From: Pingfan Liu <kernelfans@gmail.com>
To: x86@kernel.org
Cc: Pingfan Liu <kernelfans@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Maciej W. Rozycki" <macro@orcam.me.uk>,
Marc Zyngier <maz@kernel.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH 5/9] x86/irq: place for_each_active_irq() in rcu read section
Date: Wed, 20 Apr 2022 22:05:17 +0800 [thread overview]
Message-ID: <20220420140521.45361-6-kernelfans@gmail.com> (raw)
In-Reply-To: <20220420140521.45361-1-kernelfans@gmail.com>
Since there are access to irq_desc, and no preemption is provided at the
involved, it requires rcu read lock to protect irq_desc.
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Cc: Marc Zyngier <maz@kernel.org>
Cc: linux-kernel@vger.kernel.org
To: x86@kernel.org
---
arch/x86/kernel/apic/io_apic.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index c1bb384935b0..4bb16edcbe4d 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1333,6 +1333,7 @@ void __init print_IO_APICs(void)
print_IO_APIC(ioapic_idx);
printk(KERN_DEBUG "IRQ to pin mappings:\n");
+ rcu_read_lock();
for_each_active_irq(irq) {
struct irq_pin_list *entry;
struct irq_chip *chip;
@@ -1352,6 +1353,7 @@ void __init print_IO_APICs(void)
pr_cont("-> %d:%d", entry->apic, entry->pin);
pr_cont("\n");
}
+ rcu_read_unlock();
printk(KERN_INFO ".................................... done.\n");
}
@@ -2009,6 +2011,7 @@ static inline void init_IO_APIC_traps(void)
struct irq_cfg *cfg;
unsigned int irq;
+ /* The early boot stage is free of irq_desc release */
for_each_active_irq(irq) {
cfg = irq_cfg(irq);
if (IO_APIC_IRQ(irq) && cfg && !cfg->vector) {
--
2.31.1
next prev parent reply other threads:[~2022-04-20 14:06 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-20 14:05 [PATCH 0/9] trival fix or improvement about irq_desc access Pingfan Liu
2022-04-20 14:05 ` [PATCH 1/9] irq/irqdesc: put the lock at the exact place in irq_sysfs_init() Pingfan Liu
2022-04-20 14:05 ` [PATCH 2/9] irq/irqdesc: change the name of delete_irq_desc() to irq_delete_desc() Pingfan Liu
2022-04-20 14:05 ` [PATCH 3/9] irq/manage: remove some unreferenced code Pingfan Liu
2022-04-20 20:56 ` Miguel Ojeda
2022-04-20 14:05 ` [PATCH 4/9] s390/irq: utilize RCU instead of irq_lock_sparse() in show_msi_interrupt() Pingfan Liu
2022-04-20 18:16 ` Heiko Carstens
2022-04-21 3:36 ` Pingfan Liu
2022-04-21 11:42 ` Heiko Carstens
2022-04-22 9:56 ` Pingfan Liu
2022-04-22 10:02 ` [PATCHv2] " Pingfan Liu
2022-04-25 11:39 ` Heiko Carstens
2022-04-20 14:05 ` Pingfan Liu [this message]
2022-04-20 14:05 ` [PATCH 6/9] pm/irq: make for_each_irq_desc() safe of irq_desc release Pingfan Liu
2022-04-20 16:23 ` Rafael J. Wysocki
2022-04-21 3:31 ` Pingfan Liu
2022-04-21 10:57 ` Rafael J. Wysocki
2022-04-22 10:43 ` Pingfan Liu
2022-04-27 6:03 ` [PATCHv2] genirq/PM: Make " Pingfan Liu
2022-04-20 14:05 ` [PATCH 7/9] irq: remove needless lock in takedown_cpu() Pingfan Liu
2022-04-21 16:11 ` Thomas Gleixner
2022-04-25 2:57 ` Pingfan Liu
2022-04-25 9:43 ` Thomas Gleixner
2022-04-27 6:01 ` Pingfan Liu
2022-04-20 14:05 ` [PATCH 8/9] irq: make irq_lock_sparse() independent of CONFIG_SPARSE_IRQ Pingfan Liu
2022-04-20 14:05 ` [PATCH 9/9] irq/irqdesc: rename sparse_irq_lock to bitmap_lock Pingfan Liu
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