[PATCH v6 33/33] kselftest/riscv: kselftest for user mode cfi

[Deepak Gupta]

On Fri, Oct 11, 2024 at 07:43:30PM +0800, Zong Li wrote:
>On Fri, Oct 11, 2024 at 6:18 PM Mark Brown <broonie at kernel.org> wrote:
>>
>> On Fri, Oct 11, 2024 at 01:44:55PM +0800, Zong Li wrote:
>> > On Wed, Oct 9, 2024 at 7:46 AM Deepak Gupta <debug at rivosinc.com> wrote:
>>
>> > > +       if (si->si_code == SEGV_CPERR) {
>>
>> > Hi Deepak,
>> > I got some errors when building this test, I suppose they should be
>> > fixed in the next version.
>>
>> > riscv_cfi_test.c: In function 'sigsegv_handler':
>> > riscv_cfi_test.c:17:28: error: 'SEGV_CPERR' undeclared (first use in
>> > this function); did you mean 'SEGV_ACCERR'?
>> >    17 |         if (si->si_code == SEGV_CPERR) {
>> >       |                            ^~~~~~~~~~
>> >       |                            SEGV_ACCERR
>> >
>>
>> Did you run "make headers_install" prior to building kselftest to get
>> the current kernel's headers available for userspace builds?
>
>Yes, I have run "make header" and "make header_install" before
>building the kselftest. This error happens when I cross compiled it,
>perhaps I can help to check if it is missing some header files or
>header search path.

That's wierd.

It doesn't fail for me even if I do not do `make headers_install`. But I am
building kernel and selftests with toolchain which supports shadow stack and
landing pad. It's defined in `siginfo.h`. When I built toolchain, I did point
it at the latest kernel headers. May be that's the trick.

"""

$ grep -nir SEGV_CPERR /scratch/debug/linux/kbuild/usr/include/*
/scratch/debug/linux/kbuild/usr/include/asm-generic/siginfo.h:240:#define SEGV_CPERR    10      /* Control protection fault */

$ grep -nir SEGV_CPERR /scratch/debug/open_src/sifive_cfi_toolchain/INSTALL_Sept18/sysroot/usr/*
/scratch/debug/open_src/sifive_cfi_toolchain/INSTALL_Sept18/sysroot/usr/include/asm-generic/siginfo.h:240:#define SEGV_CPERR    10      /* Control protection fault */
/scratch/debug/open_src/sifive_cfi_toolchain/INSTALL_Sept18/sysroot/usr/include/bits/siginfo-consts.h:139:  SEGV_CPERR                  /* Control protection fault.  */
/scratch/debug/open_src/sifive_cfi_toolchain/INSTALL_Sept18/sysroot/usr/include/bits/siginfo-consts.h:140:#  define SEGV_CPERR  SEGV_CPERR

"""