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hpet: Support 32-bit userspace

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hpet_compat_ioctl and read file operations failed to handle parameters from
32-bit userspace and thus samples/timers/hpet_example.c fails as below.

root@intel-x86-64:~# ./hpet_example-32.out poll /dev/hpet 1 2
-hpet: executing poll
hpet_poll: HPET_IRQFREQ failed

This patch fixes cmd and arg handling in hpet_compat_ioctl and adds compat
handling for 32-bit userspace in hpet_read.

hpet_example now shows that it works for both 64-bit and 32-bit.

root@intel-x86-64:~# ./hpet_example-32.out poll /dev/hpet 1 2
-hpet: executing poll
hpet_poll: info.hi_flags 0x0
hpet_poll: expired time = 0xf4298
hpet_poll: revents = 0x1
hpet_poll: data 0x1
hpet_poll: expired time = 0xf4235
hpet_poll: revents = 0x1
hpet_poll: data 0x1
root@intel-x86-64:~# ./hpet_example-64.out poll /dev/hpet 1 2
-hpet: executing poll
hpet_poll: info.hi_flags 0x0
hpet_poll: expired time = 0xf42a1
hpet_poll: revents = 0x1
hpet_poll: data 0x1
hpet_poll: expired time = 0xf4232
hpet_poll: revents = 0x1
hpet_poll: data 0x1

Cc: stable@vger.kernel.org
Signed-off-by: He Zhe <zhe.he@windriver.com>
Fixes: 54066a57c5 ("hpet: kill BKL, add compat_ioctl")
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240606123908.738733-1-zhe.he@windriver.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
He Zhe 2024-06-06 20:39:08 +08:00 committed by Greg Kroah-Hartman
parent bab2f5e8fd
commit 4e60131d0d
1 changed files with 29 additions and 5 deletions
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34
drivers/char/hpet.c
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@ -269,8 +269,13 @@ hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
if (!devp->hd_ireqfreq)
return -EIO;
if (count < sizeof(unsigned long))
return -EINVAL;
if (in_compat_syscall()) {
if (count < sizeof(compat_ulong_t))
return -EINVAL;
} else {
if (count < sizeof(unsigned long))
return -EINVAL;
}
add_wait_queue(&devp->hd_waitqueue, &wait);
@ -294,9 +299,16 @@ hpet_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
schedule();
}
retval = put_user(data, (unsigned long __user *)buf);
if (!retval)
retval = sizeof(unsigned long);
if (in_compat_syscall()) {
retval = put_user(data, (compat_ulong_t __user *)buf);
if (!retval)
retval = sizeof(compat_ulong_t);
} else {
retval = put_user(data, (unsigned long __user *)buf);
if (!retval)
retval = sizeof(unsigned long);
}
out:
__set_current_state(TASK_RUNNING);
remove_wait_queue(&devp->hd_waitqueue, &wait);
@ -651,12 +663,24 @@ struct compat_hpet_info {
unsigned short hi_timer;
};
/* 32-bit types would lead to different command codes which should be
* translated into 64-bit ones before passed to hpet_ioctl_common
*/
#define COMPAT_HPET_INFO _IOR('h', 0x03, struct compat_hpet_info)
#define COMPAT_HPET_IRQFREQ _IOW('h', 0x6, compat_ulong_t)
static long
hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct hpet_info info;
int err;
if (cmd == COMPAT_HPET_INFO)
cmd = HPET_INFO;
if (cmd == COMPAT_HPET_IRQFREQ)
cmd = HPET_IRQFREQ;
mutex_lock(&hpet_mutex);
err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
mutex_unlock(&hpet_mutex);