Hi Arnd,

On 28/08/2018 16:26:31+0200, Arnd Bergmann wrote:

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.

Since the ioctl commands are either compatible or differ in both structure and command code between 32-bit and 64-bit, we can merge the compat handler into the native one and just implement the two common compat commands (RTC_IRQP_READ, RTC_IRQP_SET) there.

The old conversion handler also deals with RTC_EPOCH_READ and RTC_EPOCH_SET, which are not handled in rtc-dev.c but only in a single device driver (rtc-vr41xx), so I'm adding the compat version in the same place. I don't expect other drivers to need those commands in the future.

Signed-off-by: Arnd Bergmann arnd@arndb.de

v2: merge compat handler into ioctl function to avoid the compat_alloc_user_space() roundtrip, based on feedback from Al Viro.

---

drivers/rtc/rtc-dev.c | 13 +++++++++- drivers/rtc/rtc-vr41xx.c | 10 ++++++++ fs/compat_ioctl.c | 53 ---------------------------------------- 3 files changed, 22 insertions(+), 54 deletions(-)

This doesn't apply on v4.19-rc1, can you rebase?

diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 43d962a9c210..7c93dc6ec629 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> @@ -364,10 +365,19 @@ static long rtc_dev_ioctl(struct file *file, mutex_unlock(&rtc->ops_lock); return rtc_update_irq_enable(rtc, 0); +#ifdef CONFIG_COMPAT +#define RTC_IRQP_SET32 _IOW('p', 0x0c, compat_ulong_t) +#define RTC_IRQP_READ32 _IOR('p', 0x0b, compat_ulong_t)

• case RTC_IRQP_SET32:

• err = rtc_irq_set_freq(rtc, arg);
  

• break;
  

• case RTC_IRQP_READ32:

• err = put_user(rtc->irq_freq, (unsigned int __user *)uarg);
  

• break;
  

+#endif case RTC_IRQP_SET: err = rtc_irq_set_freq(rtc, arg); break;

• case RTC_IRQP_READ: err = put_user(rtc->irq_freq, (unsigned long __user *)uarg); break;

@@ -439,6 +449,7 @@ static const struct file_operations rtc_dev_fops = { .read = rtc_dev_read, .poll = rtc_dev_poll, .unlocked_ioctl = rtc_dev_ioctl,

• .compat_ioctl = rtc_dev_ioctl, .open = rtc_dev_open, .release = rtc_dev_release, .fasync = rtc_dev_fasync,

diff --git a/drivers/rtc/rtc-vr41xx.c b/drivers/rtc/rtc-vr41xx.c index 70f013e692b0..1d90bde59d21 100644 --- a/drivers/rtc/rtc-vr41xx.c +++ b/drivers/rtc/rtc-vr41xx.c @@ -17,6 +17,7 @@

• along with this program; if not, write to the Free Software
• Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

*/ +#include <linux/compat.h> #include <linux/err.h> #include <linux/fs.h> #include <linux/init.h> @@ -79,6 +80,10 @@ static void __iomem *rtc2_base; #define rtc2_read(offset) readw(rtc2_base + (offset)) #define rtc2_write(offset, value) writew((value), rtc2_base + (offset)) +/* 32-bit compat for ioctls that nobody else uses */ +#define RTC_EPOCH_READ32 _IOR('p', 0x0d, compat_ulong_t) +#define RTC_EPOCH_SET32 _IOW('p', 0x0e, compat_ulong_t)

static unsigned long epoch = 1970; /* Jan 1 1970 00:00:00 */ static DEFINE_SPINLOCK(rtc_lock); @@ -195,6 +200,11 @@ static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long switch (cmd) { case RTC_EPOCH_READ: return put_user(epoch, (unsigned long __user *)arg); +#ifdef CONFIG_COMPAT

• case RTC_EPOCH_READ32:

• return put_user(epoch, (unsigned int __user *)arg);
  

• case RTC_EPOCH_SET32:

checkpatch complains about the missing fallthrough comment now.

+#endif case RTC_EPOCH_SET: /* Doesn't support before 1900 */ if (arg < 1900) diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index 5c37104b8805..9237076bdcf5 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> @@ -426,37 +425,6 @@ 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 { @@ -609,21 +577,6 @@ 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

@@ -1005,12 +958,6 @@ 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);
  

  }

/* -- 2.18.0