Hello all, I've written a program that uses SIOCGMIIREG to query various mii interfaces on my board. I'm using kernel 2.6.23 I set the ifru_data up like this in user space #include <linux/mii.h> // The user side if.h struct mii_ioctl_data mii; mii.phy_addr=myphy; mii.reg_num=myreg; ifr.ifru_data=(__caddr_t)&mii; as according to my libc (uclibc) <net/if.h> that is what ifr_data is. Then call the ioctl. This doesn't work. I get garbage in the ifr_data used by the network driver. If I add a copy_from/to_user around the call to generic_mii_ioctl, then it works. My driver isn't in the main kernel it is at stlinux.org but the ioctl function is the same as many in main tree, pcnet32_ioctl() for example. mii-tool works without me patching the driver. mii-tool sets the ioctl up like this. #include "mii.h" // it's own mmi structure struct mii_data *mii = (struct mii_data *)&ifr.ifr_data; mii->reg_num = location; in mii-tool ifr_data is a pointer not allocated storage so you shouldn't do that. However it part of a union and the biggest thing in it is bigger than mii_data, so we are not going to crap on our stack/heap. Not safe though if the structure of mii_data grows. looking at <linux/if.h> (the kernel side if.h) ifru_data is a void __user *ifru_data; i.e. it needs copy_to/from_user. Are the drivers AND mii-tool wrong? I'm feeling like either I've uncovered a long standing bug (in both mii ioctls and mmi-tool) or I'm missing something. Apologies for the verbose message but I'm trying to tell it as thoroughly as I can. -- John Paul Foster <jaypee@xxxxxxxxxxxxx>
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