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[PATCH] xen/arm: vgic: Add missing 'U' in VGIC_ICFG_MASK for shifted constant

Henry Wang posted 1 patch 2 years, 7 months ago
Patches applied successfully (tree, apply log)
git fetch https://gitlab.com/xen-project/patchew/xen tags/patchew/20230629221800.1478182-1-Henry.Wang@arm.com
xen/arch/arm/vgic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[PATCH] xen/arm: vgic: Add missing 'U' in VGIC_ICFG_MASK for shifted constant
Posted by Henry Wang 2 years, 7 months ago 
With UBSAN on some arm64 platforms, e.g. FVP_Base_RevC-2xAEMvA, the
following splat will be printed while Dom0 is booting:
```
(XEN) ==================================================================
(XEN) UBSAN: Undefined behaviour in arch/arm/vgic.c:372:15
(XEN) left shift of 1 by 31 places cannot be represented in type 'int'
(XEN) Xen WARN at common/ubsan/ubsan.c:172
(XEN) ----[ Xen-4.18-unstable  arm64  debug=y ubsan=y  Not tainted ]----
```

This is because there is a device node in the device tree with 0xf
as the interrupts property. Example of the device tree node is shown
below:
```
ethernet@202000000 {
    compatible = "smsc,lan91c111";
    reg = <0x2 0x2000000 0x10000>;
    interrupts = <0xf>;
};
```
and this value is passed to vgic_get_virq_type() as "index" then "intr"
in VGIC_ICFG_MASK.

Add the missing 'U' in VGIC_ICFG_MASK as a fix, and this should also
addressing MISRA Rule 7.2:

    A "u" or "U" suffix shall be applied to all integer constants that
    are represented in an unsigned type

Signed-off-by: Henry Wang <Henry.Wang@arm.com>
---
This patch should be based on top of Julien's series
"xen/arm: Enable UBSAN support" to test.
---
 xen/arch/arm/vgic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index c61c68870c..97d6f61066 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -358,7 +358,7 @@ void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n)
     }
 }
 
-#define VGIC_ICFG_MASK(intr) (1 << ((2 * ((intr) % 16)) + 1))
+#define VGIC_ICFG_MASK(intr) (1U << ((2 * ((intr) % 16)) + 1))
 
 /* The function should be called with the rank lock taken */
 static inline unsigned int vgic_get_virq_type(struct vcpu *v, int n, int index)
-- 
2.25.1
Re: [PATCH] xen/arm: vgic: Add missing 'U' in VGIC_ICFG_MASK for shifted constant
Posted by Stefano Stabellini 2 years, 7 months ago 
On Fri, 30 Jun 2023, Henry Wang wrote:
> With UBSAN on some arm64 platforms, e.g. FVP_Base_RevC-2xAEMvA, the
> following splat will be printed while Dom0 is booting:
> ```
> (XEN) ==================================================================
> (XEN) UBSAN: Undefined behaviour in arch/arm/vgic.c:372:15
> (XEN) left shift of 1 by 31 places cannot be represented in type 'int'
> (XEN) Xen WARN at common/ubsan/ubsan.c:172
> (XEN) ----[ Xen-4.18-unstable  arm64  debug=y ubsan=y  Not tainted ]----
> ```
> 
> This is because there is a device node in the device tree with 0xf
> as the interrupts property. Example of the device tree node is shown
> below:
> ```
> ethernet@202000000 {
>     compatible = "smsc,lan91c111";
>     reg = <0x2 0x2000000 0x10000>;
>     interrupts = <0xf>;
> };
> ```
> and this value is passed to vgic_get_virq_type() as "index" then "intr"
> in VGIC_ICFG_MASK.
> 
> Add the missing 'U' in VGIC_ICFG_MASK as a fix, and this should also
> addressing MISRA Rule 7.2:
> 
>     A "u" or "U" suffix shall be applied to all integer constants that
>     are represented in an unsigned type
> 
> Signed-off-by: Henry Wang <Henry.Wang@arm.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
> This patch should be based on top of Julien's series
> "xen/arm: Enable UBSAN support" to test.
> ---
>  xen/arch/arm/vgic.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index c61c68870c..97d6f61066 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -358,7 +358,7 @@ void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n)
>      }
>  }
>  
> -#define VGIC_ICFG_MASK(intr) (1 << ((2 * ((intr) % 16)) + 1))
> +#define VGIC_ICFG_MASK(intr) (1U << ((2 * ((intr) % 16)) + 1))
>  
>  /* The function should be called with the rank lock taken */
>  static inline unsigned int vgic_get_virq_type(struct vcpu *v, int n, int index)
> -- 
> 2.25.1
>
Re: [PATCH] xen/arm: vgic: Add missing 'U' in VGIC_ICFG_MASK for shifted constant
Posted by Julien Grall 2 years, 7 months ago 
Hi,

