* [PATCH MANUALSEL 5.17 1/6] x86/nmi: Make register_nmi_handler() more robust
@ 2022-06-05 13:53 Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 2/6] genirq/irq_sim: Make the irq_work always run in hard irq context Sasha Levin
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: Sasha Levin @ 2022-06-05 13:53 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Thomas Gleixner, Sean Christopherson, Borislav Petkov,
Sasha Levin, mingo, bp, dave.hansen, x86, jkosina, peterz
From: Thomas Gleixner <tglx@linutronix.de>
[ Upstream commit a7fed5c0431dbfa707037848830f980e0f93cfb3 ]
register_nmi_handler() has no sanity check whether a handler has been
registered already. Such an unintended double-add leads to list corruption
and hard to diagnose problems during the next NMI handling.
Init the list head in the static NMI action struct and check it for being
empty in register_nmi_handler().
[ bp: Fixups. ]
Reported-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/lkml/20220511234332.3654455-1-seanjc@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/include/asm/nmi.h | 1 +
arch/x86/kernel/nmi.c | 12 ++++++++----
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h
index 1cb9c17a4cb4..5c5f1e56c404 100644
--- a/arch/x86/include/asm/nmi.h
+++ b/arch/x86/include/asm/nmi.h
@@ -47,6 +47,7 @@ struct nmiaction {
#define register_nmi_handler(t, fn, fg, n, init...) \
({ \
static struct nmiaction init fn##_na = { \
+ .list = LIST_HEAD_INIT(fn##_na.list), \
.handler = (fn), \
.name = (n), \
.flags = (fg), \
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 4bce802d25fb..399648421223 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -157,7 +157,7 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
struct nmi_desc *desc = nmi_to_desc(type);
unsigned long flags;
- if (!action->handler)
+ if (WARN_ON_ONCE(!action->handler || !list_empty(&action->list)))
return -EINVAL;
raw_spin_lock_irqsave(&desc->lock, flags);
@@ -177,7 +177,7 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
list_add_rcu(&action->list, &desc->head);
else
list_add_tail_rcu(&action->list, &desc->head);
-
+
raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
@@ -186,7 +186,7 @@ EXPORT_SYMBOL(__register_nmi_handler);
void unregister_nmi_handler(unsigned int type, const char *name)
{
struct nmi_desc *desc = nmi_to_desc(type);
- struct nmiaction *n;
+ struct nmiaction *n, *found = NULL;
unsigned long flags;
raw_spin_lock_irqsave(&desc->lock, flags);
@@ -200,12 +200,16 @@ void unregister_nmi_handler(unsigned int type, const char *name)
WARN(in_nmi(),
"Trying to free NMI (%s) from NMI context!\n", n->name);
list_del_rcu(&n->list);
+ found = n;
break;
}
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
- synchronize_rcu();
+ if (found) {
+ synchronize_rcu();
+ INIT_LIST_HEAD(&found->list);
+ }
}
EXPORT_SYMBOL_GPL(unregister_nmi_handler);
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH MANUALSEL 5.17 2/6] genirq/irq_sim: Make the irq_work always run in hard irq context
2022-06-05 13:53 [PATCH MANUALSEL 5.17 1/6] x86/nmi: Make register_nmi_handler() more robust Sasha Levin
@ 2022-06-05 13:53 ` Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 3/6] time/sched_clock: Round the frequency reported to nearest rather than down Sasha Levin
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2022-06-05 13:53 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Sebastian Andrzej Siewior, Thomas Gleixner, Sasha Levin
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Upstream commit 21673fcb2532dcd189905ff5a5389eb7dcd0e57a ]
The IRQ simulator uses irq_work to trigger an interrupt. Without the
IRQ_WORK_HARD_IRQ flag the irq_work will be performed in thread context
on PREEMPT_RT. This causes locking errors later in handle_simple_irq()
which expects to be invoked with disabled interrupts.
