Re: arch/arm/probes/kprobes/core.c:409:30: error: .fnstart must precede .save or .vsave directives

[Russell King (Oracle)]

On Mon, Sep 26, 2022 at 10:42:45AM -0700, Nick Desaulniers wrote:
> On Mon, Sep 26, 2022 at 8:46 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
> >
> > + our mailing list, I should have added it with that message.
> >
> > On Mon, Sep 26, 2022 at 08:44:05AM -0700, Nathan Chancellor wrote:
> > > Hi Naresh,
> > >
> > > On Mon, Sep 26, 2022 at 06:57:00PM +0530, Naresh Kamboju wrote:
> > > > Following build warnings / errors noticed on arm with clang-13 / 14
> > > > on Linux next-20220923.
> > > >
> > > > Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> > > >
> > > > Regressions found on arm:
> > > >
> > > >    - build-clang-13-bcm2835_defconfig
> > > >    - build-clang-nightly-imx_v6_v7_defconfig
> > > >    - build-clang-nightly-orion5x_defconfig
> > > >    - build-clang-13-keystone_defconfig
> > > >    - build-clang-13-omap2plus_defconfig
> > > >    - build-clang-14-imx_v6_v7_defconfig
> > > >    - build-clang-nightly-omap2plus_defconfig
> > > >    - build-clang-nightly-multi_v5_defconfig
> > > >    - build-clang-nightly-bcm2835_defconfig
> > > >    - build-clang-13-imx_v6_v7_defconfig
> > > >    - build-clang-13-imx_v4_v5_defconfig
> > > >    - build-clang-14-imx_v4_v5_defconfig
> > > >    - build-clang-13-orion5x_defconfig
> > > >    - build-clang-14-multi_v5_defconfig-65236a87
> > > >    - build-clang-14-lkftconfig
> > > >    - build-clang-nightly-imx_v4_v5_defconfig
> > > >    - build-clang-13-multi_v5_defconfig
> > > >    - build-clang-13-lkftconfig
> > > >    - build-clang-nightly-keystone_defconfig
> > > >    - build-clang-14-multi_v5_defconfig
> > > >    - build-clang-14-orion5x_defconfig
> > > >    - build-clang-14-omap2plus_defconfig
> > > >    - build-clang-nightly-multi_v5_defconfig-65236a87
> > > >    - build-clang-14-bcm2835_defconfig
> > > >    - build-clang-14-keystone_defconfig
> > > >    - build-clang-nightly-lkftconfig
> > > >
> > > > arch/arm/probes/kprobes/core.c:409:30: error: .fnstart must precede
> > > > .save or .vsave directives
> > > >                 "stmdb  sp, {sp, lr, pc}        \n\t"
> > > >                                                   ^
> > > > <inline asm>:3:2: note: instantiated into assembly here
> > > >         .save   {sp, lr, pc}
> > > >         ^
> > > > /builds/linux/arch/arm/probes/kprobes/core.c:412:29: error: .fnstart
> > > > must precede .pad directive
> > > >                 "stmdb  sp!, {r0 - r11}         \n\t"
> > > >                                                   ^
> > > > <inline asm>:6:2: note: instantiated into assembly here
> > > >         .pad    #52
> > > >         ^
> > > > 2 errors generated.
> > > > make[5]: *** [/builds/linux/scripts/Makefile.build:250:
> > > > arch/arm/probes/kprobes/core.o] Error 1
> > > >
> > > > build log:
> > > > https://builds.tuxbuild.com/2FAyD1qcTlzjIYE7mjrugjCsxu1/
> > >
> > > Thank you for the testing and report! I brought this up on GitHub on
> > > Friday as I noticed this as well:
> > >
> > > https://github.com/ClangBuiltLinux/linux/issues/1718
> 
> Thanks for the reports. I'll take a look at filing additional bug
> reports against clang, then moving the definition of
> __kretprobe_trampoline to out of line assembler.

Are you saying that .save should be accepted without a .fnstart?

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