Date: Sat, 14 Feb 2015 14:21:50 -0800 From: Mark Millard <markmi@dsl-only.net> To: FreeBSD PowerPC ML <freebsd-ppc@freebsd.org> Subject: Re: PowerMac G5 powerpc64: new context where repeatedly booting varies between failing and working Message-ID: <ABDD60F1-72C0-41E0-8DFB-4CFDCA9ACA82@dsl-only.net> In-Reply-To: <7CA43EE3-8C11-4FBD-9F8A-42DF08B82362@dsl-only.net> References: <7CA43EE3-8C11-4FBD-9F8A-42DF08B82362@dsl-only.net>
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I've been able to show that the TOC entry that authnone_init accesses is =
messed up and it is so from very early on.
I took advantage of sys/rpc/auth_none.c exposing the static variable's =
address calculation result, in fact the same one that the crash happened =
for:
AUTH *
authnone_create()
{
struct authnone_private *ap =3D &authnone_private;
return (&ap->no_client);
}
The no_client even happens to be the first field of the struct pointed =
to by ap.
So I put calls of that routine where it would periodically monitor the =
calculation during the early part of booting:
root@FBSDG5M1:/usr/src # svnlite diff sys/kern/init_main.c=20
Index: sys/kern/init_main.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- sys/kern/init_main.c (revision 278443)
+++ sys/kern/init_main.c (working copy)
@@ -91,6 +91,11 @@
#include <ddb/ddb.h>
#include <ddb/db_sym.h>
=20
+#if defined(VERBOSE_SYSINIT)
+/* HACK! */
+extern void* authnone_create(void);
+#endif
+
void mi_startup(void); /* Should be elsewhere =
*/
=20
/* Components of the first process -- never freed. */
@@ -282,7 +287,9 @@
=20
#if defined(VERBOSE_SYSINIT)
if (verbose)
+{printf(" authnone_private address generation check: %p ", =
authnone_create());
printf("done.\n");
+}
#endif
So when it boots successfully it reports messages like:
malloc_init(&M_JFREEFRAG)... authnone_private address generation =
check: 0xe313a8 done.
When the boots fails the very first such message of that form shows the =
0x2400002200e313a8 value, as do all the later ones. When the boot works =
it always shows 0xe313a8.
[I have since shortened the text with:
printf(" &authnone_private: %p ", authnone_create());]
It would appear that the TOC entry generation/update is the source of =
the variations in value that are observed that can lead to a crash.
=3D=3D=3D
Mark Millard
markmi at dsl-only.net
On 2015-Feb-14, at 01:53 AM, Mark Millard <markmi at dsl-only.net> =
wrote:
FreeBSD context: PowerMac G5 Quad-Core with 16GB RAM.
root@FBSDG5M1:/usr/src # freebsd-version -ku ; uname -a
10.1-STABLE
10.1-STABLE
FreeBSD FBSDG5M1 10.1-STABLE FreeBSD 10.1-STABLE #10 r278443M: Fri Feb =
13 03:26:27 PST 2015 =
root@FBSDG5M1:/usr/obj/usr/src/sys/GENERIC64vtsc powerpc
Other configuration/context details for /boot/kernel10.1S/kernel are =
given late in this message. But I will here mention the use of:
options DDB
options GDB
options VERBOSE_SYSINIT
options BOOTVERBOSE=3D1
options BOOTHOWTO=3DRB_VERBOSE
I've got a new context where repeatedly booting via power-off then =
power-on varies between failing and working, always failing in the same =
way/place when it does.
Here are 3 addresses (&...: ...) from a successful boot of kernel10.1S, =
where the first one will be different for the failing boots (this is =
from dmesg -a):
authnone_init(0)... &authnone_private: 0xe313a8, &_null_auth: =
0xe31608, &authnone_ops: 0xc31f80 done.
where the extra output is from the added printf in:
static void
authnone_init(void *dummy)
{
struct authnone_private *ap =3D &authnone_private;
XDR xdrs;
ap->no_client.ah_cred =3D ap->no_client.ah_verf =3D _null_auth;
ap->no_client.ah_ops =3D &authnone_ops;
printf(" &authnone_private: %p, &_null_auth: %p, &authnone_ops: %p ", =
ap, &_null_auth, &authnone_ops);
xdrmem_create(&xdrs, ap->mclient, MAX_MARSHAL_SIZE, XDR_ENCODE);
xdr_opaque_auth(&xdrs, &ap->no_client.ah_cred);
xdr_opaque_auth(&xdrs, &ap->no_client.ah_verf);
ap->mcnt =3D XDR_GETPOS(&xdrs);
XDR_DESTROY(&xdrs);
}
SYSINIT(authnone_init, SI_SUB_KMEM, SI_ORDER_ANY, authnone_init, NULL);
The authnone_init code for through its first store into ap->... is:
00000000007a3ea4 <.authnone_init> mflr r0
00000000007a3ea8 <.authnone_init+0x4> std r29,-24(r1)
00000000007a3eac <.authnone_init+0x8> std r30,-16(r1)
00000000007a3eb0 <.authnone_init+0xc> std r31,-8(r1)
00000000007a3eb4 <.authnone_init+0x10> std r0,16(r1)
00000000007a3eb8 <.authnone_init+0x14> stdu r1,-192(r1)
00000000007a3ebc <.authnone_init+0x18> mr r31,r1
00000000007a3ec0 <.authnone_init+0x1c> ld r29,304(r2)
00000000007a3ec4 <.authnone_init+0x20> ld r9,312(r2)
00000000007a3ec8 <.authnone_init+0x24> ld r0,0(r9)
00000000007a3ecc <.authnone_init+0x28> ld r11,8(r9)
00000000007a3ed0 <.authnone_init+0x2c> ld r9,16(r9)
00000000007a3ed4 <.authnone_init+0x30> std r0,24(r29)
When the boots fail they fail on that last std: std r0,24(r29) , doing =
so based on
r2: 0xd2da20
r29: 0x2400002200e313a8
bad virtual address: 0x2400002200e313c0
(These are from a boot-crash time register display, so hand copied off =
screen as it is too soon for interaction with DDB. I've got a default =
ddb script in place that does the display.)
