[M3devel] formsedit crash during startup sometimes?

[Jay]

Formsedit on SOLgnu also crashes, sometimes, during startup.
It doesn't seem to crash in a debugger, but you can load up the core dump after a crash. It looks very similar as on PPC_DARWIN.
 
 
In both cases, it is dereferencing the value 4, just after calling RTHooks__CheckLoadTracedRef? Relevant? Coincidence?
 
 
-bash-3.00$ uname -a
SunOS unknown 5.10 Generic_118833-17 sun4u sparc SUNW,Sun-Blade-100
-bash-3.00$ rm core
-bash-3.00$ ./formsedit
Segmentation Fault (core dumped)
-bash-3.00$ dbx ./formsedit  ./core
...
t at 2 (l at 2) terminated by signal KILL (Killed)
0xfe3c03d0: ___nanosleep+0x0008:        bcc,a,pt  %icc,___nanosleep+0x18        ! 0xfe3c03e0
(dbx) lwps
  l at 1 LWP suspended in lwp_yield()
>l at 2 LWP suspended in ___nanosleep()
  l at 3 LWP suspended in __lwp_park()
  l at 4 LWP suspended in ___nanosleep()
  l at 11 LWP suspended in __lwp_park()
  l at 12 LWP suspended in __lwp_park()
  l at 13 LWP suspended in __lwp_park()
o l at 27 signal SIGSEGV in ScrollerVBTClass__PaintViewWithShadows()
  l at 28 LWP suspended in __lwp_park()
(dbx) lwp l at 27
t at 27 (l at 27) stopped in ScrollerVBTClass__PaintViewWithShadows at 0xff1b945c
0xff1b945c: ScrollerVBTClass__PaintViewWithShadows+0x0340:      ld       [%g1], %g1
(dbx) dis $pc - 0x10
dbx: warning: unknown language, 'c' assumed
0xff1b941c: ScrollerVBTClass__PaintViewWithShadows+0x0300:      inc      -4, %g1
0xff1b9420: ScrollerVBTClass__PaintViewWithShadows+0x0304:      ld       [%g1], %g1
0xff1b9424: ScrollerVBTClass__PaintViewWithShadows+0x0308:      sll      %g1, 22, %g1
0xff1b9428: ScrollerVBTClass__PaintViewWithShadows+0x030c:      srl      %g1, 31, %g1
0xff1b942c: ScrollerVBTClass__PaintViewWithShadows+0x0310:      btog     1, %g1
0xff1b9430: ScrollerVBTClass__PaintViewWithShadows+0x0314:      and      %g1, 255, %g1
0xff1b9434: ScrollerVBTClass__PaintViewWithShadows+0x0318:      cmp      %g1, 0
0xff1b9438: ScrollerVBTClass__PaintViewWithShadows+0x031c:      bne,pt   %icc,ScrollerVBTClass__Pain
tViewWithShadows+0x334      ! 0xff1b9450
0xff1b943c: ScrollerVBTClass__PaintViewWithShadows+0x0320:      nop
0xff1b9440: ScrollerVBTClass__PaintViewWithShadows+0x0324:      ld       [%fp - 24], %g1
(dbx) dis
0xff1b9444: ScrollerVBTClass__PaintViewWithShadows+0x0328:      mov      %g1, %o0
0xff1b9448: ScrollerVBTClass__PaintViewWithShadows+0x032c:      call     RTHooks__CheckLoadTracedRef
 [PLT]      ! 0xff2a9518
0xff1b944c: ScrollerVBTClass__PaintViewWithShadows+0x0330:      nop
0xff1b9450: ScrollerVBTClass__PaintViewWithShadows+0x0334:      ld       [%fp + 68], %g3
0xff1b9454: ScrollerVBTClass__PaintViewWithShadows+0x0338:      ld       [%fp - 24], %g1
0xff1b9458: ScrollerVBTClass__PaintViewWithShadows+0x033c:      inc      4, %g1
0xff1b945c: ScrollerVBTClass__PaintViewWithShadows+0x0340:      ld       [%g1], %g1
0xff1b9460: ScrollerVBTClass__PaintViewWithShadows+0x0344:      st       %g1, [%fp - 180]
0xff1b9464: ScrollerVBTClass__PaintViewWithShadows+0x0348:      add      %fp, -40, %g1
0xff1b9468: ScrollerVBTClass__PaintViewWithShadows+0x034c:      add      %fp, -180, %g2
(dbx) print $g1
$g1 = 4ULL
(dbx)

I believe it is on the last line of the function, the PaintTint call (due to what PPC_DARWIN showed).
 
 
PROCEDURE PaintViewWithShadows (v: T) =
  VAR
    dom   : Rect.T;
    stripe: Rect.T;
    r     : Rect.T;
    f     : Rect.Partition;
  BEGIN
    dom := VBT.Domain(v);
    stripe := ComputeStripe(v, dom);
    (* Paint the scroll.  We are careful not to draw the area of the
       trough that will be covered by the stripe.  This helps reduce
       the flicker. *)
    r := Rect.Inset(dom, v.shadowPixels);
    ShadowPaint.Border(v, Region.Full, v.shadow, Shadow.Style.Lowered,
      r, dom);
    Rect.Factor(r, stripe, f, 0, 0);
    FOR i := FIRST(f) TO LAST(f) DO
      IF i # 2 AND NOT Rect.IsEmpty(f[i]) THEN
        VBT.PaintTint(v, f[i], v.troughColor);
      END;
    END;
    (* Paint the stripe. *)
    r := Rect.Inset(stripe, v.shadowPixels);
    ShadowPaint.Border(v, Region.Full, v.shadow, Shadow.Style.Raised,
      r, stripe);
    VBT.PaintTint(v, r, v.shadow.bg);
  END PaintViewWithShadows;

 
I'm somewhat just showing people how to get started debugging it, in case folks are as afraid of command line debuggers as I used to be.
 
 
 - Jay