0d0ea60a52 /package | |
| parent | f10822d151085bcbfecd0ecf2542ac5f5623fd9d (diff) | |
| download | buildroot-394bdd11fc1f741c88c89f0e71571d87a29ab627.tar.gz buildroot-394bdd11fc1f741c88c89f0e71571d87a29ab627.zip | |
BR2_FORTIFY*: toolchain wrapper limitation note
A note is added to tie off the discussion on why moving _FORTIFY_SOURCE
related flags into the toolchain wrapper doesn't currently work.
- Currently -D_FORTIFY_SOURCE and optimizations are passed through
CFLAGS
- Packages like linux-tools ignore CFLAGS entirely and some
autotools toolchain testing cases dependent on not using
CFLAGS.
- If FORTIFY_SOURCE is passed through the wrapper, then linux-tools
will no longer be able to ignore it, because it's enforced at a
lower-level and since the optimization -Os/g/1/2/3 are via CFLAGS,
there is no optimization flag set. Therefore linux-tools will do
all its configuration tests with FORTIFY_SOURCE forcefully enabled
at the wrapper level, but no optimization enabled, and consequently
tests will fail.
Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Diffstat (limited to 'package')
| -rw-r--r-- | package/Makefile.in | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/package/Makefile.in b/package/Makefile.in index dc0eecf1d5..44761b79c5 100644 --- a/package/Makefile.in +++ b/package/Makefile.in @@ -143,6 +143,15 @@ endif TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS)) +# By design, _FORTIFY_SOURCE requires gcc optimization to be enabled. +# Therefore, we need to pass _FORTIFY_SOURCE and the optimization level +# through the same mechanism, i.e currently through CFLAGS. Passing +# _FORTIFY_SOURCE through the wrapper and the optimization level +# through CFLAGS would not work, because CFLAGS are sometimes +# ignored/overridden by packages, but the flags passed by the wrapper +# are enforced: this would cause _FORTIFY_SOURCE to be used without any +# optimization level, leading to a build / configure failure. So we keep +# passing _FORTIFY_SOURCE and the optimization level both through CFLAGS. ifeq ($(BR2_FORTIFY_SOURCE_1),y) TARGET_HARDENED += -D_FORTIFY_SOURCE=1 else ifeq ($(BR2_FORTIFY_SOURCE_2),y) |