On 30/06/2023 00:03, Stefano Stabellini wrote:
> On Fri, 30 Jun 2023, Henry Wang wrote:
>> With UBSAN on some arm64 platforms, e.g. FVP_Base_RevC-2xAEMvA, the
>> following splat will be printed while Dom0 is booting:
>> ```
>> (XEN) ==================================================================
>> (XEN) UBSAN: Undefined behaviour in arch/arm/vgic.c:372:15
>> (XEN) left shift of 1 by 31 places cannot be represented in type 'int'
>> (XEN) Xen WARN at common/ubsan/ubsan.c:172
>> (XEN) ----[ Xen-4.18-unstable  arm64  debug=y ubsan=y  Not tainted ]----
>> ```
>>
>> This is because there is a device node in the device tree with 0xf
>> as the interrupts property. Example of the device tree node is shown
>> below:
>> ```
>> ethernet@202000000 {
>>      compatible = "smsc,lan91c111";
>>      reg = <0x2 0x2000000 0x10000>;
>>      interrupts = <0xf>;
>> };
>> ```
>> and this value is passed to vgic_get_virq_type() as "index" then "intr"
>> in VGIC_ICFG_MASK.
>>
>> Add the missing 'U' in VGIC_ICFG_MASK as a fix, and this should also
>> addressing MISRA Rule 7.2:
>>
>>      A "u" or "U" suffix shall be applied to all integer constants that
>>      are represented in an unsigned type
>>
>> Signed-off-by: Henry Wang <Henry.Wang@arm.com>
> 
> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

It is now committed.

Cheers,

-- 
Julien Grall
Re: [PATCH] xen/arm: vgic: Add missing 'U' in VGIC_ICFG_MASK for shifted constant
Posted by Hongda Deng 2 years, 7 months ago 
On 2023/6/30 07:03, Stefano Stabellini wrote:
> On Fri, 30 Jun 2023, Henry Wang wrote:
>> With UBSAN on some arm64 platforms, e.g. FVP_Base_RevC-2xAEMvA, the
>> following splat will be printed while Dom0 is booting:
>> ```
>> (XEN) ==================================================================
>> (XEN) UBSAN: Undefined behaviour in arch/arm/vgic.c:372:15
>> (XEN) left shift of 1 by 31 places cannot be represented in type 'int'
>> (XEN) Xen WARN at common/ubsan/ubsan.c:172
>> (XEN) ----[ Xen-4.18-unstable  arm64  debug=y ubsan=y  Not tainted ]----
>> ```
>>
>> This is because there is a device node in the device tree with 0xf
>> as the interrupts property. Example of the device tree node is shown
>> below:
>> ```
>> ethernet@202000000 {
>>      compatible = "smsc,lan91c111";
>>      reg = <0x2 0x2000000 0x10000>;
>>      interrupts = <0xf>;
>> };
>> ```
>> and this value is passed to vgic_get_virq_type() as "index" then "intr"
>> in VGIC_ICFG_MASK.
>>
>> Add the missing 'U' in VGIC_ICFG_MASK as a fix, and this should also
>> addressing MISRA Rule 7.2:
>>
>>      A "u" or "U" suffix shall be applied to all integer constants that
>>      are represented in an unsigned type
>>
>> Signed-off-by: Henry Wang <Henry.Wang@arm.com>
> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
>
>
>> ---
>> This patch should be based on top of Julien's series
>> "xen/arm: Enable UBSAN support" to test.
>> ---
>>   xen/arch/arm/vgic.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
>> index c61c68870c..97d6f61066 100644
>> --- a/xen/arch/arm/vgic.c
>> +++ b/xen/arch/arm/vgic.c
>> @@ -358,7 +358,7 @@ void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n)
>>       }
>>   }
>>   
>> -#define VGIC_ICFG_MASK(intr) (1 << ((2 * ((intr) % 16)) + 1))
>> +#define VGIC_ICFG_MASK(intr) (1U << ((2 * ((intr) % 16)) + 1))
>>   
>>   /* The function should be called with the rank lock taken */
>>   static inline unsigned int vgic_get_virq_type(struct vcpu *v, int n, int index)
>> -- 
>> 2.25.1
>>
Reviewed-by: Hongda Deng <hongda.deng@arm.com>

Patchew 2.1-devel-b67e4c2

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