Re: [PULL 1/1] linux-user: Support futex_time64

[Laurent Vivier]

Le 02/11/2020 à 19:15, Peter Maydell a écrit :
> On Mon, 30 Mar 2020 at 11:31, Laurent Vivier <laurent@vivier.eu> wrote:
>>
>> From: Alistair Francis <alistair.francis@wdc.com>
>>
>> Add support for host and target futex_time64. If futex_time64 exists on
>> the host we try that first before falling back to the standard futex
>> syscall.
> 
> Hi; I dunno why Coverity's only just noticed this, but in
> CID 1432339 it points out:
> 
>> +#if defined(TARGET_NR_futex_time64)
>> +static int do_futex_time64(target_ulong uaddr, int op, int val, 
>> target_ulong timeout,
>> +                           target_ulong uaddr2, int val3)
>> +{
>> +    struct timespec ts, *pts;
>> +    int base_op;
>> +
>> +    /* ??? We assume FUTEX_* constants are the same on both host
>> +       and target.  */
>> +#ifdef FUTEX_CMD_MASK
>> +    base_op = op & FUTEX_CMD_MASK;
>> +#else
>> +    base_op = op;
>> +#endif
>> +    switch (base_op) {
>> +    case FUTEX_WAIT:
>> +    case FUTEX_WAIT_BITSET:
>> +        if (timeout) {
>> +            pts = &ts;
>> +            target_to_host_timespec64(pts, timeout);
> 
> ...that here we call target_to_host_timespec64(), which can
> fail with -TARGET_EFAULT, but (unlike all the other times we call
> the function) we aren't checking its return value.
> Is there missing error handling code here ?
> 

I think the code is like that because this is a cut&paste of function
do_futex() witl "s/timespec/timespec64/".

And yes I think we should check for the return value.
I'm going to fix that.

Thanks,
Laurent