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

[Laurent Vivier <laurent@vivier.eu>]

Le 25/08/2020 à 09:18, Laurent Vivier a écrit :
> 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.

I have removed it from my queue because the "TARGET_NR_utimensat_time64"
part breaks something (at least with sh4/sid on x86_64):

$ touch a
$ cp -p a b
/usr/bin/cp: preserving times for 'b': Invalid argument

Thanks,
Laurent