Messages in this thread Patch in this message | | | From | Serban Constantinescu <> | Subject | [PATCH] staging: android: ashmem: Add support for 32bit ashmem calls in a 64bit kernel | Date | Tue, 5 Mar 2013 10:18:27 +0000 |
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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).
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com> --- drivers/staging/android/ashmem.c | 22 +++++++++++++++++++++- drivers/staging/android/ashmem.h | 6 ++++++ 2 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c index 72064fc..e96f381 100644 --- a/drivers/staging/android/ashmem.c +++ b/drivers/staging/android/ashmem.c @@ -31,6 +31,7 @@ #include <linux/bitops.h> #include <linux/mutex.h> #include <linux/shmem_fs.h> +#include <linux/compat.h> #include "ashmem.h" #define ASHMEM_NAME_PREFIX "dev/ashmem/" @@ -674,6 +675,23 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 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 = { .owner = THIS_MODULE, .open = ashmem_open, @@ -682,7 +700,9 @@ static const struct file_operations ashmem_fops = { .llseek = ashmem_llseek, .mmap = ashmem_mmap, .unlocked_ioctl = ashmem_ioctl, - .compat_ioctl = ashmem_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = compat_ashmem_ioctl, +#endif }; static struct miscdevice ashmem_misc = { diff --git a/drivers/staging/android/ashmem.h b/drivers/staging/android/ashmem.h index 1976b10..2809d31 100644 --- a/drivers/staging/android/ashmem.h +++ b/drivers/staging/android/ashmem.h @@ -45,4 +45,10 @@ struct ashmem_pin { #define ASHMEM_GET_PIN_STATUS _IO(__ASHMEMIOC, 9) #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 */ -- 1.7.9.5
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