On 21 November 2011 10:52, Alexander Graf <ag...@suse.de> wrote: > On 21.11.2011, at 11:47, Peter Maydell wrote: >> Should this really be printing -1 all the time when ret isn't -1 ? > > In linux-user, the syscall emulation functions return -errno which later > gets translated to -1 with errno=-errno. That's why the code looks so > weird. So yes, it's correct.
Yes, but the syscall ABI (which is what we're implementing) returns -errno for errors; the errno variable is a purely userspace construct. I'd expected that the strace layer would be tracing exactly what the syscall ABI was. However it looks like standard userspace strace(1) also does this translation to -1 errno=thing, so it makes sense for us to do that too. -- PMM
