Re: kern/52598 (/proc/self/exe misbehaves if it's on a null mount)

[Christos Zoulas <christos%zoulas.com@localhost>]

The following reply was made to PR kern/52598; it has been noted by GNATS.

From: Christos Zoulas <christos%zoulas.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
 netbsd-bugs%netbsd.org@localhost, coypu%sdf.org@localhost
Subject: Re: kern/52598 (/proc/self/exe misbehaves if it's on a null mount)
Date: Mon, 13 Jan 2020 18:17:14 -0500

 there are many more changes needed I think in the exec code. can you reprodu=
 ce the crash on head or 9?
 
 christos
 
 
 
 > On Jan 13, 2020, at 5:35 PM, Fr=C3=A9d=C3=A9ric Fauberteau <triaxx@netbsd.=
 org> wrote:
 >=20
 > =EF=BB=BFThe following reply was made to PR kern/52598; it has been noted b=
 y GNATS.
 >=20
 > From: =3D?UTF-8?Q?Fr=3DC3=3DA9d=3DC3=3DA9ric_Fauberteau?=3D <triaxx@NetBSD=
 .org>
 > To: gnats-bugs%NetBSD.org@localhost
 > Cc: Pierre Pronchery <khorben%defora.org@localhost>, maya%NetBSD.org@localhost,
 > christos%NetBSD.org@localhost
 > Subject: Re: kern/52598 (/proc/self/exe misbehaves if it's on a null mount=
 )
 > Date: Mon, 13 Jan 2020 23:23:27 +0100
 >=20
 > I tried to apply the changes made by christos to introduce p_path in=20
 > struct proc to netbsd-8-0-RELEASE:
 > cvs rdiff -u -r1.197.2.2 -r1.200 src/sys/miscfs/procfs/procfs_vnops.c
 > cvs rdiff -u -r1.340.6.1 -r1.343 src/sys/sys/proc.h
 >=20
 > Now I get the following behavior:
 > # ls -l /proc/curproc
 > lr-xr-xr-x  1 root  wheel  2 Jan 13 23:09 /proc/curproc -> 49
 > # ls -l /proc/curproc/
 > causes a fatal page fault.
 >=20
 > The backtrace I got using crash(1):
 > # crash -M netbsd.9.core
 > Crash version 8.0, image version 8.0.
 > System panicked: trap
 > Backtrace from time of crash is available.
 > crash> bt
 > _KERNEL_OPT_NARCNET() at 0
 > ?() at ffff800064978000
 > vpanic() at vpanic+0x166
 > snprintf() at snprintf
 > trap() at trap+0xa00
 > --- trap (number 6) ---
 > strlen() at strlen+0x20
 > VOP_GETATTR() at VOP_GETATTR+0x4d
 > vn_stat() at vn_stat+0x3d
 > do_sys_statat() at do_sys_statat+0x89
 > sys___lstat50() at sys___lstat50+0x25
 > syscall() at syscall+0x1ec
 > --- syscall (number 441) ---
 > 7f5df9ca17ba:
 >=20