[PATCH 2/2] rtc: move compat_ioctl handling into rtc-dev.c

From: Arnd Bergmann
Date: Mon Aug 27 2018 - 16:04:20 EST


We no longer need the rtc compat handling to be in common code, now that
all drivers are either moved to the rtc-class framework, or (rarely)
exist in drivers/char for architectures without compat mode (m68k,
alpha and ia64, respectively).

I checked the list of ioctl commands in drivers, and the ones that are
not already handled are all compatible, again with the one exception of
m68k driver, which implements RTC_PLL_GET and RTC_PLL_SET, but has no
compat mode.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/rtc/rtc-dev.c | 50 +++++++++++++++++++++++++++++++++++++++
fs/compat_ioctl.c | 54 -------------------------------------------
2 files changed, 50 insertions(+), 54 deletions(-)

diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 43d962a9c210..50b03e175263 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -13,6 +13,7 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

+#include <linux/compat.h>
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/sched/signal.h>
@@ -405,6 +406,52 @@ static long rtc_dev_ioctl(struct file *file,
return err;
}

+#ifdef CONFIG_COMPAT
+#define RTC_IRQP_READ32 _IOR('p', 0x0b, compat_ulong_t)
+#define RTC_IRQP_SET32 _IOW('p', 0x0c, compat_ulong_t)
+#define RTC_EPOCH_READ32 _IOR('p', 0x0d, compat_ulong_t)
+#define RTC_EPOCH_SET32 _IOW('p', 0x0e, compat_ulong_t)
+
+static long rtc_dev_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+ unsigned long __user *valp;
+ compat_ulong_t __user *argp = compat_ptr(arg);
+ unsigned long val;
+ int ret;
+
+ switch (cmd) {
+ /* pointer to 'long' needs translation. */
+ case RTC_IRQP_READ32:
+ case RTC_EPOCH_READ32: {
+ valp = compat_alloc_user_space(sizeof(*valp));
+ if (valp == NULL)
+ return -EFAULT;
+ ret = rtc_dev_ioctl(file, (cmd == RTC_IRQP_READ32) ?
+ RTC_IRQP_READ : RTC_EPOCH_READ,
+ (unsigned long)valp);
+ if (ret)
+ return ret;
+ if (get_user(val, valp) || put_user(val, argp))
+ return -EFAULT;
+ return 0;
+ }
+
+ /* arguments are compatible, command number is not */
+ case RTC_IRQP_SET32:
+ return rtc_dev_ioctl(file, RTC_IRQP_SET, arg);
+ case RTC_EPOCH_SET32:
+ return rtc_dev_ioctl(file, RTC_EPOCH_SET, arg);
+ }
+
+ /*
+ * all other rtc ioctls are compatible, or only
+ * exist on architectures without compat mode
+ */
+
+ return rtc_dev_ioctl(file, cmd, (unsigned long)argp);
+}
+#endif
+
static int rtc_dev_fasync(int fd, struct file *file, int on)
{
struct rtc_device *rtc = file->private_data;
@@ -439,6 +486,9 @@ static const struct file_operations rtc_dev_fops = {
.read = rtc_dev_read,
.poll = rtc_dev_poll,
.unlocked_ioctl = rtc_dev_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = rtc_dev_compat_ioctl,
+#endif
.open = rtc_dev_open,
.release = rtc_dev_release,
.fasync = rtc_dev_fasync,
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index a9b00942e87d..a5c86a2fa8e6 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -46,7 +46,6 @@
#include <linux/raw.h>
#include <linux/blkdev.h>
#include <linux/elevator.h>
-#include <linux/rtc.h>
#include <linux/pci.h>
#include <linux/serial.h>
#include <linux/if_tun.h>
@@ -623,37 +622,6 @@ static int serial_struct_ioctl(struct file *file,
return err;
}

-#define RTC_IRQP_READ32 _IOR('p', 0x0b, compat_ulong_t)
-#define RTC_IRQP_SET32 _IOW('p', 0x0c, compat_ulong_t)
-#define RTC_EPOCH_READ32 _IOR('p', 0x0d, compat_ulong_t)
-#define RTC_EPOCH_SET32 _IOW('p', 0x0e, compat_ulong_t)
-
-static int rtc_ioctl(struct file *file,
- unsigned cmd, void __user *argp)
-{
- unsigned long __user *valp = compat_alloc_user_space(sizeof(*valp));
- int ret;
-
- if (valp == NULL)
- return -EFAULT;
- switch (cmd) {
- case RTC_IRQP_READ32:
- case RTC_EPOCH_READ32:
- ret = do_ioctl(file, (cmd == RTC_IRQP_READ32) ?
- RTC_IRQP_READ : RTC_EPOCH_READ,
- (unsigned long)valp);
- if (ret)
- return ret;
- return convert_in_user(valp, (unsigned int __user *)argp);
- case RTC_IRQP_SET32:
- return do_ioctl(file, RTC_IRQP_SET, (unsigned long)argp);
- case RTC_EPOCH_SET32:
- return do_ioctl(file, RTC_EPOCH_SET, (unsigned long)argp);
- }
-
- return -ENOIOCTLCMD;
-}
-
/* on ia32 l_start is on a 32-bit boundary */
#if defined(CONFIG_IA64) || defined(CONFIG_X86_64)
struct space_resv_32 {
@@ -806,21 +774,6 @@ COMPATIBLE_IOCTL(SCSI_IOCTL_GET_PCI)
/* Big V (don't complain on serial console) */
IGNORE_IOCTL(VT_OPENQRY)
IGNORE_IOCTL(VT_GETMODE)
-/* Little p (/dev/rtc, /dev/envctrl, etc.) */
-COMPATIBLE_IOCTL(RTC_AIE_ON)
-COMPATIBLE_IOCTL(RTC_AIE_OFF)
-COMPATIBLE_IOCTL(RTC_UIE_ON)
-COMPATIBLE_IOCTL(RTC_UIE_OFF)
-COMPATIBLE_IOCTL(RTC_PIE_ON)
-COMPATIBLE_IOCTL(RTC_PIE_OFF)
-COMPATIBLE_IOCTL(RTC_WIE_ON)
-COMPATIBLE_IOCTL(RTC_WIE_OFF)
-COMPATIBLE_IOCTL(RTC_ALM_SET)
-COMPATIBLE_IOCTL(RTC_ALM_READ)
-COMPATIBLE_IOCTL(RTC_RD_TIME)
-COMPATIBLE_IOCTL(RTC_SET_TIME)
-COMPATIBLE_IOCTL(RTC_WKALM_SET)
-COMPATIBLE_IOCTL(RTC_WKALM_RD)
/*
* These two are only for the sbus rtc driver, but
* hwclock tries them on every rtc device first when
@@ -1297,13 +1250,6 @@ static long do_ioctl_trans(unsigned int cmd,
case TIOCGSERIAL:
case TIOCSSERIAL:
return serial_struct_ioctl(file, cmd, argp);
- /* Not implemented in the native kernel */
- case RTC_IRQP_READ32:
- case RTC_IRQP_SET32:
- case RTC_EPOCH_READ32:
- case RTC_EPOCH_SET32:
- return rtc_ioctl(file, cmd, argp);
-
/* dvb */
case VIDEO_GET_EVENT:
return do_video_get_event(file, cmd, argp);
--
2.18.0