egcs-980115, solaris-2.4, bus error with builtin memset

[Chris Johns]

hi

Testing an RTEMS snapshot on the solaris target with egcs-980115, the
posix unix specific cpu module generates a bus error during
initialisation. The small test program following generates the problem.
When using -fno-builtin, no bus error is generated.

I do not know the sparc instruction set or gcc internals so cannot
provide much help.

Regards

**************** cpu.c *************

#include <setjmp.h>
#include <string.h>   /* memset */

typedef unsigned int   unsigned32;

typedef struct {
  char      Area[ 0x34  ] __attribute__ ((aligned (8))) ;
} Context_Control;

typedef struct {
  jmp_buf   regs;
  unsigned32  isr_level;
} Context_Control_overlay;

static Context_Control_overlay
          _CPU_Context_Default_with_ISRs_enabled __attribute__ ((aligned
(32))) ;
static Context_Control_overlay
          _CPU_Context_Default_with_ISRs_disabled __attribute__
((aligned (32))) ;

void _CPU_Context_From_CPU_Init()
{
  (void) memset(
    &_CPU_Context_Default_with_ISRs_enabled,
    0,
    sizeof(Context_Control)
  );
  (void) memset(
    &_CPU_Context_Default_with_ISRs_disabled,
    0,
    sizeof(Context_Control)
  );
}

int main(void)
{
  _CPU_Context_From_CPU_Init();

  return 0;
}

*********

$ gcc -O2 -Wall -fasm -ansi -g -o cpu cpu.c

*********

gdb output:

(gdb) r
Starting program:
/home/projects/coresw/rtems/solaris/c/src/exec/score/cpu/unix/cpu 

Program received signal SIGBUS, Bus error.
0x107f8 in _CPU_Context_From_CPU_Init () at cpu.c:28
28        (void) memset(
(gdb) x /i $pc
0x107f8 <_CPU_Context_From_CPU_Init+48>:        
    std  %o0, [ %g2 + 0x19c ]   ! 0x2199c
<_CPU_Context_Default_with_ISRs_disabled>
(gdb) info register
g0             0x0      0
g1             0xef7616f8       -277473544
g2             0x21800  137216
g3             0x0      0
g4             0x0      0
g5             0x0      0
g6             0x0      0
g7             0x0      0
o0             0x0      0
o1             0x0      0
o2             0x4      4
o3             0x10000  65536
o4             0x2      2
o5             0xef77da10       -277358064
sp             0xeffff328       -268438744
o7             0x10820  67616
l0             0xef780780       -277346432
l1             0x0      0
l2             0xef7d3ac0       -277005632
l3             0x8      8
l4             0x4      4
l5             0x4      4
l6             0x7      7
l7             0xef77b580       -277367424
i0             0x0      0
i1             0xeffff3fc       -268438532
i2             0xeffff404       -268438524
i3             0x21940  137536
i4             0x0      0
i5             0x0      0
fp             0xeffff398       -268438632
i7             0x106b8  67256
y              0x0      0
psr            0x40400086       1077936262
wim            0x0      0
tbr            0x0      0
pc             0x107f8  67576
npc            0x107fc  67580
fpsr           0x820    2080
cpsr           0x0      0

-- 
 Chris Johns  Networks, Plessey Asia Pacfic Pty. Ltd.
  mailto:ccj@acm.org    mailto:cjohns@plessey.com.au