When it boots okay r29 =3D 0x00e313a8 and the address accessed is =
0x00e313c0 instead: see the first address that I started with above (for =
&authnone_private).
In other words: The difference is the upper half of r29. I've no =
evidence that r2 is corrupt for failing boots for this code.
So either 304(r2) accesses different values from one time to the next =
for booting or the r29 register is corrupted somehow between
00000000007a3ec0 <.authnone_init+0x1c> ld r29,304(r2)
and
00000000007a3ed4 <.authnone_init+0x30> std r0,24(r29)
(such as an interrupt not restoring the 64bit-ABI's register value =
fully).
At this point I've no clue if variability in the TOC contents that =
304(r2) references makes any sense or not. I've yet to figure out how it =
is established.
More FreeBSD configuration details:
10.1-STABLE's buildworld kernel and installworld were all done from the =
PowerMac G5 itself.
root@FBSDG5M1:/usr/src # more sys/powerpc/conf/GENERIC64
GENERIC64 GENERIC64vtsc =20
root@FBSDG5M1:/usr/src # more sys/powerpc/conf/GENERIC64vtsc=20
include GENERIC64
ident GENERIC64vtsc
nooptions PS3 #Sony Playstation 3 =
HACK!!! to allow sc
options DDB # HACK!!! to dump early crash =
info (but 11.0-CURRENT already has it)
options GDB # HACK!!! ...
options VERBOSE_SYSINIT
options BOOTVERBOSE=3D1
options BOOTHOWTO=3DRB_VERBOSE
#options KTR
#options KTR_MASK=3DKTR_TRAP
#options KTR_CPUMASK=3D0xF
#options KTR_VERBOSE
# HACK!!! to allow sc for 2560x1440 display on Radeon X1950 that vt =
historically mishandled during booting
device sc
#device kbdmux # HACK: already listed by vt
options SC_OFWFB # OFW frame buffer
options SC_DFLT_FONT # compile font in
makeoptions SC_DFLT_FONT=3Dcp437
# Disable extra checking typically used for FreeBSD 11.0-CURRENT:
nooptions DEADLKRES #Enable the deadlock resolver
nooptions INVARIANTS #Enable calls of extra sanity =
checking
nooptions INVARIANT_SUPPORT #Extra sanity checks of internal =
structures, required by INVARIANTS
nooptions WITNESS #Enable checks to detect =
deadlocks and cycles
nooptions WITNESS_SKIPSPIN #Don't run witness on spinlocks =
for speed
nooptions MALLOC_DEBUG_MAXZONES # Separate malloc(9) zones
root@FBSDG5M1:/usr/src # svnlite status
? .snap
M sys/ddb/db_main.c
M sys/ddb/db_script.c
M sys/powerpc/conf
? sys/powerpc/conf/GENERIC64vtsc
M sys/powerpc/ofw/ofw_machdep.c
M sys/powerpc/ofw/ofwcall64.S
M sys/powerpc/powermac/powermac_thermal.c
M sys/rpc/auth_none.c
root@FBSDG5M1:/usr/src # more /boot/loader.conf=20
#kernel=3D"kernel"
#kernel=3D"kernel10.1RE"
kernel=3D"kernel10.1S"
#kernel=3D"kernel11C"
verbose_loading=3D"YES"
kern.vty=3Dvt
root@FBSDG5M1:/usr/src # more /etc/make.conf=20
WRKDIRPREFIX=3D/usr/obj/portswork
WITH_DEBUG=3D
MALLOC_PRODUCTION=3D
root@FBSDG5M1:/usr/src # more /etc/src.conf
CFLAGS+=3D-DELF_VERBOSE
#WITH_DEBUG_FILES=3D
#WITHOUT_CLANG=3D
Other than powermac_thermal.c (from Justin H.) the source changes are =
for investigation of various early-boot problems for PowerMac G5's. The =
PowerMac G5 that powermac_thermal.c was put in place to experiment with =
is no longer around but I've not yet removed the powermac_thermal.c =
update from my environment.
=3D=3D=3D
Mark Millard
markmi at dsl-only.net
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