From: Don Zickus <dzickus@xxxxxxxxxx>
There are two parts to this fix. One is using the recommended way
to disable LTO. The other is to make it work for the kernel.spec
file.
Various kernel-tool programs (like perf) can not handle LTO yet, so
they are disabled.
This is done with '%define _lto_cflags {nil}'.
However that doesn't quite work for the kernel for the %install
section. It works for the %build section.
Oddly, back at the birth of dist-git, the initial kernel.spec
file was imported with a line at the top
%global __spec_install_pre %{___build_pre}
For whatever reason, the kernel was deemed special and that line
pre-built the %install scripts _before_ the lto_cflags could
dynamically be disabled.
Moving the _lto_cflags line above the _pre line disables LTO
for both the %build and %install sections of the spec file.
However, because that _pre line is unintiutive and caused hours
of debugging headache, I hacked up the output to see what the
%__spec_install_pre and ___build_pre looked like at the
beginning of the %install section. The idea was __build_pre
is what we want going forward.
Of the 20 or so env vars defined, the only differences besides
the LTO flags was -fcommon. This made sense because
_legacy_common_support is also set (enabled -fcommon) after
the _pre line. Therefore the %install section was correctly
using -fno-common.
In other words having
%global __spec_install_pre %{___build_pre}
is now useless after 10 years. Let's just get rid of
that and save future headaches and issues and use the
recommended way of disabling LTO.
Cc: Jeff Law <law@xxxxxxxxxx>
Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>
---
redhat/kernel.spec.template | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/redhat/kernel.spec.template b/redhat/kernel.spec.template
index 7cbfb9c139eb..439c22be33c9 100644
--- a/redhat/kernel.spec.template
+++ b/redhat/kernel.spec.template
@@ -1,5 +1,4 @@
-# We have to override the new %%install behavior because, well... the kernel is special.
-%global __spec_install_pre %{___build_pre}
+%global _lto_cflags %{nil}
# Short-term fix so the package builds with GCC 10.
# This should go away soon.
--
GitLab
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