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Message-ID: <51ADAB5F.70902@arm.com>
Date: Tue, 04 Jun 2013 09:54:55 +0100
From: Serban Constantinescu <Serban.Constantinescu@....com>
To: Arve Hjønnevåg <arve@...roid.com>
CC: LKML <linux-kernel@...r.kernel.org>,
Greg KH <gregkh@...uxfoundation.org>,
Android Kernel Team <kernel-team@...roid.com>,
John Stultz <john.stultz@...aro.org>,
Dave Butcher <Dave.Butcher@....com>
Subject: Re: [PATCH v4 2/6] staging: android: binder: fix binder interface
for 64bit compat layer
On 03/06/13 22:41, Arve Hjønnevåg wrote:
> On Wed, May 22, 2013 at 3:12 AM, Serban Constantinescu
> <serban.constantinescu@....com> wrote:
>> The changes in this patch will fix the binder interface for use on 64bit
>> machines and stand as the base of the 64bit compat support. The changes
>> apply to the structures that are passed between the kernel and
>> userspace.
>>
>> Most of the changes applied mirror the change to struct binder_version
>> where there is no need for a 64bit wide protocol_version(on 64bit
>> machines). The change inlines with the existing 32bit userspace(the
>> structure has the same size) and simplifies the compat layer such that
>> the same handler can service the BINDER_VERSION ioctl.
>>
>> Other changes make use of kernel types as well as user-exportable ones
>> and fix format specifier issues.
>>
>> The changes do not affect existing 32bit ABI.
>>
>> Signed-off-by: Serban Constantinescu <serban.constantinescu@....com>
>> ---
>> drivers/staging/android/binder.c | 20 ++++++++++----------
>> drivers/staging/android/binder.h | 8 ++++----
>> 2 files changed, 14 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
>> index ce70909..ca79084 100644
>> --- a/drivers/staging/android/binder.c
>> +++ b/drivers/staging/android/binder.c
>> @@ -1271,7 +1271,7 @@ static void binder_transaction_buffer_release(struct binder_proc *proc,
>> case BINDER_TYPE_WEAK_HANDLE: {
>> struct binder_ref *ref = binder_get_ref(proc, fp->handle);
>> if (ref == NULL) {
>> - pr_err("transaction release %d bad handle %ld\n",
>> + pr_err("transaction release %d bad handle %d\n",
>> debug_id, fp->handle);
>> break;
>> }
>> @@ -1283,13 +1283,13 @@ static void binder_transaction_buffer_release(struct binder_proc *proc,
>>
>> case BINDER_TYPE_FD:
>> binder_debug(BINDER_DEBUG_TRANSACTION,
>> - " fd %ld\n", fp->handle);
>> + " fd %d\n", fp->handle);
>> if (failed_at)
>> task_close_fd(proc, fp->handle);
>> break;
>>
>> default:
>> - pr_err("transaction release %d bad object type %lx\n",
>> + pr_err("transaction release %d bad object type %x\n",
>> debug_id, fp->type);
>> break;
>> }
>> @@ -1547,7 +1547,7 @@ static void binder_transaction(struct binder_proc *proc,
>> case BINDER_TYPE_WEAK_HANDLE: {
>> struct binder_ref *ref = binder_get_ref(proc, fp->handle);
>> if (ref == NULL) {
>> - binder_user_error("%d:%d got transaction with invalid handle, %ld\n",
>> + binder_user_error("%d:%d got transaction with invalid handle, %d\n",
>> proc->pid,
>> thread->pid, fp->handle);
>> return_error = BR_FAILED_REPLY;
>> @@ -1590,13 +1590,13 @@ static void binder_transaction(struct binder_proc *proc,
>>
>> if (reply) {
>> if (!(in_reply_to->flags & TF_ACCEPT_FDS)) {
>> - binder_user_error("%d:%d got reply with fd, %ld, but target does not allow fds\n",
>> + binder_user_error("%d:%d got reply with fd, %d, but target does not allow fds\n",
>> proc->pid, thread->pid, fp->handle);
>> return_error = BR_FAILED_REPLY;
>> goto err_fd_not_allowed;
>> }
>> } else if (!target_node->accept_fds) {
>> - binder_user_error("%d:%d got transaction with fd, %ld, but target does not allow fds\n",
>> + binder_user_error("%d:%d got transaction with fd, %d, but target does not allow fds\n",
>> proc->pid, thread->pid, fp->handle);
>> return_error = BR_FAILED_REPLY;
>> goto err_fd_not_allowed;
>> @@ -1604,7 +1604,7 @@ static void binder_transaction(struct binder_proc *proc,
