On Thu, Apr 25, 2019 at 08:14:52AM -0700, Yu-cheng Yu wrote: > On Thu, 2019-04-25 at 12:02 +0100, Dave Martin wrote: > > On Mon, Nov 19, 2018 at 01:48:05PM -0800, Yu-cheng Yu wrote: > > > Look in .note.gnu.property of an ELF file and check if Shadow Stack needs > > > to be enabled for the task. > > > > What's the status of this series? I don't see anything in linux-next > > yet. > > > > For describing ELF features, Arm has recently adopted > > NT_GNU_PROPERTY_TYPE_0, with properties closely modelled on > > GNU_PROPERTY_X86_FEATURE_1_AND etc. [1] > > > > So, arm64 will be need something like this patch for supporting new > > features (such as the Branch Target Identification feature of ARMv8.5-A > > [2]). > > > > If this series isn't likely to merge soon, can we split this patch into > > generic and x86-specific parts and handle them separately? > > > > It would be good to see the generic ELF note parsing move to common > > code -- I'll take a look and comment in more detail. > > Yes, I will work on that. Thanks. I may try to hack something in the meantime based on your patch. One other question: according to the draft spec at https://github.com/hjl-tools/linux-abi/wiki/Linux-Extensions-to-gABI, it looks like the .note.gnu.property section is supposed to be marked with SHF_ALLOC in object files. I think that means that the linker will map it with a PT_LOAD entry in the program header table in addition to the PT_NOTE that describes the location of the note. I need to check what the toolchain actually does. If so, can we simply rely on the notes being already mapped, rather than needing to do additional I/O on the ELF file to fetch the notes? [...] Cheers ---Dave