Triggering individual interrupts in hardirq context should not lead to
unexpected high latencies since this is also what the hardware
controller does. Also it is used as a simulator so...
Use IRQ_WORK_INIT_HARD() to carry out the irq_work in hardirq context on
PREEMPT_RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/YnuZBoEVMGwKkLm+@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/irq/irq_sim.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c
index 0cd02efa3a74..dd76323ea3fd 100644
--- a/kernel/irq/irq_sim.c
+++ b/kernel/irq/irq_sim.c
@@ -181,7 +181,7 @@ struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
goto err_free_bitmap;
work_ctx->irq_count = num_irqs;
- init_irq_work(&work_ctx->work, irq_sim_handle_irq);
+ work_ctx->work = IRQ_WORK_INIT_HARD(irq_sim_handle_irq);
return work_ctx->domain;
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH MANUALSEL 5.17 3/6] time/sched_clock: Round the frequency reported to nearest rather than down
2022-06-05 13:53 [PATCH MANUALSEL 5.17 1/6] x86/nmi: Make register_nmi_handler() more robust Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 2/6] genirq/irq_sim: Make the irq_work always run in hard irq context Sasha Levin
@ 2022-06-05 13:53 ` Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 4/6] lib/irq_poll: Prevent softirq pending leak in irq_poll_cpu_dead() Sasha Levin
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2022-06-05 13:53 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Maciej W. Rozycki, Thomas Gleixner, John Stultz, Sasha Levin
From: "Maciej W. Rozycki" <macro@orcam.me.uk>
[ Upstream commit 92067440f1311dfa4d77b57a9da6b3706f5da32e ]
The frequency reported for clock sources are rounded down, which gives
misleading figures, e.g.:
I/O ASIC clock frequency 24999480Hz
sched_clock: 32 bits at 24MHz, resolution 40ns, wraps every 85901132779ns
MIPS counter frequency 59998512Hz
sched_clock: 32 bits at 59MHz, resolution 16ns, wraps every 35792281591ns
Rounding to nearest is more adequate:
I/O ASIC clock frequency 24999664Hz
sched_clock: 32 bits at 25MHz, resolution 40ns, wraps every 85900499947ns
MIPS counter frequency 59999728Hz
sched_clock: 32 bits at 60MHz, resolution 16ns, wraps every 35791556599ns
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204240055590.9383@angie.orcam.me.uk
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/time/sched_clock.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index b1b9b12899f5..ee07f3ac1e5b 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -8,6 +8,7 @@
#include <linux/jiffies.h>
#include <linux/ktime.h>
#include <linux/kernel.h>
+#include <linux/math.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
@@ -199,11 +200,11 @@ sched_clock_register(u64 (*read)(void), int bits, unsigned long rate)
r = rate;
if (r >= 4000000) {
- r /= 1000000;
+ r = DIV_ROUND_CLOSEST(r, 1000000);
r_unit = 'M';
} else {
if (r >= 1000) {
- r /= 1000;
+ r = DIV_ROUND_CLOSEST(r, 1000);
r_unit = 'k';
} else {
r_unit = ' ';
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH MANUALSEL 5.17 4/6] lib/irq_poll: Prevent softirq pending leak in irq_poll_cpu_dead()
2022-06-05 13:53 [PATCH MANUALSEL 5.17 1/6] x86/nmi: Make register_nmi_handler() more robust Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 2/6] genirq/irq_sim: Make the irq_work always run in hard irq context Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 3/6] time/sched_clock: Round the frequency reported to nearest rather than down Sasha Levin
@ 2022-06-05 13:53 ` Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 5/6] genirq/msi: Shutdown managed interrupts with unsatifiable affinities Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 6/6] x86/PCI: Add PIRQ routing table range checks Sasha Levin
4 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2022-06-05 13:53 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Sebastian Andrzej Siewior, Thomas Gleixner, Sasha Levin
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Upstream commit 75d8cce128c516fe6cf4b8683e8fe1a59e919902 ]
irq_poll_cpu_dead() pulls the blk_cpu_iopoll backlog from the dead CPU and
raises the POLL softirq with __raise_softirq_irqoff() on the CPU it is
running on. That just sets the bit in the pending softirq mask.
