Re: [PATCH 03/21] linux-user/arm: Force v2 frames for fdpic

[Philippe Mathieu-Daudé]

Hi Richard,

On 6/16/21 3:11 AM, Richard Henderson wrote:
> The value of get_os_release may be controlled by a command
> line option.  Since fdpic was added in v4.14, and v2 frame
> were added in v2.6.12, this makes no change under normal conditions.
> 
> Split out a helper function to perform the test.
> 
> Cc: qemu-arm@nongnu.org
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  linux-user/arm/signal.c | 20 ++++++++++++++++----
>  1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/linux-user/arm/signal.c b/linux-user/arm/signal.c
> index 32b68ee302..2d30345fc2 100644
> --- a/linux-user/arm/signal.c
> +++ b/linux-user/arm/signal.c
> @@ -165,6 +165,18 @@ static inline int valid_user_regs(CPUARMState *regs)
>      return 1;
>  }
>  
> +static bool v2_frame(void)
> +{
> +    /*
> +     * We do not create fdpic trampolines for v1 frames.
> +     * Thus we force v2 frames, regardless of what uname says.
> +     * Support for fdpic dates from Linux 4.14, so this is not
> +     * really a behaviour change.
> +     */
> +    int is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info);
> +    return is_fdpic || get_osversion() >= 0x020612;
> +}

Could you refactor v2_frame() in a previous patch and add the
is_fdpic check in another one please?