Messages in this thread | | | Date | Tue, 17 Mar 2020 18:10:16 +0000 | From | Sergei Trofimovich <> | Subject | Re: [PATCH] x86: fix early boot crash on gcc-10 |
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On Tue, 17 Mar 2020 12:46:05 +0100 Jakub Jelinek <jakub@redhat.com> wrote:
> So, a few comments. > > One thing I've noticed in the command line is that > --param=allow-store-data-races=0 > got dropped. That is fine, the parameter is gone, but it has been replaced > in https://gcc.gnu.org/PR92046 by the > -fno-allow-store-data-races > option. Like the param which defaulted to 0 and has been enabled only with > -Ofast this option is also -fno-allow-store-data-races by default unless > -Ofast, but if kernel wanted to be explicit or make sure not to introduce > them even with -Ofast, I'd say it should: > # Tell gcc to never replace conditional load with a non-conditional one > KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) > +KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races) > in the toplevel Makefile.
Yeah, I noticed it yesterday as well and sent out exactly the same change: https://lkml.org/lkml/2020/3/16/1012 I also checked that flag does not change code generation on -O2 for smpboot.c
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Sergei
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