On 07/28/17 at 11:55am, Ingo Molnar wrote: > > * Matt Fleming <m...@codeblueprint.co.uk> wrote: > > > On Fri, 21 Jul, at 09:19:56PM, Baoquan He wrote: > > > > > > There are places where the efi map is getting and used like this. E.g > > > in efi_high_alloc() of drivers/firmware/efi/libstub/efi-stub-helper.c. > > > EFI developers worry the size of efi_memory_desc_t could not be the same > > > as e->efi_memdesc_size? > > > > > > Hi Matt, > > > > > > Could you help have a look at this? > > > > You're exactly right. The code guards against the size of the > > efi_memory_desc_t struct changing. The UEFI spec says to traverse the > > memory map this way. > > This is not obvious and looks pretty ugly as well, and open coded in several > places. > > At minimum we should have an efi_memdesc_ptr(efi, i) wrapper inline (or so) > that > gives us the entry pointer, plus a comment that points out that > ->memdesc_size > might not be equal to sizeof(efi_memory_memdesc_t).
Seems for_each_efi_memory_desc_in_map() can be used to hide the calculation and type cast each time for better memmap loop.
