Re: [PATCH v3] tools/9pfsd: Fix build error caused by strerror_r

[Jürgen Groß <jgross@xxxxxxxx>]

On 07.03.24 14:56, Henry Wang wrote:
> Below error can be seen when doing Yocto build of the toolstack:
>
> | io.c: In function 'p9_error':
> | io.c:684:5: error: ignoring return value of 'strerror_r' declared
>    with attribute 'warn_unused_result' [-Werror=unused-result]
> |   684 |     strerror_r(err, ring->buffer, ring->ring_size);
> |       |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | cc1: all warnings being treated as errors
>
> Using strerror_r() without special casing different build environments
> is impossible due to the different return types (int vs char *)
> depending on the environment. As p9_error() is not on a performance
> critical path, using strerror() with a mutex ought to be fine. So,
> fix the build by using strerror() to replace strerror_r(). The steps
> would then become: Acquire the mutex first, invoke strerror(), copy
> the string from strerror() to the designated buffer and then drop the
> mutex.
>
> Fixes: f4900d6d69b5 ("9pfsd: allow building with old glibc")
> Signed-off-by: Henry Wang <xin.wang2@xxxxxxx>
> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>


Juergen