2020-09-21 08:06:31

by Liu Shixin

Subject: [PATCH -next] binder: simplify the return expression of binder_mmap

Simplify the return expression.

Signed-off-by: Liu Shixin <[email protected]>
---
drivers/android/binder.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 37a505c41dec..1f929e0cf39f 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -5204,10 +5204,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_ops = &binder_vm_ops;
vma->vm_private_data = proc;

- ret = binder_alloc_mmap_handler(&proc->alloc, vma);
- if (ret)
- return ret;
- return 0;
+ return binder_alloc_mmap_handler(&proc->alloc, vma);

err_bad_arg:
pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
--
2.25.1

2020-09-21 08:13:32

by Christian Brauner

Subject: Re: [PATCH -next] binder: simplify the return expression of binder_mmap

On Mon, Sep 21, 2020 at 04:24:23PM +0800, Liu Shixin wrote:
> Simplify the return expression.
>
> Signed-off-by: Liu Shixin <[email protected]>
> ---

Why not is all I can really say. :) But if this is about simplifying you
could get rid of the "ret" and "failure string" variables, and the goto
in that function completely by doing sm like this (__completely
untested__):

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index f936530a19b0..26f4dc81b008 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -5182,9 +5182,7 @@ static const struct vm_operations_struct binder_vm_ops = {

static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
{
- int ret;
struct binder_proc *proc = filp->private_data;
- const char *failure_string;

if (proc->tsk != current->group_leader)
return -EINVAL;
@@ -5196,9 +5194,9 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
(unsigned long)pgprot_val(vma->vm_page_prot));

if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
- ret = -EPERM;
- failure_string = "bad vm_flags";
- goto err_bad_arg;
+ pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
+ proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM);
+ return -EPERM;
}
vma->vm_flags |= VM_DONTCOPY | VM_MIXEDMAP;
vma->vm_flags &= ~VM_MAYWRITE;
@@ -5206,15 +5204,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_ops = &binder_vm_ops;
vma->vm_private_data = proc;

- ret = binder_alloc_mmap_handler(&proc->alloc, vma);
- if (ret)
- return ret;
- return 0;
-
-err_bad_arg:
- pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
- proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
- return ret;
+ return binder_alloc_mmap_handler(&proc->alloc, vma);
}

Christian

2020-09-21 10:44:20

by Liu Shixin

Subject: Re: [PATCH -next] binder: simplify the return expression of binder_mmap

On 2020/9/21 16:08, Christian Brauner wrote:

> On Mon, Sep 21, 2020 at 04:24:23PM +0800, Liu Shixin wrote:
>> Simplify the return expression.
>>
>> Signed-off-by: Liu Shixin <[email protected]>
>> ---
> Why not is all I can really say. :) But if this is about simplifying you
> could get rid of the "ret" and "failure string" variables, and the goto
> in that function completely by doing sm like this (__completely
> untested__):

Thanks for your advice. I will modify and test it.

Regards,
Liu Shixin

>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index f936530a19b0..26f4dc81b008 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -5182,9 +5182,7 @@ static const struct vm_operations_struct binder_vm_ops = {
>
> static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> {
> - int ret;
> struct binder_proc *proc = filp->private_data;
> - const char *failure_string;
>
> if (proc->tsk != current->group_leader)
> return -EINVAL;
> @@ -5196,9 +5194,9 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> (unsigned long)pgprot_val(vma->vm_page_prot));
>
> if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
> - ret = -EPERM;
> - failure_string = "bad vm_flags";
> - goto err_bad_arg;
> + pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
> + proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM);
> + return -EPERM;
> }
> vma->vm_flags |= VM_DONTCOPY | VM_MIXEDMAP;
> vma->vm_flags &= ~VM_MAYWRITE;
> @@ -5206,15 +5204,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> vma->vm_ops = &binder_vm_ops;
> vma->vm_private_data = proc;
>
> - ret = binder_alloc_mmap_handler(&proc->alloc, vma);
> - if (ret)
> - return ret;
> - return 0;
> -
> -err_bad_arg:
> - pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
> - proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
> - return ret;
> + return binder_alloc_mmap_handler(&proc->alloc, vma);
> }
>
> Christian
> .
>

2020-09-21 11:29:13

by Liu Shixin

Subject: [PATCH -next] binder: simplify the return expression of binder_mmap

Simplify the return expression.

