Messages in this thread | | | Date | Fri, 20 Jan 2023 05:07:48 +0000 | From | Al Viro <> | Subject | Re: [PATCH v3 4/4] fs/sysv: Replace kmap() with kmap_local_page() |
| |
On Fri, Jan 20, 2023 at 04:54:51AM +0000, Matthew Wilcox wrote:
> > Sure, but... there's also this: > > > > static inline void __kunmap_local(const void *addr) > > { > > #ifdef ARCH_HAS_FLUSH_ON_KUNMAP > > kunmap_flush_on_unmap(addr); > > #endif > > } > > > > Are you sure that the guts of that thing will be happy with address that is not > > page-aligned? I've looked there at some point, got scared of parisc (IIRC) > > MMU details and decided not to rely upon that... > > Ugh, PA-RISC (the only implementor) definitely will flush the wrong > addresses. I think we should do this, as having bugs that only manifest > on one not-well-tested architecture seems Bad. > > static inline void __kunmap_local(const void *addr) > { > #ifdef ARCH_HAS_FLUSH_ON_KUNMAP > - kunmap_flush_on_unmap(addr); > + kunmap_flush_on_unmap(PAGE_ALIGN_DOWN(addr)); > #endif > }
PTR_ALIGN_DOWN(addr, PAGE_SIZE), perhaps?
| |