Re: [PULL 32/47] bsd-user: Add RISC-V signal trampoline setup function

[Ajeet Singh]

Hi, I had already fixed it and sent a patchv6,

I will send another one with the other changes.

On Mon, 16 Sept, 2024, 5:51 am Daniel Henrique Barboza, <dbarboza@ventanamicro.com> wrote:

On 9/12/24 2:29 AM, Alistair Francis wrote:
> From: Mark Corbin <mark@dibsco.co.uk>
>
> Implemented the 'setup_sigtramp' function for setting up the signal
> trampoline code in the RISC-V architecture.
>
> Signed-off-by: Mark Corbin <mark@dibsco.co.uk>
> Signed-off-by: Ajeet Singh <itachis@FreeBSD.org>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Message-ID: <20240907031927.1908-8-itachis@FreeBSD.org>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>   bsd-user/riscv/target_arch_sigtramp.h | 42 +++++++++++++++++++++++++++
>   1 file changed, 42 insertions(+)
>   create mode 100644 bsd-user/riscv/target_arch_sigtramp.h
>
> diff --git a/bsd-user/riscv/target_arch_sigtramp.h b/bsd-user/riscv/target_arch_sigtramp.h
> new file mode 100644
> index 0000000000..83345f3961
> --- /dev/null
> +++ b/bsd-user/riscv/target_arch_sigtramp.h
> @@ -0,0 +1,42 @@
> +/*
> + * RISC-V sigcode
> + *
> + * Copyright (c) 2019 Mark Corbin
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef TARGET_ARCH_SIGTRAMP_H
> +#define TARGET_ARCH_SIGTRAMP_H
> +
> +/* Compare with sigcode() in riscv/riscv/locore.S */
> +static inline abi_long setup_sigtramp(abi_ulong offset, unsigned sigf_uc,
> +        unsigned sys_sigreturn)
> +{
> +    int i;

There's no 'i' var being used. This will throw an 'unused variable' warning when building.

> +    uint32_t sys_exit = TARGET_FREEBSD_NR_exit;
> +
> +    static const uint32_t sigtramp_code[] = {
> +    /*1*/ const_le32(0x00010513),                        /*mv a0, sp*/
> +    /*2*/ const_le32(0x00050513 + (sigf_uc << 20)),      /*addi a0,a0,sigf_uc*/
> +    /*3*/ const_le32(0x00000293 + (sys_sigreturn << 20)),/*li t0,sys_sigreturn*/
> +    /*4*/ const_le32(0x00000073),                        /*ecall*/
> +    /*5*/ const_le32(0x00000293 + (sys_exit << 20)),     /*li t0,sys_exit*/
> +    /*6*/ const_le32(0x00000073),                        /*ecall*/
> +    /*7*/ const_le32(0xFF1FF06F)                         /*b -16*/
> +    };


And this will throw the following error:

../bsd-user/riscv/target_arch_sigtramp.h:32:33: error: initializer element is not a compile-time constant
    32 |     /*2*/ const_le32(0x00050513 + (sigf_uc << 20)),      /*addi a0,a0,sigf_uc*/
                       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~
/tmp/cirrus-ci-build/include/qemu/bswap.h:168:26: note: expanded from macro 'const_le32'
   168 | # define const_le32(_x) (_x)
       |                          ^~
1 error generated.


One solution is to remove the 'static const' qualifier from the array, like
bsd-user/arm/target_arch_sigtramp.h is doing.


This diff will fix the build:


diff --git a/bsd-user/riscv/target_arch_sigtramp.h b/bsd-user/riscv/target_arch_sigtramp.h
index 83345f3961..dfe5076739 100644
--- a/bsd-user/riscv/target_arch_sigtramp.h
+++ b/bsd-user/riscv/target_arch_sigtramp.h
@@ -24,10 +24,9 @@
  static inline abi_long setup_sigtramp(abi_ulong offset, unsigned sigf_uc,
          unsigned sys_sigreturn)
  {
-    int i;
      uint32_t sys_exit = TARGET_FREEBSD_NR_exit;

-    static const uint32_t sigtramp_code[] = {
+    uint32_t sigtramp_code[] = {
      /*1*/ const_le32(0x00010513),                        /*mv a0, sp*/
      /*2*/ const_le32(0x00050513 + (sigf_uc << 20)),      /*addi a0,a0,sigf_uc*/
      /*3*/ const_le32(0x00000293 + (sys_sigreturn << 20)),/*li t0,sys_sigreturn*/




Thanks,

Daniel



> +
> +    return memcpy_to_target(offset, sigtramp_code, TARGET_SZSIGCODE);
> +}
> +#endif /* TARGET_ARCH_SIGTRAMP_H */