Re: [PATCH v4 09/13] LoongArch: Linux ABI

[Arnd Bergmann <arnd@arndb.de>]

On Wed, May 18, 2022 at 4:40 AM caiyinyu <caiyinyu@loongson.cn> wrote:
> 在 2022/5/11 下午3:08, Arnd Bergmann 写道:
> > On Mon, May 9, 2022 at 4:26 AM caiyinyu <caiyinyu@loongson.cn> wrote:
>
> There are struct flock and flock64 we need in glibc bits/fcntl.h, but
> the macro F_GETLK64 F_SETLK64 F_SETLKW64 in
> sysdeps/unix/sysv/linux/bits/fcntl-linux.h are:
>
> ...
> # define F_GETLK64      12      /* Get record locking info.  */
> # define F_SETLK64      13      /* Set record locking info
> (non-blocking).  */
> # define F_SETLKW64     14      /* Set record locking info (blocking).  */
> ...
>
> what we need:
>
> +#define F_GETLK64 5  /* Get record locking info.  */
> +#define F_SETLK64 6  /* Set record locking info (non-blocking). */
> +#define F_SETLKW64 7 /* Set record locking info (blocking).  */
>
> x86 ia64 s390 and aarch64 have the same problem and they all use their
> own fcntl.h.
>
> Define new value of these macro in
> sysdeps/unix/sysv/linux/bits/fcntl-linux.h or
> add fcntl-linux.h in loongarch port or keep the status quo??
>
> any ideas??

I think the problem is different views of the macros in Linux and glibc:

- In Linux, all 32-bit architectures use the 'flock64' interface, while
  all 64-bit architectures use 'flock'. Older 32-bit architectures
  also provide the 32-bit 'off_t' interfaces with 'flock' for compatibility
  with existing user space.

- glibc describes the same interfaces differently. Here, all architectures
  have both the traditional 'flock' and the new 'flock64' version that
  gets used when building with largerfile64 support enabled, but they
  may get aliased to the same one depending on which off_t definition
  glibc was using when the port was started.

Adhemerval's suggestion for addressing this in glibc sounds good to
me, so you can just keep you extra copy of the same logic for
the moment and someone can consolidate the workarounds for
64-bit architectures in the future.

          Arnd