Re: [PATCH v2 18/41] linux-user/signal: Drop HOST_SIGNAL_PLACEHOLDER

[Warner Losh]

> On Sep 18, 2021, at 12:45 PM, Richard Henderson 
> <richard.henderson@linaro.org> wrote:
> 
> Now that all of the linux-user hosts have been converted
> to host-signal.h, drop the compatibility code.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> include/exec/exec-all.h | 12 ------------
> linux-user/signal.c     | 13 -------------
> 2 files changed, 25 deletions(-)

Reviewed by: Warner Losh <imp@bsdimp.com>

> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
> index 5f94d799aa..5dd663c153 100644
> --- a/include/exec/exec-all.h
> +++ b/include/exec/exec-all.h
> @@ -685,18 +685,6 @@ MMUAccessType adjust_signal_pc(uintptr_t *pc, bool 
> is_write);
> bool handle_sigsegv_accerr_write(CPUState *cpu, sigset_t *old_set,
>                                  uintptr_t host_pc, abi_ptr guest_addr);
> 
> -/**
> - * cpu_signal_handler
> - * @signum: host signal number
> - * @pinfo: host siginfo_t
> - * @puc: host ucontext_t
> - *
> - * To be called from the SIGBUS and SIGSEGV signal handler to inform the
> - * virtual cpu of exceptions.  Returns true if the signal was handled by
> - * the virtual CPU.
> - */
> -int cpu_signal_handler(int signum, void *pinfo, void *puc);
> -
> #else
> static inline void mmap_lock(void) {}
> static inline void mmap_unlock(void) {}
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index 6f953f10d4..e6531fdfa0 100644
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -773,16 +773,6 @@ static void host_signal_handler(int host_sig, siginfo_t 
> *info, void *puc)
>     ucontext_t *uc = puc;
>     struct emulated_sigtable *k;
>     int guest_sig;
> -
> -#ifdef HOST_SIGNAL_PLACEHOLDER
> -    /* the CPU emulator uses some host signals to detect exceptions,
> -       we forward to it some signals */
> -    if ((host_sig == SIGSEGV || host_sig == SIGBUS)
> -        && info->si_code > 0) {
> -        if (cpu_signal_handler(host_sig, info, puc))
> -            return;
> -    }
> -#else
>     uintptr_t pc = 0;
>     bool sync_sig = false;
> 
> @@ -842,7 +832,6 @@ static void host_signal_handler(int host_sig, siginfo_t 
> *info, void *puc)
> 
>         sync_sig = true;
>     }
> -#endif
> 
>     /* get target signal number */
>     guest_sig = host_to_target_signal(host_sig);
> @@ -857,7 +846,6 @@ static void host_signal_handler(int host_sig, siginfo_t 
> *info, void *puc)
>     k->pending = guest_sig;
>     ts->signal_pending = 1;
> 
> -#ifndef HOST_SIGNAL_PLACEHOLDER
>     /*
>      * For synchronous signals, unwind the cpu state to the faulting
>      * insn and then exit back to the main loop so that the signal
> @@ -867,7 +855,6 @@ static void host_signal_handler(int host_sig, siginfo_t 
> *info, void *puc)
>         cpu->exception_index = EXCP_INTERRUPT;
>         cpu_loop_exit_restore(cpu, pc);
>     }
> -#endif
> 
>     rewind_if_in_safe_syscall(puc);
> 
> -- 
> 2.25.1
> 
>