Date: Mon, 28 Sep 2009 09:24:40 -0700 (PDT) From: Leunam Elebek <forensec@yahoo.de> To: freebsd-hackers@freebsd.org Subject: Trouble with copyout, memcpy.... Message-ID: <112995.77056.qm@web28510.mail.ukl.yahoo.com>
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Hey list,I currently code a driver under Current 8.0 for Current 8.0.But th=
ere are some problems with kernel/user-space interaction.I've the following=
structure:struct daq_kitinfo {=A0 =A0 =A0 =A0 uint32_t ki_maxdata;=A0 =A0 =
=A0 =A0 uint32_t ki_flags;=A0 =A0 =A0 =A0 uint32_t ki_rng_type;=A0 =A0 =A0 =
=A0 int =A0 =A0 =A0 =A0 =A0 ki_type;=A0 =A0 =A0 =A0 int =A0 =A0 =A0 =A0 =A0=
ki_nchan;=A0 =A0 =A0 =A0 int =A0 =A0 =A0 =A0 =A0 ki_len_chanl;};The above =
structure is used in my user-space app:int main(void) {=A0 =A0 =A0 =A0 stru=
ct daq_kitinfo *info;=A0 =A0 =A0 =A0 struct daq_kit kit; =A0 =A0 =A0 =A0 in=
t fd, size; =A0 =A0 =A0 =A0 ...=A0 =A0 =A0 =A0 ...=A0 =A0 =A0 =A0 ...=A0 =
=A0 =A0 =A0 /* =A0 =A0 =A0 =A0 =A0* At this point I'll
try to alloc memory. Notice that =A0 =A0 =A0 =A0 =A0* the size i dependet =
from another struct entry.=A0 =A0 =A0 =A0 =A0*/=A0 =A0 =A0 =A0 size =3D siz=
eof(*info) * kit.k_nkits;=A0 =A0 =A0 =A0 info =3D malloc(size);=A0 =A0 =A0 =
=A0 if (info =3D=3D NULL)=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 exit(ENOMEM);=A0 =
=A0 =A0 =A0=A0=A0 =A0 =A0 =A0 /*=A0 =A0 =A0 =A0 =A0* The next step is to ca=
ll the drivers ioctl() interface=A0 =A0 =A0 =A0 =A0* (the reason for that i=
s described below).=A0 =A0 =A0 =A0 =A0*/=A0 =A0 =A0 =A0 if (ioctl(fd, DAQ_K=
ITINFO, info)) {=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 printf("errno: %d\n", errno=
); =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0exit(errno);=A0 =A0 =A0 =A0 }=A0 =A0 =
=A0 =A0 =A0printf("[ki_nchan] %d\n", ki_nchan);=A0 =A0 =A0 =A0 =A0...=A0 =
=A0 =A0 =A0 =A0...=A0 =A0 =A0 =A0 =A0return (0);}and inside the driver (put=
it simply):static intmy_ioctl(struct cdev *dev, u_long cmd, caddr_t
arg, int flags,=A0 =A0 struct thread *td){=A0 =A0 =A0 =A0 struct daq_kitin=
fo *info;=A0 =A0 =A0 =A0 struct daq_kit =3D dev->si_drv1; =A0 =A0 =A0 =A0 i=
nt size; =A0 =A0 =A0 =A0 ...=A0 =A0 =A0 =A0 /* Do something useful e.g mute=
x'ing... */=A0 =A0 =A0 =A0 ...=A0 =A0 =A0 =A0 /* The same as in user-space.=
.. */=A0 =A0 =A0 =A0 size =3D sizeof(*info) * kit.k_nkits;=A0 =A0 =A0 =A0 i=
nfo =3D malloc(sz, M_DAQ, M_NOWAIT | M_ZERO);=A0 =A0 =A0 =A0 if (info =3D=
=3D NULL)=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ....=A0 =A0 =A0 =A0 /*=A0 =A0 =A0 =
=A0 =A0* Here I want to copy struct info from kernel to user-space.=A0 =A0 =
=A0 =A0 =A0* If i use memcpy, the result is that the system hangs=A0 =A0 =
=A0 =A0 =A0* and I need to reboot the machine. OK, I thought=A0 =A0 =A0 =A0=
=A0* copyout() should be able to do the job for me...=A0 =A0 =A0 =A0 =A0*/=
=A0 =A0 =A0 =A0 =A0if (copyout(info, arg, sz))=A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0/*=A0 =A0 =A0
=A0 =A0 =A0 =A0 =A0 =A0 * Fuc[k-k] i still come inside this block. I alway=
s=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 * get an EFAULT error. =A0 =A0 =A0 =A0=
=A0 =A0 =A0 =A0 =A0 */}I really don't know what I should do to let the dri=
ver workingproperly. The driver should grap some informations/attributes,an=
d fill up the info structure, so we can copy the filled info structto the u=
ser's app.I hope somebody can help me to resolve that problem.Ah, the corre=
sponding ioctl is:#define GRP =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0'd'#define DAQ_KITINFO =A0 =A0 =A0 =A0_IOR(GRP, 3, struct daq_kitinfo)Th=
anks for attention and greatz from germanyMG=0A=0A=0A
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