Re: [Qemu-devel] [PATCH v4 06/16] linux-user: Propagate goto unimplemented to default

[Philippe Mathieu-Daudé]

On 08/18/2018 04:01 PM, Richard Henderson wrote:
> There is no point in listing a syscall if you want the same effect as
> not listing it.  In one less trivial case, the goto was demonstrably
> not reachable.
> 
> Reviewed-by: Peter Maydell <address@hidden>
> Signed-off-by: Richard Henderson <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>  linux-user/syscall.c | 144 +------------------------------------------
>  1 file changed, 1 insertion(+), 143 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 812fb27fa1..ef3b9b623c 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -8341,14 +8341,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          unlock_user(p, arg1, 0);
>          return ret;
>  #endif
> -#ifdef TARGET_NR_break
> -    case TARGET_NR_break:
> -        goto unimplemented;
> -#endif
> -#ifdef TARGET_NR_oldstat
> -    case TARGET_NR_oldstat:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_lseek
>      case TARGET_NR_lseek:
>          return get_errno(lseek(arg1, arg2, arg3));
> @@ -8435,16 +8427,10 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>              return get_errno(stime(&host_time));
>          }
>  #endif
> -    case TARGET_NR_ptrace:
> -        goto unimplemented;
>  #ifdef TARGET_NR_alarm /* not on alpha */
>      case TARGET_NR_alarm:
>          return alarm(arg1);
>  #endif
> -#ifdef TARGET_NR_oldfstat
> -    case TARGET_NR_oldfstat:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_pause /* not on alpha */
>      case TARGET_NR_pause:
>          if (!block_signals()) {
> @@ -8515,14 +8501,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          }
>          return ret;
>  #endif
> -#ifdef TARGET_NR_stty
> -    case TARGET_NR_stty:
> -        goto unimplemented;
> -#endif
> -#ifdef TARGET_NR_gtty
> -    case TARGET_NR_gtty:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_access
>      case TARGET_NR_access:
>          if (!(p = lock_user_string(arg1))) {
> @@ -8544,10 +8522,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>  #ifdef TARGET_NR_nice /* not on alpha */
>      case TARGET_NR_nice:
>          return get_errno(nice(arg1));
> -#endif
> -#ifdef TARGET_NR_ftime
> -    case TARGET_NR_ftime:
> -        goto unimplemented;
>  #endif
>      case TARGET_NR_sync:
>          sync();
> @@ -8661,14 +8635,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>                  ret = host_to_target_clock_t(ret);
>          }
>          return ret;
> -#ifdef TARGET_NR_prof
> -    case TARGET_NR_prof:
> -        goto unimplemented;
> -#endif
> -#ifdef TARGET_NR_signal
> -    case TARGET_NR_signal:
> -        goto unimplemented;
> -#endif
>      case TARGET_NR_acct:
>          if (arg1 == 0) {
>              ret = get_errno(acct(NULL));
> @@ -8687,31 +8653,15 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          ret = get_errno(umount2(p, arg2));
>          unlock_user(p, arg1, 0);
>          return ret;
> -#endif
> -#ifdef TARGET_NR_lock
> -    case TARGET_NR_lock:
> -        goto unimplemented;
>  #endif
>      case TARGET_NR_ioctl:
>          return do_ioctl(arg1, arg2, arg3);
>  #ifdef TARGET_NR_fcntl
>      case TARGET_NR_fcntl:
>          return do_fcntl(arg1, arg2, arg3);
> -#endif
> -#ifdef TARGET_NR_mpx
> -    case TARGET_NR_mpx:
> -        goto unimplemented;
>  #endif
>      case TARGET_NR_setpgid:
>          return get_errno(setpgid(arg1, arg2));
> -#ifdef TARGET_NR_ulimit
> -    case TARGET_NR_ulimit:
> -        goto unimplemented;
> -#endif
> -#ifdef TARGET_NR_oldolduname
> -    case TARGET_NR_oldolduname:
> -        goto unimplemented;
> -#endif
>      case TARGET_NR_umask:
>          return get_errno(umask(arg1));
>      case TARGET_NR_chroot:
> @@ -8720,10 +8670,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          ret = get_errno(chroot(p));
>          unlock_user(p, arg1, 0);
>          return ret;
> -#ifdef TARGET_NR_ustat
> -    case TARGET_NR_ustat:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_dup2
>      case TARGET_NR_dup2:
>          ret = get_errno(dup2(arg1, arg2));
> @@ -9432,10 +9378,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          }
>          return ret;
>  #endif
> -#ifdef TARGET_NR_oldlstat
> -    case TARGET_NR_oldlstat:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_readlink
>      case TARGET_NR_readlink:
>          {
> @@ -9489,10 +9431,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          }
>          return ret;
>  #endif
> -#ifdef TARGET_NR_uselib
> -    case TARGET_NR_uselib:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_swapon
>      case TARGET_NR_swapon:
>          if (!(p = lock_user_string(arg1)))
> @@ -9514,10 +9452,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>             ret = get_errno(reboot(arg1, arg2, arg3, NULL));
>          }
>          return ret;
> -#ifdef TARGET_NR_readdir
> -    case TARGET_NR_readdir:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_mmap
>      case TARGET_NR_mmap:
