Hi Lukas, Thanks for putting this together. On 2 January 2017 at 10:24, Lukas Wunner <lukas@xxxxxxxxx> wrote: > When disassembling the EFI stub I noticed that GUIDs and efi_char16_t > strings are not placed in rodata but generated on the stack at runtime. > GUIDs occupy up to 80 bytes of text instead of just 16 bytes rodata > which annoyed me enough to go down the rabbit hole of fixing it. > This series constifies all GUIDs and EFI-related strings I could find. > > The most important patch is [10/10] to constify the EFI_GUID() macro. > This has to be at the end of the series to avoid compiler warnings. > Reviewers may want to read its commit message first as it contains > background information. In particular it explains why this series > only fixes the kernel side of things. Additional work is necessary > on the compiler side to actually have all the GUIDs and strings in > rodata. At the moment both gcc and clang achieve that only partially. > > Ard Biesheuvel expressed an interest in these patches in November but > stressed the importance that arguments to EFI boot/runtime/protocol > services may only be declared const if the spec marks them "IN": > https://lkml.org/lkml/2016/11/21/459 > Indeed. I think it is reasonable to infer constness from the IN (and not OUT) annotation of by-reference arguments. In general, I think the complete lack of distinction between read-write and read-execute is a huge oversight, and anything that improves the situation on either side of the firmware-OS boundary is a welcome change IMO. > Hence I've split the series by boot/runtime/protocol services to allow > for easy verification of this fact. Constification of GetVariable() / > SetVariable() is further split in one patch for the function signatures > and another for the actual arguments because changing the function > signatures is quite involved in this case. > > efi.git/next needs to be rebased on v4.10-rc1 before this series can be > applied because it requires commits f6697df36bdf ("x86/efi: Prevent mixed > mode boot corruption with CONFIG_VMAP_STACK=y") and 2fbadc3002c5 > ("arm/arm64: xen: Move shared architecture headers to include/xen/arm"). > > Unfortunately I was not able to compile-test on ia64, there's no cross- > compiler package available on Debian. :-( I did not receive complaints > from 0-day, so I'm cautiously optimistic that I didn't cause breakage > there. > > I've pushed the patches to GitHub to ease reviewing/fetching: > https://github.com/l1k/linux/commits/efi_const_v1 > > Thanks, > > Lukas > > > Ard Biesheuvel (1): > efi: use typed function pointers for runtime services table > > Lukas Wunner (9): > efi: Constify GetVariable() / SetVariable() signatures > efi: Constify GetVariable() / SetVariable() arguments > efi: Constify HandleProtocol() / LocateHandle() / LocateProtocol() > efi: Constify InstallConfigurationTable() > efi: Constify EFI_FILE_PROTOCOL.GetInfo() > efi: Constify EFI_RNG_PROTOCOL.GetRNG() > efi: Constify EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL.OutputString() > efi: Constify efi_guidcmp() arguments > uuid: Constify UUID compound literals > > arch/ia64/kernel/efi.c | 24 ++++------ > arch/x86/boot/compressed/eboot.c | 50 ++++++++++----------- > arch/x86/include/asm/xen/interface.h | 1 + > arch/x86/platform/efi/efi_64.c | 18 ++++---- > arch/x86/platform/efi/quirks.c | 2 +- > drivers/firmware/efi/efi-pstore.c | 10 ++--- > drivers/firmware/efi/efibc.c | 3 +- > drivers/firmware/efi/libstub/arm-stub.c | 17 +++---- > drivers/firmware/efi/libstub/arm32-stub.c | 2 +- > drivers/firmware/efi/libstub/efi-stub-helper.c | 7 ++- > drivers/firmware/efi/libstub/efistub.h | 2 +- > drivers/firmware/efi/libstub/fdt.c | 3 +- > drivers/firmware/efi/libstub/gop.c | 12 +++-- > drivers/firmware/efi/libstub/random.c | 16 +++---- > drivers/firmware/efi/runtime-wrappers.c | 15 ++++--- > drivers/firmware/google/gsmi.c | 10 ++--- > drivers/infiniband/hw/hfi1/efivar.c | 6 +-- > drivers/scsi/isci/probe_roms.c | 2 +- > drivers/xen/efi.c | 12 ++--- > include/linux/efi.h | 61 ++++++++++++++------------ > include/uapi/linux/uuid.h | 4 +- > include/xen/arm/interface.h | 1 + > include/xen/interface/platform.h | 11 ++++- > include/xen/xen-ops.h | 12 ++--- > 24 files changed, 143 insertions(+), 158 deletions(-) > > -- > 2.11.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
