On Thu, Apr 30, 2020 at 7:03 AM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Thu, Apr 30, 2020 at 1:41 AM Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > > > > With the above realizations the name "mcsafe" is no longer accurate and > > copy_safe() is proposed as its replacement. x86 grows a copy_safe_fast() > > implementation as a default implementation that is independent of > > detecting the presence of x86-MCA. > > How is this then different from "probe_kernel_read()" and > "probe_kernel_write()"? Other than the obvious "it does it for both > reads and writes"? > > IOW, wouldn't it be sensible to try to match the naming and try to > find some unified model for all these things? > > "probe_kernel_copy()"? I don't like this whole concept. If I'm going to copy from memory that might be bad but is at least a valid pointer, I want a function to do this. If I'm going to copy from memory that might be entirely bogus, that's a different operation. In other words, if I'm writing e.g. filesystem that is touching get_user_pages()'d persistent memory, I don't want to panic if the memory fails, but I do want at least a very loud warning if I follow a wild pointer. So I think that probe_kernel_copy() is not a valid replacement for memcpy_mcsafe(). --Andy
