From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Qian Cai <cai@redhat.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
Heiko Carstens <hca@linux.ibm.com>,
Sasha Levin <sashal@kernel.org>,
linux-s390@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 15/21] s390/smp: move rcu_cpu_starting() earlier
Date: Mon, 9 Nov 2020 22:55:35 -0500 [thread overview]
Message-ID: <20201110035541.424648-15-sashal@kernel.org> (raw)
In-Reply-To: <20201110035541.424648-1-sashal@kernel.org>
From: Qian Cai <cai@redhat.com>
[ Upstream commit de5d9dae150ca1c1b5c7676711a9ca139d1a8dec ]
The call to rcu_cpu_starting() in smp_init_secondary() is not early
enough in the CPU-hotplug onlining process, which results in lockdep
splats as follows:
WARNING: suspicious RCU usage
-----------------------------
kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
no locks held by swapper/1/0.
Call Trace:
show_stack+0x158/0x1f0
dump_stack+0x1f2/0x238
__lock_acquire+0x2640/0x4dd0
lock_acquire+0x3a8/0xd08
_raw_spin_lock_irqsave+0xc0/0xf0
clockevents_register_device+0xa8/0x528
init_cpu_timer+0x33e/0x468
smp_init_secondary+0x11a/0x328
smp_start_secondary+0x82/0x88
This is avoided by moving the call to rcu_cpu_starting up near the
beginning of the smp_init_secondary() function. Note that the
raw_smp_processor_id() is required in order to avoid calling into
lockdep before RCU has declared the CPU to be watched for readers.
Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/
Signed-off-by: Qian Cai <cai@redhat.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/s390/kernel/smp.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 8e31dfd85de32..888f247c9261a 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -831,7 +831,7 @@ void __init smp_detect_cpus(void)
*/
static void smp_start_secondary(void *cpuvoid)
{
- int cpu = smp_processor_id();
+ int cpu = raw_smp_processor_id();
S390_lowcore.last_update_clock = get_tod_clock();
S390_lowcore.restart_stack = (unsigned long) restart_stack;
@@ -844,6 +844,7 @@ static void smp_start_secondary(void *cpuvoid)
set_cpu_flag(CIF_ASCE_PRIMARY);
set_cpu_flag(CIF_ASCE_SECONDARY);
cpu_init();
+ rcu_cpu_starting(cpu);
preempt_disable();
init_cpu_timer();
vtime_init();
--
2.27.0
next prev parent reply other threads:[~2020-11-10 3:59 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 3:55 [PATCH AUTOSEL 4.19 01/21] usb: gadget: goku_udc: fix potential crashes in probe Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 02/21] ALSA: hda: Reinstate runtime_allow() for all hda controllers Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 03/21] gfs2: Free rd_bits later in gfs2_clear_rgrpd to fix use-after-free Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 04/21] gfs2: Add missing truncate_inode_pages_final for sd_aspace Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 05/21] gfs2: check for live vs. read-only file system in gfs2_fitrim Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 06/21] scsi: hpsa: Fix memory leak in hpsa_init_one() Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 07/21] drm/amdgpu: perform srbm soft reset always on SDMA resume Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 08/21] drm/amd/pm: perform SMC reset on suspend/hibernation Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 09/21] drm/amd/pm: do not use ixFEATURE_STATUS for checking smc running Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 10/21] mac80211: fix use of skb payload instead of header Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 11/21] mac80211: always wind down STA state Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 12/21] cfg80211: regulatory: Fix inconsistent format argument Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 13/21] scsi: scsi_dh_alua: Avoid crash during alua_bus_detach() Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 14/21] iommu/amd: Increase interrupt remapping table limit to 512 entries Sasha Levin
2020-11-10 3:55 ` Sasha Levin [this message]
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 16/21] vfio: platform: fix reference leak in vfio_platform_open Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 17/21] net: usb: qmi_wwan: add Telit LE910Cx 0x1230 composition Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 18/21] kprobes: Tell lockdep about kprobe nesting Sasha Levin
2020-11-10 6:44 ` Masami Hiramatsu
2020-11-14 22:58 ` Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 19/21] selftests: proc: fix warning: _GNU_SOURCE redefined Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 20/21] tpm_tis: Disable interrupts on ThinkPad T490s Sasha Levin
2020-11-10 3:55 ` [PATCH AUTOSEL 4.19 21/21] vt: Disable KD_FONT_OP_COPY Sasha Levin
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