On Wed, 18 Oct 2000 00:42:54 -0400,
Paul Gortmaker <p_gortmaker@yahoo.com> wrote:
>As an alternative to sprinkling MOD_DEC_USE_COUNT throughout the failure
>paths of each net driver init sequence, maybe we should get the module use
>counters out of the drivers entirely. The driver source(s) look cleaner
IOW, exactly what AL Viro did for VFS.
> /*
>+ * Make sure module is marked in
>+ * use in case dev->open sleeps.
>+ */
>+
>+ if (dev->module)
>+ __MOD_INC_USE_COUNT(dev->module);
That needs to be try_inc_mod_count with a test on the result to close
this race
if (dev->module) rmmod
usercount == 0, OK to unload
__MOD_INC_USE_COUNT(dev->module);
unload
dev->open(), oops
There is a problem with devices, you can ioctl a device without having
a corresponding open().
# strace ifconfig eth0 promisc
execve("/sbin/ifconfig", ["ifconfig", "eth0", "promisc"], [/* 33 vars */]) = 0
.....
socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 4
.....
ioctl(4, SIOCGIFFLAGS, 0xbffffa64) = 0
No open on the device so no use count, what keeps the mod count up to
prevent unloading?
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