This means the handling of the softirq is delayed until the next interrupt
or a local_bh_disable/enable() pair. As a consequence the CPU on which this
code runs can reach idle with the POLL softirq pending, which triggers a
warning in the NOHZ idle code.
Add a local_bh_disable/enable() pair around the interrupts disabled section
in irq_poll_cpu_dead(). local_bh_enable will handle the pending softirq.
[tglx: Massaged changelog and comment]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87k0bxgl27.ffs@tglx
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
lib/irq_poll.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/lib/irq_poll.c b/lib/irq_poll.c
index 2f17b488d58e..2d5329a42105 100644
--- a/lib/irq_poll.c
+++ b/lib/irq_poll.c
@@ -188,14 +188,18 @@ EXPORT_SYMBOL(irq_poll_init);
static int irq_poll_cpu_dead(unsigned int cpu)
{
/*
- * If a CPU goes away, splice its entries to the current CPU
- * and trigger a run of the softirq
+ * If a CPU goes away, splice its entries to the current CPU and
+ * set the POLL softirq bit. The local_bh_disable()/enable() pair
+ * ensures that it is handled. Otherwise the current CPU could
+ * reach idle with the POLL softirq pending.
*/
+ local_bh_disable();
local_irq_disable();
list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
this_cpu_ptr(&blk_cpu_iopoll));
__raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
local_irq_enable();
+ local_bh_enable();
return 0;
}
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH MANUALSEL 5.17 5/6] genirq/msi: Shutdown managed interrupts with unsatifiable affinities
2022-06-05 13:53 [PATCH MANUALSEL 5.17 1/6] x86/nmi: Make register_nmi_handler() more robust Sasha Levin
` (2 preceding siblings ...)
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 4/6] lib/irq_poll: Prevent softirq pending leak in irq_poll_cpu_dead() Sasha Levin
@ 2022-06-05 13:53 ` Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 6/6] x86/PCI: Add PIRQ routing table range checks Sasha Levin
4 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2022-06-05 13:53 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Marc Zyngier, John Garry, David Decotigny, Thomas Gleixner, Sasha Levin
From: Marc Zyngier <maz@kernel.org>
[ Upstream commit d802057c7c553ad426520a053da9f9fe08e2c35a ]
When booting with maxcpus=<small number>, interrupt controllers
such as the GICv3 ITS may not be able to satisfy the affinity of
some managed interrupts, as some of the HW resources are simply
not available.
The same thing happens when loading a driver using managed interrupts
while CPUs are offline.
In order to deal with this, do not try to activate such interrupt
if there is no online CPU capable of handling it. Instead, place
it in shutdown state. Once a capable CPU shows up, it will be
activated.
Reported-by: John Garry <john.garry@huawei.com>
Reported-by: David Decotigny <ddecotig@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20220405185040.206297-2-maz@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/irq/msi.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 2bdfce5edafd..a9ee535293eb 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -818,6 +818,21 @@ static int msi_init_virq(struct irq_domain *domain, int virq, unsigned int vflag
irqd_clr_can_reserve(irqd);
if (vflags & VIRQ_NOMASK_QUIRK)
irqd_set_msi_nomask_quirk(irqd);
+
+ /*
+ * If the interrupt is managed but no CPU is available to
+ * service it, shut it down until better times. Note that
+ * we only do this on the !RESERVE path as x86 (the only
+ * architecture using this flag) deals with this in a
+ * different way by using a catch-all vector.