Signed-off-by: Liu Shixin <[email protected]>
---
drivers/android/binder.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 37a505c41dec..49c0700816a5 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -5180,9 +5180,7 @@ static const struct vm_operations_struct binder_vm_ops = {

static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
{
- int ret;
struct binder_proc *proc = filp->private_data;
- const char *failure_string;

if (proc->tsk != current->group_leader)
return -EINVAL;
@@ -5194,9 +5192,9 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
(unsigned long)pgprot_val(vma->vm_page_prot));

if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
- ret = -EPERM;
- failure_string = "bad vm_flags";
- goto err_bad_arg;
+ pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
+ proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM);
+ return -EPERM;
}
vma->vm_flags |= VM_DONTCOPY | VM_MIXEDMAP;
vma->vm_flags &= ~VM_MAYWRITE;
@@ -5204,15 +5202,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_ops = &binder_vm_ops;
vma->vm_private_data = proc;

- ret = binder_alloc_mmap_handler(&proc->alloc, vma);
- if (ret)
- return ret;
- return 0;
-
-err_bad_arg:
- pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
- proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
- return ret;
+ return binder_alloc_mmap_handler(&proc->alloc, vma);
}

static int binder_open(struct inode *nodp, struct file *filp)
--
2.25.1

2020-09-27 12:36:49

by Greg Kroah-Hartman

Subject: Re: [PATCH -next] binder: simplify the return expression of binder_mmap

On Mon, Sep 21, 2020 at 07:47:34PM +0800, Liu Shixin wrote:
> Simplify the return expression.
>
> Signed-off-by: Liu Shixin <[email protected]>
> ---
> drivers/android/binder.c | 18 ++++--------------
> 1 file changed, 4 insertions(+), 14 deletions(-)

Is this a v2 patch?

If so, please properly label it and say what changed from the v1 version
below the --- line.

Please fix up and resend a v3.

thanks,

greg k-h

2020-09-29 01:32:09

by Liu Shixin

Subject: [PATCH v3 -next] binder: simplify the return expression of binder_mmap

Simplify the return expression.

Signed-off-by: Liu Shixin <[email protected]>
---
v3: Add the change description.
v2: Get rid of the "ret" and "failure string" variables.
v1: Simplify the return expression.
---
drivers/android/binder.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 37a505c41dec..49c0700816a5 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -5180,9 +5180,7 @@ static const struct vm_operations_struct binder_vm_ops = {

static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
{
- int ret;
struct binder_proc *proc = filp->private_data;
- const char *failure_string;

if (proc->tsk != current->group_leader)
return -EINVAL;
@@ -5194,9 +5192,9 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
(unsigned long)pgprot_val(vma->vm_page_prot));

if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
- ret = -EPERM;
- failure_string = "bad vm_flags";
- goto err_bad_arg;
+ pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
+ proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM);
+ return -EPERM;
}
vma->vm_flags |= VM_DONTCOPY | VM_MIXEDMAP;
vma->vm_flags &= ~VM_MAYWRITE;
@@ -5204,15 +5202,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_ops = &binder_vm_ops;
vma->vm_private_data = proc;

- ret = binder_alloc_mmap_handler(&proc->alloc, vma);
- if (ret)
- return ret;
- return 0;
-
-err_bad_arg:
- pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
- proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
- return ret;
+ return binder_alloc_mmap_handler(&proc->alloc, vma);
}

static int binder_open(struct inode *nodp, struct file *filp)
--
2.25.1

2020-10-02 13:49:36

by Greg Kroah-Hartman

Subject: Re: [PATCH v3 -next] binder: simplify the return expression of binder_mmap

