* [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text
@ 2020-04-23 9:36 Will Deacon
2020-04-23 9:49 ` Mark Rutland
2020-04-23 9:55 ` Catalin Marinas
0 siblings, 2 replies; 3+ messages in thread
From: Will Deacon @ 2020-04-23 9:36 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: Mark Rutland, Will Deacon, kernel-team, Catalin Marinas
Although we require that the loaded kernel Image has been cleaned to the
PoC, we neglect to spell out the state of the I-cache. Although this
should be reasonably obvious, it doesn't hurt to be explicit.
Require that the I-cache doesn't hold any stale entries for the kernel
Image at boot.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
Documentation/arm64/booting.rst | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst
index a3f1a47b6f1c..d063c05d5fb0 100644
--- a/Documentation/arm64/booting.rst
+++ b/Documentation/arm64/booting.rst
@@ -173,7 +173,8 @@ Before jumping into the kernel, the following conditions must be met:
- Caches, MMUs
The MMU must be off.
- Instruction cache may be on or off.
+ The instruction cache may be on or off, and must not hold any stale
+ entries corresponding to the loaded kernel image.
The address range corresponding to the loaded kernel image must be
cleaned to the PoC. In the presence of a system cache or other
coherent masters with caches enabled, this will typically require
--
2.26.1.301.g55bc3eb7cb9-goog
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^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text
2020-04-23 9:36 [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text Will Deacon
@ 2020-04-23 9:49 ` Mark Rutland
2020-04-23 9:55 ` Catalin Marinas
1 sibling, 0 replies; 3+ messages in thread
From: Mark Rutland @ 2020-04-23 9:49 UTC (permalink / raw)
To: Will Deacon; +Cc: Catalin Marinas, kernel-team, linux-arm-kernel
On Thu, Apr 23, 2020 at 10:36:58AM +0100, Will Deacon wrote:
> Although we require that the loaded kernel Image has been cleaned to the
> PoC, we neglect to spell out the state of the I-cache. Although this
> should be reasonably obvious, it doesn't hurt to be explicit.
>
> Require that the I-cache doesn't hold any stale entries for the kernel
> Image at boot.
>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Will Deacon <will@kernel.org>
This was certianly the intent, so:
Acked-by: Mark Rutland <mark.rutland@arm.com>
Thanks,
Mark.
> ---
> Documentation/arm64/booting.rst | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst
> index a3f1a47b6f1c..d063c05d5fb0 100644
> --- a/Documentation/arm64/booting.rst
> +++ b/Documentation/arm64/booting.rst
> @@ -173,7 +173,8 @@ Before jumping into the kernel, the following conditions must be met:
> - Caches, MMUs
>
> The MMU must be off.
> - Instruction cache may be on or off.
> + The instruction cache may be on or off, and must not hold any stale
> + entries corresponding to the loaded kernel image.
> The address range corresponding to the loaded kernel image must be
> cleaned to the PoC. In the presence of a system cache or other
> coherent masters with caches enabled, this will typically require
> --
> 2.26.1.301.g55bc3eb7cb9-goog
>
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linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text
2020-04-23 9:36 [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text Will Deacon
2020-04-23 9:49 ` Mark Rutland
@ 2020-04-23 9:55 ` Catalin Marinas
1 sibling, 0 replies; 3+ messages in thread
From: Catalin Marinas @ 2020-04-23 9:55 UTC (permalink / raw)
To: Will Deacon; +Cc: Mark Rutland, kernel-team, linux-arm-kernel
On Thu, Apr 23, 2020 at 10:36:58AM +0100, Will Deacon wrote:
> Although we require that the loaded kernel Image has been cleaned to the
> PoC, we neglect to spell out the state of the I-cache. Although this
> should be reasonably obvious, it doesn't hurt to be explicit.
>
> Require that the I-cache doesn't hold any stale entries for the kernel
> Image at boot.
>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-04-23 9:36 [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text Will Deacon
2020-04-23 9:49 ` Mark Rutland
2020-04-23 9:55 ` Catalin Marinas
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