Hey list,I currently code a driver under Current 8.0 for Current 8.0.But there
are some problems with kernel/user-space interaction.I've the following
structure:struct daq_kitinfo { uint32_t ki_maxdata; uint32_t
ki_flags; uint32_t ki_rng_type; int ki_type; int
ki_nchan; int ki_len_chanl;};The above structure is
used in my user-space app:int main(void) { struct daq_kitinfo *info;
struct daq_kit kit; int fd, size; ... ... ...
/* * At this point I'll
try to alloc memory. Notice that * the size i dependet from another
struct entry. */ size = sizeof(*info) * kit.k_nkits; info
= malloc(size); if (info == NULL) exit(ENOMEM);
/* * The next step is to call the drivers ioctl() interface
* (the reason for that is described below). */ if (ioctl(fd,
DAQ_KITINFO, info)) { printf("errno: %d\n", errno);
exit(errno); } printf("[ki_nchan] %d\n", ki_nchan);
... ... return (0);}and inside the driver (put it
simply):static intmy_ioctl(struct cdev *dev, u_long cmd, caddr_t
arg, int flags, struct thread *td){ struct daq_kitinfo *info;
struct daq_kit = dev->si_drv1; int size; ... /* Do
something useful e.g mutex'ing... */ ... /* The same as in
user-space... */ size = sizeof(*info) * kit.k_nkits; info =
malloc(sz, M_DAQ, M_NOWAIT | M_ZERO); if (info == NULL)
.... /* * Here I want to copy struct info from kernel to
user-space. * If i use memcpy, the result is that the system hangs
* and I need to reboot the machine. OK, I thought * copyout() should
be able to do the job for me... */ if (copyout(info, arg, sz))
/*
* Fuc[k-k] i still come inside this block. I always
* get an EFAULT error. */}I really don't know what I should
do to let the driver workingproperly. The driver should grap some
informations/attributes,and fill up the info structure, so we can copy the
filled info structto the user's app.I hope somebody can help me to resolve that
problem.Ah, the corresponding ioctl is:#define GRP
'd'#define DAQ_KITINFO _IOR(GRP, 3, struct daq_kitinfo)Thanks for
attention and greatz from germanyMG
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