[PATCH] task: delete task_euid()

[Alice Ryhl]

On Thu, Feb 19, 2026 at 10:27:01PM +0800, Alex Shi wrote:
> 
> 
> On 2026/2/19 20:14, Alice Ryhl wrote:
> > task_euid() is a very weird operation. You can see how weird it is by
> > grepping for task_euid() - binder is its only user. task_euid() obtains
> > the objective effective UID - it looks at the credentials of the task
> > for purposes of acting on it as an object, but then accesses the
> > effective UID (which the credentials.7 man page describes as "[...] used
> > by the kernel to determine the permissions that the process will have
> > when accessing shared resources [...]").
> > 
> > Since usage in Binder has now been removed, get rid of the resulting
> > dead code.
> > 
> > Changes to the zh_CN translation was carried out with the help of
> > Gemini and Google Translate.

> > diff --git a/Documentation/translations/zh_CN/security/credentials.rst b/Documentation/translations/zh_CN/security/credentials.rst
> > index 88fcd9152ffe91d79fc10bfc7b2a37d301b4938a..f0b2efec342438b81be415dc513622c961bb7e59 100644
> > --- a/Documentation/translations/zh_CN/security/credentials.rst
> > +++ b/Documentation/translations/zh_CN/security/credentials.rst
> > @@ -337,15 +337,13 @@ const指针上操作，因此不需要进行类型转换，但需要临时放弃
> >      ``__task_cred()`` 的结果不应直接传递给 ``get_cred()`` ，
> >      因为这可能与 ``commit_cred()`` 发生竞争条件。
> > -还有一些方便的函数可以访问另一个任务凭据的特定部分，将RCU操作对调用方隐藏起来::
> > +有一个方便的函数可用于访问另一个任务凭据的特定部分，从而对调用方隐藏RCU机制::
> 
> LGTM.
> 
> >   	uid_t task_uid(task)		Task's real UID
> > -	uid_t task_euid(task)		Task's effective UID
> > -如果调用方在此时已经持有RCU读锁，则应使用::
> > +如果调用方在此时已经持有RCU读锁，则应改为使用::
> 
> Please keep the old version. the new one is a bit ambiguous.

Thanks for checking!

Alice