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Groups > linux.kernel > #1616572
| From | Al Viro <viro@ZenIV.linux.org.uk> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | ia64 exceptions (Re: [RFC][CFT][PATCHSET v1] uaccess unification) |
| Date | 2017-04-05 07:10 +0200 |
| Message-ID | <tsLmF-6Gn-5@gated-at.bofh.it> (permalink) |
| References | <tqeOd-2vj-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Mar 29, 2017 at 06:57:06AM +0100, Al Viro wrote:
> And again, metag and ia64 parts are simply not there - both architectures
> zero-pad in __copy_from_user_inatomic() and that really needs fixing.
> In case of metag there's __copy_to_user() breakage as well, AFAICS, and
> I've been unable to find any documentation describing the architecture
> wrt exceptions, and that part is apparently fairly weird. In case of
> ia64... I can test mckinley side of things, but not the generic __copy_user()
> and ia64 is about as weird as it gets. With no reliable emulator, at that...
> So these two are up to respective maintainers.
Speaking of ia64: copy_user.S contains the following oddity:
2:
EX(.failure_in3,(p16) ld8 val1[0]=[src1],16)
(p16) ld8 val2[0]=[src2],16
src1 is 16-byte aligned, src2 is src1 + 8.
What guarantees that we can't race with e.g. TLB shootdown from a thread on
another CPU, ending up with the second insn taking a fault and oopsing?
AFAICS, other places where we have such pairs of loads or stores (e.g.
EX(.ex_handler, (p16) ld8 r34=[src0],16)
EK(.ex_handler, (p16) ld8 r38=[src1],16)
in the memcpy_mck.S counterpart of that code) both have exception table
entries associated with them.
Is that one intentional and correct for some subtle reason, or is it a very
narrow race on the hardware nobody gives a damn anymore? It is pre-mckinley
stuff, after all...
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[RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-29 08:00 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2017-03-29 22:20 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-29 22:40 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-29 23:10 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-29 23:30 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 01:20 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-30 01:50 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 17:40 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-29 22:40 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2017-03-29 23:20 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 01:50 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2017-03-30 02:10 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-30 02:40 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 03:20 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2017-03-30 22:50 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-30 23:10 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-31 01:30 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Martin Schwidefsky <schwidefsky@de.ibm.com> - 2017-03-30 14:40 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 16:50 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-30 18:30 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 18:50 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-30 19:20 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 20:50 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-30 21:00 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 21:00 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-30 21:00 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 21:20 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Linus Torvalds <torvalds@linux-foundation.org> - 2017-03-30 21:30 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-03-30 23:20 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Kees Cook <keescook@chromium.org> - 2017-03-31 02:30 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification James Hogan <james.hogan@imgtec.com> - 2017-03-31 15:40 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification James Morse <james.morse@arm.com> - 2017-04-03 18:30 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Max Filippov <jcmvbkbc@gmail.com> - 2017-04-04 22:30 +0200
Re: [RFC][CFT][PATCHSET v1] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-04-04 23:00 +0200
ia64 exceptions (Re: [RFC][CFT][PATCHSET v1] uaccess unification) Al Viro <viro@ZenIV.linux.org.uk> - 2017-04-05 07:10 +0200
Re: ia64 exceptions (Re: [RFC][CFT][PATCHSET v1] uaccess unification) Al Viro <viro@ZenIV.linux.org.uk> - 2017-04-05 10:10 +0200
Re: ia64 exceptions (Re: [RFC][CFT][PATCHSET v1] uaccess unification) Tony Luck <tony.luck@gmail.com> - 2017-04-05 20:50 +0200
Re: ia64 exceptions (Re: [RFC][CFT][PATCHSET v1] uaccess unification) Al Viro <viro@ZenIV.linux.org.uk> - 2017-04-05 22:40 +0200
[RFC][CFT][PATCHSET v2] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-04-07 02:30 +0200
Re: [RFC][CFT][PATCHSET v2] uaccess unification Al Viro <viro@ZenIV.linux.org.uk> - 2017-04-07 02:40 +0200
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