* Re: RFC: userspace exception fixups
From: Linus Torvalds @ 2018-11-01 19:06 UTC (permalink / raw)
To: luto
Cc: dave.hansen, sean.j.christopherson, jethro, jarkko.sakkinen,
fweimer, linux-api, Jann Horn, x86, linux-arch,
Linux Kernel Mailing List, Peter Zijlstra, dalias, nhorman,
npmccallum, serge.ayoun, shay.katz-zamir, linux-sgx,
andriy.shevchenko, tglx, Ingo Molnar, bp
In-Reply-To: <CALCETrWdpoDkbZjkucKL91GWpDPG9p=VqYrULade2pFDR7S=GQ@mail.gmail.com>
On Thu, Nov 1, 2018 at 10:53 AM Andy Lutomirski <luto@kernel.org> wrote:
>
> There's been some discussion of adding a vDSO entry point to wrap
> EENTER and do something sensible with the exceptions,
I think that's likely the right thing to do, and would be similar to sysenter.
> The basic idea would be to allow libc, or maybe even any library, to
> register a handler that gets a chance to act on an exception caused by
> a user instruction before a signal is delivered. As a straw-man
> example for how this could work, there could be a new syscall:
>
> long register_exception_handler(void (*handler)(int, siginfo_t *, void *));
I'm not a huge fan of signals, but the above is an abomination.
It has all the problems of signals _and_ then some.
And it in absolutely no way fixes the problem with libraires. In fact,
it arguably makes it much much worse, since now there's only one
single library that can register it.
Yes yes, maybe a library would then expose _another_ interface to
other libraries and act as some kind of dispatch point, but on the
whole the above is just crazy and fundamentally broken.
If you want to register an exception, you need to make it clear
(a) which _thread_ the exception registration is valid for
(b) which _range_ the exception registration is valid for
(c) which _fault_ the exception registration is valid for (page
fault, div-by-zero, whatever)
(d) which save area (aka stack) and exception handler point.
Note that (b) might be more than just an exception IP range. It might
well be interesting to register the exception by page fault address
(in addition to code range).
If you do something that does all of (a)-(d), and you allow some
limited number of exception registrations, then maybe. Because at that
point, you have something that is actually actively more powerful than
signal handling is.
But your suggested "just register a broken form of signal handling for
a special case" is just wrong. Don't do it.
Linus
^ permalink raw reply
* Re: RFC: userspace exception fixups
From: Jarkko Sakkinen @ 2018-11-01 19:00 UTC (permalink / raw)
To: Florian Weimer
Cc: Andy Lutomirski, Dave Hansen, Christopherson, Sean J,
Jethro Beekman, Jarkko Sakkinen, Linux API, Jann Horn,
Linus Torvalds, X86 ML, linux-arch, LKML, Peter Zijlstra,
Rich Felker, nhorman, npmccallum, Ayoun, Serge, shay.katz-zamir,
linux-sgx, Andy Shevchenko, Thomas Gleixner
In-Reply-To: <877ehwisaa.fsf@oldenburg.str.redhat.com>
On Thu, 1 Nov 2018, Florian Weimer wrote:
> * Andy Lutomirski:
>
>> The basic idea would be to allow libc, or maybe even any library, to
>> register a handler that gets a chance to act on an exception caused by
>> a user instruction before a signal is delivered. As a straw-man
>> example for how this could work, there could be a new syscall:
>>
>> long register_exception_handler(void (*handler)(int, siginfo_t *, void *));
>>
>> If a handler is registered, then, if a synchronous exception happens
>> (page fault, etc), the kernel would set up an exception frame as usual
>> but, rather than checking for signal handlers, it would just call the
>> registered handler. That handler is expected to either handle the
>> exception entirely on its own or to call one of two new syscalls to
>> ask for normal signal delivery or to ask to retry the faulting
>> instruction.
>
> Would the exception handler be a per-thread resource?
For SGX purposes it would *need* to be per-thread resource so that the
run-time (not just Intel but any user space support code for SGX) is
able to act on thread that caused this exception inside the enclave.
/Jarkko
^ permalink raw reply
* Re: RFC: userspace exception fixups
From: Rich Felker @ 2018-11-01 18:52 UTC (permalink / raw)
To: Jann Horn
Cc: Andy Lutomirski, Dave Hansen, sean.j.christopherson, jethro,
jarkko.sakkinen, Florian Weimer, Linux API, Linus Torvalds,
the arch/x86 maintainers, linux-arch, kernel list, Peter Zijlstra,
nhorman, npmccallum, serge.ayoun, shay.katz-zamir, linux-sgx,
andriy.shevchenko, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
carlos, adhemerval.zanella
In-Reply-To: <CAG48ez0vBqL0tyfWwmuc_cq+OAUoEi88=r+t6h64a-Fw8z59zA@mail.gmail.com>
On Thu, Nov 01, 2018 at 07:33:33PM +0100, Jann Horn wrote:
> > but I'm
> > wondering if a more general mechanism would be helpful.
> >
> > The basic idea would be to allow libc, or maybe even any library, to
> > register a handler that gets a chance to act on an exception caused by
> > a user instruction before a signal is delivered. As a straw-man
> > example for how this could work, there could be a new syscall:
> >
> > long register_exception_handler(void (*handler)(int, siginfo_t *, void *));
> >
> > If a handler is registered, then, if a synchronous exception happens
> > (page fault, etc), the kernel would set up an exception frame as usual
> > but, rather than checking for signal handlers, it would just call the
> > registered handler.
>
> > That handler is expected to either handle the
> > exception entirely on its own or to call one of two new syscalls to
> > ask for normal signal delivery
>
> If you do it this way, these exception handlers would have to chain,
There's no need to chain if the handler is specific to the context
where the fault happens. You just replace the handler with the one
relevant to the code you're about to run before you run it.
> > or to ask to retry the faulting instruction.
>
> Why would that have to be a syscall? For signal handlers registered
> with SA_NODEFER, you can basically leave the signal handler with a
> longjmp, right?
longjmp needs a jmp_buf; it can't return to the faulting instruction.
Normally (though this is not defined) signal handlers return to the
faulting instruction if they return, but if returning from the
exception handler meant passing through to the signal disposition,
a different mechanism would be needed to signal that you want to retry
the faulting instruction.
Rich
^ permalink raw reply
* Re: [RFC PATCH for 4.21 03/16] mm: Replace BUG_ON() by WARN_ON() in vm_unmap_ram()
From: Steven Rostedt @ 2018-11-01 18:46 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Mathieu Desnoyers, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
linux-kernel, linux-api, Andy Lutomirski, Dave Watson,
Paul Turner, Andrew Morton, Russell King, Ingo Molnar,
H . Peter Anvin, Andi Kleen, Chris Lameter, Ben Maurer,
Josh Triplett, Linus Torvalds, Catalin Marinas, Will Deacon
In-Reply-To: <alpine.DEB.2.21.1811011320160.1642@nanos.tec.linutronix.de>
On Thu, 1 Nov 2018 13:21:12 +0100 (CET)
Thomas Gleixner <tglx@linutronix.de> wrote:
> Mathieu,
>
> On Thu, 1 Nov 2018, Mathieu Desnoyers wrote:
>
> > It is encouraged to warn and return rather than use BUG_ON() when
> > the condition can be recovered from in ways that are more graceful than
> > halting the whole system.
>
> You're failing to desribe how that graceful recovery works.
>
I think the graceful recovery is to simply return:
if (WARN_ON(cond))
return;
is better than just
BUG_ON(cond);
As that's what Linus made pretty clear at the Maintainer's Summit.
-- Steve
^ permalink raw reply
* Re: RFC: userspace exception fixups
From: Jann Horn @ 2018-11-01 18:33 UTC (permalink / raw)
To: Andy Lutomirski
Cc: Dave Hansen, sean.j.christopherson, jethro, jarkko.sakkinen,
Florian Weimer, Linux API, Linus Torvalds,
the arch/x86 maintainers, linux-arch, kernel list, Peter Zijlstra,
dalias, nhorman, npmccallum, serge.ayoun, shay.katz-zamir,
linux-sgx, andriy.shevchenko, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, carlos, adhemerval.zanella
In-Reply-To: <CALCETrWdpoDkbZjkucKL91GWpDPG9p=VqYrULade2pFDR7S=GQ@mail.gmail.com>
On Thu, Nov 1, 2018 at 6:53 PM Andy Lutomirski <luto@kernel.org> wrote:
> The people working on SGX enablement are grappling with a somewhat
> annoying issue: the x86 EENTER instruction is used from user code and
> can, as part of its normal-ish operation, raise an exception. It is
> also highly likely to be used from a library, and signal handling in
> libraries is unpleasant at best.
>
> There's been some discussion of adding a vDSO entry point to wrap
> EENTER and do something sensible with the exceptions,
This sounds reasonable to me.
> but I'm
> wondering if a more general mechanism would be helpful.
>
> The basic idea would be to allow libc, or maybe even any library, to
> register a handler that gets a chance to act on an exception caused by
> a user instruction before a signal is delivered. As a straw-man
> example for how this could work, there could be a new syscall:
>
> long register_exception_handler(void (*handler)(int, siginfo_t *, void *));
>
> If a handler is registered, then, if a synchronous exception happens
> (page fault, etc), the kernel would set up an exception frame as usual
> but, rather than checking for signal handlers, it would just call the
> registered handler.
> That handler is expected to either handle the
> exception entirely on its own or to call one of two new syscalls to
> ask for normal signal delivery
If you do it this way, these exception handlers would have to chain,
with an API convention that you're obligated to always ask for
resumption of signal delivery if you don't recognize the address,
right? Kind of like a notifier chain. (Except that, unless this is
implemented in the vDSO, each notifier invocation would cross the
kernel-user boundary twice.)
> or to ask to retry the faulting instruction.
Why would that have to be a syscall? For signal handlers registered
with SA_NODEFER, you can basically leave the signal handler with a
longjmp, right?
> Alternatively, we could do something a lot more like the kernel's
> internal fixups where there's a table in user memory that maps
> potentially faulting instructions to landing pads that handle
> exceptions.
I like this direction more, although I'm not sure whether the table
the kernel sees should be at instruction-level granularity. Perhaps
you could associate an exception handler with a VMA? Any instruction
that faults in the VMA triggers the fault handler?
> Do you think this would be useful? Here are some use cases that I
> think are valid:
>
> (a) Enter an SGX enclave and handle errors. There would be two
> instructions that would need special handling: EENTER and ERESUME.
>
> (b) Do some math and catch division by zero. I think it would be a
> bad idea to have user code call a function and say that it wants to
> handle *any* division by zero, but having certain specified division
> instructions have special handling seems entirely reasonable.
>
> (c) Ditto for floating point errors.
>
> (d) Try an instruction and see if it gets #UD.
>
> (e) Run a bunch of code and handle page faults to a given address
> range by faulting something in. This is not like the others, in that
> a handler wants to handle a range of target addresses, not
> instructions. And userfaultfd is plausibly a better solution anyway.
>
> (f) Run NaCl-like sandboxed code where the code can cause page faults
> to certain mapped-but-intentionally-not-present ranges and those need
> to be handled.
>
> On Windows, you can use SEH to do crazy things like running
> known-buggy code and eating the page faults. I don't think we want to
> go there.
>
> All of this makes me think that the right solution is to have a way to
> register fault handlers for instructions to cover (a) - (d) and to
> treat (e) and (f) as something else entirely if there's enough demand.
^ permalink raw reply
* Re: RFC: userspace exception fixups
From: Rich Felker @ 2018-11-01 18:30 UTC (permalink / raw)
To: Florian Weimer
Cc: Andy Lutomirski, Dave Hansen, Christopherson, Sean J,
Jethro Beekman, Jarkko Sakkinen, Linux API, Jann Horn,
Linus Torvalds, X86 ML, linux-arch, LKML, Peter Zijlstra, nhorman,
npmccallum, Ayoun, Serge, shay.katz-zamir, linux-sgx,
Andy Shevchenko, Thomas Gleixner, Ingo Molnar, Borislav Petkov
In-Reply-To: <877ehwisaa.fsf@oldenburg.str.redhat.com>
On Thu, Nov 01, 2018 at 07:09:17PM +0100, Florian Weimer wrote:
> * Andy Lutomirski:
>
> > The basic idea would be to allow libc, or maybe even any library, to
> > register a handler that gets a chance to act on an exception caused by
> > a user instruction before a signal is delivered. As a straw-man
> > example for how this could work, there could be a new syscall:
> >
> > long register_exception_handler(void (*handler)(int, siginfo_t *, void *));
> >
> > If a handler is registered, then, if a synchronous exception happens
> > (page fault, etc), the kernel would set up an exception frame as usual
> > but, rather than checking for signal handlers, it would just call the
> > registered handler. That handler is expected to either handle the
> > exception entirely on its own or to call one of two new syscalls to
> > ask for normal signal delivery or to ask to retry the faulting
> > instruction.
>
> Would the exception handler be a per-thread resource?
>
> If it is: Would the setup and teardown overhead be prohibitive for many
> use cases (at least those do not expect a fault)?
>
> Something peripherally related to this interface: Wrappers for signal
> handlers (and not just CPU exceptions). Ideally, we want to maintain a
> flag that indicates whether we are in a signal handler, and save and
> restore errno around the installed handler.
I think the right way to make it per-thread AND low-cost would be to
register not the handler, but the (per-thread) address of a
function-pointer object pointing to the handler. Then switching the
handler just requires a single volatile store to thread-local memory,
no syscall.
Rich
^ permalink raw reply
* Re: RFC: userspace exception fixups
From: Rich Felker @ 2018-11-01 18:27 UTC (permalink / raw)
To: Andy Lutomirski
Cc: Dave Hansen, Christopherson, Sean J, Jethro Beekman,
Jarkko Sakkinen, Florian Weimer, Linux API, Jann Horn,
Linus Torvalds, X86 ML, linux-arch, LKML, Peter Zijlstra, nhorman,
npmccallum, Ayoun, Serge, shay.katz-zamir, linux-sgx,
Andy Shevchenko, Thomas Gleixner, Ingo Molnar,
Borislav Petkov <bp@
In-Reply-To: <CALCETrWdpoDkbZjkucKL91GWpDPG9p=VqYrULade2pFDR7S=GQ@mail.gmail.com>
On Thu, Nov 01, 2018 at 10:53:40AM -0700, Andy Lutomirski wrote:
> Hi all-
>
> The people working on SGX enablement are grappling with a somewhat
> annoying issue: the x86 EENTER instruction is used from user code and
> can, as part of its normal-ish operation, raise an exception. It is
> also highly likely to be used from a library, and signal handling in
> libraries is unpleasant at best.
>
> There's been some discussion of adding a vDSO entry point to wrap
> EENTER and do something sensible with the exceptions, but I'm
> wondering if a more general mechanism would be helpful.
