From 138d22ae4abf49d9694a4398857fb4be5114f103 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Mon, 22 May 2023 14:22:55 +0100 Subject: [PATCH] pps: Compatibility hack should be X86-specific As of [1], using PPS_FETCH on a 64-bit ARM kernel with a 32-bit userland is broken, returning a timeout. This is because the requested 4-byte alignment for struct pps_ktime_compat (illegal on arm64) results in the timeout flags field being uninitialised. Make the hack specific to X86_64 builds with CONFIG_COMPAT defined. [1] commit c2a49fe8eeef ("pps: fix padding issue with PPS_FETCH for ioctl_compat") See: https://github.com/raspberrypi/linux/issues/5430 Fixes: c2a49fe8eeef ("pps: fix padding issue with PPS_FETCH for ioctl_compat") Signed-off-by: Phil Elwell --- drivers/pps/pps.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -249,12 +249,13 @@ static long pps_cdev_ioctl(struct file * static long pps_cdev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - struct pps_device *pps = file->private_data; - void __user *uarg = (void __user *) arg; cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *)); +#ifdef CONFIG_X86_64 if (cmd == PPS_FETCH) { + struct pps_device *pps = file->private_data; + void __user *uarg = (void __user *) arg; struct pps_fdata_compat compat; struct pps_fdata fdata; int err; @@ -289,6 +290,7 @@ static long pps_cdev_compat_ioctl(struct return copy_to_user(uarg, &compat, sizeof(struct pps_fdata_compat)) ? -EFAULT : 0; } +#endif return pps_cdev_ioctl(file, cmd, arg); }