+ */
+ if ((vflags & VIRQ_ACTIVATE) &&
+ irqd_affinity_is_managed(irqd) &&
+ !cpumask_intersects(irq_data_get_affinity_mask(irqd),
+ cpu_online_mask)) {
+ irqd_set_managed_shutdown(irqd);
+ return 0;
+ }
}
if (!(vflags & VIRQ_ACTIVATE))
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH MANUALSEL 5.17 6/6] x86/PCI: Add PIRQ routing table range checks
2022-06-05 13:53 [PATCH MANUALSEL 5.17 1/6] x86/nmi: Make register_nmi_handler() more robust Sasha Levin
` (3 preceding siblings ...)
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 5/6] genirq/msi: Shutdown managed interrupts with unsatifiable affinities Sasha Levin
@ 2022-06-05 13:53 ` Sasha Levin
4 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2022-06-05 13:53 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Maciej W. Rozycki, Thomas Gleixner, Sasha Levin, bhelgaas, mingo,
bp, dave.hansen, x86, linux-pci
From: "Maciej W. Rozycki" <macro@orcam.me.uk>
[ Upstream commit 5d64089aa4a5bd3d7e00e3d6ddf4943dd34627b3 ]
Verify that the PCI IRQ Routing Table header as well as individual slot
entries are all wholly contained within the BIOS memory area. Do not
even call the checksum calculator if the header would overrun the area
and then bail out early if any slot would.
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2203301735510.22465@angie.orcam.me.uk
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/pci/irq.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index 97b63e35e152..13513003303e 100644
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -68,7 +68,8 @@ void (*pcibios_disable_irq)(struct pci_dev *dev) = pirq_disable_irq;
* and perform checksum verification.
*/
-static inline struct irq_routing_table *pirq_check_routing_table(u8 *addr)
+static inline struct irq_routing_table *pirq_check_routing_table(u8 *addr,
+ u8 *limit)
{
struct irq_routing_table *rt;
int i;
@@ -78,7 +79,8 @@ static inline struct irq_routing_table *pirq_check_routing_table(u8 *addr)
if (rt->signature != PIRQ_SIGNATURE ||
rt->version != PIRQ_VERSION ||
rt->size % 16 ||
- rt->size < sizeof(struct irq_routing_table))
+ rt->size < sizeof(struct irq_routing_table) ||
+ (limit && rt->size > limit - addr))
return NULL;
sum = 0;
for (i = 0; i < rt->size; i++)
@@ -99,17 +101,22 @@ static inline struct irq_routing_table *pirq_check_routing_table(u8 *addr)
static struct irq_routing_table * __init pirq_find_routing_table(void)
{
+ u8 * const bios_start = (u8 *)__va(0xf0000);
+ u8 * const bios_end = (u8 *)__va(0x100000);
u8 *addr;
struct irq_routing_table *rt;
if (pirq_table_addr) {
- rt = pirq_check_routing_table((u8 *) __va(pirq_table_addr));
+ rt = pirq_check_routing_table((u8 *)__va(pirq_table_addr),
+ NULL);
if (rt)
return rt;
printk(KERN_WARNING "PCI: PIRQ table NOT found at pirqaddr\n");
}
- for (addr = (u8 *) __va(0xf0000); addr < (u8 *) __va(0x100000); addr += 16) {
- rt = pirq_check_routing_table(addr);
+ for (addr = bios_start;
+ addr < bios_end - sizeof(struct irq_routing_table);
+ addr += 16) {
+ rt = pirq_check_routing_table(addr, bios_end);
if (rt)
return rt;
}
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-06-05 13:55 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2022-06-05 13:53 [PATCH MANUALSEL 5.17 1/6] x86/nmi: Make register_nmi_handler() more robust Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 2/6] genirq/irq_sim: Make the irq_work always run in hard irq context Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 3/6] time/sched_clock: Round the frequency reported to nearest rather than down Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 4/6] lib/irq_poll: Prevent softirq pending leak in irq_poll_cpu_dead() Sasha Levin
2022-06-05 13:53 ` [PATCH MANUALSEL 5.17 5/6] genirq/msi: Shutdown managed interrupts with unsatifiable affinities Sasha Levin
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