>
> The basic idea would be to allow libc, or maybe even any library, to
> register a handler that gets a chance to act on an exception caused by
> a user instruction before a signal is delivered. As a straw-man
> example for how this could work, there could be a new syscall:
>
> long register_exception_handler(void (*handler)(int, siginfo_t *, void *));
>
> If a handler is registered, then, if a synchronous exception happens
> (page fault, etc), the kernel would set up an exception frame as usual
> but, rather than checking for signal handlers, it would just call the
> registered handler. That handler is expected to either handle the
> exception entirely on its own or to call one of two new syscalls to
> ask for normal signal delivery or to ask to retry the faulting
> instruction.
>
> Alternatively, we could do something a lot more like the kernel's
> internal fixups where there's a table in user memory that maps
> potentially faulting instructions to landing pads that handle
> exceptions.
This strikes me as just an "extra layer of signal handlers"; rather
than replacing global state with something that's library-safe, it's
just making new global state that has to have a singleton owner
managing it. If these handlers were thread-local (vs process-global
signal disposition) then you could just register/unregister them on
entry/exit to the library code that needs them, but that has
nontrivial execution time cost.
Moreover, thread-local signal handlers can already be done really
nicely if you don't care about having a global handler (which doesn't
really make sense for synchronous signals). I have fairly canonical
draft code I wrote to demonstrate this a while back which I can share
if there's interest.
One possible advantage of your approach is that it could distinguish
actual synchronous signals from ones sent by kill/sigqueue/etc. This
matters in contexts where the application wants the signal blocked or
ignored. For example if you temporarily set a handler for SIGILL or
SIGSEGV, then unblock it and try to do something that might generate
the signal, you risk consuming an unrelated pending signal sent by
kill/sigqueue/etc. As far as I know there is no way to do this
"transparently". It came up as an issue for why libc init code cannot
do this kind of probing for instruction availability at startup (or
any time).
> Do you think this would be useful? Here are some use cases that I
> think are valid:
>
> (a) Enter an SGX enclave and handle errors. There would be two
> instructions that would need special handling: EENTER and ERESUME.
I'm not familiar with SGX but the vdso approach sounds like a better
abstraction.
> (b) Do some math and catch division by zero. I think it would be a
> bad idea to have user code call a function and say that it wants to
> handle *any* division by zero, but having certain specified division
> instructions have special handling seems entirely reasonable.
I don't think this is useful. If you really need a division that needs
to survive invalid operands, a simple check before the div
(100%-predictable branch in non-erroneous usage) is dirt cheap.
> (c) Ditto for floating point errors.
Signaling floating point exceptions (rather than sticky flags) are
something of an oddity that's never enabled by default, not supported
on all platforms, and largely (IMO) useless. Generating code that can
support them can be moderately costly too.
> (d) Try an instruction and see if it gets #UD.
In general this seems fairly useful.
> (e) Run a bunch of code and handle page faults to a given address
> range by faulting something in. This is not like the others, in that
> a handler wants to handle a range of target addresses, not
> instructions. And userfaultfd is plausibly a better solution anyway.
Agree re: userfaultfd.
> (f) Run NaCl-like sandboxed code where the code can cause page faults
> to certain mapped-but-intentionally-not-present ranges and those need
> to be handled.
>
> On Windows, you can use SEH to do crazy things like running
> known-buggy code and eating the page faults. I don't think we want to
> go there.
Agree, this is a huge rabbit hole of filth. Don't go there.
Rich
^ permalink raw reply
* Re: RFC: userspace exception fixups
From: Florian Weimer @ 2018-11-01 18:09 UTC (permalink / raw)
To: Andy Lutomirski
Cc: Dave Hansen, Christopherson, Sean J, Jethro Beekman,
Jarkko Sakkinen, Linux API, Jann Horn, Linus Torvalds, X86 ML,
linux-arch, LKML, Peter Zijlstra, Rich Felker, nhorman,
npmccallum, Ayoun, Serge, shay.katz-zamir, linux-sgx,
Andy Shevchenko, Thomas Gleixner, Ingo Molnar, Borislav Petkov
In-Reply-To: <CALCETrWdpoDkbZjkucKL91GWpDPG9p=VqYrULade2pFDR7S=GQ@mail.gmail.com>
* Andy Lutomirski:
> The basic idea would be to allow libc, or maybe even any library, to
> register a handler that gets a chance to act on an exception caused by
> a user instruction before a signal is delivered. As a straw-man
> example for how this could work, there could be a new syscall:
>
> long register_exception_handler(void (*handler)(int, siginfo_t *, void *));
>
> If a handler is registered, then, if a synchronous exception happens
> (page fault, etc), the kernel would set up an exception frame as usual
> but, rather than checking for signal handlers, it would just call the
> registered handler. That handler is expected to either handle the
> exception entirely on its own or to call one of two new syscalls to
> ask for normal signal delivery or to ask to retry the faulting
> instruction.
Would the exception handler be a per-thread resource?
If it is: Would the setup and teardown overhead be prohibitive for many
use cases (at least those do not expect a fault)?
Something peripherally related to this interface: Wrappers for signal
handlers (and not just CPU exceptions). Ideally, we want to maintain a
flag that indicates whether we are in a signal handler, and save and
restore errno around the installed handler.
> Alternatively, we could do something a lot more like the kernel's
> internal fixups where there's a table in user memory that maps
> potentially faulting instructions to landing pads that handle
> exceptions.
GCC already supports that on most Linux targets. You can unwind from
synchronously invoked signal handlers if you compile with
-fnon-call-exceptions.
However, it's tough to set up a temporary signal handler to trigger such
unwinding because those aren't per-thread.
> On Windows, you can use SEH to do crazy things like running
> known-buggy code and eating the page faults. I don't think we want to
> go there.
The original SEH was also a rich target for exploiting vulnerabilities.
That's something we really should avoid as well.
I wonder if it would be possible to tack this function onto rseq.
Thanks,
Florian
^ permalink raw reply
* RFC: userspace exception fixups
From: Andy Lutomirski @ 2018-11-01 17:53 UTC (permalink / raw)
To: Dave Hansen, Christopherson, Sean J, Jethro Beekman,
Jarkko Sakkinen, Florian Weimer, Linux API, Jann Horn,
Linus Torvalds, X86 ML, linux-arch, LKML, Peter Zijlstra,
Rich Felker, nhorman, npmccallum, Ayoun, Serge, shay.katz-zamir,
linux-sgx, Andy Shevchenko, Thomas Gleixner
Hi all-
The people working on SGX enablement are grappling with a somewhat
annoying issue: the x86 EENTER instruction is used from user code and
can, as part of its normal-ish operation, raise an exception. It is
also highly likely to be used from a library, and signal handling in
libraries is unpleasant at best.
There's been some discussion of adding a vDSO entry point to wrap
EENTER and do something sensible with the exceptions, but I'm
wondering if a more general mechanism would be helpful.
The basic idea would be to allow libc, or maybe even any library, to
register a handler that gets a chance to act on an exception caused by
a user instruction before a signal is delivered. As a straw-man
example for how this could work, there could be a new syscall:
long register_exception_handler(void (*handler)(int, siginfo_t *, void *));
If a handler is registered, then, if a synchronous exception happens
(page fault, etc), the kernel would set up an exception frame as usual
but, rather than checking for signal handlers, it would just call the
registered handler. That handler is expected to either handle the
exception entirely on its own or to call one of two new syscalls to
ask for normal signal delivery or to ask to retry the faulting
instruction.
Alternatively, we could do something a lot more like the kernel's
internal fixups where there's a table in user memory that maps
potentially faulting instructions to landing pads that handle
exceptions.
Do you think this would be useful? Here are some use cases that I
think are valid:
(a) Enter an SGX enclave and handle errors. There would be two
instructions that would need special handling: EENTER and ERESUME.
(b) Do some math and catch division by zero. I think it would be a
bad idea to have user code call a function and say that it wants to
handle *any* division by zero, but having certain specified division
instructions have special handling seems entirely reasonable.
(c) Ditto for floating point errors.
(d) Try an instruction and see if it gets #UD.
(e) Run a bunch of code and handle page faults to a given address
range by faulting something in. This is not like the others, in that
a handler wants to handle a range of target addresses, not
instructions. And userfaultfd is plausibly a better solution anyway.
(f) Run NaCl-like sandboxed code where the code can cause page faults
to certain mapped-but-intentionally-not-present ranges and those need
to be handled.
On Windows, you can use SEH to do crazy things like running
known-buggy code and eating the page faults. I don't think we want to
go there.
All of this makes me think that the right solution is to have a way to
register fault handlers for instructions to cover (a) - (d) and to
treat (e) and (f) as something else entirely if there's enough demand.
--Andy
^ permalink raw reply
* Re: [RFC PATCH for 4.21 00/16] rseq updates, new cpu_opv system call (v2)
From: Linus Torvalds @ 2018-11-01 15:33 UTC (permalink / raw)
To: Mathieu Desnoyers
Cc: Peter Zijlstra, Paul McKenney, boqun.feng,
Linux Kernel Mailing List, linux-api, tglx, luto, davejwatson,
pjt, Andrew Morton, linux, Ingo Molnar, Peter Anvin, andi,
Christoph Lameter, bmaurer, rostedt, josh, Catalin Marinas,
will.deacon, mtk.manpages, joelaf
In-Reply-To: <20181101095844.24462-1-mathieu.desnoyers@efficios.com>
On Thu, Nov 1, 2018 at 2:59 AM Mathieu Desnoyers
<mathieu.desnoyers@efficios.com> wrote:
>
> Here is an updated patchset submitted as RFC for 4.21 (next merge
> window).
So I'm not willing to take the cpu_opv system call until I see the the
regular rseq code getting more real-life use.
Maybe people are using it. Maybe they aren't. I want to hold off and
wait until we _know_ it's getting used, and not just in test
libraries.
Linus
^ permalink raw reply
* Re: [PATCH v8 1/2] seccomp: add a return code to trap to userspace
From: Oleg Nesterov @ 2018-11-01 14:48 UTC (permalink / raw)
To: Tycho Andersen
Cc: Kees Cook, Andy Lutomirski, Eric W . Biederman, Serge E . Hallyn,
Christian Brauner, Tyler Hicks, Akihiro Suda, Aleksa Sarai,
linux-kernel, containers, linux-api
In-Reply-To: <20181030153231.GB7343@cisco>
On 10/30, Tycho Andersen wrote:
>
> > I am not sure I understand the value of signaled/SECCOMP_NOTIF_FLAG_SIGNALED...
> > I mean, why it is actually useful?
> >
> > Sorry if this was already discussed.
>
> :) no problem, many people have complained about this. This is an
> implementation of Andy's suggestion here:
> https://lkml.org/lkml/2018/3/15/1122
>
> You can see some more detailed discussion here:
> https://lkml.org/lkml/2018/9/21/138
Cough, sorry, I simply can't understand what are you talking about ;)
It seems that I need to read all the previous emails... So let me ask
a stupid question below.
> > But my main concern is that either way wait_for_completion_killable() allows
> > to trivially create a process which doesn't react to SIGSTOP, not good...
> >
> > Note also that this can happen if, say, both the tracer and tracee run in the
> > same process group and SIGSTOP is sent to their pgid, if the tracer gets the
> > signal first the tracee won't stop.
> >
> > Of freezer. try_to_freeze_tasks() can fail if it freezes the tracer before
> > it does SECCOMP_IOCTL_NOTIF_SEND.
>
> I think in general the way this is intended to be used these things
> wouldn't happen.
Why?
> was malicious and had the ability to create a user namespace to
> exhaust pids this way,
Not sure I understand how this connects to my question... nevermind.
> so perhaps we should drop this part of the
> patch. I have no real need for it, but perhaps Andy can elaborate?
Yes I think it would be nice to avoid wait_for_completion_killable().
So please help me to understand the problem. Once again, why can not
seccomp_do_user_notification() use wait_for_completion_interruptible() only?
This is called before the task actually starts the syscall, so
-ERESTARTNOINTR if signal_pending() can't hurt.
Now lets suppose seccomp_do_user_notification() simply does
err = wait_for_completion_interruptible(&n.ready);
if (err < 0 && state != SECCOMP_NOTIFY_REPLIED) {
syscall_set_return_value(ERESTARTNOINTR);
list_del(&n.list);
return -1;
}
(I am ignoring the locking/etc). Now the obvious problem is that the listener
doing SECCOMP_IOCTL_NOTIF_SEND can't distinguish -ENOENT from the case when the
tracee was killed, yes?
Is it that important?
Any other problem?
Oleg.
^ permalink raw reply
* Re: [PATCH v6 0/1] ns: introduce binfmt_misc namespace
From: Jann Horn @ 2018-11-01 14:44 UTC (permalink / raw)
To: James Bottomley
Cc: Laurent Vivier, kernel list, Linux API, containers, dima, Al Viro,
linux-fsdevel, Eric W. Biederman
In-Reply-To: <1541081413.2853.6.camel@HansenPartnership.com>
On Thu, Nov 1, 2018 at 3:10 PM James Bottomley
<James.Bottomley@hansenpartnership.com> wrote:
> On Thu, 2018-11-01 at 04:51 +0100, Jann Horn wrote:
> > On Thu, Nov 1, 2018 at 3:59 AM James Bottomley
> > <James.Bottomley@hansenpartnership.com> wrote:
> > >
> > > On Tue, 2018-10-16 at 11:52 +0200, Laurent Vivier wrote:
> > > > Hi,
> > > >
> > > > Any comment on this last version?
> > > >
> > > > Any chance to be merged?
> > >
> > > I've got a use case for this: I went to one of the Graphene talks
> > > in Edinburgh and it struck me that we seem to keep reinventing the
> > > type of sandboxing that qemu-user already does. However if you
> > > want to do an x86 on x86 sandbox, you can't currently use the
> > > binfmt_misc mechanism because that has you running *every* binary
> > > on the system emulated. Doing it per user namespace fixes this
> > > problem and allows us to at least cut down on all the pointless
> > > duplication.
> >
> > Waaaaaait. What? qemu-user does not do "sandboxing". qemu-user makes
> > your code slower and *LESS* secure. As far as I know, qemu-user is
> > only intended for purposes like development and testing.
>
> Sandboxing is about protecting the cloud service provider (and other
> tenants) from horizontal attack by reducing calls to the shared kernel.
> I think it's pretty indisputable that full emulation is an effective
> sandbox in that regard.
>
> We can argue for about bugginess vs completeness, but technologically
> qemu-user already has most of the system calls, which seems to be a
> significant problem with other sandboxes. I also can't dispute it's
> slower, but that's a tradeoff for people to make.
I'm pretty sure you don't understand how qemu-user works.
When the emulated code makes a syscall, QEMU just forwards the syscall
to the native kernel.
QEMU doesn't even prevent you from accessing the address space used by
the emulation logic.
qemu-user is not for sandboxing. qemu-user is not for security.
qemu-user is for running binaries from architecture A on architecture
B, with as much direct access to the kernel's syscall surface as
possible.
An example:
$ cat blah.c
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
int main(void) {
open("/foo/bar/blah", O_RDONLY);
char c;
printf("ptr is %p\n", &c);
read(1337, &c, 1);
*(volatile char *)0x13371338;
}
$ aarch64-linux-gnu-gcc -static -o blah blah.c && strace -f qemu-aarch64 ./blah
[...]
