tenshi% acid -l rot13.acid -l trump ./6.rot13
./6.rot13:amd64 plan 9 executable
/sys/lib/acid/port
/sys/lib/acid/amd64
/sys/lib/acid/trump
acid: win()
acid: trump()
0x00401b00 realloc 0x00000004 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
0x00401b40 realloc 0x00000004 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
0x00401b80 realloc 0x00000004 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
0x00401bc0 realloc 0x00000005 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
0x00401c00 realloc 0x00000005 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
0x00401c40 realloc 0x00000005 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
0x00401c80 realloc 0x00000025 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
0x00401cc0 realloc 0x00000064 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
<stdin>:3: (error) msg: pid=412171 startstop: interrupted
acid: lstk()
pread(a0=0x0)+0xe /sys/src/libc/9syscall/pread.s:6
read(buf=0x7ffffeffcef5,n=0x7fff00002000)+0x27 /sys/src/libc/9sys/read.c:7
bioread(v=0x7ffffeffcef5,n=0x2000)+0x1e /sys/src/libbio/binit.c:56
Brdstr(bp=0x7ffffeffce98,delim=0xa,nulldelim=0x1)+0x19e /sys/src/libbio/brdstr.c:72
	ip=0x7ffffeffcef5
	i=0x0
	p=0x0
	j=0xb1
	ep=0x7ffffeffcf57
main()+0x87 /usr/seh/repos/plan9/C/rot13.c:26
	in=0x0
	out=0xffffe00000000000
	str=0x401cc0
	len=0x62
_main+0x40 /sys/src/libc/amd64/main9.s:15
acid: untrump()
no breakpoint at sbrkalloc
no breakpoint at sbrkmerge
# [Pressed Delete]
acid: trump()
0x00401d80 realloc 0x00000004 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
<stdin>:6: (error) msg: pid=412171 startstop: interrupted
acid: src(badd+0x25)
/sys/src/libbio/brdstr.c:13
 8		int n;
 9		char *p;
 10
 11		n = *np;
 12		p = realloc(oldp, n+ndata+1);
>13		if(p){
 14			memmove(p+n, data, ndata);
 15			n += ndata;
 16			if(n>0 && nulldelim && p[n-1]==delim)
 17				p[--n] = '\0';
 18			else
acid: src(Brdstr+0x2db)
/sys/src/libbio/brdstr.c:104
 99						memmove(ip, bp->bbuf, i);
 100						bp->gbuf = (uchar*)ip;
 101					}
 102					j = (ep - (char*)bp->bbuf) + 1;
 103					bp->icount = j - i;
>104					p = badd(p, &bp->rdline, ip, j, delim, nulldelim);
 105					goto out;
 106				}
 107				ip += j;
 108			}
 109
acid: untrump()
<stdin>:9: (error) msg: pid=412171 stop: interrupted
acid: trump()
breakpoint already set at malloc
breakpoint already set at mallocz
breakpoint already set at free
breakpoint already set at realloc
0x00401dc0 realloc 0x00000006 -1 # src(badd+0x25); src(Brdstr+0x2db); src(main+0x87); src(_main+0x40);
# [Pressed ctrl+d in 6.rot13 window]
412171: page fault	strlen+0xd	REPNE SCASB	(DI),AL
Notes pending:
	sys: trap: fault read addr=0x0
no breakpoint at sbrkalloc
no breakpoint at sbrkmerge
acid: src(strlen+0xd)
/sys/src/libc/amd64/strlen.s:11
 6	/*
 7	 * look for end of string
 8	 */
 9
 10		MOVQ	RARG, DI
>11		REPN;	SCASB
 12
 13		MOVQ	DI, AX
 14		SUBQ	RARG, AX
 15		SUBQ	$1, AX
 16		RET
acid:
echo kill > /proc/412171/ctl
tenshi% echo kill > /proc/412171/ctl