Re: [PATCH v2 2/2] linux-user: Add support for utimensat_time64() and semtimedop_time64()

[Laurent Vivier]

Le 25/08/2020 à 00:30, Filip Bozuta a écrit :
> This patch introduces functionality for following time64 syscalls:
> 
> *utimensat_time64()
> 
>     int utimensat(int dirfd, const char *pathname,
>                   const struct timespec times[2], int flags);
>     -- change file timestamps with nanosecond precision --
>     man page: https://man7.org/linux/man-pages/man2/utimensat.2.html
> 
> *semtimedop_time64()
> 
>     int semtimedop(int semid, struct sembuf *sops, size_t nsops,
>                    const struct timespec *timeout);
>     -- System V semaphore operations --
>     man page: https://www.man7.org/linux/man-pages/man2/semtimedop.2.html
> 
> Implementation notes:
> 
>    Syscall 'utimensat_time64()' is implemented in similar way as its
>    regular variants only difference being that time64 converting function
>    is used to convert values of 'struct timespec' between host and target
>    ('target_to_host_timespec64()').
> 
>    For syscall 'semtimedop_time64()' and additional argument is added
>    in function 'do_semtimedop()' through which the aproppriate 'struct 
> timespec'
>    converting function is called (false for regular target_to_host_timespec()
>    and true for target_to_host_timespec64()). For 'do_ipc()' a
>    check was added as that additional argument: 'TARGET_ABI_BITS == 64'.
> 
> Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
> ---
>  linux-user/syscall.c | 60 ++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 50 insertions(+), 10 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index fc6a6e32e4..4d460af744 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -1253,7 +1253,8 @@ static inline abi_long target_to_host_timespec(struct 
> timespec *host_ts,
>  #endif
>  
>  #if defined(TARGET_NR_clock_settime64) || defined(TARGET_NR_futex_time64) || 
> \
> -    defined(TARGET_NR_pselect6_time64) || defined(TARGET_NR_ppoll_time64)
> +    defined(TARGET_NR_pselect6_time64) || defined(TARGET_NR_ppoll_time64) || 
> \
> +    defined(TARGET_NR_utimensat_time64) || 
> defined(TARGET_NR_semtimedop_time64)
>  static inline abi_long target_to_host_timespec64(struct timespec *host_ts,
>                                                   abi_ulong target_addr)
>  {
> @@ -4117,7 +4118,7 @@ static inline abi_long target_to_host_sembuf(struct 
> sembuf *host_sembuf,
>  }
>  
>  #if defined(TARGET_NR_ipc) || defined(TARGET_NR_semop) || \
> -    defined(TARGET_NR_semtimedop)
> +    defined(TARGET_NR_semtimedop) || defined(TARGET_NR_semtimedop_time64)
>  
>  /*
>   * This macro is required to handle the s390 variants, which passes the
> @@ -4134,7 +4135,7 @@ static inline abi_long target_to_host_sembuf(struct 
> sembuf *host_sembuf,
>  static inline abi_long do_semtimedop(int semid,
>                                       abi_long ptr,
>                                       unsigned nsops,
> -                                     abi_long timeout)
> +                                     abi_long timeout, bool time64)
>  {
>      struct sembuf sops[nsops];
>      struct timespec ts, *pts = NULL;
> @@ -4142,8 +4143,14 @@ static inline abi_long do_semtimedop(int semid,
>  
>      if (timeout) {
>          pts = &ts;
> -        if (target_to_host_timespec(pts, timeout)) {
> -            return -TARGET_EFAULT;
> +        if (time64) {
> +            if (target_to_host_timespec64(pts, timeout)) {
> +                return -TARGET_EFAULT;
> +            }
> +        } else {
> +            if (target_to_host_timespec(pts, timeout)) {
> +                return -TARGET_EFAULT;
> +            }
>          }
>      }
>  
> @@ -4657,7 +4664,7 @@ static abi_long do_ipc(CPUArchState *cpu_env,
>  
>      switch (call) {
>      case IPCOP_semop:
> -        ret = do_semtimedop(first, ptr, second, 0);
> +        ret = do_semtimedop(first, ptr, second, 0, false);
>          break;
>      case IPCOP_semtimedop:
>      /*
> @@ -4667,9 +4674,9 @@ static abi_long do_ipc(CPUArchState *cpu_env,
>       * to a struct timespec where the generic variant uses fifth parameter.
>       */
>  #if defined(TARGET_S390X)
> -        ret = do_semtimedop(first, ptr, second, third);
> +        ret = do_semtimedop(first, ptr, second, third, TARGET_ABI_BITS == 
> 64);
>  #else
> -        ret = do_semtimedop(first, ptr, second, fifth);
> +        ret = do_semtimedop(first, ptr, second, fifth, TARGET_ABI_BITS == 
> 64);
>  #endif
>          break;
>  
> @@ -9887,11 +9894,15 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>  #endif
>  #ifdef TARGET_NR_semop
>      case TARGET_NR_semop:
> -        return do_semtimedop(arg1, arg2, arg3, 0);
> +        return do_semtimedop(arg1, arg2, arg3, 0, false);
>  #endif
>  #ifdef TARGET_NR_semtimedop
>      case TARGET_NR_semtimedop:
> -        return do_semtimedop(arg1, arg2, arg3, arg4);
> +        return do_semtimedop(arg1, arg2, arg3, arg4, false);
> +#endif
> +#ifdef TARGET_NR_semtimedop_time64
> +    case TARGET_NR_semtimedop_time64:
> +        return do_semtimedop(arg1, arg2, arg3, arg4, true);
>  #endif
>  #ifdef TARGET_NR_semctl
>      case TARGET_NR_semctl:
> @@ -11938,6 +11949,35 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          }
>          return ret;
>  #endif
> +#ifdef TARGET_NR_utimensat_time64
> +    case TARGET_NR_utimensat_time64:
> +        {
> +            struct timespec *tsp, ts[2];
> +            if (!arg3) {
> +                tsp = NULL;
> +            } else {
> +                if (target_to_host_timespec64(ts, arg3)) {
> +                    return -TARGET_EFAULT;
> +                }
> +                if (target_to_host_timespec64(ts + 1, arg3 +
> +                                     sizeof(struct 
> target__kernel_timespec))) {
> +                    return -TARGET_EFAULT;
> +                }
> +                tsp = ts;
> +            }
> +            if (!arg2)
> +                ret = get_errno(sys_utimensat(arg1, NULL, tsp, arg4));
> +            else {
> +                p = lock_user_string(arg2);
> +                if (!p) {
> +                    return -TARGET_EFAULT;
> +                }
> +                ret = get_errno(sys_utimensat(arg1, path(p), tsp, arg4));
> +                unlock_user(p, arg2, 0);
> +            }
> +        }
> +        return ret;
> +#endif
>  #ifdef TARGET_NR_futex
>      case TARGET_NR_futex:
>          return do_futex(arg1, arg2, arg3, arg4, arg5, arg6);
> 

Applied to my linux-user-for-5.2 branch.

Thanks,
Laurent