[pid 14181] openat(AT_FDCWD, "/foo/bar/blah", O_RDONLY) = -1 ENOENT
(No such file or directory)
[pid 14181] fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 93), ...}) = 0
[pid 14181] write(1, "ptr is 0x40007fff2f\n", 20ptr is 0x40007fff2f
) = 20
[pid 14181] read(1337, 0x40007fff2f, 1) = -1 EBADF (Bad file descriptor)
[pid 14181] --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR,
si_addr=0x13371338} ---
[...]
^ permalink raw reply
* Re: [PATCH v6 0/1] ns: introduce binfmt_misc namespace
From: Eric W. Biederman @ 2018-11-01 14:16 UTC (permalink / raw)
To: Laurent Vivier
Cc: Jann Horn, James Bottomley, kernel list, Linux API, containers,
dima, Al Viro, linux-fsdevel
In-Reply-To: <fcebfa0c-b389-5c4d-19b8-2f08b487ec25@vivier.eu>
Laurent Vivier <laurent@vivier.eu> writes:
> On 01/11/2018 04:51, Jann Horn wrote:
>> On Thu, Nov 1, 2018 at 3:59 AM James Bottomley
>> <James.Bottomley@hansenpartnership.com> wrote:
>>>
>>> On Tue, 2018-10-16 at 11:52 +0200, Laurent Vivier wrote:
>>>> Hi,
>>>>
>>>> Any comment on this last version?
>>>>
>>>> Any chance to be merged?
>>>
>>> I've got a use case for this: I went to one of the Graphene talks in
>>> Edinburgh and it struck me that we seem to keep reinventing the type of
>>> sandboxing that qemu-user already does. However if you want to do an
>>> x86 on x86 sandbox, you can't currently use the binfmt_misc mechanism
>>> because that has you running *every* binary on the system emulated.
>>> Doing it per user namespace fixes this problem and allows us to at
>>> least cut down on all the pointless duplication.
>>
>> Waaaaaait. What? qemu-user does not do "sandboxing". qemu-user makes
>> your code slower and *LESS* secure. As far as I know, qemu-user is
>> only intended for purposes like development and testing.
>>
>
> I think the idea here is not to run qemu, but to use an interpreter
> (something like gVisor) into a container to control the binaries
> execution inside the container without using this interpreter on the
> host itself (container and host shares the same binfmt_misc
> magic/mask).
Please remind me of this patchset after the merge window is over, and if
there are no issues I will take it via my user namespace branch.
Last I looked I had a concern that some of the permission check issues
were being papered over by using override cred instead of fixing the
deaper code. Sometimes they are necessary but seeing work-arounds
instead of fixes for problems tends to be a maintenance issue, possibly
with security consequences. Best is if the everyone agrees on how all
of the interfaces work so their are no surprises.
Eric
^ permalink raw reply
* Re: [PATCH v6 0/1] ns: introduce binfmt_misc namespace
From: James Bottomley @ 2018-11-01 14:10 UTC (permalink / raw)
To: Jann Horn
Cc: Laurent Vivier, kernel list, Linux API, containers, dima, Al Viro,
linux-fsdevel, Eric W. Biederman
In-Reply-To: <CAG48ez3HnkRM6bUZMNjuTy5DgujgamEKhZOEWDfCjqW7fTJSzQ@mail.gmail.com>
On Thu, 2018-11-01 at 04:51 +0100, Jann Horn wrote:
> On Thu, Nov 1, 2018 at 3:59 AM James Bottomley
> <James.Bottomley@hansenpartnership.com> wrote:
> >
> > On Tue, 2018-10-16 at 11:52 +0200, Laurent Vivier wrote:
> > > Hi,
> > >
> > > Any comment on this last version?
> > >
> > > Any chance to be merged?
> >
> > I've got a use case for this: I went to one of the Graphene talks
> > in Edinburgh and it struck me that we seem to keep reinventing the
> > type of sandboxing that qemu-user already does. However if you
> > want to do an x86 on x86 sandbox, you can't currently use the
> > binfmt_misc mechanism because that has you running *every* binary
> > on the system emulated. Doing it per user namespace fixes this
> > problem and allows us to at least cut down on all the pointless
> > duplication.
>
> Waaaaaait. What? qemu-user does not do "sandboxing". qemu-user makes
> your code slower and *LESS* secure. As far as I know, qemu-user is
> only intended for purposes like development and testing.
Sandboxing is about protecting the cloud service provider (and other
tenants) from horizontal attack by reducing calls to the shared kernel.
I think it's pretty indisputable that full emulation is an effective
sandbox in that regard.
We can argue for about bugginess vs completeness, but technologically
qemu-user already has most of the system calls, which seems to be a
significant problem with other sandboxes. I also can't dispute it's
slower, but that's a tradeoff for people to make.
James
^ permalink raw reply
* Re: [PATCH v8 1/2] seccomp: add a return code to trap to userspace
From: Oleg Nesterov @ 2018-11-01 13:56 UTC (permalink / raw)
To: Tycho Andersen
Cc: Kees Cook, Andy Lutomirski, Eric W . Biederman, Serge E . Hallyn,
Christian Brauner, Tyler Hicks, Akihiro Suda, Aleksa Sarai,
linux-kernel, containers, linux-api
In-Reply-To: <20181029224031.29809-2-tycho@tycho.ws>
On 10/29, Tycho Andersen wrote:
>
> +static int seccomp_notify_release(struct inode *inode, struct file *file)
> +{
> + struct seccomp_filter *filter = file->private_data;
> + struct seccomp_knotif *knotif;
> +
> + mutex_lock(&filter->notify_lock);
> +
> + /*
> + * If this file is being closed because e.g. the task who owned it
> + * died, let's wake everyone up who was waiting on us.
> + */
> + list_for_each_entry(knotif, &filter->notif->notifications, list) {
> + if (knotif->state == SECCOMP_NOTIFY_REPLIED)
> + continue;
> +
> + knotif->state = SECCOMP_NOTIFY_REPLIED;
> + knotif->error = -ENOSYS;
> + knotif->val = 0;
> +
> + complete(&knotif->ready);
> + }
> +
> + wake_up_all(&filter->notif->wqh);
Why? __fput() is not possible if there is another user of this file sleeping
in seccomp_notify_poll().
> + kfree(filter->notif);
Hmm, this looks wrong... we can't kfree ->notif if its ->notifications list
is not empty, otherwise seccomp_do_user_notification()->list_del(&n.list)
can write to the freed memory.
I think _release() should do list_for_each_entry_safe() + list_del_init()
and seccomp_do_user_notification() should use list_del_init() too.
Or, simpler, seccomp_do_user_notification() should do
if (!match->notif)
goto out;
instead of "goto remove_list".
Oleg.
^ permalink raw reply
* Re: [PATCH v8 1/2] seccomp: add a return code to trap to userspace
From: Oleg Nesterov @ 2018-11-01 13:40 UTC (permalink / raw)
To: Tycho Andersen
Cc: Kees Cook, Andy Lutomirski, Eric W . Biederman, Serge E . Hallyn,
Christian Brauner, Tyler Hicks, Akihiro Suda, Aleksa Sarai,
linux-kernel, containers, linux-api
In-Reply-To: <20181029224031.29809-2-tycho@tycho.ws>
On 10/29, Tycho Andersen wrote:
>
> +static struct file *init_listener(struct seccomp_filter *filter)
> +{
> + struct file *ret = ERR_PTR(-EBUSY);
> + struct seccomp_filter *cur, *last_locked = NULL;
> + int filter_nesting = 0;
> +
> + for (cur = current->seccomp.filter; cur; cur = cur->prev) {
> + mutex_lock_nested(&cur->notify_lock, filter_nesting);
> + filter_nesting++;
> + last_locked = cur;
> + if (cur->notif)
> + goto out;
> + }
Somehow I no longer understand why do you need to take all locks. Isn't
the first filter's notify_lock enough? IOW,
for (cur = current->seccomp.filter; cur; cur = cur->prev) {
if (cur->notif)
return ERR_PTR(-EBUSY);
first = cur;
}
if (first)
mutex_lock(&first->notify_lock);
... initialize filter->notif ...
out:
if (first)
mutex_unlock(&first->notify_lock);
return ret;
Oleg.
^ permalink raw reply
* Re: [PATCH v6 0/1] ns: introduce binfmt_misc namespace
From: Laurent Vivier @ 2018-11-01 12:28 UTC (permalink / raw)
To: Jann Horn, James Bottomley
Cc: kernel list, Linux API, containers, dima, Al Viro, linux-fsdevel,
Eric W. Biederman
In-Reply-To: <CAG48ez3HnkRM6bUZMNjuTy5DgujgamEKhZOEWDfCjqW7fTJSzQ@mail.gmail.com>
On 01/11/2018 04:51, Jann Horn wrote:
> On Thu, Nov 1, 2018 at 3:59 AM James Bottomley
> <James.Bottomley@hansenpartnership.com> wrote:
>>
>> On Tue, 2018-10-16 at 11:52 +0200, Laurent Vivier wrote:
>>> Hi,
>>>
>>> Any comment on this last version?
>>>
>>> Any chance to be merged?
>>
>> I've got a use case for this: I went to one of the Graphene talks in
>> Edinburgh and it struck me that we seem to keep reinventing the type of
>> sandboxing that qemu-user already does. However if you want to do an
>> x86 on x86 sandbox, you can't currently use the binfmt_misc mechanism
>> because that has you running *every* binary on the system emulated.
>> Doing it per user namespace fixes this problem and allows us to at
>> least cut down on all the pointless duplication.
>
> Waaaaaait. What? qemu-user does not do "sandboxing". qemu-user makes
> your code slower and *LESS* secure. As far as I know, qemu-user is
> only intended for purposes like development and testing.
>
I think the idea here is not to run qemu, but to use an interpreter
(something like gVisor) into a container to control the binaries
execution inside the container without using this interpreter on the
host itself (container and host shares the same binfmt_misc magic/mask).
Thanks,
Laurent
^ permalink raw reply
* Re: [RFC PATCH for 4.21 03/16] mm: Replace BUG_ON() by WARN_ON() in vm_unmap_ram()
From: Thomas Gleixner @ 2018-11-01 12:21 UTC (permalink / raw)
To: Mathieu Desnoyers
Cc: Peter Zijlstra, Paul E . McKenney, Boqun Feng, linux-kernel,
linux-api, Andy Lutomirski, Dave Watson, Paul Turner,
Andrew Morton, Russell King, Ingo Molnar, H . Peter Anvin,
Andi Kleen, Chris Lameter, Ben Maurer, Steven Rostedt,
Josh Triplett, Linus Torvalds, Catalin Marinas, Will Deacon,
Michael Kerrisk
In-Reply-To: <20181101095844.24462-4-mathieu.desnoyers@efficios.com>
Mathieu,
On Thu, 1 Nov 2018, Mathieu Desnoyers wrote:
> It is encouraged to warn and return rather than use BUG_ON() when
> the condition can be recovered from in ways that are more graceful than
> halting the whole system.
You're failing to desribe how that graceful recovery works.
Thanks,
tglx
^ permalink raw reply
* [RFC PATCH for 4.21 16/16] cpu-opv/selftests: Provide Makefile, scripts, gitignore
From: Mathieu Desnoyers @ 2018-11-01 9:58 UTC (permalink / raw)
To: Peter Zijlstra, Paul E . McKenney, Boqun Feng
Cc: linux-kernel, linux-api, Thomas Gleixner, Andy Lutomirski,
Dave Watson, Paul Turner, Andrew Morton, Russell King,
Ingo Molnar, H . Peter Anvin, Andi Kleen, Chris Lameter,
Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes,
Mathieu Desnoyers
In-Reply-To: <20181101095844.24462-1-mathieu.desnoyers@efficios.com>
A run_param_test.sh script runs many variants of the parametrizable
tests.
Wire up the cpu-opv Makefile, add directory entry into MAINTAINERS file.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
MAINTAINERS | 1 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/cpu-opv/.gitignore | 6 +
tools/testing/selftests/cpu-opv/Makefile | 39 +++++++
tools/testing/selftests/cpu-opv/run_param_test.sh | 134 ++++++++++++++++++++++
5 files changed, 181 insertions(+)
create mode 100644 tools/testing/selftests/cpu-opv/.gitignore
create mode 100644 tools/testing/selftests/cpu-opv/Makefile
create mode 100755 tools/testing/selftests/cpu-opv/run_param_test.sh
diff --git a/MAINTAINERS b/MAINTAINERS
index de59c7c12c8f..ad9addbc5510 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3878,6 +3878,7 @@ L: linux-kernel@vger.kernel.org
S: Supported
F: kernel/cpu_opv.c
F: include/uapi/linux/cpu_opv.h
+F: tools/testing/selftests/cpu-opv/
CRAMFS FILESYSTEM
M: Nicolas Pitre <nico@linaro.org>
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index f1fe492c8e17..42bcc6e5fc5d 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -6,6 +6,7 @@ TARGETS += capabilities
TARGETS += cgroup
TARGETS += cpufreq
TARGETS += cpu-hotplug
+TARGETS += cpu-opv
TARGETS += efivarfs
TARGETS += exec
TARGETS += filesystems
diff --git a/tools/testing/selftests/cpu-opv/.gitignore b/tools/testing/selftests/cpu-opv/.gitignore
new file mode 100644
index 000000000000..8c7bb1f8be79
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/.gitignore
@@ -0,0 +1,6 @@
+basic_cpu_opv_test
+basic_percpu_ops_test
+param_test
+param_test_benchmark
+param_test_compare_twice
+param_test_skip_fastpath
diff --git a/tools/testing/selftests/cpu-opv/Makefile b/tools/testing/selftests/cpu-opv/Makefile
new file mode 100644
index 000000000000..46f49bf30bae
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/Makefile
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: GPL-2.0+ OR MIT
+CFLAGS += -O2 -Wall -g -I./ -I../rseq/ -I../../../../usr/include/ -L./ -Wl,-rpath=./
+LDLIBS += -lpthread
+
+# Own dependencies because we only want to build against 1st prerequisite, but
+# still track changes to header files and depend on shared object.
