Re: [9front] ip/torrent crash

Re: [9front] ip/torrent crash

[qwx]

> so this means the block index is wrong. can you make a stacktrace
> and see where the block index comes from?
> 
> --
> cinap

; ip/torrent -pv < ../idgames_archive.torrent | aux/statusbar idgames
idgames/idgames-2013-07-31.zip
idgames/.____padding_file/0
idgames/idgames_meta.xml
idgames/.____padding_file/2
torrent 18533: suicide: sys: trap: fault read addr=0x18 pc=0x2004a4

; acid 18533
/proc/18533/text:amd64 plan 9 executable
/sys/lib/acid/port
/sys/lib/acid/amd64
acid: lstk()
rwpiece(data=0x42a0b8,len=0x7fff67b5cbe4,index=0xb91,poff=0x7fff00000000,wr=0x400000)+0xa7 /sys/src/cmd/ip/torrent.c:205
	n=0x42a0b800000000
havepiece(x=0xb91,from=0x429a3d)+0x91 /sys/src/cmd/ip/torrent.c:225
	m=0x42a0b840
	p=0x42a0b8
	n=0xfeffadf867b5cbe4
	hash=0x52200007ffffe
webseed(w=0x429a18,f=0x429c58)+0x1e8 /sys/src/cmd/ip/torrent.c:815
	w0=0x429a18
	fd=0x20444d0000000b
	err=0xb00000000
	off=0x2e4400000
	len=0x0
	buf=0x0
	y=0xb9100000b91
	o=0xb6800000522
	n=0x0
	x=0xb91
	m=0xb68
	p=0x52200000000
main(argc=0x0,argv=0x7ffffeffefa0)+0x8a2 /sys/src/cmd/ip/torrent.c:1376
	wlist=0x429a18
	alist=0x429838
	cflag=0x100000000
	vflag=0x100000001
	pflag=0x1
	sflag=0x204d7900000000
	_argc=0x76
	_args=0x41a620
	s=0x41a805
	fd=0x0
	p=0x406e38
	n=0x70000ed59
	torrent=0x418c00
	d=0x41a8a0
	l=0x429a18
	info=0x419420
	fp=0x429c58
	f=0x429c58
	di=0x41a620
	len=0x2e4400000
	i=0x7
_main+0x40 /sys/src/libc/amd64/main9.s:15


Thanks for the help,

qwx

Re: [9front] ip/torrent crash

[qwx]

The torrent completed and was verified successfully.

Pushed.

Thanks for the help!

qwx

Re: [9front] ip/torrent crash

[qwx]

> yeah, that makes more sense.
> 
> --
> cinap

I'll push the patch once the torrent downloads and I verify it completed
successfully.

Thanks again for the help!

qwx

Re: [9front] ip/torrent crash

[cinap_lenrek]

yeah, that makes more sense.

--
cinap

Re: [9front] ip/torrent crash

[qwx]

> we want to find the file that the block at "off" belongs to,
> but this block appears to be part of no file at all, so we crash.
> 
> off == end means the block is just PAST the file. so changing the
> check from > to >= is wrong.
> 
> so this means the block index is wrong. [...]

How about this?

diff -r b048db97b5ea sys/src/cmd/ip/torrent.c
--- a/sys/src/cmd/ip/torrent.c	Fri Jan 04 02:51:29 2019 +0100
+++ b/sys/src/cmd/ip/torrent.c	Mon Jan 07 13:33:44 2019 +0100
@@ -811,7 +811,8 @@
 			}
 		}
 	}
-	havepiece(off / blocksize, w->str);
+	if(off < f->off + f->len)
+		havepiece(off / blocksize, w->str);
 	havepiece(f->off / blocksize, w->str);
 	close(fd);
 	exits(0);

Re: [9front] ip/torrent crash

[cinap_lenrek]

no. this is wrong.

a file goes from:

[start, end)

start = f->off
end = f->off + f->len

we want to find the file that the block at "off" belongs to,
but this block appears to be part of no file at all, so we crash.

off == end means the block is just PAST the file. so changing the
check from > to >= is wrong.

so this means the block index is wrong. can you make a stacktrace
and see where the block index comes from?

--
cinap