Re: Kernel panic on earm

[Michael Blatt <michael.blatt%gmail.com@localhost>]

I can confirm that with a different kernel build, same panic, different addresses but same error line in the same place:

addr2line -e netbsd/src/sys/arch/evbarm/compile/obj/NSA320s/netbsd.gdb -f c04cce88

ifioctl_common
/home/michael/netbsd/src/sys/net/if.c:2988

in function ifioctl_common()

2986     case SIOCGIFCAP:
2987         ifcr = data;
2988         ifcr->ifcr_capabilities = ifp->if_capabilities;
2989         ifcr->ifcr_capenable = ifp->if_capenable;
2990         break;

Michael

On Thu, 25 Oct 2018 at 22:50, Michael Blatt <michael.blatt%gmail.com@localhost> wrote:

Right, here we go...

the panic happens when setting up the loopback interface as I initially suspected. I've added the addr2line info next to the backtrace addresses below.

The key seems to be in ifioctl_common() at src/sys/net/if.c:2988

Starting network.
[  32.8299972] Fatal kernel mode data abort: 'Alignment Fault 1'
[  32.8299972] trapframe: 0xcc7d1bc8
[  32.8299972] FSR=00000001, FAR=cc7d1ddc, spsr=60000013
[  32.8299972] r0 =c29b23c0, r1 =cc7d1dcc, r2 =00000000, r3 =00000000
[  32.8299972] r4 =c04f1e5c, r5 =00022078, r6 =bfffdfd0, r7 =00000010
[  32.8299972] r8 =bbc0d180, r9 =bfffe0a8, r10=bbc17b65, r11=cc7d1c44
[  32.8299972] r12=cc7d1c48, ssp=cc7d1c18, slr=c04f9798, pc =c04f1a2c

Stopped in pid 95.1 (ifconfig) at       c04f1a2c:       strd    r2, [r1, #0x10]
db> bt
0xcc7d1c44: c04f14e4 ifioctl_common /home/michael/netbsd/src/sys/net/if.c:2888
0xcc7d1c74: c04f9798 loioctl /home/michael/netbsd/src/sys/net/if_loop.c:523
0xcc7d1d74: c04f2350 doifioctl /home/michael/netbsd/src/sys/net/if.c:3248
0xcc7d1da4: c045d68c soo_ioctl /home/michael/netbsd/src/sys/kern/sys_socket.c:212
0xcc7d1e84: c044dd48 sys_ioctl /home/michael/netbsd/src/sys/kern/sys_generic.c:671
0xcc7d1eac: c001aa28 sy_call /home/michael/netbsd/src/sys/sys/syscallvar.h:65
0xcc7d1edc: c001ab10 sy_invoke /home/michael/netbsd/src/sys/sys/syscallvar.h:94
0xcc7d1f8c: c001b058 syscall /home/michael/netbsd/src/sys/arch/arm/arm/syscall.c:250
0xcc7d1fac: c001ad34 swi_handler /home/michael/netbsd/src/sys/arch/arm/arm/syscall.c:172

addr2line -e sys/arch/evbarm/compile/obj/NSA320s/netbsd.gdb -f c04f1a2c
ifioctl_common

/home/michael/netbsd/src/sys/net/if.c:2988

I noticed that the addresses vary slightly for each kernel build (I should probably enable MKREPRO and all that), so will re-run the same tests tomorrow and check whether the bt is any different.

Michael

On Thu, 25 Oct 2018 at 18:47, Nick Hudson <nick.hudson%gmx.co.uk@localhost> wrote:

On 25/10/2018 17:49, Michael Blatt wrote:
> OK, so...
> I inserted boothowto |= AB_DEBUG to
> sys/arch/evbarm/marvell/marvell_machdep.c under initarm() as that made
> sense, is this correct?
>
> the panic is
> Starting network.
> [  32.7799960] Fatal kernel mode data abort: 'Alignment Fault 1'
> [  32.7799960] trapframe: 0xcc7d1bc8
> [  32.7799960] FSR=00000001, FAR=cc7d1ddc, spsr=60000013
> [  32.7799960] r0 =c29b33c0, r1 =cc7d1dcc, r2 =00000000, r3 =00000000
> [  32.7799960] r4 =c04f060c, r5 =00022078, r6 =bfffdfd0, r7 =00000010
> [  32.7799960] r8 =bbc0d180, r9 =bfffe0a8, r10=bbc17b65, r11=cc7d1c44
> [  32.7799960] r12=cc7d1c48, ssp=cc7d1c18, slr=c04f7f48, pc =c04f01dc
>
> Stopped in pid 95.1 (ifconfig) at       c04f01dc:       strd    r2, [r1, #0x10]
> db>
>
> db> bt
> 0xcc7d1c44: c04efc94
> 0xcc7d1c74: c04f7f48
> 0xcc7d1d74: c04f0b00
> 0xcc7d1da4: c045be3c
> 0xcc7d1e84: c044c4f8
> 0xcc7d1eac: c001a568
> 0xcc7d1edc: c001a650
> 0xcc7d1f8c: c001ab98
> 0xcc7d1fac: c001a874

Left hand number is stack (or frame pointer, I forget which) and right
is the PC values that need to run through addr2line

Doesn't look like stack is ever aligned :S

>
> On another NetBSD machine (armv6) I looked at the kernel used:
> addr2line -e netbsd -f 0xc04f01dc

You need to use a netbsd.gdb

./build.sh -m evbearmv5-el -O ../obj.evbearmv5-el tools

on your fastest unix-like machine will give you a cross addr2line

Nick