On Sun, Aug 14 2022, Jeremie Courreges-Anglas <[email protected]> wrote:
> On Thu, Jul 28 2022, Alexander Bluhm <[email protected]> wrote:
>> Hi,
>>
>> The netlock for SIOCSIFMEDIA and SIOCGIFMEDIA ioctl is not necessary.
>> Legacy drivers run with kernel lock, interface media is MP safe or
>> has kernel lock.
>>
>> ixl(4) talks about net lock but in fact has kernel lock.
>>
>> Problem is that smtpd(8) periodically checks media status. This
>> stops network if netlock was taken.
>>
>> ok?
>
> I'm seeing fallout with cad(4) in the RAMDISK and GENERIC.MP kernels
> (didn't try GENERIC). RAMDISK after
>
> OpenBSD 7.2-beta (RAMDISK) #140: Sat Aug 6 02:06:57 MDT 2022
>
> hangs some time after mounting root. On GENERIC.MP I get a panic:
>
> --8<--
> Automatic boot in progress: starting file system checks.
> /dev/sd0a (c92bac01c037a788.a): file system is clean; not checking
> /dev/sd0m (c92bac01c037a788.m): file system is clean; not checking
> /dev/sd0j (c92bac01c037a788.j): file system is clean; not checking
> /dev/sd0d (c92bac01c037a788.d): file system is clean; not checking
> /dev/sd0e (c92bac01c037a788.e): file system is clean; not checking
> /dev/sd0f (c92bac01c037a788.f): file system is clean; not checking
> /dev/sd0g (c92bac01c037a788.g): file system is clean; not checking
> /dev/sd0h (c92bac01c037a788.h): file system is clean; not checking
> /dev/sd0k (c92bac01c037a788.k): file system is clean; not checking
> /dev/sd0l (c92bac01c037a788.l): file system is clean; not checking
> /dev/sd0o (c92bac01c037a788.o): file system is clean; not checking
> /dev/sd0n (c92bac01c037a788.n): file system is clean; not checking
> /dev/sd0p (c92bac01c037a788.p): file system is clean; not checking
> pf enabled
> kern.bufcachepercent: 20 -> 80
> sysctl: kern.allowdt: value is not available
> ddb.console: 0 -> 1
> starting network
> panic: netlock: lock not held
> Stopped at panic+0x106: addi a0,zero,256 TID PID UID
> PR
> FLAGS PFLAGS CPU COMMAND
> *464996 1081 0 0x3 0 0 ifconfig
> 492269 29052 0 0x14000 0x200 1 zerothread
> panic() at panic+0x106
> rw_exit_write() at rw_exit_write+0x94
> cad_ioctl() at cad_ioctl+0x34
> ifioctl() at ifioctl+0xaaa
> soo_ioctl() at soo_ioctl+0x152
> sys_ioctl() at sys_ioctl+0x230
> svc_handler() at svc_handler+0x284
> do_trap_user() at do_trap_user+0x15c
> cpu_exception_handler_user() at cpu_exception_handler_user+0x7c
> end of kernel
> end trace frame: 0x5408b2ae8, count: 6
> https://www.openbsd.org/ddb.html describes the minimum info required in bug
> reports. Insufficient info makes it difficult to find and fix bugs.
>
> -->8--
>
> The diff below fixes GENERIC.MP, I have yet to build and try RAMDISK.
Done, the diff fixes bsd.rd too.
> I'm not completely sure this is the best way to solve it but I can't
> spot other uses of ifp->if_ioctl() not protected by the NET_LOCK() in
> ifioctl(). Except SIOCGIFSFFPAGE but that seems fine...
Thoughts? ok?
> Index: dev/fdt/if_cad.c
> ===================================================================
> RCS file: /home/cvs/src/sys/dev/fdt/if_cad.c,v
> retrieving revision 1.11
> diff -u -p -r1.11 if_cad.c
> --- dev/fdt/if_cad.c 8 Mar 2022 16:13:08 -0000 1.11
> +++ dev/fdt/if_cad.c 14 Aug 2022 13:04:41 -0000
> @@ -553,9 +553,11 @@ cad_ioctl(struct ifnet *ifp, u_long cmd,
> int error = 0;
> int s;
>
> - NET_UNLOCK();
> + if (cmd != SIOCGIFMEDIA && cmd != SIOCSIFMEDIA)
> + NET_UNLOCK();
> rw_enter_write(&sc->sc_cfg_lock);
> - NET_LOCK();
> + if (cmd != SIOCGIFMEDIA && cmd != SIOCSIFMEDIA)
> + NET_LOCK();
> s = splnet();
>
> switch (cmd) {
--
jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
