On Sun, 25 Dec 2022 at 03:17, Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > On Thu, Dec 22, 2022 at 8:53 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > > > On Wed, 21 Dec 2022 at 17:29, Thorsten Leemhuis > > <regressions@xxxxxxxxxxxxx> wrote: > > > > > > On 21.12.22 16:39, Masahiro Yamada wrote: > > > > On Wed, Dec 21, 2022 at 5:23 PM Thorsten Leemhuis > > > > <regressions@xxxxxxxxxxxxx> wrote: > > > >> > > > >> Hi, this is your Linux kernel regression tracker. CCing the regression > > > >> mailing list, as it should be in the loop for all regressions: > > > >> https://docs.kernel.org/admin-guide/reporting-regressions.html > > > >> > > > >> On 18.12.22 21:51, Dennis Gilmore wrote: > > > >>> The changes in https://lore.kernel.org/linux-arm-kernel/166783716442.32724.935158280857906499.b4-ty@xxxxxxxxxx/T/ > > > >>> result in vmlinux no longer having a build-id. > > > >> > > > >> FWIW, that's 994b7ac1697b ("arm64: remove special treatment for the link > > > >> order of head.o") from Masahiro merged through Will this cycle. > > > >> > > > >>> At the least, this > > > >>> causes rpm builds to fail. Reverting the patch does bring back a > > > >>> build-id, but there may be a different way to fix the regression > > > >> > > > >> Makes me wonder if other distros or CIs relying on the build-id are > > > >> broken, too. > > > >> > > > >> Anyway, the holiday season is upon us, hence I also wonder if it would > > > >> be best to revert above change quickly and leave further debugging for 2023. > > > >> > > > >> Masahiro, Will, what's your option on this? > > > > > > Masahiro, many thx for looking into this. > > > > > > > I do not understand why you rush into the revert so quickly. > > > > We are before -rc1. > > > > We have 7 weeks before the 6.2 release > > > > (assuming we will have up to -rc7). > > > > > > > > If we get -rc6 or -rc7 and we still do not > > > > solve the issue, we should consider reverting it. > > > > > > Because it looked like a regression that makes it harder for people and > > > CI systems to build and test mainline. To quote > > > Documentation/process/handling-regressions.rst ( > > > https://docs.kernel.org/process/handling-regressions.html ): > > > > > > """ > > > * Fix regressions within two or three days, if they are critical for > > > some reason – for example, if the issue is likely to affect many users > > > of the kernel series in question on all or certain architectures. Note, > > > this includes mainline, as issues like compile errors otherwise might > > > prevent many testers or continuous integration systems from testing the > > > series. > > > """ > > > > > > I suspect that other distros rely on the build-id as well. Maybe I'm > > > wrong with that, but even if only Fedora and derivatives are effected it > > > will annoy some people. Sure, each can apply the revert, but before that > > > everyone affected will spend time debugging the issue first. A quick > > > revert in mainline (with a reapply later together with a fix) thus IMHO > > > is the most efficient approach afaics. > > > > > > > Agree with Masahiro here. > > > > The issue seems to be caused by the fact that whichever object gets > > linked first gets to decide the type of a section, and so the .notes > > section will be of type NOTE if head.o gets linked first, or PROGBITS > > otherwise. The latter PROGBITS type seems to be the result of the > > compiler emitting .note.GNU-stack as PROGBITS rather than NOTE. > > > > The hunk below fixes it for me, by avoiding notes emitted as PROGBITS. > > I'll leave it to Masahiro to decide whether this should be fixed for > > arm64 only or for all architectures, but I suspect the latter would be > > most appropriate. > > > > Note that the kernel's rpm-pkg and binrpm-pkg targets seem to be > > unaffected by this. > > > Thanks for root-causing this. > > > I like to fix this for all architectures because riscv is also broken. > > https://lore.kernel.org/lkml/20221224192751.810363-1-masahiroy@xxxxxxxxxx/ > > > > > > diff --git a/arch/arm64/include/asm/assembler.h > > b/arch/arm64/include/asm/assembler.h > > index 376a980f2bad08bb..10a172601fe7f53f 100644 > > --- a/arch/arm64/include/asm/assembler.h > > +++ b/arch/arm64/include/asm/assembler.h > > @@ -818,7 +818,7 @@ alternative_endif > > > > #ifdef GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT > > .macro emit_aarch64_feature_1_and, feat=GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT > > - .pushsection .note.gnu.property, "a" > > + .pushsection .note.gnu.property, "a", %note > > .align 3 > > .long 2f - 1f > > .long 6f - 3f > > > I did not fold this hunk in my patch. > > I compiled with CONFIG_ARM64_BTI_KERNEL=y. > > .note.gnu.property section in VDSO was already NOTE > without this hunk. > You're right - the VDSO is completely separate anyway, so this should not be needed. It did seem to make a difference when I was playing around with this, but I probably made a mistake somewhere, as this macro is never used in .o files that are actually linked into vmlinux