+OVERRIDE_TARGETS = 1
+
+TEST_GEN_PROGS = basic_cpu_opv_test basic_percpu_ops_test \
+ param_test param_test_skip_fastpath \
+ param_test_benchmark param_test_compare_twice
+
+TEST_GEN_PROGS_EXTENDED = librseq.so libcpu-op.so
+
+TEST_PROGS = run_param_test.sh
+
+include ../lib.mk
+
+$(OUTPUT)/libcpu-op.so: cpu-op.c cpu-op.h
+ $(CC) $(CFLAGS) -shared -fPIC $< $(LDLIBS) -o $@
+
+$(OUTPUT)/librseq.so: ../rseq/rseq.c ../rseq/rseq.h ../rseq/rseq-*.h
+ $(CC) $(CFLAGS) -shared -fPIC $< $(LDLIBS) -o $@
+
+$(OUTPUT)/%: %.c $(TEST_GEN_PROGS_EXTENDED) ../rseq/rseq.h ../rseq/rseq-*.h cpu-op.h percpu-op.h
+ $(CC) $(CFLAGS) $< $(LDLIBS) -lrseq -lcpu-op -o $@
+
+$(OUTPUT)/param_test_skip_fastpath: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
+ ../rseq/rseq.h ../rseq/rseq-*.h cpu-op.h percpu-op.h
+ $(CC) $(CFLAGS) -DRSEQ_SKIP_FASTPATH $< $(LDLIBS) -lrseq -lcpu-op -o $@
+
+$(OUTPUT)/param_test_benchmark: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
+ ../rseq/rseq.h ../rseq/rseq-*.h cpu-op.h percpu-op.h
+ $(CC) $(CFLAGS) -DBENCHMARK $< $(LDLIBS) -lrseq -lcpu-op -o $@
+
+$(OUTPUT)/param_test_compare_twice: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
+ ../rseq/rseq.h ../rseq/rseq-*.h cpu-op.h percpu-op.h
+ $(CC) $(CFLAGS) -DRSEQ_COMPARE_TWICE $< $(LDLIBS) -lrseq -lcpu-op -o $@
+
diff --git a/tools/testing/selftests/cpu-opv/run_param_test.sh b/tools/testing/selftests/cpu-opv/run_param_test.sh
new file mode 100755
index 000000000000..066d2479893c
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/run_param_test.sh
@@ -0,0 +1,134 @@
+#!/bin/bash
+
+NR_CPUS=`grep '^processor' /proc/cpuinfo | wc -l`
+
+EXTRA_ARGS=${@}
+
+OLDIFS="$IFS"
+IFS=$'\n'
+TEST_LIST=(
+ "-T s"
+ "-T l"
+ "-T b"
+ "-T b -M"
+ "-T m"
+ "-T m -M"
+ "-T i"
+)
+
+TEST_NAME=(
+ "spinlock"
+ "list"
+ "buffer"
+ "buffer with barrier"
+ "memcpy"
+ "memcpy with barrier"
+ "increment"
+)
+IFS="$OLDIFS"
+
+REPS=1000
+SLOW_REPS=100
+NR_THREADS=$((6*${NR_CPUS}))
+
+function do_tests()
+{
+ local i=0
+ while [ "$i" -lt "${#TEST_LIST[@]}" ]; do
+ echo "Running test ${TEST_NAME[$i]}"
+ ./param_test ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
+ echo "Running skip fast-path test ${TEST_NAME[$i]}"
+ ./param_test_skip_fastpath ${TEST_LIST[$i]} -r ${SLOW_REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
+ echo "Running compare-twice test ${TEST_NAME[$i]}"
+ ./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
+ let "i++"
+ done
+}
+
+echo "Default parameters"
+do_tests
+
+echo "Loop injection: 10000 loops"
+
+OLDIFS="$IFS"
+IFS=$'\n'
+INJECT_LIST=(
+ "1"
+ "2"
+ "3"
+ "4"
+ "5"
+ "6"
+ "7"
+ "8"
+ "9"
+)
+IFS="$OLDIFS"
+
+NR_LOOPS=10000
+
+i=0
+while [ "$i" -lt "${#INJECT_LIST[@]}" ]; do
+ echo "Injecting at <${INJECT_LIST[$i]}>"
+ do_tests -${INJECT_LIST[i]} ${NR_LOOPS}
+ let "i++"
+done
+NR_LOOPS=
+
+function inject_blocking()
+{
+ OLDIFS="$IFS"
+ IFS=$'\n'
+ INJECT_LIST=(
+ "7"
+ "8"
+ "9"
+ )
+ IFS="$OLDIFS"
+
+ NR_LOOPS=-1
+
+ i=0
+ while [ "$i" -lt "${#INJECT_LIST[@]}" ]; do
+ echo "Injecting at <${INJECT_LIST[$i]}>"
+ do_tests -${INJECT_LIST[i]} -1 ${@}
+ let "i++"
+ done
+ NR_LOOPS=
+}
+
+echo "Yield injection (25%)"
+inject_blocking -m 4 -y
+
+echo "Yield injection (50%)"
+inject_blocking -m 2 -y
+
+echo "Yield injection (100%)"
+inject_blocking -m 1 -y
+
+echo "Kill injection (25%)"
+inject_blocking -m 4 -k
+
+echo "Kill injection (50%)"
+inject_blocking -m 2 -k
+
+echo "Kill injection (100%)"
+inject_blocking -m 1 -k
+
+echo "Sleep injection (1ms, 25%)"
+inject_blocking -m 4 -s 1
+
+echo "Sleep injection (1ms, 50%)"
+inject_blocking -m 2 -s 1
+
+echo "Sleep injection (1ms, 100%)"
+inject_blocking -m 1 -s 1
+
+echo "Disable rseq for 25% threads"
+do_tests -D 4
+
+echo "Disable rseq for 50% threads"
+do_tests -D 2
+
+echo "Disable rseq"
+do_tests -d
--
2.11.0
^ permalink raw reply related
* [RFC PATCH for 4.21 15/16] cpu-opv/selftests: Provide parametrized tests
From: Mathieu Desnoyers @ 2018-11-01 9:58 UTC (permalink / raw)
To: Peter Zijlstra, Paul E . McKenney, Boqun Feng
Cc: linux-kernel, linux-api, Thomas Gleixner, Andy Lutomirski,
Dave Watson, Paul Turner, Andrew Morton, Russell King,
Ingo Molnar, H . Peter Anvin, Andi Kleen, Chris Lameter,
Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes,
Mathieu Desnoyers
In-Reply-To: <20181101095844.24462-1-mathieu.desnoyers@efficios.com>
"param_test" is a parametrizable percpu operations test using
both restartable sequences and cpu_opv. See the "--help" output for
usage.
"param_test_benchmark" is the same as "param_test", but it removes
testing book-keeping code to allow accurate benchmarks.
"param_test_compare_twice" is the same as "param_test", but it performs
each comparison within rseq critical section twice, thus validating
invariants. If any of the second comparisons fails, an error message
is printed and the test aborts.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
tools/testing/selftests/cpu-opv/param_test.c | 1187 ++++++++++++++++++++++++++
1 file changed, 1187 insertions(+)
create mode 100644 tools/testing/selftests/cpu-opv/param_test.c
diff --git a/tools/testing/selftests/cpu-opv/param_test.c b/tools/testing/selftests/cpu-opv/param_test.c
new file mode 100644
index 000000000000..c62e75f07385
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/param_test.c
@@ -0,0 +1,1187 @@
+// SPDX-License-Identifier: LGPL-2.1
+#define _GNU_SOURCE
+#include <assert.h>
+#include <pthread.h>
+#include <sched.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <unistd.h>
+#include <poll.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <errno.h>
+#include <stddef.h>
+
+static inline pid_t gettid(void)
+{
+ return syscall(__NR_gettid);
+}
+
+#define NR_INJECT 9
+static int loop_cnt[NR_INJECT + 1];
+
+static int loop_cnt_1 asm("asm_loop_cnt_1") __attribute__((used));
+static int loop_cnt_2 asm("asm_loop_cnt_2") __attribute__((used));
+static int loop_cnt_3 asm("asm_loop_cnt_3") __attribute__((used));
+static int loop_cnt_4 asm("asm_loop_cnt_4") __attribute__((used));
+static int loop_cnt_5 asm("asm_loop_cnt_5") __attribute__((used));
+static int loop_cnt_6 asm("asm_loop_cnt_6") __attribute__((used));
+
+static int opt_modulo, verbose;
+
+static int opt_yield, opt_signal, opt_sleep,
+ opt_disable_rseq, opt_threads = 200,
+ opt_disable_mod = 0, opt_test = 's', opt_mb = 0;
+
+#ifndef RSEQ_SKIP_FASTPATH
+static long long opt_reps = 5000;
+#else
+static long long opt_reps = 100;
+#endif
+
+static __thread __attribute__((tls_model("initial-exec")))
+unsigned int signals_delivered;
+
+#ifndef BENCHMARK
+
+static __thread __attribute__((tls_model("initial-exec"), unused))
+unsigned int yield_mod_cnt, nr_abort;
+
+#define printf_verbose(fmt, ...) \
+ do { \
+ if (verbose) \
+ printf(fmt, ## __VA_ARGS__); \
+ } while (0)
+
+#ifdef __i386__
+
+#define INJECT_ASM_REG "eax"
+
+#define RSEQ_INJECT_CLOBBER \
+ , INJECT_ASM_REG
+
+#define RSEQ_INJECT_ASM(n) \
+ "mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \
+ "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
+ "jz 333f\n\t" \
+ "222:\n\t" \
+ "dec %%" INJECT_ASM_REG "\n\t" \
+ "jnz 222b\n\t" \
+ "333:\n\t"
+
+#elif defined(__x86_64__)
+
+#define INJECT_ASM_REG_P "rax"
+#define INJECT_ASM_REG "eax"
+
+#define RSEQ_INJECT_CLOBBER \
+ , INJECT_ASM_REG_P \
+ , INJECT_ASM_REG
+
+#define RSEQ_INJECT_ASM(n) \
+ "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \
+ "mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \
+ "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
+ "jz 333f\n\t" \
+ "222:\n\t" \
+ "dec %%" INJECT_ASM_REG "\n\t" \
+ "jnz 222b\n\t" \
+ "333:\n\t"
+
+#elif defined(__ARMEL__)
+
+#define RSEQ_INJECT_INPUT \
+ , [loop_cnt_1]"m"(loop_cnt[1]) \
+ , [loop_cnt_2]"m"(loop_cnt[2]) \
+ , [loop_cnt_3]"m"(loop_cnt[3]) \
+ , [loop_cnt_4]"m"(loop_cnt[4]) \
+ , [loop_cnt_5]"m"(loop_cnt[5]) \
+ , [loop_cnt_6]"m"(loop_cnt[6])
+
+#define INJECT_ASM_REG "r4"
+
+#define RSEQ_INJECT_CLOBBER \
+ , INJECT_ASM_REG
+
+#define RSEQ_INJECT_ASM(n) \
+ "ldr " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
+ "cmp " INJECT_ASM_REG ", #0\n\t" \
+ "beq 333f\n\t" \
+ "222:\n\t" \
+ "subs " INJECT_ASM_REG ", #1\n\t" \
+ "bne 222b\n\t" \
+ "333:\n\t"
+
+#elif __PPC__
+
+#define RSEQ_INJECT_INPUT \
+ , [loop_cnt_1]"m"(loop_cnt[1]) \
+ , [loop_cnt_2]"m"(loop_cnt[2]) \
+ , [loop_cnt_3]"m"(loop_cnt[3]) \
+ , [loop_cnt_4]"m"(loop_cnt[4]) \
+ , [loop_cnt_5]"m"(loop_cnt[5]) \
+ , [loop_cnt_6]"m"(loop_cnt[6])
+
+#define INJECT_ASM_REG "r18"
+
+#define RSEQ_INJECT_CLOBBER \
+ , INJECT_ASM_REG
+
+#define RSEQ_INJECT_ASM(n) \
+ "lwz %%" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
+ "cmpwi %%" INJECT_ASM_REG ", 0\n\t" \
+ "beq 333f\n\t" \
+ "222:\n\t" \
+ "subic. %%" INJECT_ASM_REG ", %%" INJECT_ASM_REG ", 1\n\t" \
+ "bne 222b\n\t" \
+ "333:\n\t"
+#else
+#error unsupported target
+#endif
+
+#define RSEQ_INJECT_FAILED \
+ nr_abort++;
+
+#define RSEQ_INJECT_C(n) \
+{ \
+ int loc_i, loc_nr_loops = loop_cnt[n]; \
+ \
+ for (loc_i = 0; loc_i < loc_nr_loops; loc_i++) { \
+ rseq_barrier(); \
+ } \
+ if (loc_nr_loops == -1 && opt_modulo) { \
+ if (yield_mod_cnt == opt_modulo - 1) { \
+ if (opt_sleep > 0) \
+ poll(NULL, 0, opt_sleep); \
+ if (opt_yield) \
+ sched_yield(); \
+ if (opt_signal) \
+ raise(SIGUSR1); \
+ yield_mod_cnt = 0; \
+ } else { \
+ yield_mod_cnt++; \
+ } \
+ } \
+}
+
+#else
+
+#define printf_verbose(fmt, ...)
+
+#endif /* BENCHMARK */
+
+#include "percpu-op.h"
+
+struct percpu_lock_entry {
+ intptr_t v;
+} __attribute__((aligned(128)));
+
+struct percpu_lock {
+ struct percpu_lock_entry c[CPU_SETSIZE];
+};
+
+struct test_data_entry {
+ intptr_t count;
+} __attribute__((aligned(128)));
+
+struct spinlock_test_data {
+ struct percpu_lock lock;
+ struct test_data_entry c[CPU_SETSIZE];
+};
+
+struct spinlock_thread_test_data {
+ struct spinlock_test_data *data;
+ long long reps;
+ int reg;
+};
+
+struct inc_test_data {
+ struct test_data_entry c[CPU_SETSIZE];
+};
+
+struct inc_thread_test_data {
+ struct inc_test_data *data;
+ long long reps;
+ int reg;
+};
+
+struct percpu_list_node {
+ intptr_t data;
+ struct percpu_list_node *next;
+};
+
+struct percpu_list_entry {
+ struct percpu_list_node *head;
+} __attribute__((aligned(128)));
+
+struct percpu_list {
+ struct percpu_list_entry c[CPU_SETSIZE];
+};
+
+#define BUFFER_ITEM_PER_CPU 100
+
+struct percpu_buffer_node {
+ intptr_t data;
+};
+
+struct percpu_buffer_entry {
+ intptr_t offset;
+ intptr_t buflen;
+ struct percpu_buffer_node **array;
+} __attribute__((aligned(128)));
+
+struct percpu_buffer {
+ struct percpu_buffer_entry c[CPU_SETSIZE];
+};
+
+#define MEMCPY_BUFFER_ITEM_PER_CPU 100
+
+struct percpu_memcpy_buffer_node {
+ intptr_t data1;
+ uint64_t data2;
+};
+
+struct percpu_memcpy_buffer_entry {
+ intptr_t offset;
+ intptr_t buflen;
+ struct percpu_memcpy_buffer_node *array;
+} __attribute__((aligned(128)));
+
+struct percpu_memcpy_buffer {
+ struct percpu_memcpy_buffer_entry c[CPU_SETSIZE];
+};
+
+/* A simple percpu spinlock. */
+static void rseq_percpu_lock(struct percpu_lock *lock, int cpu)
+{
+ for (;;) {
+ int ret;
+
+ ret = percpu_cmpeqv_storev(&lock->c[cpu].v,
+ 0, 1, cpu);
+ if (rseq_likely(!ret))
+ break;
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ /* Retry if comparison fails. */
+ }
+ /*
+ * Acquire semantic when taking lock after control dependency.
