From: Anton Ivanov
This is a fix for a very old UML bug which can be triggered with stock
UML. It takes a lot of effort to trigger it there because the
lseek()/read() | write() mechanics of the UBD driver implicitly sync the
memory all the time by hitting the appropriate barrier implementation
Am 26.09.2014 13:49, schrieb anton.iva...@kot-begemot.co.uk:
> From: Anton Ivanov
>
> This is a fix for a very old UML bug which can be triggered with stock
> UML. It takes a lot of effort to trigger it there because the
> lseek()/read() | write() mechanics of the UBD driver implicitly sync the
On 26/09/14 12:56, Richard Weinberger wrote:
[snip]
> +#ifdef CONFIG_X86_32
> + alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2);
> +#else
> + asm volatile("mfence":::"memory");
> +#endif
> Why not mb()?
> I'm not sure whether this fix is correct.
Looking at the actual d
On 26/09/14 12:56, Richard Weinberger wrote:
> Am 26.09.2014 13:49, schrieb anton.iva...@kot-begemot.co.uk:
>> From: Anton Ivanov
>>
>> This is a fix for a very old UML bug which can be triggered with stock
>> UML. It takes a lot of effort to trigger it there because the
>> lseek()/read() | writ
