linux - Segmentation fault happens when accessing array in a fortran program -

i have fortran program. subroutine below.the program gives segmentation fault after executing line 1434 , printing below:

i:          115           256             2 segmentation fault (core dumped) 

the parameters n1=258, n2=258, , n3=258. nr=46480. why segmentation fault happen?

75       double precision u(nr),v(nv),r(nr),a(0:3),c(0:3) 76       common /noautom/ u,v,r ...... 196       call zero3(u,n1,n2,n3) ...... 1418       subroutine zero3(z,n1,n2,n3) 1419  1420 c--------------------------------------------------------------------- 1421 c--------------------------------------------------------------------- 1422  1423       implicit none 1424  1425  1426       integer n1, n2, n3 1427       double precision z(n1,n2,n3) 1428       integer i1, i2, i3 1429  1430 !$omp parallel default(shared) private(i1,i2,i3) 1431        i3=1,n3 1432           i2=1,n2 1433              i1=1,n1 1434                print*,"i: ",i1, " ", i2 , " " ,i3 1435                z(i1,i2,i3)=0.0d0 1436             enddo 1437          enddo 1438       enddo 1439  1440       return 1441       end 

your variable definition sets aside storage 46480 double in array u (and sets aside space v , r.

your function call zero3() claims there enough storage 258*258*258 = 17173512 doubles in array passing.

when tries access element far enough outside bounds of actual array, program crashes — trying access memory not allocated program.

either need change nr smaller number (35*35*35 = 42875, zero3(u, 35, 35, 35) should safe (non-crashing), or need allocate more space u:

double u(258,258,258) 

or similar (it's while since last wrote fortran; standard fortran 77 @ time).