[PATCH] genirq/irqdomain: Make sure all irq domain flags are distinct

[PATCH] genirq/irqdomain: Make sure all irq domain flags are distinct

[Zenghui Yu]

This was noticed when printing debugfs for MSIs on my ARM64 server.
The new dstate IRQD_MSI_NOMASK_QUIRK came out surprisingly while it
should only be the x86 stuff for the time being...

It's the overlap in irqdomain flags which leads to this confusion.
(1 << 1) might be a good choice for old IRQ_DOMAIN_NAME_ALLOCATED,
use it to avoid this overlap.

Fixes: 6f1a4891a592 ("x86/apic/msi: Plug non-maskable MSI affinity race")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
---
 include/linux/irqdomain.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index b2d47571ab67..8d062e86d954 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -192,7 +192,7 @@ enum {
 	IRQ_DOMAIN_FLAG_HIERARCHY	= (1 << 0),
 
 	/* Irq domain name was allocated in __irq_domain_add() */
-	IRQ_DOMAIN_NAME_ALLOCATED	= (1 << 6),
+	IRQ_DOMAIN_NAME_ALLOCATED	= (1 << 1),
 
 	/* Irq domain is an IPI domain with virq per cpu */
 	IRQ_DOMAIN_FLAG_IPI_PER_CPU	= (1 << 2),
-- 
2.19.1

Re: [PATCH] genirq/irqdomain: Make sure all irq domain flags are distinct

[Marc Zyngier]

On 2020-02-21 02:07, Zenghui Yu wrote:
> This was noticed when printing debugfs for MSIs on my ARM64 server.
> The new dstate IRQD_MSI_NOMASK_QUIRK came out surprisingly while it
> should only be the x86 stuff for the time being...
> 
> It's the overlap in irqdomain flags which leads to this confusion.
> (1 << 1) might be a good choice for old IRQ_DOMAIN_NAME_ALLOCATED,
> use it to avoid this overlap.
> 
> Fixes: 6f1a4891a592 ("x86/apic/msi: Plug non-maskable MSI affinity 
> race")

To be fair, the real source of the bug is this:

6a6544e520abe ("genirq/irqdomain: Remove auto-recursive hierarchy 
support")

> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
> ---
>  include/linux/irqdomain.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index b2d47571ab67..8d062e86d954 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -192,7 +192,7 @@ enum {
>  	IRQ_DOMAIN_FLAG_HIERARCHY	= (1 << 0),
> 
>  	/* Irq domain name was allocated in __irq_domain_add() */
> -	IRQ_DOMAIN_NAME_ALLOCATED	= (1 << 6),
> +	IRQ_DOMAIN_NAME_ALLOCATED	= (1 << 1),
> 
>  	/* Irq domain is an IPI domain with virq per cpu */
>  	IRQ_DOMAIN_FLAG_IPI_PER_CPU	= (1 << 2),

Acked-by: Marc Zyngier <maz@kernel.org>

Thomas, do you mind picking this one up, as I don't have anything
else for the time being?


         M.
-- 
Jazz is not dead. It just smells funny...

[tip: irq/urgent] genirq/irqdomain: Make sure all irq domain flags are distinct

[tip-bot2 for Zenghui Yu]

The following commit has been merged into the irq/urgent branch of tip:

Commit-ID:     2546287c5fb363a0165933ae2181c92f03e701d0
Gitweb:        https://git.kernel.org/tip/2546287c5fb363a0165933ae2181c92f03e701d0
Author:        Zenghui Yu <yuzenghui@huawei.com>
AuthorDate:    Fri, 21 Feb 2020 10:07:25 +08:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Fri, 21 Feb 2020 11:29:15 +01:00

genirq/irqdomain: Make sure all irq domain flags are distinct

This was noticed when printing debugfs for MSIs on my ARM64 server.  The
new dstate IRQD_MSI_NOMASK_QUIRK came out surprisingly while it should only
be the x86 stuff for the time being...

The new MSI quirk flag uses the same bit as IRQ_DOMAIN_NAME_ALLOCATED which
is oddly defined as bit 6 for no good reason.

Switch it to the non used bit 1.

Fixes: 6f1a4891a592 ("x86/apic/msi: Plug non-maskable MSI affinity race")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200221020725.2038-1-yuzenghui@huawei.com
---
 include/linux/irqdomain.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index b2d4757..8d062e8 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -192,7 +192,7 @@ enum {
 	IRQ_DOMAIN_FLAG_HIERARCHY	= (1 << 0),
 
 	/* Irq domain name was allocated in __irq_domain_add() */
-	IRQ_DOMAIN_NAME_ALLOCATED	= (1 << 6),
+	IRQ_DOMAIN_NAME_ALLOCATED	= (1 << 1),
 
 	/* Irq domain is an IPI domain with virq per cpu */
 	IRQ_DOMAIN_FLAG_IPI_PER_CPU	= (1 << 2),

Re: [PATCH] genirq/irqdomain: Make sure all irq domain flags are distinct

[Thomas Gleixner]

Marc Zyngier <maz@kernel.org> writes:
> On 2020-02-21 02:07, Zenghui Yu wrote:
>> Fixes: 6f1a4891a592 ("x86/apic/msi: Plug non-maskable MSI affinity 
>> race")
>
> To be fair, the real source of the bug is this:
>
> 6a6544e520abe ("genirq/irqdomain: Remove auto-recursive hierarchy 
> support")

Yes, but up to the MSI commit it was not a problem :)