summaryrefslogtreecommitdiff
path: root/arch/mips
diff options
context:
space:
mode:
authorStefan Wiehler <stefan.wiehler@nokia.com>2023-11-06 13:12:07 +0100
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>2023-12-05 18:43:05 +0100
commit55702ec9603ebeffb15e6f7b113623fe1d8872f4 (patch)
treed112e9f4e9aa5da5611e08217c7e2b901563b182 /arch/mips
parent33cc938e65a98f1d29d0a18403dbbee050dcad9a (diff)
mips/smp: Call rcutree_report_cpu_starting() earlier
rcutree_report_cpu_starting() must be called before clockevents_register_device() to avoid the following lockdep splat triggered by calling list_add() when CONFIG_PROVE_RCU_LIST=y: WARNING: suspicious RCU usage ... ----------------------------- kernel/locking/lockdep.c:3680 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: [<ffffffff8012a434>] show_stack+0x64/0x158 [<ffffffff80a93d98>] dump_stack_lvl+0x90/0xc4 [<ffffffff801c9e9c>] __lock_acquire+0x1404/0x2940 [<ffffffff801cbf3c>] lock_acquire+0x14c/0x448 [<ffffffff80aa4260>] _raw_spin_lock_irqsave+0x50/0x88 [<ffffffff8021e0c8>] clockevents_register_device+0x60/0x1e8 [<ffffffff80130ff0>] r4k_clockevent_init+0x220/0x3a0 [<ffffffff801339d0>] start_secondary+0x50/0x3b8 raw_smp_processor_id() is required in order to avoid calling into lockdep before RCU has declared the CPU to be watched for readers. See also commit 29368e093921 ("x86/smpboot: Move rcu_cpu_starting() earlier"), commit de5d9dae150c ("s390/smp: move rcu_cpu_starting() earlier") and commit 99f070b62322 ("powerpc/smp: Call rcu_cpu_starting() earlier"). Signed-off-by: Stefan Wiehler <stefan.wiehler@nokia.com> Reviewed-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/kernel/smp.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 8fbef537fb88..82e2e051b416 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -351,10 +351,11 @@ early_initcall(mips_smp_ipi_init);
*/
asmlinkage void start_secondary(void)
{
- unsigned int cpu;
+ unsigned int cpu = raw_smp_processor_id();
cpu_probe();
per_cpu_trap_init(false);
+ rcutree_report_cpu_starting(cpu);
mips_clockevent_init();
mp_ops->init_secondary();
cpu_report();
@@ -366,7 +367,6 @@ asmlinkage void start_secondary(void)
*/
calibrate_delay();
- cpu = smp_processor_id();
cpu_data[cpu].udelay_val = loops_per_jiffy;
set_cpu_sibling_map(cpu);