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Groups > linux.kernel > #1336909
| From | Andy Lutomirski <luto@amacapital.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 33/33] x86, pkeys: execute-only support |
| Date | 2016-02-18 01:50 +0100 |
| Message-ID | <r3kX8-5Re-25@gated-at.bofh.it> (permalink) |
| References | <r1t8t-3TO-3@gated-at.bofh.it> <r1t8v-3TO-39@gated-at.bofh.it> <r3hPA-3LD-27@gated-at.bofh.it> <r3iBY-4nq-23@gated-at.bofh.it> <r3jeF-4Do-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Feb 17, 2016 at 2:53 PM, Dave Hansen <dave@sr71.net> wrote: > On 02/17/2016 02:17 PM, Andy Lutomirski wrote: >>> > Is there a way to detect this feature's availability without userspace >>> > having to set up a segv handler and attempting to read a >>> > PROT_EXEC-only region? (i.e. cpu flag for protection keys, or a way to >>> > check the protection to see if PROT_READ got added automatically, >>> > etc?) >>> > >> We could add an HWCAP. > > I'll bite. What's an HWCAP? It's a CPU capability vector that's passed to every program as an auxv entry. On x86, ELF_HWCAP is useless (it's already fully used up for pointless purposes for CPUID stuff), but ELF_HWCAP2 could be added and a bit could be defined like HWCAP2_PROT_EXEC_ONLY. Some day, WRFSBASE, etc will be advertised via ELF_HWCAP2, I suspect. --Andy -- Andy Lutomirski AMA Capital Management, LLC
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[PATCH 33/33] x86, pkeys: execute-only support Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
Re: [PATCH 33/33] x86, pkeys: execute-only support Kees Cook <keescook@google.com> - 2016-02-17 22:30 +0100
Re: [PATCH 33/33] x86, pkeys: execute-only support Dave Hansen <dave@sr71.net> - 2016-02-17 22:40 +0100
Re: [PATCH 33/33] x86, pkeys: execute-only support Kees Cook <keescook@google.com> - 2016-02-17 22:40 +0100
Re: [PATCH 33/33] x86, pkeys: execute-only support Andy Lutomirski <luto@amacapital.net> - 2016-02-17 23:20 +0100
Re: [PATCH 33/33] x86, pkeys: execute-only support Dave Hansen <dave@sr71.net> - 2016-02-18 00:00 +0100
Re: [PATCH 33/33] x86, pkeys: execute-only support Andy Lutomirski <luto@amacapital.net> - 2016-02-18 01:50 +0100
[tip:mm/pkeys] mm/core, x86/mm/pkeys: Add execute-only protection keys support tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
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