powerpc/lpar: Don't crash on H_PROTECT errors

Michael Ellerman mpe at ellerman.id.au
Tue Mar 1 10:01:41 AEDT 2016


On Mon, 2016-29-02 at 11:52:32 UTC, Anshuman Khandual wrote:
> There are certain condition in which H_PROTECT can return error code
> other than H_NOT_FOUND and H_SUCCESS. One such being an attempt to
> update an hpte owned by adjunct partition. Return 0 in that case so
> that user space will retry the access. In adjunct case this mean we
> will not make much progress in the user space. But atleast we get a
> chance to kill the task and avoid taking down the entire box.

Why is it OK to do nothing and return 0?

The function's contract is that it either does the update or returns -1, you
can't change that without auditing all callers - and describing that in the
change log.

cheers


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