#444 Divide by zero problem in dump_rel() of readelf.c

[antiAgainst]

Based on r2983.

The problem is that at line 2862 of readelf.c, s->entsize is not checked against 0. So there could be a divide by zero fault. A test case is attached and command is readelf -a readelf-6-312-A. gdb output:

Program received signal SIGFPE, Arithmetic exception.
0x0000000000406a7b in dump_rel (re=0x7fffffffceb0, s=0x66f220, d=0x66f6b0) at readelf.c:2862
2862            len = d->d_size / s->entsize;

#0  0x0000000000406a7b in dump_rel (re=0x7fffffffceb0, s=0x66f220, d=0x66f6b0) at readelf.c:2862
#1  0x0000000000406fe1 in dump_reloc (re=0x7fffffffceb0) at readelf.c:2961
#2  0x0000000000410b83 in dump_elf (re=0x7fffffffceb0) at readelf.c:6210
#3  0x000000000041139a in dump_object (re=0x7fffffffceb0) at readelf.c:6374
#4  0x00000000004123ea in main (argc=1, argv=0x7fffffffd098) at readelf.c:6841

[Ed Maste]

Proposed fix in https://reviews.freebsd.org/D2338

[Ed Maste]

Fixed by [r3227]