+ * Matches rseq_smp_store_release().
+ */
+ rseq_smp_acquire__after_ctrl_dep();
+}
+
+static void rseq_percpu_unlock(struct percpu_lock *lock, int cpu)
+{
+ assert(lock->c[cpu].v == 1);
+ /*
+ * Release lock, with release semantic. Matches
+ * rseq_smp_acquire__after_ctrl_dep().
+ */
+ rseq_smp_store_release(&lock->c[cpu].v, 0);
+}
+
+void *test_percpu_spinlock_thread(void *arg)
+{
+ struct spinlock_thread_test_data *thread_data = arg;
+ struct spinlock_test_data *data = thread_data->data;
+ long long i, reps;
+
+ if (!opt_disable_rseq && thread_data->reg &&
+ rseq_register_current_thread())
+ abort();
+ reps = thread_data->reps;
+ for (i = 0; i < reps; i++) {
+ int cpu = rseq_cpu_start();
+
+ rseq_percpu_lock(&data->lock, cpu);
+ data->c[cpu].count++;
+ rseq_percpu_unlock(&data->lock, cpu);
+#ifndef BENCHMARK
+ if (i != 0 && !(i % (reps / 10)))
+ printf_verbose("tid %d: count %lld\n", (int) gettid(), i);
+#endif
+ }
+ printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
+ (int) gettid(), nr_abort, signals_delivered);
+ if (!opt_disable_rseq && thread_data->reg &&
+ rseq_unregister_current_thread())
+ abort();
+ return NULL;
+}
+
+/*
+ * A simple test which implements a sharded counter using a per-cpu
+ * lock. Obviously real applications might prefer to simply use a
+ * per-cpu increment; however, this is reasonable for a test and the
+ * lock can be extended to synchronize more complicated operations.
+ */
+void test_percpu_spinlock(void)
+{
+ const int num_threads = opt_threads;
+ int i, ret;
+ uint64_t sum;
+ pthread_t test_threads[num_threads];
+ struct spinlock_test_data data;
+ struct spinlock_thread_test_data thread_data[num_threads];
+
+ memset(&data, 0, sizeof(data));
+ for (i = 0; i < num_threads; i++) {
+ thread_data[i].reps = opt_reps;
+ if (opt_disable_mod <= 0 || (i % opt_disable_mod))
+ thread_data[i].reg = 1;
+ else
+ thread_data[i].reg = 0;
+ thread_data[i].data = &data;
+ ret = pthread_create(&test_threads[i], NULL,
+ test_percpu_spinlock_thread,
+ &thread_data[i]);
+ if (ret) {
+ errno = ret;
+ perror("pthread_create");
+ abort();
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ ret = pthread_join(test_threads[i], NULL);
+ if (ret) {
+ errno = ret;
+ perror("pthread_join");
+ abort();
+ }
+ }
+
+ sum = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ sum += data.c[i].count;
+
+ assert(sum == (uint64_t)opt_reps * num_threads);
+}
+
+void *test_percpu_inc_thread(void *arg)
+{
+ struct inc_thread_test_data *thread_data = arg;
+ struct inc_test_data *data = thread_data->data;
+ long long i, reps;
+
+ if (!opt_disable_rseq && thread_data->reg &&
+ rseq_register_current_thread())
+ abort();
+ reps = thread_data->reps;
+ for (i = 0; i < reps; i++) {
+ int cpu, ret;
+
+ cpu = rseq_cpu_start();
+ ret = percpu_addv(&data->c[cpu].count, 1, cpu);
+ if (rseq_unlikely(ret)) {
+ perror("cpu_opv");
+ abort();
+ }
+#ifndef BENCHMARK
+ if (i != 0 && !(i % (reps / 10)))
+ printf_verbose("tid %d: count %lld\n", (int) gettid(), i);
+#endif
+ }
+ printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
+ (int) gettid(), nr_abort, signals_delivered);
+ if (!opt_disable_rseq && thread_data->reg &&
+ rseq_unregister_current_thread())
+ abort();
+ return NULL;
+}
+
+void test_percpu_inc(void)
+{
+ const int num_threads = opt_threads;
+ int i, ret;
+ uint64_t sum;
+ pthread_t test_threads[num_threads];
+ struct inc_test_data data;
+ struct inc_thread_test_data thread_data[num_threads];
+
+ memset(&data, 0, sizeof(data));
+ for (i = 0; i < num_threads; i++) {
+ thread_data[i].reps = opt_reps;
+ if (opt_disable_mod <= 0 || (i % opt_disable_mod))
+ thread_data[i].reg = 1;
+ else
+ thread_data[i].reg = 0;
+ thread_data[i].data = &data;
+ ret = pthread_create(&test_threads[i], NULL,
+ test_percpu_inc_thread,
+ &thread_data[i]);
+ if (ret) {
+ errno = ret;
+ perror("pthread_create");
+ abort();
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ ret = pthread_join(test_threads[i], NULL);
+ if (ret) {
+ errno = ret;
+ perror("pthread_join");
+ abort();
+ }
+ }
+
+ sum = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ sum += data.c[i].count;
+
+ assert(sum == (uint64_t)opt_reps * num_threads);
+}
+
+void percpu_list_push(struct percpu_list *list,
+ struct percpu_list_node *node,
+ int cpu)
+{
+ for (;;) {
+ intptr_t *targetptr, newval, expect;
+ int ret;
+
+ /* Load list->c[cpu].head with single-copy atomicity. */
+ expect = (intptr_t)RSEQ_READ_ONCE(list->c[cpu].head);
+ newval = (intptr_t)node;
+ targetptr = (intptr_t *)&list->c[cpu].head;
+ node->next = (struct percpu_list_node *)expect;
+ ret = percpu_cmpeqv_storev(targetptr, expect, newval, cpu);
+ if (rseq_likely(!ret))
+ break;
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ /* Retry if comparison fails. */
+ }
+}
+
+/*
+ * Unlike a traditional lock-less linked list; the availability of a
+ * rseq primitive allows us to implement pop without concerns over
+ * ABA-type races.
+ */
+struct percpu_list_node *percpu_list_pop(struct percpu_list *list,
+ int cpu)
+{
+ struct percpu_list_node *head;
+ intptr_t *targetptr, expectnot, *load;
+ off_t offset;
+ int ret;
+
+ targetptr = (intptr_t *)&list->c[cpu].head;
+ expectnot = (intptr_t)NULL;
+ offset = offsetof(struct percpu_list_node, next);
+ load = (intptr_t *)&head;
+ ret = percpu_cmpnev_storeoffp_load(targetptr, expectnot,
+ offset, load, cpu);
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ if (ret > 0)
+ return NULL;
+ return head;
+}
+
+void *test_percpu_list_thread(void *arg)
+{
+ long long i, reps;
+ struct percpu_list *list = (struct percpu_list *)arg;
+
+ if (!opt_disable_rseq && rseq_register_current_thread())
+ abort();
+
+ reps = opt_reps;
+ for (i = 0; i < reps; i++) {
+ struct percpu_list_node *node;
+
+ node = percpu_list_pop(list, rseq_cpu_start());
+ if (opt_yield)
+ sched_yield(); /* encourage shuffling */
+ if (node)
+ percpu_list_push(list, node, rseq_cpu_start());
+ }
+
+ printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
+ (int) gettid(), nr_abort, signals_delivered);
+ if (!opt_disable_rseq && rseq_unregister_current_thread())
+ abort();
+
+ return NULL;
+}
+
+/* Simultaneous modification to a per-cpu linked list from many threads. */
+void test_percpu_list(void)
+{
+ const int num_threads = opt_threads;
+ int i, j, ret;
+ uint64_t sum = 0, expected_sum = 0;
+ struct percpu_list list;
+ pthread_t test_threads[num_threads];
+ cpu_set_t allowed_cpus;
+
+ memset(&list, 0, sizeof(list));
+
+ /* Generate list entries for every usable cpu. */
+ sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ if (!CPU_ISSET(i, &allowed_cpus))
+ continue;
+ for (j = 1; j <= 100; j++) {
+ struct percpu_list_node *node;
+
+ expected_sum += j;
+
+ node = malloc(sizeof(*node));
+ assert(node);
+ node->data = j;
+ node->next = list.c[i].head;
+ list.c[i].head = node;
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ ret = pthread_create(&test_threads[i], NULL,
+ test_percpu_list_thread, &list);
+ if (ret) {
+ errno = ret;
+ perror("pthread_create");
+ abort();
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ ret = pthread_join(test_threads[i], NULL);
+ if (ret) {
+ errno = ret;
+ perror("pthread_join");
+ abort();
+ }
+ }
+
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ struct percpu_list_node *node;
+
+ if (!CPU_ISSET(i, &allowed_cpus))
+ continue;
+
+ while ((node = percpu_list_pop(&list, i))) {
+ sum += node->data;
+ free(node);
+ }
+ }
+
+ /*
+ * All entries should now be accounted for (unless some external
+ * actor is interfering with our allowed affinity while this
+ * test is running).
+ */
+ assert(sum == expected_sum);
+}
+
+bool percpu_buffer_push(struct percpu_buffer *buffer,
+ struct percpu_buffer_node *node,
+ int cpu)
+{
+ for (;;) {
+ intptr_t *targetptr_spec, newval_spec;
+ intptr_t *targetptr_final, newval_final;
+ intptr_t offset;
+ int ret;
+
+ offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
+ if (offset == buffer->c[cpu].buflen)
+ return false;
+ newval_spec = (intptr_t)node;
+ targetptr_spec = (intptr_t *)&buffer->c[cpu].array[offset];
+ newval_final = offset + 1;
+ targetptr_final = &buffer->c[cpu].offset;
+ if (opt_mb)
+ ret = percpu_cmpeqv_storev_storev_release(
+ targetptr_final, offset, targetptr_spec,
+ newval_spec, newval_final, cpu);
+ else
+ ret = percpu_cmpeqv_storev_storev(targetptr_final,
+ offset, targetptr_spec, newval_spec,
+ newval_final, cpu);
+ if (rseq_likely(!ret))
+ break;
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ /* Retry if comparison fails. */
+ }
+ return true;
+}
+
+struct percpu_buffer_node *percpu_buffer_pop(struct percpu_buffer *buffer,
+ int cpu)
+{
+ struct percpu_buffer_node *head;
+
+ for (;;) {
+ intptr_t *targetptr, newval;
+ intptr_t offset;
+ int ret;
+
+ /* Load offset with single-copy atomicity. */
+ offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
+ if (offset == 0)
+ return NULL;
+ head = RSEQ_READ_ONCE(buffer->c[cpu].array[offset - 1]);
+ newval = offset - 1;
+ targetptr = (intptr_t *)&buffer->c[cpu].offset;
+ ret = percpu_cmpeqv_cmpeqv_storev(targetptr, offset,
+ (intptr_t *)&buffer->c[cpu].array[offset - 1],
+ (intptr_t)head, newval, cpu);
+ if (rseq_likely(!ret))
+ break;
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ /* Retry if comparison fails. */
+ }
+ return head;
+}
+
+void *test_percpu_buffer_thread(void *arg)
+{
+ long long i, reps;
+ struct percpu_buffer *buffer = (struct percpu_buffer *)arg;
+
+ if (!opt_disable_rseq && rseq_register_current_thread())
+ abort();
+
+ reps = opt_reps;
+ for (i = 0; i < reps; i++) {
+ struct percpu_buffer_node *node;
+
+ node = percpu_buffer_pop(buffer, rseq_cpu_start());
+ if (opt_yield)
+ sched_yield(); /* encourage shuffling */
+ if (node) {
+ if (!percpu_buffer_push(buffer, node,
+ rseq_cpu_start())) {
+ /* Should increase buffer size. */
+ abort();
+ }
+ }
+ }
+
+ printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
+ (int) gettid(), nr_abort, signals_delivered);
+ if (!opt_disable_rseq && rseq_unregister_current_thread())
+ abort();
+
+ return NULL;
+}
+
+/* Simultaneous modification to a per-cpu buffer from many threads. */
+void test_percpu_buffer(void)
+{
+ const int num_threads = opt_threads;
+ int i, j, ret;
+ uint64_t sum = 0, expected_sum = 0;
+ struct percpu_buffer buffer;
+ pthread_t test_threads[num_threads];
+ cpu_set_t allowed_cpus;
+
+ memset(&buffer, 0, sizeof(buffer));
+
+ /* Generate list entries for every usable cpu. */
+ sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ if (!CPU_ISSET(i, &allowed_cpus))
+ continue;
+ /* Worse-case is every item in same CPU. */
+ buffer.c[i].array =
+ malloc(sizeof(*buffer.c[i].array) * CPU_SETSIZE *
+ BUFFER_ITEM_PER_CPU);
+ assert(buffer.c[i].array);
+ buffer.c[i].buflen = CPU_SETSIZE * BUFFER_ITEM_PER_CPU;
+ for (j = 1; j <= BUFFER_ITEM_PER_CPU; j++) {
+ struct percpu_buffer_node *node;
+
+ expected_sum += j;
+
+ /*
+ * We could theoretically put the word-sized
+ * "data" directly in the buffer. However, we
+ * want to model objects that would not fit
+ * within a single word, so allocate an object
+ * for each node.
+ */
+ node = malloc(sizeof(*node));
+ assert(node);
+ node->data = j;
+ buffer.c[i].array[j - 1] = node;
+ buffer.c[i].offset++;
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ ret = pthread_create(&test_threads[i], NULL,
+ test_percpu_buffer_thread, &buffer);
+ if (ret) {
+ errno = ret;
+ perror("pthread_create");
+ abort();
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ ret = pthread_join(test_threads[i], NULL);
+ if (ret) {
+ errno = ret;
+ perror("pthread_join");
+ abort();
+ }
+ }
+
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ struct percpu_buffer_node *node;
+
+ if (!CPU_ISSET(i, &allowed_cpus))
+ continue;
+
+ while ((node = percpu_buffer_pop(&buffer, i))) {
+ sum += node->data;
+ free(node);
+ }
+ free(buffer.c[i].array);
+ }
+
+ /*
+ * All entries should now be accounted for (unless some external
+ * actor is interfering with our allowed affinity while this
+ * test is running).
