From 53bb724f94f57b67213e08a4c155c8c5eb74c644 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Mon, 21 Sep 2015 13:26:59 -0700 Subject: mtd: provide proper 32/64-bit compat_ioctl() support for BLKPG After a bit of poking around wondering why my 32-bit user-space can't seem to send a proper ioctl(BLKPG) to an MTD on my 64-bit kernel (ARM64), I noticed that struct blkpg_ioctl_arg is actually pretty unsuitable for use in the ioctl() ABI, due to its use of raw pointers, and its lack of alignment/packing restrictions (32-bit arch'es tend to pack the 4 fields into 4 32-bit words, whereas 64-bit arch'es would add padding after the third int, and make this 6 32-bit words). Anyway, this means BLKPG deserves some special compat_ioctl handling. Do the conversion in a small shim for MTD. block/compat_ioctl.c already has compat support for the block subsystem, but it does so by a re-marshalling data to/from user-space (see compat_blkpg_ioctl()). Personally, I think this approach is cleaner. Tested only on MTD, with an ARM32 user space on an ARM64 kernel. Signed-off-by: Brian Norris --- include/uapi/linux/blkpg.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/blkpg.h b/include/uapi/linux/blkpg.h index a851944..63739a0 100644 --- a/include/uapi/linux/blkpg.h +++ b/include/uapi/linux/blkpg.h @@ -1,5 +1,5 @@ -#ifndef _LINUX_BLKPG_H -#define _LINUX_BLKPG_H +#ifndef _UAPI__LINUX_BLKPG_H +#define _UAPI__LINUX_BLKPG_H /* * Partition table and disk geometry handling @@ -56,4 +56,4 @@ struct blkpg_partition { char volname[BLKPG_VOLNAMELTH]; /* volume label */ }; -#endif /* _LINUX_BLKPG_H */ +#endif /* _UAPI__LINUX_BLKPG_H */ -- cgit v1.1