Re: [PATCH v3 2/5] linux-user/riscv: Allow restore_sigcontext to return error

[Alistair Francis <alistair23@gmail.com>]

On Sun, Mar 22, 2026 at 12:16 AM Nicholas Piggin <npiggin@gmail.com> wrote:
>
> Linux can return error from restore_sigcontext in some conditions, which
> forces a SIGSEGV. Plumb through this error handling which will be used
> by the next change.
>
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  linux-user/riscv/signal.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/linux-user/riscv/signal.c b/linux-user/riscv/signal.c
> index 22b1b8149f..ece276f85f 100644
> --- a/linux-user/riscv/signal.c
> +++ b/linux-user/riscv/signal.c
> @@ -145,7 +145,7 @@ badframe:
>      force_sig(TARGET_SIGSEGV);
>  }
>
> -static void restore_sigcontext(CPURISCVState *env, struct target_sigcontext *sc)
> +static bool restore_sigcontext(CPURISCVState *env, struct target_sigcontext *sc)
>  {
>      int i;
>
> @@ -161,9 +161,11 @@ static void restore_sigcontext(CPURISCVState *env, struct target_sigcontext *sc)
>      uint32_t fcsr;
>      __get_user(fcsr, &sc->fcsr);
>      riscv_csr_write(env, CSR_FCSR, fcsr);
> +
> +    return true;
>  }
>
> -static void restore_ucontext(CPURISCVState *env, struct target_ucontext *uc)
> +static bool restore_ucontext(CPURISCVState *env, struct target_ucontext *uc)
>  {
>      sigset_t blocked;
>      target_sigset_t target_set;
> @@ -177,7 +179,7 @@ static void restore_ucontext(CPURISCVState *env, struct target_ucontext *uc)
>      target_to_host_sigset_internal(&blocked, &target_set);
>      set_sigmask(&blocked);
>
> -    restore_sigcontext(env, &uc->uc_mcontext);
> +    return restore_sigcontext(env, &uc->uc_mcontext);
>  }
>
>  long do_rt_sigreturn(CPURISCVState *env)
> @@ -191,7 +193,10 @@ long do_rt_sigreturn(CPURISCVState *env)
>          goto badframe;
>      }
>
> -    restore_ucontext(env, &frame->uc);
> +    if (!restore_ucontext(env, &frame->uc)) {
> +        goto badframe;
> +    }
> +
>      target_restore_altstack(&frame->uc.uc_stack, env);
>
>      unlock_user_struct(frame, frame_addr, 0);
> --
> 2.51.0
>
>