+ */
+ assert(sum == expected_sum);
+}
+
+bool percpu_memcpy_buffer_push(struct percpu_memcpy_buffer *buffer,
+ struct percpu_memcpy_buffer_node item, int cpu)
+{
+ for (;;) {
+ intptr_t *targetptr_final, newval_final, offset;
+ char *destptr, *srcptr;
+ size_t copylen;
+ int ret;
+
+ /* Load offset with single-copy atomicity. */
+ offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
+ if (offset == buffer->c[cpu].buflen)
+ return false;
+ destptr = (char *)&buffer->c[cpu].array[offset];
+ srcptr = (char *)&item;
+ /* copylen must be <= 4kB. */
+ copylen = sizeof(item);
+ newval_final = offset + 1;
+ targetptr_final = &buffer->c[cpu].offset;
+ if (opt_mb)
+ ret = percpu_cmpeqv_memcpy_storev_release(
+ targetptr_final, offset,
+ destptr, srcptr, copylen,
+ newval_final, cpu);
+ else
+ ret = percpu_cmpeqv_memcpy_storev(targetptr_final,
+ offset, destptr, srcptr, copylen,
+ newval_final, cpu);
+ if (rseq_likely(!ret))
+ break;
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ /* Retry if comparison fails. */
+ }
+ return true;
+}
+
+bool percpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
+ struct percpu_memcpy_buffer_node *item, int cpu)
+{
+ for (;;) {
+ intptr_t *targetptr_final, newval_final, offset;
+ char *destptr, *srcptr;
+ size_t copylen;
+ int ret;
+
+ /* Load offset with single-copy atomicity. */
+ offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
+ if (offset == 0)
+ return false;
+ destptr = (char *)item;
+ srcptr = (char *)&buffer->c[cpu].array[offset - 1];
+ /* copylen must be <= 4kB. */
+ copylen = sizeof(*item);
+ newval_final = offset - 1;
+ targetptr_final = &buffer->c[cpu].offset;
+ ret = percpu_cmpeqv_memcpy_storev(targetptr_final,
+ offset, destptr, srcptr, copylen,
+ newval_final, cpu);
+ if (rseq_likely(!ret))
+ break;
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ /* Retry if comparison fails. */
+ }
+ return true;
+}
+
+void *test_percpu_memcpy_buffer_thread(void *arg)
+{
+ long long i, reps;
+ struct percpu_memcpy_buffer *buffer = (struct percpu_memcpy_buffer *)arg;
+
+ if (!opt_disable_rseq && rseq_register_current_thread())
+ abort();
+
+ reps = opt_reps;
+ for (i = 0; i < reps; i++) {
+ struct percpu_memcpy_buffer_node item;
+ bool result;
+
+ result = percpu_memcpy_buffer_pop(buffer, &item,
+ rseq_cpu_start());
+ if (opt_yield)
+ sched_yield(); /* encourage shuffling */
+ if (result) {
+ if (!percpu_memcpy_buffer_push(buffer, item,
+ rseq_cpu_start())) {
+ /* Should increase buffer size. */
+ abort();
+ }
+ }
+ }
+
+ printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
+ (int) gettid(), nr_abort, signals_delivered);
+ if (!opt_disable_rseq && rseq_unregister_current_thread())
+ abort();
+
+ return NULL;
+}
+
+/* Simultaneous modification to a per-cpu buffer from many threads. */
+void test_percpu_memcpy_buffer(void)
+{
+ const int num_threads = opt_threads;
+ int i, j, ret;
+ uint64_t sum = 0, expected_sum = 0;
+ struct percpu_memcpy_buffer buffer;
+ pthread_t test_threads[num_threads];
+ cpu_set_t allowed_cpus;
+
+ memset(&buffer, 0, sizeof(buffer));
+
+ /* Generate list entries for every usable cpu. */
+ sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ if (!CPU_ISSET(i, &allowed_cpus))
+ continue;
+ /* Worse-case is every item in same CPU. */
+ buffer.c[i].array =
+ malloc(sizeof(*buffer.c[i].array) * CPU_SETSIZE *
+ MEMCPY_BUFFER_ITEM_PER_CPU);
+ assert(buffer.c[i].array);
+ buffer.c[i].buflen = CPU_SETSIZE * MEMCPY_BUFFER_ITEM_PER_CPU;
+ for (j = 1; j <= MEMCPY_BUFFER_ITEM_PER_CPU; j++) {
+ expected_sum += 2 * j + 1;
+
+ /*
+ * We could theoretically put the word-sized
+ * "data" directly in the buffer. However, we
+ * want to model objects that would not fit
+ * within a single word, so allocate an object
+ * for each node.
+ */
+ buffer.c[i].array[j - 1].data1 = j;
+ buffer.c[i].array[j - 1].data2 = j + 1;
+ buffer.c[i].offset++;
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ ret = pthread_create(&test_threads[i], NULL,
+ test_percpu_memcpy_buffer_thread,
+ &buffer);
+ if (ret) {
+ errno = ret;
+ perror("pthread_create");
+ abort();
+ }
+ }
+
+ for (i = 0; i < num_threads; i++) {
+ ret = pthread_join(test_threads[i], NULL);
+ if (ret) {
+ errno = ret;
+ perror("pthread_join");
+ abort();
+ }
+ }
+
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ struct percpu_memcpy_buffer_node item;
+
+ if (!CPU_ISSET(i, &allowed_cpus))
+ continue;
+
+ while (percpu_memcpy_buffer_pop(&buffer, &item, i)) {
+ sum += item.data1;
+ sum += item.data2;
+ }
+ free(buffer.c[i].array);
+ }
+
+ /*
+ * All entries should now be accounted for (unless some external
+ * actor is interfering with our allowed affinity while this
+ * test is running).
+ */
+ assert(sum == expected_sum);
+}
+
+static void test_signal_interrupt_handler(int signo)
+{
+ signals_delivered++;
+}
+
+static int set_signal_handler(void)
+{
+ int ret = 0;
+ struct sigaction sa;
+ sigset_t sigset;
+
+ ret = sigemptyset(&sigset);
+ if (ret < 0) {
+ perror("sigemptyset");
+ return ret;
+ }
+
+ sa.sa_handler = test_signal_interrupt_handler;
+ sa.sa_mask = sigset;
+ sa.sa_flags = 0;
+ ret = sigaction(SIGUSR1, &sa, NULL);
+ if (ret < 0) {
+ perror("sigaction");
+ return ret;
+ }
+
+ printf_verbose("Signal handler set for SIGUSR1\n");
+
+ return ret;
+}
+
+static void show_usage(int argc, char **argv)
+{
+ printf("Usage : %s <OPTIONS>\n",
+ argv[0]);
+ printf("OPTIONS:\n");
+ printf(" [-1 loops] Number of loops for delay injection 1\n");
+ printf(" [-2 loops] Number of loops for delay injection 2\n");
+ printf(" [-3 loops] Number of loops for delay injection 3\n");
+ printf(" [-4 loops] Number of loops for delay injection 4\n");
+ printf(" [-5 loops] Number of loops for delay injection 5\n");
+ printf(" [-6 loops] Number of loops for delay injection 6\n");
+ printf(" [-7 loops] Number of loops for delay injection 7 (-1 to enable -m)\n");
+ printf(" [-8 loops] Number of loops for delay injection 8 (-1 to enable -m)\n");
+ printf(" [-9 loops] Number of loops for delay injection 9 (-1 to enable -m)\n");
+ printf(" [-m N] Yield/sleep/kill every modulo N (default 0: disabled) (>= 0)\n");
+ printf(" [-y] Yield\n");
+ printf(" [-k] Kill thread with signal\n");
+ printf(" [-s S] S: =0: disabled (default), >0: sleep time (ms)\n");
+ printf(" [-t N] Number of threads (default 200)\n");
+ printf(" [-r N] Number of repetitions per thread (default 5000)\n");
+ printf(" [-d] Disable rseq system call (no initialization)\n");
+ printf(" [-D M] Disable rseq for each M threads\n");
+ printf(" [-T test] Choose test: (s)pinlock, (l)ist, (b)uffer, (m)emcpy, (i)ncrement\n");
+ printf(" [-M] Push into buffer and memcpy buffer with memory barriers.\n");
+ printf(" [-v] Verbose output.\n");
+ printf(" [-h] Show this help.\n");
+ printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+ int i;
+
+ for (i = 1; i < argc; i++) {
+ if (argv[i][0] != '-')
+ continue;
+ switch (argv[i][1]) {
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ case '8':
+ case '9':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ loop_cnt[argv[i][1] - '0'] = atol(argv[i + 1]);
+ i++;
+ break;
+ case 'm':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ opt_modulo = atol(argv[i + 1]);
+ if (opt_modulo < 0) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ i++;
+ break;
+ case 's':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ opt_sleep = atol(argv[i + 1]);
+ if (opt_sleep < 0) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ i++;
+ break;
+ case 'y':
+ opt_yield = 1;
+ break;
+ case 'k':
+ opt_signal = 1;
+ break;
+ case 'd':
+ opt_disable_rseq = 1;
+ break;
+ case 'D':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ opt_disable_mod = atol(argv[i + 1]);
+ if (opt_disable_mod < 0) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ i++;
+ break;
+ case 't':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ opt_threads = atol(argv[i + 1]);
+ if (opt_threads < 0) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ i++;
+ break;
+ case 'r':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ opt_reps = atoll(argv[i + 1]);
+ if (opt_reps < 0) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ i++;
+ break;
+ case 'h':
+ show_usage(argc, argv);
+ goto end;
+ case 'T':
+ if (argc < i + 2) {
+ show_usage(argc, argv);
+ goto error;
+ }
+ opt_test = *argv[i + 1];
+ switch (opt_test) {
+ case 's':
+ case 'l':
+ case 'i':
+ case 'b':
+ case 'm':
+ break;
+ default:
+ show_usage(argc, argv);
+ goto error;
+ }
+ i++;
+ break;
+ case 'v':
+ verbose = 1;
+ break;
+ case 'M':
+ opt_mb = 1;
+ break;
+ default:
+ show_usage(argc, argv);
+ goto error;
+ }
+ }
+
+ loop_cnt_1 = loop_cnt[1];
+ loop_cnt_2 = loop_cnt[2];
+ loop_cnt_3 = loop_cnt[3];
+ loop_cnt_4 = loop_cnt[4];
+ loop_cnt_5 = loop_cnt[5];
+ loop_cnt_6 = loop_cnt[6];
+
+ if (set_signal_handler())
+ goto error;
+
+ if (!opt_disable_rseq && rseq_register_current_thread())
+ goto error;
+ switch (opt_test) {
+ case 's':
+ printf_verbose("spinlock\n");
+ test_percpu_spinlock();
+ break;
+ case 'l':
+ printf_verbose("linked list\n");
+ test_percpu_list();
+ break;
+ case 'b':
+ printf_verbose("buffer\n");
+ test_percpu_buffer();
+ break;
+ case 'm':
+ printf_verbose("memcpy buffer\n");
+ test_percpu_memcpy_buffer();
+ break;
+ case 'i':
+ printf_verbose("counter increment\n");
+ test_percpu_inc();
+ break;
+ }
+ if (!opt_disable_rseq && rseq_unregister_current_thread())
+ abort();
+end:
+ return 0;
+
+error:
+ return -1;
+}
--
2.11.0
^ permalink raw reply related
* [RFC PATCH for 4.21 14/16] cpu-opv/selftests: Provide basic percpu ops test
From: Mathieu Desnoyers @ 2018-11-01 9:58 UTC (permalink / raw)
To: Peter Zijlstra, Paul E . McKenney, Boqun Feng
Cc: linux-kernel, linux-api, Thomas Gleixner, Andy Lutomirski,
Dave Watson, Paul Turner, Andrew Morton, Russell King,
Ingo Molnar, H . Peter Anvin, Andi Kleen, Chris Lameter,
Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes,
Mathieu Desnoyers
In-Reply-To: <20181101095844.24462-1-mathieu.desnoyers@efficios.com>
"basic_percpu_ops_test" implements a few simple per-cpu operations and
testing their correctness.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
.../selftests/cpu-opv/basic_percpu_ops_test.c | 295 +++++++++++++++++++++
1 file changed, 295 insertions(+)
create mode 100644 tools/testing/selftests/cpu-opv/basic_percpu_ops_test.c
diff --git a/tools/testing/selftests/cpu-opv/basic_percpu_ops_test.c b/tools/testing/selftests/cpu-opv/basic_percpu_ops_test.c
new file mode 100644
index 000000000000..2ce5202f25b2
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/basic_percpu_ops_test.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: LGPL-2.1
+#define _GNU_SOURCE
+#include <assert.h>
+#include <pthread.h>
+#include <sched.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stddef.h>
+
+#include "percpu-op.h"
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+struct percpu_lock_entry {
+ intptr_t v;
+} __attribute__((aligned(128)));
+
+struct percpu_lock {
+ struct percpu_lock_entry c[CPU_SETSIZE];
+};
+
+struct test_data_entry {
+ intptr_t count;
+} __attribute__((aligned(128)));
+
+struct spinlock_test_data {
+ struct percpu_lock lock;
+ struct test_data_entry c[CPU_SETSIZE];
+ int reps;
+};
+
+struct percpu_list_node {
+ intptr_t data;
+ struct percpu_list_node *next;
+};
+
+struct percpu_list_entry {
+ struct percpu_list_node *head;
+} __attribute__((aligned(128)));
+
+struct percpu_list {
+ struct percpu_list_entry c[CPU_SETSIZE];
+};
+
+/* A simple percpu spinlock. */
+void rseq_percpu_lock(struct percpu_lock *lock, int cpu)
+{
+ for (;;) {
+ int ret;
+
+ ret = percpu_cmpeqv_storev(&lock->c[cpu].v,
+ 0, 1, cpu);
+ if (rseq_likely(!ret))
+ break;
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ /* Retry if comparison fails. */
+ }
+ /*
+ * Acquire semantic when taking lock after control dependency.
+ * Matches rseq_smp_store_release().
+ */
+ rseq_smp_acquire__after_ctrl_dep();
+}
+
+void rseq_percpu_unlock(struct percpu_lock *lock, int cpu)
+{
+ assert(lock->c[cpu].v == 1);
+ /*
+ * Release lock, with release semantic. Matches
+ * rseq_smp_acquire__after_ctrl_dep().
+ */
+ rseq_smp_store_release(&lock->c[cpu].v, 0);
+}
+
+void *test_percpu_spinlock_thread(void *arg)
+{
+ struct spinlock_test_data *data = arg;
+ int i;
+
+ if (rseq_register_current_thread()) {
+ fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
+ errno, strerror(errno));
+ abort();
+ }
+ for (i = 0; i < data->reps; i++) {
+ int cpu = percpu_current_cpu();
+
+ rseq_percpu_lock(&data->lock, cpu);
+ data->c[cpu].count++;
+ rseq_percpu_unlock(&data->lock, cpu);
+ }
+ if (rseq_unregister_current_thread()) {
+ fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
+ errno, strerror(errno));
+ abort();
+ }
+
+ return NULL;
+}
+
+/*
+ * A simple test which implements a sharded counter using a per-cpu
+ * lock. Obviously real applications might prefer to simply use a
+ * per-cpu increment; however, this is reasonable for a test and the
+ * lock can be extended to synchronize more complicated operations.
