[lkcd-devel] Bug/Patch on ia64: sial_exemem() wrong bits

[Nick B. <ni...@sg...>]

Using the following sial script (note this is on ia64/sn2 system):
string stats_usage() { return ""; }

string stats_help() { return "Displays CXFS client statistics data.";}

void stats()
{
    cxfsstat_client_info_t *pStats
    pStats = (cxfsstat_client_info_t*)cxfsclientstats;

    printf("Struct member address:\n");

    p = &pStats->cxfs_vfssync;

    printf("&stats = %lx\n", pStats);
    printf("&stats->cxfs_vfssync = %lx (offset = %d)\n",
    &pStats->cxfs_vfssync,
    &pStats->cxfs_vfssync - pStats);

    printf("Struct member value (incorrect):\n");
    printf("stats->cxfs_vfssync = %d\n", pStats->cxfs_vfssync);

    printf("Struct member value (using correct offset):\n");
    printf("*(int *)&pSatst->cxfs_vfssync = %d\n",
                *(int *)&pStats->cxfs_vfssync);
}

I get the following (incorrect) output:
 >> load stats.sial
 >> stats
Struct member address:
&stats = a0000002055a4d60
&stats->cxfs_vfssync = a0000002055a5000 (offset = 672)
Struct member value (incorrect):
stats->cxfs_vfssync = 2
Struct member value (using correct offset):
*(int *)&pStats->cxfs_vfssync = 378

The returned value for cxfs_vfssync is incorrect. It seems that this 
chunk of code (in sial_exemem()) is making some bad assumptions:
                case 4:
                    if(sizeof(long) == 8){ /* XXX */
                        API_GETMEM(mempos, &v->v.ull, 8);
                        v->v.ul = API_GET_UINT32(((char*)&(v-> v.ul)) + 4);
                    } else {
                        API_GETMEM(mempos, &v->v.ul, 4);
                        v->v.ul = API_GET_UINT32(&v->v.ul);
                    }
                break;

This results in the wrong 4 bytes been used for the value. Removing the 
top 4 lines fixes this problem and I get the correct results from the 
stats script.

Thanks

Nick