Minor bug in libmisc

[Joel Sherrill]

Thanks. I have pushed this.

--joel

On Wed, Jan 23, 2019 at 10:23 AM Maksim Kozlov <maksim.e.kozlov at gmail.com>
wrote:

> Hi,
>
> I encountered an error when tried launch 'top' command from RTEMS Sell:
>
> SHLL [/] # top
>
> *** FATAL ***
> fatal source: 0 (INTERNAL_ERROR_CORE)
> fatal code: 38 (INTERNAL_ERROR_ILLEGAL_USE_OF_FLOATING_POINT_UNIT)
> RTEMS version: 5.0.0.97cce5c9a18563f58aadc2af1049957420ad561d-modified
> RTEMS tools: 7.4.0 20181206 (RTEMS 5, RSB
> 0bb29a38fb73342c3c25c6917884e08f7386a6f4, Newlib
> dc6e94551f09d3a983afd571478d)
> executing thread ID: 0x08a010004
> executing thread name: CPlt
> Idle loop start...
>
> After some investigation, I found out that this occurs because lazy
> floating point switch mechanism triggered here:
>
> 040536d4 <_vfprintf_r>:
>
>  40537a0:       03 01 01 b4     sethi  %hi(0x406d000), %g1
>  40537a4:       c0 27 bf 54     clr  [ %fp + -172 ]
>  40537a8:       d1 18 63 58     ldd  [ %g1 + 0x358 ], %f8
>  40537ac:       c0 27 bf 50     clr  [ %fp + -176 ]
>  40537b0:       25 01 01 b5     sethi  %hi(0x406d400), %l2
>  40537b4:       c0 27 be ac     clr  [ %fp + -340 ]
>  40537b8:       d1 3f be b8     std  %f8, [ %fp + -328 ]
>  40537bc:       c0 27 be a0     clr  [ %fp + -352 ]
>
> and after following check in cpukit/score/cpu/sparc/syscall.S we get
> mentioned error
>
> /* Ensure that we are a proper floating point thread */
> cmp    %l6, 0
> be    .Lillegal_use_of_floating_point_unit
>  ld    [%l4 + %lo(SPARC_THREAD_CONTROL_REGISTERS_FP_CONTEXT_OFFSET)], %l6
>
> This is because in rtems_task_create(), at first, was swapped modes and
> attributes, and, at second, was not enabled FP flag. So, I hope the
> attached small patch resolves this.
> --
> Best regards,
> Maksim Kozlov
>
> From d48f4c13c61a9287ddf55b33564ce4816e77f40b Mon Sep 17 00:00:00 2001
> From: Maksim E. Kozlov <maksim.e.kozlov at gmail.com>
> Date: Wed, 23 Jan 2019 15:17:44 +0300
> Subject: [PATCH] libmisc: Fix swapped parameters and enable floating point
>  usage.
>
> ---
>  cpukit/libmisc/cpuuse/cpuusagetop.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/cpukit/libmisc/cpuuse/cpuusagetop.c
> b/cpukit/libmisc/cpuuse/cpuusagetop.c
> index 8e0063bc88..c4bfa704d1 100644
> --- a/cpukit/libmisc/cpuuse/cpuusagetop.c
> +++ b/cpukit/libmisc/cpuuse/cpuusagetop.c
> @@ -530,8 +530,8 @@ void rtems_cpu_usage_top_with_plugin(
>    name = rtems_build_name('C', 'P', 'l', 't');
>
>    sc = rtems_task_create (name, priority, 4 * 1024,
> -                          RTEMS_NO_FLOATING_POINT | RTEMS_LOCAL,
>                            RTEMS_PREEMPT | RTEMS_TIMESLICE | RTEMS_NO_ASR,
> +                          RTEMS_FLOATING_POINT | RTEMS_LOCAL,
>                            &id);
>
>    if (sc != RTEMS_SUCCESSFUL)
> --
> 2.17.1
> _______________________________________________
> devel mailing list
> devel at rtems.org
> http://lists.rtems.org/mailman/listinfo/devel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/devel/attachments/20190123/c8003fe2/attachment-0002.html>