Messages in this thread | | | Date | Fri, 28 Jul 2017 19:26:03 +0800 | From | Baoquan He <> | Subject | Re: [PATCH v6 RESEND] x86/boot/KASLR: Restrict kernel to be randomized in mirror regions |
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Hi Matt,
On 07/28/17 at 11:55am, Ingo Molnar wrote: > > * Matt Fleming <matt@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).
I can make a efi_memdesc_ptr(efi, i) wrapper as Ingo suggested and use it here if you agree. Seems it might be not good to add another for_each_efi_memory_desc_xxxx wrapper since there are different memmap data structures in x86 boot and in general efi libstub. Or any other idea?
Thanks Baoquan
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