[PATCH V3 0/7] riscv: Add GENERIC_ENTRY, irq stack support

[Guo Ren]

Hi Conor,

I've found the root cause, you are using llvm:

$ grep "bare sym" llvm -rn |grep RISCV
llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp:1296: return
Error(ErrorLoc, "operand must be a bare symbol name");
llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp:1304: return
Error(ErrorLoc, "operand must be a bare symbol name");

That means we could fix up Binutils with a warning at least.

Thx for pointing it out.

On Wed, Sep 7, 2022 at 8:54 AM Guo Ren <guoren at kernel.org> wrote:
>
> On Wed, Sep 7, 2022 at 1:42 AM <Conor.Dooley at microchip.com> wrote:
> >
> > On 06/09/2022 04:54, guoren at kernel.org wrote:
> > > From: Guo Ren <guoren at linux.alibaba.com>
> > >
> > > The patches convert riscv to use the generic entry infrastructure from
> > > kernel/entry/*. Add independent irq stacks (IRQ_STACKS) for percpu to
> > > prevent kernel stack overflows. Add the HAVE_SOFTIRQ_ON_OWN_STACK
> > > feature for the IRQ_STACKS config. You can try it directly with [1].
> >
> > Hey Guo Ren,
> > I applied this patchset to v6.0-rc4 & ran into a build error:
> > /stuff/linux/arch/riscv/kernel/entry.S:347:9: error: operand must be a bare symbol name
> >  la a3, ((1 << (12)) << (2 + 0))
> Yes, please try:
> -       la      a3, IRQ_STACK_SIZE
> +       li      a3, IRQ_STACK_SIZE
>
> la is for the symbol, not immediate. But why does my toolchain not
> report the error?
>
> ➜  linux git:(generic_entry_v3) make ARCH=riscv
> CROSS_COMPILE=riscv64-unknown-linux-gnu- EXTRA_CFLAGS+=-g
> O=../build-riscv/ -kj62 all -kj
> ➜  linux git:(generic_entry_v3) riscv64-unknown-linux-gnu-gcc -v
> Using built-in specs.
> COLLECT_GCC=riscv64-unknown-linux-gnu-gcc
> COLLECT_LTO_WRAPPER=/opt/riscv/libexec/gcc/riscv64-unknown-linux-gnu/11.1.0/lto-wrapper
> Target: riscv64-unknown-linux-gnu
> Configured with:
> /home/guoren/source/riscv-gnu-toolchain/riscv-gcc/configure
> --target=riscv64-unknown-linux-gnu --prefix=/opt/riscv
> --with-sysroot=/opt/riscv/sysroot --with-pkgversion=g5964b5cd7272
> --with-system-zlib --enable-shared --enable-tls
> --enable-languages=c,c++,fortran --disable-libmudflap --disable-libssp
> --disable-libquadmath --disable-libsanitizer --disable-nls
> --disable-bootstrap --src=.././riscv-gcc --enable-multilib
> --with-abi=lp64d --with-arch=rv64imafdc --with-tune=rocket
> --with-isa-spec=2.2 'CFLAGS_FOR_TARGET=-O2   -mcmodel=medlow'
> 'CXXFLAGS_FOR_TARGET=-O2   -mcmodel=medlow'
> Thread model: posix
> Supported LTO compression algorithms: zlib
> gcc version 11.1.0 (g5964b5cd7272)
>
>
>
> >         ^
> >   CC      arch/riscv/kernel/process.o
> > make[5]: *** [/stuff/linux/scripts/Makefile.build:322: arch/riscv/kernel/entry.o] Error 1
> > make[5]: *** Waiting for unfinished jobs....
> >
> > Thanks,
> > Conor.
> > >
> > > [1] https://github.com/guoren83/linux/tree/generic_entry_v3
> > >
> > > V3:
> > >  - Fixup CONFIG_COMPAT=n compile error
> > >  - Add THREAD_SIZE_ORDER config
> > >  - Optimize elf_kexec.c warning fixup
> > >  - Add static to irq_stack_ptr definition
> > >
> > > V2:
> > >  Link: https://lore.kernel.org/linux-riscv/20220904072637.8619-1-guoren@kernel.org/
> > >  - Fixup compile error by include "riscv: ptrace: Remove duplicate
> > >    operation"
> > >  - Fixup compile warning
> > >    Reported-by: kernel test robot <lkp at intel.com>
> > >  - Add test repo link in cover letter
> > >
> > > V1:
> > >  Link: https://lore.kernel.org/linux-riscv/20220903163808.1954131-1-guoren@kernel.org/
> > >
> > > Guo Ren (7):
> > >   riscv: elf_kexec: Fixup compile warning
> > >   riscv: compat_syscall_table: Fixup compile warning
> > >   riscv: ptrace: Remove duplicate operation
> > >   riscv: convert to generic entry
> > >   riscv: Support HAVE_IRQ_EXIT_ON_IRQ_STACK
> > >   riscv: Support HAVE_SOFTIRQ_ON_OWN_STACK
> > >   riscv: Add config of thread stack size
> > >
> > >  arch/riscv/Kconfig                    |  19 ++
> > >  arch/riscv/include/asm/csr.h          |   1 -
> > >  arch/riscv/include/asm/entry-common.h |   8 +
> > >  arch/riscv/include/asm/irq.h          |   3 +
> > >  arch/riscv/include/asm/ptrace.h       |  10 +-
> > >  arch/riscv/include/asm/stacktrace.h   |   5 +
> > >  arch/riscv/include/asm/syscall.h      |   6 +
> > >  arch/riscv/include/asm/thread_info.h  |  19 +-
> > >  arch/riscv/include/asm/vmap_stack.h   |  28 +++
> > >  arch/riscv/kernel/Makefile            |   1 +
> > >  arch/riscv/kernel/elf_kexec.c         |   2 +-
> > >  arch/riscv/kernel/entry.S             | 255 +++++---------------------
> > >  arch/riscv/kernel/irq.c               |  75 ++++++++
> > >  arch/riscv/kernel/ptrace.c            |  41 -----
> > >  arch/riscv/kernel/signal.c            |  21 +--
> > >  arch/riscv/kernel/sys_riscv.c         |  27 +++
> > >  arch/riscv/kernel/traps.c             |  11 ++
> > >  arch/riscv/mm/fault.c                 |  12 +-
> > >  18 files changed, 259 insertions(+), 285 deletions(-)
> > >  create mode 100644 arch/riscv/include/asm/entry-common.h
> > >  create mode 100644 arch/riscv/include/asm/vmap_stack.h
> > >
>
>
>
> --
> Best Regards
>  Guo Ren



-- 
Best Regards
 Guo Ren