On 14/03/25 2:14 am, Matthew Wilcox wrote:
On Thu, Mar 13, 2025 at 11:44:14PM +0530, Dev Jain wrote:
Since pxd_clear_bad() is an operation changing the state of the page tables,
we should call arch_sync_kernel_mappings() post this.
Could you explain why? What effect does not calling
arch_sync_kernel_mappings() have in this case?
Apologies, I again forgot to explain the userspace effect.
I just found this by code inspection, using the logic the fixes commit
uses: we should sync when we change the pxd.
The question I have been pondering on is, what is the use of the
pxd_bad() macros, when do we actually hit a bad state, and why don't we
just trigger a BUG when we hit pxd_bad()?
