Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version

Check the pos parameter before calling into kernel.
This does prevent the unwanted side effect of reading or writing at the current
file pointer position when the functions are called with a -1 position.
It's save to do this check in user space, because calling the _kern_* function
with -1 pos has the same effect as calling the normal read/write posix functions.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21701 a95241bf-73f2-0310-859d-f6bbb57e9c96

Renamed src/kernel to src/system.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12359 a95241bf-73f2-0310-859d-f6bbb57e9c96

Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version

Check the pos parameter before calling into kernel.
This does prevent the unwanted side effect of reading or writing at the current
file pointer position when the functions are called with a -1 position.
It's save to do this check in user space, because calling the _kern_* function
with -1 pos has the same effect as calling the normal read/write posix functions.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21701 a95241bf-73f2-0310-859d-f6bbb57e9c96

Renamed src/kernel to src/system.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12359 a95241bf-73f2-0310-859d-f6bbb57e9c96