On Fri, Feb 9, 2018, at 3:46 PM, Theo de Raadt wrote:
> > On Thu, Feb 8, 2018, at 9:01 PM, Theo de Raadt wrote:
> > > CVSROOT: /cvs
> > > Module name: src
> > > Changes by: dera...@cvs.openbsd.org 2018/02/08 20:01:24
> > >
> > > Modified files:
> > > sys/dev : rnd.c
> > >
> > > Log message:
> > > Situation occur where bootloader cannot supply kernel with early
> > > random data. But a new source of entropy arrived a few months ago
> > > -- KARL generates highly disturbed images for some kernels (well,
> > > not for bsd.rd)
> > > This assumes the tail of text (just before etext[]) is readable.
> > > We are trying to use a portable symbol name, and also avoid reading
> > > a locore0 which has been unmapped...
> > > ok mortimer
> > >
> >
> > I'm seeing an unaligned access fault on armv7. But should etext be aligned,
> > or should the code using it take alignment into account?
>
> Please add printf's and figure out what is going on.
>
>
etext is coming from the linker script, and as such isn't necessarily aligned
like clang assumes it is. So clang generates LDR instead of LDRB and loses.
I have also been seeing other similar problems for a while now (relinked
kernels getting stuck in early boot, crashes before going multiuser, etc.) on
armv7 that I think might also be alignment problems. I've been digging around
in it for a while now but don't have it 100% nailed yet.
I will continue to look into this.
Press SPACE to abort autoboot in 2 seconds
switch to partitions #0, OK
mmc0 is current device
SD/MMC found on device 0
** Unable to read file boot.scr **
** Unable to read file uEnv.txt **
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:1...
reading /am335x-boneblack.dtb
35930 bytes read in 9 ms (3.8 MiB/s)
Found EFI removable media binary efi/boot/bootarm.efi
Scanning disks on usb...
Scanning disks on mmc...
MMC Device 2 not found
MMC Device 3 not found
Found 6 disks
reading efi/boot/bootarm.efi
76528 bytes read in 14 ms (5.2 MiB/s)
## Starting EFI application at 82000000 ...
>> OpenBSD/armv7 BOOTARM 1.0
boot>
booting sd0a:/bsd: 4535443+206344+562616 [277544+90+282224+244902]=0x5d8520
OpenBSD/armv7 booting ...
arg0 0xc08d8520 arg1 0xe05 arg2 0x88000000
Allocating page tables
freestart = 0x808d9000, free_pages = 128807 (0x0001f727)
IRQ stack: p0x80907000 v0xc0907000
ABT stack: p0x80908000 v0xc0908000
UND stack: p0x80909000 v0xc0909000
SVC stack: p0x8090a000 v0xc090a000
Creating L1 page table at 0x808dc000
Mapping kernel
Constructing L2 page tables
undefined page pmap [ using 805216 bytes of bsd ELF symbol table ]
board type: 3589
Copyright (c) 1982, 1986, 1989, 1991, 1993
The Regents of the University of California. All rights reserved.
Copyright (c) 1995-2018 OpenBSD. All rights reserved. https://www.OpenBSD.org
OpenBSD 6.2-current (GENERIC) #1: Sun Jan 28 16:48:36 CST 2018
r...@beagle3.east.rtk0.net:/usr/src/sys/arch/armv7/compile/GENERIC
real mem = 536870912 (512MB)
avail mem = 516878336 (492MB)
Fatal kernel mode data abort: 'Alignment fault'
trapframe: 0xc090bf38
DFSR=00000001, DFAR=c0733493, spsr=20000193
r0 =c0733493, r1 =00000800, r2 =c07efcdc, r3 =c073b234
r4 =c07acce0, r5 =00000005, r6 =00000007, r7 =00000006
r8 =c07d3288, r9 =00000332, r10=0000019a, r11=c090bfa8
r12=0000000b, ssp=c090bf8c, slr=c05da2e4, pc =c05d8f50
Stopped at add_entropy_words+0x5c: ldr r8, [r0], #0x004
ddb> show registers
spsr 0x20000193
r0 0xc0733493 ieee80211_mira_valid_tx_mcs.max_mcs+0xf8b
r1 0x800 fiqvector+0x7e4
r2 0xc07efcdc entropy_add_ptr
r3 0xc073b234 add_entropy_words.twist_table
r4 0xc07acce0 entropy_pool
r5 0x5
r6 0x7
r7 0x6
r8 0xc07d3288 cpu_info_primary
r9 0x332 fiqvector+0x316
r10 0x19a fiqvector+0x17e
r11 0xc090bfa8 _bss_end__+0xf83e8
r12 0xb
usr_sp 0
usr_lr 0
svc_sp 0xc090bf8c _bss_end__+0xf83cc
svc_lr 0xc05da2e4 random_start+0x8c
pc 0xc05d8f50 add_entropy_words+0x5c
und_sp 0xc090a000 _bss_end__+0xf6440
abt_sp 0xc0909000 _bss_end__+0xf5440
irq_sp 0xc0908000 _bss_end__+0xf4440
add_entropy_words+0x5c: ldr r8, [r0], #0x004
-------------
This patch fixes the abort for me.
Index: sys/arch/arm/conf/ldscript.tail
===================================================================
RCS file: /cvs/src/sys/arch/arm/conf/ldscript.tail,v
retrieving revision 1.5
diff -u -p -u -r1.5 ldscript.tail
--- sys/arch/arm/conf/ldscript.tail 26 Oct 2017 19:01:06 -0000 1.5
+++ sys/arch/arm/conf/ldscript.tail 9 Feb 2018 23:28:43 -0000
@@ -1,5 +1,6 @@
/* $OpenBSD: ldscript.tail,v 1.5 2017/10/26 19:01:06 kettenis Exp $
*/
} =0
+ . = ALIGN(4);
PROVIDE (__etext = .);
PROVIDE (_etext = .);
PROVIDE (etext = .);