>  #if (defined(TARGET_I386) && defined(TARGET_ABI32)) || \
> @@ -9638,10 +9572,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          return ret;
>      case TARGET_NR_setpriority:
>          return get_errno(setpriority(arg1, arg2, arg3));
> -#ifdef TARGET_NR_profil
> -    case TARGET_NR_profil:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_statfs
>      case TARGET_NR_statfs:
>          if (!(p = lock_user_string(arg1))) {
> @@ -9713,10 +9643,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          ret = get_errno(fstatfs(arg1, &stfs));
>          goto convert_statfs64;
>  #endif
> -#ifdef TARGET_NR_ioperm
> -    case TARGET_NR_ioperm:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_socketcall
>      case TARGET_NR_socketcall:
>          return do_socketcall(arg1, arg2);
> @@ -9935,21 +9861,9 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>              }
>          }
>          return ret;
> -#endif
> -#ifdef TARGET_NR_olduname
> -    case TARGET_NR_olduname:
> -        goto unimplemented;
> -#endif
> -#ifdef TARGET_NR_iopl
> -    case TARGET_NR_iopl:
> -        goto unimplemented;
>  #endif
>      case TARGET_NR_vhangup:
>          return get_errno(vhangup());
> -#ifdef TARGET_NR_idle
> -    case TARGET_NR_idle:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_syscall
>      case TARGET_NR_syscall:
>          return do_syscall(cpu_env, arg1 & 0xffff, arg2, arg3, arg4, arg5,
> @@ -10122,8 +10036,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>      case TARGET_NR_modify_ldt:
>          return do_modify_ldt(cpu_env, arg1, arg2, arg3);
>  #if !defined(TARGET_X86_64)
> -    case TARGET_NR_vm86old:
> -        goto unimplemented;
>      case TARGET_NR_vm86:
>          return do_vm86(cpu_env, arg1, arg2);
>  #endif
> @@ -10160,35 +10072,12 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          }
>          return ret;
>  #endif
> -#ifdef TARGET_NR_create_module
> -    case TARGET_NR_create_module:
> -#endif
> -    case TARGET_NR_init_module:
> -    case TARGET_NR_delete_module:
> -#ifdef TARGET_NR_get_kernel_syms
> -    case TARGET_NR_get_kernel_syms:
> -#endif
> -        goto unimplemented;
> -    case TARGET_NR_quotactl:
> -        goto unimplemented;
>      case TARGET_NR_getpgid:
>          return get_errno(getpgid(arg1));
>      case TARGET_NR_fchdir:
>          return get_errno(fchdir(arg1));
> -#ifdef TARGET_NR_bdflush /* not on x86_64 */
> -    case TARGET_NR_bdflush:
> -        goto unimplemented;
> -#endif
> -#ifdef TARGET_NR_sysfs
> -    case TARGET_NR_sysfs:
> -        goto unimplemented;
> -#endif
>      case TARGET_NR_personality:
>          return get_errno(personality(arg1));
> -#ifdef TARGET_NR_afs_syscall
> -    case TARGET_NR_afs_syscall:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR__llseek /* Not on alpha */
>      case TARGET_NR__llseek:
>          {
> @@ -10702,14 +10591,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>              }
>          }
>          return ret;
> -#ifdef TARGET_NR_query_module
> -    case TARGET_NR_query_module:
> -        goto unimplemented;
> -#endif
> -#ifdef TARGET_NR_nfsservctl
> -    case TARGET_NR_nfsservctl:
> -        goto unimplemented;
> -#endif
>      case TARGET_NR_prctl:
>          switch (arg1) {
>          case PR_GET_PDEATHSIG:
> @@ -10795,7 +10676,7 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>  #if defined(TARGET_I386) && !defined(TARGET_ABI32)
>          return do_arch_prctl(cpu_env, arg1, arg2);
>  #else
> -        goto unimplemented;
> +#error unreachable
>  #endif
>  #endif
>  #ifdef TARGET_NR_pread64
> @@ -10945,21 +10826,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          return ret;
>      }
>  #endif
> -#else
> -    case TARGET_NR_sendfile:
> -#ifdef TARGET_NR_sendfile64
> -    case TARGET_NR_sendfile64:
> -#endif
> -        goto unimplemented;
> -#endif
> -
> -#ifdef TARGET_NR_getpmsg
> -    case TARGET_NR_getpmsg:
> -        goto unimplemented;
> -#endif
> -#ifdef TARGET_NR_putpmsg
> -    case TARGET_NR_putpmsg:
> -        goto unimplemented;
>  #endif
>  #ifdef TARGET_NR_vfork
>      case TARGET_NR_vfork:
> @@ -11502,9 +11368,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>      case TARGET_NR_setfsgid32:
>          return get_errno(setfsgid(arg1));
>  #endif
> -
> -    case TARGET_NR_pivot_root:
> -        goto unimplemented;
>  #ifdef TARGET_NR_mincore
>      case TARGET_NR_mincore:
>          {
> @@ -11662,10 +11525,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          /* self-modifying code is handled automatically, so nothing needed */
>          return 0;
>  #endif
> -#ifdef TARGET_NR_security
> -    case TARGET_NR_security:
> -        goto unimplemented;
> -#endif
>  #ifdef TARGET_NR_getpagesize
>      case TARGET_NR_getpagesize:
>          return TARGET_PAGE_SIZE;
> @@ -12631,7 +12490,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>  #endif
>  
>      default:
> -    unimplemented:
>          qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
>          return -TARGET_ENOSYS;
>      }
>