+ */
+void test_percpu_spinlock(void)
+{
+ const int num_threads = 200;
+ int i;
+ uint64_t sum;
+ pthread_t test_threads[num_threads];
+ struct spinlock_test_data data;
+
+ memset(&data, 0, sizeof(data));
+ data.reps = 5000;
+
+ for (i = 0; i < num_threads; i++)
+ pthread_create(&test_threads[i], NULL,
+ test_percpu_spinlock_thread, &data);
+
+ for (i = 0; i < num_threads; i++)
+ pthread_join(test_threads[i], NULL);
+
+ sum = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ sum += data.c[i].count;
+
+ assert(sum == (uint64_t)data.reps * num_threads);
+}
+
+int percpu_list_push(struct percpu_list *list, struct percpu_list_node *node,
+ int cpu)
+{
+ for (;;) {
+ intptr_t *targetptr, newval, expect;
+ int ret;
+
+ /* Load list->c[cpu].head with single-copy atomicity. */
+ expect = (intptr_t)RSEQ_READ_ONCE(list->c[cpu].head);
+ newval = (intptr_t)node;
+ targetptr = (intptr_t *)&list->c[cpu].head;
+ node->next = (struct percpu_list_node *)expect;
+ ret = percpu_cmpeqv_storev(targetptr, expect, newval, cpu);
+ if (rseq_likely(!ret))
+ break;
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ /* Retry if comparison fails. */
+ }
+ return cpu;
+}
+
+/*
+ * Unlike a traditional lock-less linked list; the availability of a
+ * rseq primitive allows us to implement pop without concerns over
+ * ABA-type races.
+ */
+struct percpu_list_node *percpu_list_pop(struct percpu_list *list,
+ int cpu)
+{
+ struct percpu_list_node *head;
+ intptr_t *targetptr, expectnot, *load;
+ off_t offset;
+ int ret;
+
+ targetptr = (intptr_t *)&list->c[cpu].head;
+ expectnot = (intptr_t)NULL;
+ offset = offsetof(struct percpu_list_node, next);
+ load = (intptr_t *)&head;
+ ret = percpu_cmpnev_storeoffp_load(targetptr, expectnot,
+ offset, load, cpu);
+ if (rseq_unlikely(ret < 0)) {
+ perror("cpu_opv");
+ abort();
+ }
+ if (ret > 0)
+ return NULL;
+ return head;
+}
+
+void *test_percpu_list_thread(void *arg)
+{
+ int i;
+ struct percpu_list *list = (struct percpu_list *)arg;
+
+ if (rseq_register_current_thread()) {
+ fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
+ errno, strerror(errno));
+ abort();
+ }
+
+ for (i = 0; i < 100000; i++) {
+ struct percpu_list_node *node;
+
+ node = percpu_list_pop(list, percpu_current_cpu());
+ sched_yield(); /* encourage shuffling */
+ if (node)
+ percpu_list_push(list, node, percpu_current_cpu());
+ }
+
+ if (rseq_unregister_current_thread()) {
+ fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
+ errno, strerror(errno));
+ abort();
+ }
+
+ return NULL;
+}
+
+/* Simultaneous modification to a per-cpu linked list from many threads. */
+void test_percpu_list(void)
+{
+ int i, j;
+ uint64_t sum = 0, expected_sum = 0;
+ struct percpu_list list;
+ pthread_t test_threads[200];
+ cpu_set_t allowed_cpus;
+
+ memset(&list, 0, sizeof(list));
+
+ /* Generate list entries for every usable cpu. */
+ sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ if (!CPU_ISSET(i, &allowed_cpus))
+ continue;
+ for (j = 1; j <= 100; j++) {
+ struct percpu_list_node *node;
+
+ expected_sum += j;
+
+ node = malloc(sizeof(*node));
+ assert(node);
+ node->data = j;
+ node->next = list.c[i].head;
+ list.c[i].head = node;
+ }
+ }
+
+ for (i = 0; i < 200; i++)
+ pthread_create(&test_threads[i], NULL,
+ test_percpu_list_thread, &list);
+
+ for (i = 0; i < 200; i++)
+ pthread_join(test_threads[i], NULL);
+
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ struct percpu_list_node *node;
+
+ if (!CPU_ISSET(i, &allowed_cpus))
+ continue;
+
+ while ((node = percpu_list_pop(&list, i))) {
+ sum += node->data;
+ free(node);
+ }
+ }
+
+ /*
+ * All entries should now be accounted for (unless some external
+ * actor is interfering with our allowed affinity while this
+ * test is running).
+ */
+ assert(sum == expected_sum);
+}
+
+int main(int argc, char **argv)
+{
+ if (rseq_register_current_thread()) {
+ fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
+ errno, strerror(errno));
+ goto error;
+ }
+ printf("spinlock\n");
+ test_percpu_spinlock();
+ printf("percpu_list\n");
+ test_percpu_list();
+ if (rseq_unregister_current_thread()) {
+ fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
+ errno, strerror(errno));
+ goto error;
+ }
+ return 0;
+
+error:
+ return -1;
+}
+
--
2.11.0
^ permalink raw reply related
* [RFC PATCH for 4.21 13/16] cpu-opv/selftests: Provide percpu_op API
From: Mathieu Desnoyers @ 2018-11-01 9:58 UTC (permalink / raw)
To: Peter Zijlstra, Paul E . McKenney, Boqun Feng
Cc: linux-kernel, linux-api, Thomas Gleixner, Andy Lutomirski,
Dave Watson, Paul Turner, Andrew Morton, Russell King,
Ingo Molnar, H . Peter Anvin, Andi Kleen, Chris Lameter,
Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes,
Mathieu Desnoyers
In-Reply-To: <20181101095844.24462-1-mathieu.desnoyers@efficios.com>
Introduce percpu-op.h API. It uses rseq internally as fast-path if
invoked from the right CPU, else cpu_opv as slow-path if called
from the wrong CPU or if rseq fails.
This allows acting on per-cpu data from various CPUs transparently from
user-space: cpu_opv will take care of migrating the thread to the
requested CPU. Use-cases such as rebalancing memory across per-cpu
memory pools, or migrating tasks for a user-space scheduler, are thus
facilitated. This also handles debugger single-stepping.
The use from userspace is, e.g. for a counter increment:
int cpu, ret;
cpu = percpu_current_cpu();
ret = percpu_addv(&data->c[cpu].count, 1, cpu);
if (unlikely(ret)) {
perror("percpu_addv");
return -1;
}
return 0;
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Russell King <linux@arm.linux.org.uk>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Paul Turner <pjt@google.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andi Kleen <andi@firstfloor.org>
CC: Dave Watson <davejwatson@fb.com>
CC: Chris Lameter <cl@linux.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Ben Maurer <bmaurer@fb.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: linux-kselftest@vger.kernel.org
CC: linux-api@vger.kernel.org
---
tools/testing/selftests/cpu-opv/percpu-op.h | 151 ++++++++++++++++++++++++++++
1 file changed, 151 insertions(+)
create mode 100644 tools/testing/selftests/cpu-opv/percpu-op.h
diff --git a/tools/testing/selftests/cpu-opv/percpu-op.h b/tools/testing/selftests/cpu-opv/percpu-op.h
new file mode 100644
index 000000000000..918171e585d7
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/percpu-op.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * percpu-op.h
+ *
+ * (C) Copyright 2017-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef PERCPU_OP_H
+#define PERCPU_OP_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <stdlib.h>
+#include "rseq.h"
+#include "cpu-op.h"
+
+static inline uint32_t percpu_current_cpu(void)
+{
+ return rseq_current_cpu();
+}
+
+static inline __attribute__((always_inline))
+int percpu_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv,
+ int cpu)
+{
+ int ret;
+
+ ret = rseq_cmpeqv_storev(v, expect, newv, cpu);
+ if (rseq_unlikely(ret)) {
+ if (ret > 0)
+ return ret;
+ return cpu_op_cmpeqv_storev(v, expect, newv, cpu);
+ }
+ return 0;
+}
+
+static inline __attribute__((always_inline))
+int percpu_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
+ off_t voffp, intptr_t *load, int cpu)
+{
+ int ret;
+
+ ret = rseq_cmpnev_storeoffp_load(v, expectnot, voffp, load, cpu);
+ if (rseq_unlikely(ret)) {
+ if (ret > 0)
+ return ret;
+ return cpu_op_cmpnev_storeoffp_load(v, expectnot, voffp,
+ load, cpu);
+ }
+ return 0;
+}
+
+static inline __attribute__((always_inline))
+int percpu_addv(intptr_t *v, intptr_t count, int cpu)
+{
+ if (rseq_unlikely(rseq_addv(v, count, cpu)))
+ return cpu_op_addv(v, count, cpu);
+ return 0;
+}
+
+static inline __attribute__((always_inline))
+int percpu_cmpeqv_storev_storev(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t newv2,
+ intptr_t newv, int cpu)
+{
+ int ret;
+
+ ret = rseq_cmpeqv_trystorev_storev(v, expect, v2, newv2,
+ newv, cpu);
+ if (rseq_unlikely(ret)) {
+ if (ret > 0)
+ return ret;
+ return cpu_op_cmpeqv_storev_storev(v, expect, v2, newv2,
+ newv, cpu);
+ }
+ return 0;
+}
+
+static inline __attribute__((always_inline))
+int percpu_cmpeqv_storev_storev_release(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t newv2,
+ intptr_t newv, int cpu)
+{
+ int ret;
+
+ ret = rseq_cmpeqv_trystorev_storev_release(v, expect, v2, newv2,
+ newv, cpu);
+ if (rseq_unlikely(ret)) {
+ if (ret > 0)
+ return ret;
+ return cpu_op_cmpeqv_storev_storev_release(v, expect, v2, newv2,
+ newv, cpu);
+ }
+ return 0;
+}
+
+static inline __attribute__((always_inline))
+int percpu_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t expect2,
+ intptr_t newv, int cpu)
+{
+ int ret;
+
+ ret = rseq_cmpeqv_cmpeqv_storev(v, expect, v2, expect2, newv, cpu);
+ if (rseq_unlikely(ret)) {
+ if (ret > 0)
+ return ret;
+ return cpu_op_cmpeqv_cmpeqv_storev(v, expect, v2, expect2,
+ newv, cpu);
+ }
+ return 0;
+}
+
+static inline __attribute__((always_inline))
+int percpu_cmpeqv_memcpy_storev(intptr_t *v, intptr_t expect,
+ void *dst, void *src, size_t len,
+ intptr_t newv, int cpu)
+{
+ int ret;
+
+ ret = rseq_cmpeqv_trymemcpy_storev(v, expect, dst, src, len,
+ newv, cpu);
+ if (rseq_unlikely(ret)) {
+ if (ret > 0)
+ return ret;
+ return cpu_op_cmpeqv_memcpy_storev(v, expect, dst, src, len,
+ newv, cpu);
+ }
+ return 0;
+}
+
+static inline __attribute__((always_inline))
+int percpu_cmpeqv_memcpy_storev_release(intptr_t *v, intptr_t expect,
+ void *dst, void *src, size_t len,
+ intptr_t newv, int cpu)
+{
+ int ret;
+
+ ret = rseq_cmpeqv_trymemcpy_storev_release(v, expect, dst, src, len,
+ newv, cpu);
+ if (rseq_unlikely(ret)) {
+ if (ret > 0)
+ return ret;
+ return cpu_op_cmpeqv_memcpy_storev_release(v, expect, dst, src,
+ len, newv, cpu);
+ }
+ return 0;
+}
+
+#endif /* PERCPU_OP_H_ */
--
2.11.0
^ permalink raw reply related
* [RFC PATCH for 4.21 12/16] cpu-opv/selftests: Provide basic test
From: Mathieu Desnoyers @ 2018-11-01 9:58 UTC (permalink / raw)
To: Peter Zijlstra, Paul E . McKenney, Boqun Feng
Cc: linux-kernel, linux-api, Thomas Gleixner, Andy Lutomirski,
Dave Watson, Paul Turner, Andrew Morton, Russell King,
Ingo Molnar, H . Peter Anvin, Andi Kleen, Chris Lameter,
Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes,
Mathieu Desnoyers
In-Reply-To: <20181101095844.24462-1-mathieu.desnoyers@efficios.com>
"basic_cpu_opv_test" tests basic functionality of cpu_opv.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
.../testing/selftests/cpu-opv/basic_cpu_opv_test.c | 1207 ++++++++++++++++++++
1 file changed, 1207 insertions(+)
create mode 100644 tools/testing/selftests/cpu-opv/basic_cpu_opv_test.c
diff --git a/tools/testing/selftests/cpu-opv/basic_cpu_opv_test.c b/tools/testing/selftests/cpu-opv/basic_cpu_opv_test.c
new file mode 100644
index 000000000000..28221b0260fa
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/basic_cpu_opv_test.c
@@ -0,0 +1,1207 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Basic test coverage for cpu_opv system call.
