Commit e9f5b814 authored by Serban Constantinescu's avatar Serban Constantinescu Committed by Greg Kroah-Hartman
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staging: android: ashmem: Add support for 32bit ashmem calls in a 64bit kernel 



Android's shared memory subsystem, Ashmem, does not support calls from a
32bit userspace in a 64 bit kernel. This patch adds support for syscalls
coming from a 32bit userspace in a 64bit kernel.

The patch has been successfully tested on ARMv8 AEM(64bit
platform model) and Versatile Express A9(32bit platform).

v2: Fix missing compat.h include.

Signed-off-by: default avatarSerban Constantinescu <serban.constantinescu@arm.com>
Acked-by: default avatarArve Hjønnevåg <arve@android.com>
Acked-by: default avatarJohn Stultz <john.stultz@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5db5a20a

drivers/staging/android/ashmem.c

+20 −1
Original line number Original line Diff line number Diff line
@@ -702,6 +702,23 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	return ret;

	return ret;

}

}





/* support of 32bit userspace on 64bit platforms */

#ifdef CONFIG_COMPAT

static long compat_ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{



	switch (cmd) {

	case COMPAT_ASHMEM_SET_SIZE:

		cmd = ASHMEM_SET_SIZE;

		break;

	case COMPAT_ASHMEM_SET_PROT_MASK:

		cmd = ASHMEM_SET_PROT_MASK;

		break;

	}

	return ashmem_ioctl(file, cmd, arg);

}

#endif



static const struct file_operations ashmem_fops = {

static const struct file_operations ashmem_fops = {

	.owner = THIS_MODULE,

	.owner = THIS_MODULE,

	.open = ashmem_open,

	.open = ashmem_open,
@@ -710,7 +727,9 @@ static const struct file_operations ashmem_fops = { 
	.llseek = ashmem_llseek,

	.llseek = ashmem_llseek,

	.mmap = ashmem_mmap,

	.mmap = ashmem_mmap,

	.unlocked_ioctl = ashmem_ioctl,

	.unlocked_ioctl = ashmem_ioctl,

	.compat_ioctl = ashmem_ioctl,

#ifdef CONFIG_COMPAT

	.compat_ioctl = compat_ashmem_ioctl,

#endif

};

};





static struct miscdevice ashmem_misc = {

static struct miscdevice ashmem_misc = {

drivers/staging/android/ashmem.h

+7 −0
Original line number Original line Diff line number Diff line
@@ -14,6 +14,7 @@ 




#include <linux/limits.h>

#include <linux/limits.h>

#include <linux/ioctl.h>

#include <linux/ioctl.h>

#include <linux/compat.h>





#define ASHMEM_NAME_LEN		256

#define ASHMEM_NAME_LEN		256
@@ -45,4 +46,10 @@ struct ashmem_pin { 
#define ASHMEM_GET_PIN_STATUS	_IO(__ASHMEMIOC, 9)

#define ASHMEM_GET_PIN_STATUS	_IO(__ASHMEMIOC, 9)

#define ASHMEM_PURGE_ALL_CACHES	_IO(__ASHMEMIOC, 10)

#define ASHMEM_PURGE_ALL_CACHES	_IO(__ASHMEMIOC, 10)





/* support of 32bit userspace on 64bit platforms */

#ifdef CONFIG_COMPAT

#define COMPAT_ASHMEM_SET_SIZE		_IOW(__ASHMEMIOC, 3, compat_size_t)

#define COMPAT_ASHMEM_SET_PROT_MASK	_IOW(__ASHMEMIOC, 5, unsigned int)

#endif



#endif	/* _LINUX_ASHMEM_H */
 
#endif	/* _LINUX_ASHMEM_H */