On Wed, Sep 4, 2019 at 3:28 PM Vaibhav Rustagi <vaibhavrust...@google.com> wrote: > > On Wed, Sep 4, 2019 at 3:19 PM Nick Desaulniers <ndesaulni...@google.com> > wrote: > > > > + (folks recommended by ./scripts/get_maintainer.pl <patchfile>) > > (See also, step 7: > > https://nickdesaulniers.github.io/blog/2017/05/16/submitting-your-first-patch-to-the-linux-kernel-and-responding-to-feedback/) > > > > On Wed, Sep 4, 2019 at 2:45 PM Steve Wahl <steve.w...@hpe.com> wrote: > > > > > > The last change to this Makefile caused relocation errors when loading > > > > It's good to add a fixes tag like below when a patch fixes a > > regression, so that stable backports the fix as far back as the > > regression: > > Fixes: b059f801a937 ("x86/purgatory: Use CFLAGS_REMOVE rather than > > reset KBUILD_CFLAGS") > > > > > a kdump kernel. This change restores the appropriate flags, without > > > reverting to the former practice of resetting KBUILD_CFLAGS. > > > > > > Signed-off-by: Steve Wahl <steve.w...@hpe.com> > > > --- > > > arch/x86/purgatory/Makefile | 35 +++++++++++++++++++---------------- > > > 1 file changed, 19 insertions(+), 16 deletions(-) > > > > > > diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile > > > index 8901a1f89cf5..9f0bfef1f5db 100644 > > > --- a/arch/x86/purgatory/Makefile > > > +++ b/arch/x86/purgatory/Makefile > > > @@ -18,37 +18,40 @@ targets += purgatory.ro > > > KASAN_SANITIZE := n > > > KCOV_INSTRUMENT := n > > > > > > +# These are adjustments to the compiler flags used for objects that > > > +# make up the standalone porgatory.ro > > > + > > > +PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel > > > +PURGATORY_CFLAGS := -mcmodel=large -ffreestanding > > > -fno-zero-initialized-in-bss > > > > Thanks for confirming the fix. While it sounds like -mcmodel=large is > > the only necessary change, I don't object to -ffreestanding of > > -fno-zero-initialized-in-bss being readded, especially since I think > > what you've done with PURGATORY_CFLAGS_REMOVE is more concise. > > Reviewed-by: Nick Desaulniers <ndesaulni...@google.com> > > Vaibhav, do you still have an environment setup to quickly test this > > again w/ Clang builds? > > I will setup the environment and will try the changes. > I tried the changes and kdump was working.
> > Tglx, we'll likely want to get this into 5.3 if it's not too late (I > > saw Miguel Ojeda mention there might be an -rc8)? > > > > > + > > > # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. > > > That > > > # in turn leaves some undefined symbols like __fentry__ in purgatory and > > > not > > > # sure how to relocate those. > > > ifdef CONFIG_FUNCTION_TRACER > > > -CFLAGS_REMOVE_sha256.o += $(CC_FLAGS_FTRACE) > > > -CFLAGS_REMOVE_purgatory.o += $(CC_FLAGS_FTRACE) > > > -CFLAGS_REMOVE_string.o += $(CC_FLAGS_FTRACE) > > > -CFLAGS_REMOVE_kexec-purgatory.o += $(CC_FLAGS_FTRACE) > > > +PURGATORY_CFLAGS_REMOVE += $(CC_FLAGS_FTRACE) > > > endif > > > > > > ifdef CONFIG_STACKPROTECTOR > > > -CFLAGS_REMOVE_sha256.o += -fstack-protector > > > -CFLAGS_REMOVE_purgatory.o += -fstack-protector > > > -CFLAGS_REMOVE_string.o += -fstack-protector > > > -CFLAGS_REMOVE_kexec-purgatory.o += -fstack-protector > > > +PURGATORY_CFLAGS_REMOVE += -fstack-protector > > > endif > > > > > > ifdef CONFIG_STACKPROTECTOR_STRONG > > > -CFLAGS_REMOVE_sha256.o += -fstack-protector-strong > > > -CFLAGS_REMOVE_purgatory.o += -fstack-protector-strong > > > -CFLAGS_REMOVE_string.o += -fstack-protector-strong > > > -CFLAGS_REMOVE_kexec-purgatory.o += -fstack-protector-strong > > > +PURGATORY_CFLAGS_REMOVE += -fstack-protector-strong > > > endif > > > > > > ifdef CONFIG_RETPOLINE > > > -CFLAGS_REMOVE_sha256.o += $(RETPOLINE_CFLAGS) > > > -CFLAGS_REMOVE_purgatory.o += $(RETPOLINE_CFLAGS) > > > -CFLAGS_REMOVE_string.o += $(RETPOLINE_CFLAGS) > > > -CFLAGS_REMOVE_kexec-purgatory.o += $(RETPOLINE_CFLAGS) > > > +PURGATORY_CFLAGS_REMOVE += $(RETPOLINE_CFLAGS) > > > endif > > > > > > +CFLAGS_REMOVE_purgatory.o += $(PURGATORY_CFLAGS_REMOVE) > > > +CFLAGS_purgatory.o += $(PURGATORY_CFLAGS) > > > + > > > +CFLAGS_REMOVE_sha256.o += $(PURGATORY_CFLAGS_REMOVE) > > > +CFLAGS_sha256.o += $(PURGATORY_CFLAGS) > > > + > > > +CFLAGS_REMOVE_string.o += $(PURGATORY_CFLAGS_REMOVE) > > > +CFLAGS_string.o += $(PURGATORY_CFLAGS) > > > + > > > $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE > > > $(call if_changed,ld) > > > > > > -- > > > 2.12.3 > > > > > > > > > -- > > Thanks, > > ~Nick Desaulniers