>>
>> file = fget(fp->handle);
>> if (file == NULL) {
>> - binder_user_error("%d:%d got transaction with invalid fd, %ld\n",
>> + binder_user_error("%d:%d got transaction with invalid fd, %d\n",
>> proc->pid, thread->pid, fp->handle);
>> return_error = BR_FAILED_REPLY;
>> goto err_fget_failed;
>> @@ -1618,13 +1618,13 @@ static void binder_transaction(struct binder_proc *proc,
>> task_fd_install(target_proc, target_fd, file);
>> trace_binder_transaction_fd(t, fp->handle, target_fd);
>> binder_debug(BINDER_DEBUG_TRANSACTION,
>> - " fd %ld -> %d\n", fp->handle, target_fd);
>> + " fd %d -> %d\n", fp->handle, target_fd);
>> /* TODO: fput? */
>> fp->handle = target_fd;
>> } break;
>>
>> default:
>> - binder_user_error("%d:%d got transaction with invalid object type, %lx\n",
>> + binder_user_error("%d:%d got transaction with invalid object type, %x\n",
>> proc->pid, thread->pid, fp->type);
>> return_error = BR_FAILED_REPLY;
>> goto err_bad_object_type;
>> @@ -2578,7 +2578,7 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>> goto err;
>> }
>> binder_debug(BINDER_DEBUG_READ_WRITE,
>> - "%d:%d write %zd at %08lx, read %zd at %08lx\n",
>> + "%d:%d write %zd at %016lx, read %zd at %016lx\n",
>> proc->pid, thread->pid, bwr.write_size,
>> bwr.write_buffer, bwr.read_size, bwr.read_buffer);
>>
>> diff --git a/drivers/staging/android/binder.h b/drivers/staging/android/binder.h
>> index edab249..2f94d16 100644
>> --- a/drivers/staging/android/binder.h
>> +++ b/drivers/staging/android/binder.h
>> @@ -48,13 +48,13 @@ enum {
>> */
>> struct flat_binder_object {
>> /* 8 bytes for large_flat_header. */
>> - unsigned long type;
>> - unsigned long flags;
>> + __u32 type;
>> + __u32 flags;
>>
>> /* 8 bytes of data. */
>> union {
>> void __user *binder; /* local object */
>> - signed long handle; /* remote object */
>> + __s32 handle; /* remote object */
>
> This should be unsigned to match the handle in binder_transaction_data
> and other uses in the driver, but it is currently also used to pass
> file descriptors. Perhaps this is better (if sou also change size of
> the handle in binder_transaction_data to match):
> __u32 handle; /* remote object */
> __s32 fd; /* file descriptor */
I will add this union and fix any uses of remote object/ file descriptor
accordingly.
>
>> };
>>
>> /* extra data associated with local object */
>> @@ -78,7 +78,7 @@ struct binder_write_read {
>> /* Use with BINDER_VERSION, driver fills in fields. */
>> struct binder_version {
>> /* driver protocol version -- increment with incompatible change */
>> - signed long protocol_version;
>> + __s32 protocol_version;
>> };
>>
>> /* This is the current protocol version. */
>> --
>> 1.7.9.5
>>
>
> I still think the protocol_version size change on 64 bit systems
> should go after all your other changes that affect 64 bits systems.
> That way you don't have to change the protocol version later.
At the end of this patch set we will have support for 32/32 and 64/64
binder calls. This patch does not add compat support for 64/32 systems
and will not work for this configuration.
However until we add:
> static const struct file_operations binder_fops = {
> .owner = THIS_MODULE,
> .poll = binder_poll,
> .unlocked_ioctl = binder_ioctl,
> + .compat_ioctl = binder_ioctl,
> .mmap = binder_mmap,
> .open = binder_open,
> .flush = binder_flush,
The return value for any binder ioctl from a 32bit userspace running on
top of a 64bit kernel will be EINVAL (this happens only for 64/32
systems). Once we have the compat layer upstreamed we will add the above
change, but until that point querying the binder version or any other
binder iocall will fail (on 64/32).
Let me know if you consider that changing the binder version to use
__s32 when adding the compat layer would be better.
Thanks for your feedback and help,
Serban
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