On Mon, Dec 09, 2024 at 10:42:57AM +0800, Tong Tiangen wrote: > The copy_mc_to_kernel() helper is memory copy implementation that handles > source exceptions. It can be used in memory copy scenarios that tolerate > hardware memory errors(e.g: pmem_read/dax_copy_to_iter). > > Currently, only x86 and ppc support this helper, Add this for ARM64 as > well, if ARCH_HAS_COPY_MC is defined, by implementing copy_mc_to_kernel() > and memcpy_mc() functions. > > Because there is no caller-saved GPR is available for saving "bytes not > copied" in memcpy(), the memcpy_mc() is referenced to the implementation > of copy_from_user(). In addition, the fixup of MOPS insn is not considered > at present. Same question as on the previous patch, can we not avoid the memcpy() duplication if the only difference is entries in the exception table? IIUC in patch 2 fixup_exception() even ignores the new type. The error must come on the do_sea() path. -- Catalin
