On 1/11/19 2:17 AM, Laurent Vivier wrote:
> On 19/12/2018 05:21, Richard Henderson wrote:
>> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
>> ---
>> linux-user/syscall-defs.h | 14 ++++
>> linux-user/syscall-file.inc.c | 124 ++++++++++++++++++++++++++++++++++
>> linux-user/syscall.c | 93 -------------------------
>> linux-user/strace.list | 18 -----
>> 4 files changed, 138 insertions(+), 111 deletions(-)
>>
> ...
>> diff --git a/linux-user/syscall-file.inc.c b/linux-user/syscall-file.inc.c
>> index 11e75044c1..410a763eee 100644
>> --- a/linux-user/syscall-file.inc.c
>> +++ b/linux-user/syscall-file.inc.c
>> @@ -315,6 +315,104 @@ SYSCALL_IMPL(openat)
> ...
>> +
>> +/*
>> + * Both preadv and pwritev merge args 4/5 into a 64-bit offset.
>> + * Moreover, the parts are *always* in little-endian order.
>> + */
>> +#if TARGET_ABI_BITS == 32
>> +SYSCALL_ARGS(preadv_pwritev)
>> +{
>> + /* We have already assigned out[0-2]. */
>> + abi_ulong lo = in[3], hi = in[4];
>> + out[3] = ((hi << (TARGET_ABI_BITS - 1)) << 1) | lo;
>> + return def;
>> +}
>> +#else
>> +#define args_preadv_pwritev NULL
>> +#endif
>> +
>> +/* Perform the inverse operation for the host. */
>> +static inline void host_offset64_low_high(unsigned long *l, unsigned long
>> *h,
>> + uint64_t off)
>> +{
>> + *l = off;
>> + *h = (off >> (HOST_LONG_BITS - 1)) >> 1;
>> +}
>
>
> I have an error with preadv() on a 32bit target (powerpc, LTP test preadv02).
>
> It works if I use:
>
> static inline void host_offset64_low_high(unsigned long *hlow,
> unsigned long *hhigh,
> abi_ulong tlow,
> abi_ulong thigh)
> {
> uint64_t off = tlow |
> ((unsigned long long)thigh << TARGET_LONG_BITS / 2) <<
> TARGET_LONG_BITS / 2;
>
> *hlow = off;
> *hhigh = (off >> HOST_LONG_BITS / 2) >> HOST_LONG_BITS / 2;
> }
This doesn't make any sense. Where are "tlow" and "thigh" coming from?
I think the bug will be
SYSCALL_ARGS(preadv_pwritev)
{
/* We have already assigned out[0-2]. */
abi_ulong lo = in[3], hi = in[4];
- out[3] = ((hi << (TARGET_ABI_BITS - 1)) << 1) | lo;
+ out[3] = (((uint64_t)hi << (TARGET_ABI_BITS - 1)) << 1) | lo;
return def;
}
r~
