Re: 2.0000

Ricky Beam (root@defiant.interpath.net)
Thu, 3 Apr 1997 03:19:10 -0500 (EST)


Letting the chips far where they may, I quote Greg Alexander:
>I, for one, can find no such problem. I tried what I thought would cause
>the problem discussed on the list, gave up, "well, his code causes it, so
>let's start there." And, uh, your code doesn't do anything toooo unusual.
>(I did these tests with a test full of random blah).

With the liberal use of my delete finger, I musta completely missed the MMAP
discussions...

>I get a segfault before anything is printed with this as it is now. If I

As do I. The error occurs with the first access to the mmaped data area
via 'p'.

>add a buf[100]=0; after that strncpy and change it to PROT_READ, I get no
>error. We get SIGBUS if the only change is changing that to MAP_SHARED.

Changing to protection is not the thing to do... PROT_WRITE is to stop the
data from being altered while you are playing with it.

> I see no bug. If anyone _can_ produce this bug (for real), please
>send it to me, I would like to at least dig. From the comments others have
>made, this should hopefully be fairly uncomplex to, at the least, kludge
>around.

See: <URL:http://lacota.interpath.net/~jfbeam/MMAP/>

All the crap is in there -- "test" was the netscape bookmarks file if you
don't figure that part out.

Machine:
Tyan Tomcat III
Dual P200
128M EDO
AHA2940 + Quantum XP34300W (L915) [plus other drives, not active]
Uname: Linux dominion 2.0.29-SMP #10 Tue Apr 1 02:21:52 EST 1997 i586
(Build time 0:04:35)
Libs: libc.5.2.18/libm.5.0.6

--Ricky

PS: If you want to see it for yourself -- and can live with the 28.8
connection, then feel free to ask for a login.