On 22/01/2021 13:39, Valentin Schneider wrote:
[...]
> @@ -1705,7 +1702,7 @@ void sched_init_numa(void)
> /* Compute default topology size */
> for (i = 0; sched_domain_topology[i].mask; i++);
>
> - tl = kzalloc((i + level + 1) *
> + tl = kzalloc((i + nr_levels) *
> sizeof(struct sched_domain_topology_level), GFP_KERNEL);
> if (!tl)
> return;
This hunk creates issues during startup on my Arm64 juno board on
tip/sched/core.
---8<---
From: Dietmar Eggemann <dietmar.eggem...@arm.com>
Date: Mon, 1 Feb 2021 09:58:04 +0100
Subject: [PATCH] sched/topology: Fix sched_domain_topology_level alloc in
sched_init_numa
Commit "sched/topology: Make sched_init_numa() use a set for the
deduplicating sort" allocates 'i + nr_levels (level)' instead of
'i + nr_levels + 1' sched_domain_topology_level.
This led to an Oops (on Arm64 juno with CONFIG_SCHED_DEBUG):
sched_init_domains
build_sched_domains()
__free_domain_allocs()
__sdt_free() {
...
for_each_sd_topology(tl)
...
sd = *per_cpu_ptr(sdd->sd, j); <--
...
}
Signed-off-by: Dietmar Eggemann <dietmar.eggem...@arm.com>
---
./scripts/decode_stacktrace.sh ./vmlinux < input.log
[ 0.495693] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[ 0.501280] Modules linked in:
[ 0.504342] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
5.11.0-rc2-00025-g7a976f77bb96 #95
[ 0.512455] Hardware name: ARM Juno development board (r0) (DT)
[ 0.518386] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
[ 0.524409] pc : build_sched_domains (kernel/sched/topology.c:1872
kernel/sched/topology.c:1288 kernel/sched/topology.c:2120)
[ 0.529132] lr : build_sched_domains (kernel/sched/topology.c:1868
kernel/sched/topology.c:1288 kernel/sched/topology.c:2120)
[ 0.533847] sp : ffff800011efbd00
[ 0.537165] x29: ffff800011efbd00 x28: ffff800011b69a38
[ 0.542496] x27: 0000000000000000 x26: 0000000000000000
[ 0.547827] x25: ffff000800191600 x24: 0000000000000000
[ 0.553157] x23: ffff800011b69a40 x22: 0000000000000001
[ 0.558487] x21: ffff000800056e00 x20: ffff00080016f380
[ 0.563818] x19: ffff800011b6a410 x18: 0000000000000000
[ 0.569149] x17: 0000000000000000 x16: 0000000000000000
[ 0.574478] x15: 0000000000000030 x14: ffffffffffffffff
[ 0.579809] x13: ffff800011b82d38 x12: 0000000000000189
[ 0.585139] x11: 0000000000000083 x10: ffff800011bdad38
[ 0.590469] x9 : 00000000fffff000 x8 : ffff800011b82d38
[ 0.595800] x7 : 00000000000000e0 x6 : 000000000000003f
[ 0.601130] x5 : 0000000000000000 x4 : 0000000000000000
[ 0.606460] x3 : 0000000000000000 x2 : ffff80096d857000
[ 0.611790] x1 : 0000000000000001 x0 : 0000000000000001
[ 0.617120] Call trace:
[ 0.619566] build_sched_domains (kernel/sched/topology.c:1872
kernel/sched/topology.c:1288 kernel/sched/topology.c:2120)
[ 0.623934] sched_init_domains (kernel/sched/topology.c:2194)
[ 0.627954] sched_init_smp (kernel/sched/core.c:7727)
[ 0.631629] kernel_init_freeable (init/main.c:1528)
[ 0.635914] kernel_init (init/main.c:1417)
[ 0.639416] ret_from_fork (arch/arm64/kernel/entry.S:959)
[ 0.643008] Code: b4000360 93407f1b aa0003e1 f87b7ae2 (f8626821)
All code
========
0: 60 (bad)
1: 03 00 add (%rax),%eax
3: b4 1b mov $0x1b,%ah
5: 7f 40 jg 0x47
7: 93 xchg %eax,%ebx
8: e1 03 loope 0xd
a: 00 aa e2 7a 7b f8 add %ch,-0x784851e(%rdx)
10:* 21 68 62 and %ebp,0x62(%rax) <-- trapping
instruction
13: f8 clc
Code starting with the faulting instruction
===========================================
0: 21 68 62 and %ebp,0x62(%rax)
3: f8 clc
[ 0.649129] ---[ end trace 4453f742a7781011 ]---
[ 0.653772] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x0000000b
[ 0.661449] SMP: stopping secondary CPUs
[ 0.665389] ---[ end Kernel panic - not syncing: Attempted to kill init!
exitcode=0x0000000b ]---
kernel/sched/topology.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index bf5c9bd10bfe..09d35044bd88 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1702,7 +1702,7 @@ void sched_init_numa(void)
/* Compute default topology size */
for (i = 0; sched_domain_topology[i].mask; i++);
- tl = kzalloc((i + nr_levels) *
+ tl = kzalloc((i + nr_levels + 1) *
sizeof(struct sched_domain_topology_level), GFP_KERNEL);
if (!tl)
return;
--
2.25.1