On Tue, Sep 29, 2020 at 09:52:16AM +0800, Liu Shixin wrote:
> Simplify the return expression.
>
> Signed-off-by: Liu Shixin <[email protected]>
> ---
> v3: Add the change description.
> v2: Get rid of the "ret" and "failure string" variables.
> v1: Simplify the return expression.
> ---
> drivers/android/binder.c | 18 ++++--------------
> 1 file changed, 4 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 37a505c41dec..49c0700816a5 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -5180,9 +5180,7 @@ static const struct vm_operations_struct binder_vm_ops = {
>
> static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> {
> - int ret;
> struct binder_proc *proc = filp->private_data;
> - const char *failure_string;
>
> if (proc->tsk != current->group_leader)
> return -EINVAL;
> @@ -5194,9 +5192,9 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> (unsigned long)pgprot_val(vma->vm_page_prot));
>
> if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
> - ret = -EPERM;
> - failure_string = "bad vm_flags";
> - goto err_bad_arg;
> + pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
> + proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM);
> + return -EPERM;
> }
> vma->vm_flags |= VM_DONTCOPY | VM_MIXEDMAP;
> vma->vm_flags &= ~VM_MAYWRITE;
> @@ -5204,15 +5202,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> vma->vm_ops = &binder_vm_ops;
> vma->vm_private_data = proc;
>
> - ret = binder_alloc_mmap_handler(&proc->alloc, vma);
> - if (ret)
> - return ret;
> - return 0;
> -
> -err_bad_arg:
> - pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
> - proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
> - return ret;
> + return binder_alloc_mmap_handler(&proc->alloc, vma);
> }
>
> static int binder_open(struct inode *nodp, struct file *filp)
> --
> 2.25.1

Todd and other Binder maintainers, what do you think of this?

thanks,

greg k-h

2020-10-02 14:20:00

by Martijn Coenen

Subject: Re: [PATCH v3 -next] binder: simplify the return expression of binder_mmap

Thanks!

On Tue, Sep 29, 2020 at 3:30 AM Liu Shixin <[email protected]> wrote:
>
> Simplify the return expression.
>
> Signed-off-by: Liu Shixin <[email protected]>

Acked-by: Martijn Coenen <[email protected]>

> ---
> v3: Add the change description.
> v2: Get rid of the "ret" and "failure string" variables.
> v1: Simplify the return expression.
> ---
> drivers/android/binder.c | 18 ++++--------------
> 1 file changed, 4 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 37a505c41dec..49c0700816a5 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -5180,9 +5180,7 @@ static const struct vm_operations_struct binder_vm_ops = {
>
> static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> {
> - int ret;
> struct binder_proc *proc = filp->private_data;
> - const char *failure_string;
>
> if (proc->tsk != current->group_leader)
> return -EINVAL;
> @@ -5194,9 +5192,9 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> (unsigned long)pgprot_val(vma->vm_page_prot));
>
> if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
> - ret = -EPERM;
> - failure_string = "bad vm_flags";
> - goto err_bad_arg;
> + pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
> + proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM);
> + return -EPERM;
> }
> vma->vm_flags |= VM_DONTCOPY | VM_MIXEDMAP;
> vma->vm_flags &= ~VM_MAYWRITE;
> @@ -5204,15 +5202,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
> vma->vm_ops = &binder_vm_ops;
> vma->vm_private_data = proc;
>
> - ret = binder_alloc_mmap_handler(&proc->alloc, vma);
> - if (ret)
> - return ret;
> - return 0;
> -
> -err_bad_arg:
> - pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
> - proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
> - return ret;
> + return binder_alloc_mmap_handler(&proc->alloc, vma);
> }
>
> static int binder_open(struct inode *nodp, struct file *filp)
> --
> 2.25.1
>

2020-10-02 14:29:49

by Christian Brauner

Subject: Re: [PATCH v3 -next] binder: simplify the return expression of binder_mmap

On Tue, Sep 29, 2020 at 09:52:16AM +0800, Liu Shixin wrote:
> Simplify the return expression.
>
> Signed-off-by: Liu Shixin <[email protected]>
> ---

Thanks!
Acked-by: Christian Brauner <[email protected]>