* [PATCH] x86/mtrr: Check if fixed MTRRs exist before saving them
@ 2024-01-05 16:37 Andi Kleen
2024-01-09 19:06 ` Thomas Gleixner
0 siblings, 1 reply; 4+ messages in thread
From: Andi Kleen @ 2024-01-05 16:37 UTC (permalink / raw)
To: x86; +Cc: linux-kernel, Andi Kleen
This one place forgot to check the fixed capability.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/kernel/cpu/mtrr/mtrr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c
index 767bf1c71aad..2a2fc14955cd 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.c
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.c
@@ -609,7 +609,7 @@ void mtrr_save_state(void)
{
int first_cpu;
- if (!mtrr_enabled())
+ if (!mtrr_enabled() || !mtrr_state.have_fixed)
return;
first_cpu = cpumask_first(cpu_online_mask);
--
2.43.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] x86/mtrr: Check if fixed MTRRs exist before saving them
2024-01-05 16:37 [PATCH] x86/mtrr: Check if fixed MTRRs exist before saving them Andi Kleen
@ 2024-01-09 19:06 ` Thomas Gleixner
2024-01-10 4:24 ` Andi Kleen
0 siblings, 1 reply; 4+ messages in thread
From: Thomas Gleixner @ 2024-01-09 19:06 UTC (permalink / raw)
To: Andi Kleen, x86; +Cc: linux-kernel
On Fri, Jan 05 2024 at 08:37, Andi Kleen wrote:
> This one place forgot to check the fixed capability.
What's the consequence of that missing check and shouldn't this have a
Fixes tag?
Thanks,
tglx
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] x86/mtrr: Check if fixed MTRRs exist before saving them
2024-01-09 19:06 ` Thomas Gleixner
@ 2024-01-10 4:24 ` Andi Kleen
2024-01-10 14:20 ` Thomas Gleixner
0 siblings, 1 reply; 4+ messages in thread
From: Andi Kleen @ 2024-01-10 4:24 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: x86, linux-kernel
On Tue, Jan 09, 2024 at 08:06:26PM +0100, Thomas Gleixner wrote:
> On Fri, Jan 05 2024 at 08:37, Andi Kleen wrote:
> > This one place forgot to check the fixed capability.
>
> What's the consequence of that missing chec
You get a WARN_ON for a WRMSR failing if you don't have the MSR.
> and shouldn't this have a Fixes tag?
It's more an ancient bug back dating back to my tenure in 2007, but here it is:
Fixes: 2b1f6278d77c ("[PATCH] x86: Save the MTRRs of the BSP before")
-Andi
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] x86/mtrr: Check if fixed MTRRs exist before saving them
2024-01-10 4:24 ` Andi Kleen
@ 2024-01-10 14:20 ` Thomas Gleixner
0 siblings, 0 replies; 4+ messages in thread
From: Thomas Gleixner @ 2024-01-10 14:20 UTC (permalink / raw)
To: Andi Kleen; +Cc: x86, linux-kernel
On Tue, Jan 09 2024 at 20:24, Andi Kleen wrote:
> On Tue, Jan 09, 2024 at 08:06:26PM +0100, Thomas Gleixner wrote:
>> On Fri, Jan 05 2024 at 08:37, Andi Kleen wrote:
>> > This one place forgot to check the fixed capability.
>>
>> What's the consequence of that missing chec
>
> You get a WARN_ON for a WRMSR failing if you don't have the MSR.
>
>> and shouldn't this have a Fixes tag?
>
> It's more an ancient bug back dating back to my tenure in 2007, but here it is:
>
> Fixes: 2b1f6278d77c ("[PATCH] x86: Save the MTRRs of the BSP before")
Care to send a V2 with a less meager changelog?
^ permalink raw reply [flat|nested] 4+ messages in thread
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2024-01-05 16:37 [PATCH] x86/mtrr: Check if fixed MTRRs exist before saving them Andi Kleen
2024-01-09 19:06 ` Thomas Gleixner
2024-01-10 4:24 ` Andi Kleen
2024-01-10 14:20 ` Thomas Gleixner
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