Several ioctl structs change size between native 32-bit (ia32) and x32 applications, because x32 follows the native 64-bit (amd64) integer alignment rules and uses 64-bit time_t. In these instances, the ioctl number changes so userspace simply gets -ENOTTY. This scenario can be handled by simply adding more cases. Looking at the different ioctls implemented here: - All the ones marked 'No size or alignment issue on any arch' should presumably all be fine. - All the ones under BROKEN_X86_ALIGNMENT are different under integer alignment rules. Since x32 matches amd64 here, we just need both sets of cases handled. - XFS_IOC_SWAPEXT has both integer alignment differences and time_t differences. Since x32 matches amd64 here, we need to add a case which calls the native implementation. - The remaining ioctls have neither 64-bit integers nor time_t, so x32 matches ia32 here and no change is required at this level. The bulkstat ioctl implementations have some pointer chasing which is handled separately. Signed-off-by: Nick Bowler <nbowler@xxxxxxxxxx> --- fs/xfs/xfs_ioctl32.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c index 6a759c0ffb54..c5b48e1f46fe 100644 --- a/fs/xfs/xfs_ioctl32.c +++ b/fs/xfs/xfs_ioctl32.c @@ -564,8 +564,12 @@ xfs_file_compat_ioctl( case FS_IOC_GETFSMAP: case XFS_IOC_SCRUB_METADATA: return xfs_file_ioctl(filp, cmd, p); -#ifndef BROKEN_X86_ALIGNMENT - /* These are handled fine if no alignment issues */ +#if !defined(BROKEN_X86_ALIGNMENT) || defined(CONFIG_X86_X32) + /* + * These are handled fine if no alignment issues. To support x32 + * which uses native 64-bit alignment we must emit these cases in + * addition to the ia-32 compat set below. + */ case XFS_IOC_ALLOCSP: case XFS_IOC_FREESP: case XFS_IOC_RESVSP: @@ -578,8 +582,16 @@ xfs_file_compat_ioctl( case XFS_IOC_FSGROWFSDATA: case XFS_IOC_FSGROWFSRT: case XFS_IOC_ZERO_RANGE: +#ifdef CONFIG_X86_X32 + /* + * x32 special: this gets a different cmd number from the ia-32 compat + * case below; the associated data will match native 64-bit alignment. + */ + case XFS_IOC_SWAPEXT: +#endif return xfs_file_ioctl(filp, cmd, p); -#else +#endif +#if defined(BROKEN_X86_ALIGNMENT) case XFS_IOC_ALLOCSP_32: case XFS_IOC_FREESP_32: case XFS_IOC_ALLOCSP64_32: -- 2.16.1