+ */
+
+#define _GNU_SOURCE
+#include <assert.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <sys/mman.h>
+#include <sched.h>
+
+#include "../kselftest.h"
+
+#include "cpu-op.h"
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+#define TESTBUFLEN 4096
+#define TESTBUFLEN_CMP 16
+
+#define TESTBUFLEN_PAGE_MAX 65536
+
+#define NR_PF_ARRAY 16384
+#define PF_ARRAY_LEN 4096
+
+#define NR_HUGE_ARRAY 512
+#define HUGEMAPLEN (NR_HUGE_ARRAY * PF_ARRAY_LEN)
+
+/* 64 MB arrays for page fault testing. */
+char pf_array_dst[NR_PF_ARRAY][PF_ARRAY_LEN];
+char pf_array_src[NR_PF_ARRAY][PF_ARRAY_LEN];
+
+static int test_ops_supported(void)
+{
+ const char *test_name = "test_ops_supported";
+ int ret;
+
+ ret = cpu_opv(NULL, 0, -1, CPU_OP_NR_FLAG);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret < NR_CPU_OPS) {
+ ksft_test_result_fail("%s test: only %d operations supported, expecting at least %d\n",
+ test_name, ret, NR_CPU_OPS);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_compare_eq_op(char *a, char *b, size_t len)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = len,
+ .u.compare_op.a = (unsigned long)a,
+ .u.compare_op.b = (unsigned long)b,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ };
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_compare_eq_same(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN];
+ char buf2[TESTBUFLEN];
+ const char *test_name = "test_compare_eq same";
+
+ /* Test compare_eq */
+ for (i = 0; i < TESTBUFLEN; i++)
+ buf1[i] = (char)i;
+ for (i = 0; i < TESTBUFLEN; i++)
+ buf2[i] = (char)i;
+ ret = test_compare_eq_op(buf2, buf1, TESTBUFLEN);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret > 0) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 0);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_compare_eq_diff(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN];
+ char buf2[TESTBUFLEN];
+ const char *test_name = "test_compare_eq different";
+
+ for (i = 0; i < TESTBUFLEN; i++)
+ buf1[i] = (char)i;
+ memset(buf2, 0, TESTBUFLEN);
+ ret = test_compare_eq_op(buf2, buf1, TESTBUFLEN);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret == 0) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 1);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_compare_ne_op(char *a, char *b, size_t len)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_NE_OP,
+ .len = len,
+ .u.compare_op.a = (unsigned long)a,
+ .u.compare_op.b = (unsigned long)b,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ };
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_compare_ne_same(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN];
+ char buf2[TESTBUFLEN];
+ const char *test_name = "test_compare_ne same";
+
+ /* Test compare_ne */
+ for (i = 0; i < TESTBUFLEN; i++)
+ buf1[i] = (char)i;
+ for (i = 0; i < TESTBUFLEN; i++)
+ buf2[i] = (char)i;
+ ret = test_compare_ne_op(buf2, buf1, TESTBUFLEN);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret == 0) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 1);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_compare_ne_diff(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN];
+ char buf2[TESTBUFLEN];
+ const char *test_name = "test_compare_ne different";
+
+ for (i = 0; i < TESTBUFLEN; i++)
+ buf1[i] = (char)i;
+ memset(buf2, 0, TESTBUFLEN);
+ ret = test_compare_ne_op(buf2, buf1, TESTBUFLEN);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret != 0) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 0);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_2compare_eq_op(char *a, char *b, char *c, char *d,
+ size_t len)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = len,
+ .u.compare_op.a = (unsigned long)a,
+ .u.compare_op.b = (unsigned long)b,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = len,
+ .u.compare_op.a = (unsigned long)c,
+ .u.compare_op.b = (unsigned long)d,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ };
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_2compare_eq_index(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN_CMP];
+ char buf2[TESTBUFLEN_CMP];
+ char buf3[TESTBUFLEN_CMP];
+ char buf4[TESTBUFLEN_CMP];
+ const char *test_name = "test_2compare_eq index";
+
+ for (i = 0; i < TESTBUFLEN_CMP; i++)
+ buf1[i] = (char)i;
+ memset(buf2, 0, TESTBUFLEN_CMP);
+ memset(buf3, 0, TESTBUFLEN_CMP);
+ memset(buf4, 0, TESTBUFLEN_CMP);
+
+ /* First compare failure is op[0], expect 1. */
+ ret = test_2compare_eq_op(buf2, buf1, buf4, buf3, TESTBUFLEN_CMP);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret != 1) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 1);
+ return -1;
+ }
+
+ /* All compares succeed. */
+ for (i = 0; i < TESTBUFLEN_CMP; i++)
+ buf2[i] = (char)i;
+ ret = test_2compare_eq_op(buf2, buf1, buf4, buf3, TESTBUFLEN_CMP);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret != 0) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 0);
+ return -1;
+ }
+
+ /* First compare failure is op[1], expect 2. */
+ for (i = 0; i < TESTBUFLEN_CMP; i++)
+ buf3[i] = (char)i;
+ ret = test_2compare_eq_op(buf2, buf1, buf4, buf3, TESTBUFLEN_CMP);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret != 2) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 2);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_2compare_ne_op(char *a, char *b, char *c, char *d,
+ size_t len)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_NE_OP,
+ .len = len,
+ .u.compare_op.a = (unsigned long)a,
+ .u.compare_op.b = (unsigned long)b,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_COMPARE_NE_OP,
+ .len = len,
+ .u.compare_op.a = (unsigned long)c,
+ .u.compare_op.b = (unsigned long)d,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ };
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_2compare_ne_index(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN_CMP];
+ char buf2[TESTBUFLEN_CMP];
+ char buf3[TESTBUFLEN_CMP];
+ char buf4[TESTBUFLEN_CMP];
+ const char *test_name = "test_2compare_ne index";
+
+ memset(buf1, 0, TESTBUFLEN_CMP);
+ memset(buf2, 0, TESTBUFLEN_CMP);
+ memset(buf3, 0, TESTBUFLEN_CMP);
+ memset(buf4, 0, TESTBUFLEN_CMP);
+
+ /* First compare ne failure is op[0], expect 1. */
+ ret = test_2compare_ne_op(buf2, buf1, buf4, buf3, TESTBUFLEN_CMP);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret != 1) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 1);
+ return -1;
+ }
+
+ /* All compare ne succeed. */
+ for (i = 0; i < TESTBUFLEN_CMP; i++)
+ buf1[i] = (char)i;
+ for (i = 0; i < TESTBUFLEN_CMP; i++)
+ buf3[i] = (char)i;
+ ret = test_2compare_ne_op(buf2, buf1, buf4, buf3, TESTBUFLEN_CMP);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret != 0) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 0);
+ return -1;
+ }
+
+ /* First compare failure is op[1], expect 2. */
+ for (i = 0; i < TESTBUFLEN_CMP; i++)
+ buf4[i] = (char)i;
+ ret = test_2compare_ne_op(buf2, buf1, buf4, buf3, TESTBUFLEN_CMP);
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret != 2) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, ret, 2);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_memcpy_op(void *dst, void *src, size_t len)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)dst,
+ .u.memcpy_op.src = (unsigned long)src,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_memcpy(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN];
+ char buf2[TESTBUFLEN];
+ const char *test_name = "test_memcpy";
+
+ /* Test memcpy */
+ for (i = 0; i < TESTBUFLEN; i++)
+ buf1[i] = (char)i;
+ memset(buf2, 0, TESTBUFLEN);
+ ret = test_memcpy_op(buf2, buf1, TESTBUFLEN);
+ if (ret) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ for (i = 0; i < TESTBUFLEN; i++) {
+ if (buf2[i] != (char)i) {
+ ksft_test_result_fail("%s test: unexpected value at offset %d. Found %d. Should be %d.\n",
+ test_name, i, buf2[i], (char)i);
+ return -1;
+ }
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_memcpy_u32(void)
+{
+ int ret;
+ uint32_t v1, v2;
+ const char *test_name = "test_memcpy_u32";
+
+ /* Test memcpy_u32 */
+ v1 = 42;
+ v2 = 0;
+ ret = test_memcpy_op(&v2, &v1, sizeof(v1));
+ if (ret) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (v1 != v2) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, v2, v1);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_memcpy_memcpy_release_op(void *dst1, void *src1,
+ void *dst2, void *src2, size_t len)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)dst1,
+ .u.memcpy_op.src = (unsigned long)src1,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ [1] = {
+ .op = CPU_MEMCPY_RELEASE_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)dst2,
+ .u.memcpy_op.src = (unsigned long)src2,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_memcpy_memcpy_release(void)
+{
+ int ret;
+ int v1, v2, v3;
+ const char *test_name = "test_memcpy_memcpy_release";
+
+ /* Test memcpy */
+ v1 = 42;
+ v2 = v3 = 0;
+ ret = test_memcpy_memcpy_release_op(&v2, &v1, &v3, &v2, sizeof(int));
+ if (ret) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (v3 != v1) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, v3, v1);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_add_op(int *v, int64_t increment)
+{
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_op_add(v, increment, sizeof(*v), cpu);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_add(void)
+{
+ int orig_v = 42, v, ret;
+ int increment = 1;
+ const char *test_name = "test_add";
+
+ v = orig_v;
+ ret = test_add_op(&v, increment);
+ if (ret) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (v != orig_v + increment) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, v,
+ orig_v + increment);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_add_release_op(int *v, int64_t increment)
+{
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_op_add_release(v, increment, sizeof(*v), cpu);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_add_release(void)
+{
+ int orig_v = 42, v, ret;
+ int increment = 1;
+ const char *test_name = "test_add_release";
+
+ v = orig_v;
+ ret = test_add_release_op(&v, increment);
+ if (ret) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (v != orig_v + increment) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, v,
+ orig_v + increment);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_two_add_op(int *v, int64_t *increments)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(*v),
+ .u.arithmetic_op.p = (unsigned long)v,
+ .u.arithmetic_op.count = increments[0],
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ [1] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(*v),
+ .u.arithmetic_op.p = (unsigned long)v,
+ .u.arithmetic_op.count = increments[1],
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ };
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_two_add(void)
+{
+ int orig_v = 42, v, ret;
+ int64_t increments[2] = { 99, 123 };
+ const char *test_name = "test_two_add";
+
+ v = orig_v;
+ ret = test_two_add_op(&v, increments);
+ if (ret) {
+ ksft_test_result_fail("%s test: returned with %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (v != orig_v + increments[0] + increments[1]) {
+ ksft_test_result_fail("%s test: unexpected value %d. Should be %d.\n",
+ test_name, v,
+ orig_v + increments[0] + increments[1]);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_cmpxchg_op(void *v, void *expect, void *old, void *n,
+ size_t len)
+{
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_op_cmpxchg(v, expect, old, n, len, cpu);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_cmpxchg_success(void)
+{
+ int ret;
+ uint64_t orig_v = 1, v, expect = 1, old = 0, n = 3;
+ const char *test_name = "test_cmpxchg success";
+
+ v = orig_v;
+ ret = test_cmpxchg_op(&v, &expect, &old, &n, sizeof(uint64_t));
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret) {
+ ksft_test_result_fail("%s returned %d, expecting %d\n",
+ test_name, ret, 0);
+ return -1;
+ }
+ if (v != n) {
+ ksft_test_result_fail("%s v is %lld, expecting %lld\n",
+ test_name, (long long)v, (long long)n);
+ return -1;
+ }
+ if (old != orig_v) {
+ ksft_test_result_fail("%s old is %lld, expecting %lld\n",
+ test_name, (long long)old,
+ (long long)orig_v);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_cmpxchg_fail(void)
+{
+ int ret;
+ uint64_t orig_v = 1, v, expect = 123, old = 0, n = 3;
+ const char *test_name = "test_cmpxchg fail";
+
+ v = orig_v;
+ ret = test_cmpxchg_op(&v, &expect, &old, &n, sizeof(uint64_t));
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (ret == 0) {
+ ksft_test_result_fail("%s returned %d, expecting %d\n",
+ test_name, ret, 1);
+ return -1;
+ }
+ if (v == n) {
+ ksft_test_result_fail("%s returned %lld, expecting %lld\n",
+ test_name, (long long)v,
+ (long long)orig_v);
+ return -1;
+ }
+ if (old != orig_v) {
+ ksft_test_result_fail("%s old is %lld, expecting %lld\n",
+ test_name, (long long)old,
+ (long long)orig_v);
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_memcpy_expect_fault_op(void *dst, void *src, size_t len)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)dst,
+ .u.memcpy_op.src = (unsigned long)src,
+ .u.memcpy_op.expect_fault_dst = 0,
+ /* Return EAGAIN on fault. */
+ .u.memcpy_op.expect_fault_src = 1,
+ },
+ };
+ int cpu;
+
+ cpu = cpu_op_get_current_cpu();
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+static int test_memcpy_fault(void)
+{
+ int ret;
+ char buf1[TESTBUFLEN];
+ const char *test_name = "test_memcpy_fault";
+
+ /* Test memcpy */
+ ret = test_memcpy_op(buf1, NULL, TESTBUFLEN);
+ if (!ret || (ret < 0 && errno != EFAULT)) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ /* Test memcpy expect fault */
+ ret = test_memcpy_expect_fault_op(buf1, NULL, TESTBUFLEN);
+ if (!ret || (ret < 0 && errno != EAGAIN)) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int do_test_unknown_op(void)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = -1, /* Unknown */
+ .len = 0,
+ },
+ };
+ int cpu;
+
+ cpu = cpu_op_get_current_cpu();
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+static int test_unknown_op(void)
+{
+ int ret;
+ const char *test_name = "test_unknown_op";
+
+ ret = do_test_unknown_op();
+ if (!ret || (ret < 0 && errno != EINVAL)) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int do_test_max_ops(void)
+{
+ int v = 0;
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ [1] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ [2] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ [3] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ };
+ int cpu;
+
+ cpu = cpu_op_get_current_cpu();
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+static int test_max_ops(void)
+{
+ int ret;
+ const char *test_name = "test_max_ops";
+
+ ret = do_test_max_ops();
+ if (ret < 0) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int do_test_too_many_ops(void)
+{
+ int v = 0;
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ [1] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ [2] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ [3] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ [4] = {
+ .op = CPU_ADD_OP,
+ .len = sizeof(v),
+ .u.arithmetic_op.p = (unsigned long)&v,
+ .u.arithmetic_op.count = 0,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ };
+ int cpu;
+
+ cpu = cpu_op_get_current_cpu();
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+static int test_too_many_ops(void)
+{
+ int ret;
+ const char *test_name = "test_too_many_ops";
+
+ ret = do_test_too_many_ops();
+ if (!ret || (ret < 0 && errno != EINVAL)) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+/* Use 64kB len, largest page size known on Linux. */
+static int test_memcpy_single_too_large(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN_PAGE_MAX + 1];
+ char buf2[TESTBUFLEN_PAGE_MAX + 1];
+ const char *test_name = "test_memcpy_single_too_large";
+
+ /* Test memcpy */
+ for (i = 0; i < TESTBUFLEN_PAGE_MAX + 1; i++)
+ buf1[i] = (char)i;
+ memset(buf2, 0, TESTBUFLEN_PAGE_MAX + 1);
+ ret = test_memcpy_op(buf2, buf1, TESTBUFLEN_PAGE_MAX + 1);
+ if (!ret || (ret < 0 && errno != EINVAL)) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+static int test_memcpy_single_ok_sum_too_large_op(void *dst, void *src,
+ size_t len)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)dst,
+ .u.memcpy_op.src = (unsigned long)src,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ [1] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)dst,
+ .u.memcpy_op.src = (unsigned long)src,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+ int ret, cpu;
+
+ do {
+ cpu = cpu_op_get_current_cpu();
+ ret = cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_memcpy_single_ok_sum_too_large(void)
+{
+ int i, ret;
+ char buf1[TESTBUFLEN];
+ char buf2[TESTBUFLEN];
+ const char *test_name = "test_memcpy_single_ok_sum_too_large";
+
+ /* Test memcpy */
+ for (i = 0; i < TESTBUFLEN; i++)
+ buf1[i] = (char)i;
+ memset(buf2, 0, TESTBUFLEN);
+ ret = test_memcpy_single_ok_sum_too_large_op(buf2, buf1, TESTBUFLEN);
+ if (!ret || (ret < 0 && errno != EINVAL)) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+/*
+ * Iterate over large uninitialized arrays to trigger page faults.
+ * This includes reading from zero pages.
+ */
+int test_page_fault(void)
+{
+ int ret = 0;
+ uint64_t i;
+ const char *test_name = "test_page_fault";
+
+ for (i = 0; i < NR_PF_ARRAY; i++) {
+ ret = test_memcpy_op(pf_array_dst[i],
+ pf_array_src[i],
+ PF_ARRAY_LEN);
+ if (ret) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return ret;
+ }
+ }
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+}
+
+/*
+ * Try to use 2MB huge pages.
+ */
+int test_hugetlb(void)
+{
+ int ret = 0;
+ uint64_t i;
+ const char *test_name = "test_hugetlb";
+ int *dst, *src;
+
+ dst = mmap(NULL, HUGEMAPLEN, PROT_READ | PROT_WRITE,
+ MAP_HUGETLB | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ if (dst == MAP_FAILED) {
+ switch (errno) {
+ case ENOMEM:
+ case ENOENT:
+ case EINVAL:
+ ksft_test_result_skip("%s test.\n", test_name);
+ goto end;
+ default:
+ break;
+ }
+ perror("mmap");
+ abort();
+ }
+ src = mmap(NULL, HUGEMAPLEN, PROT_READ | PROT_WRITE,
+ MAP_HUGETLB | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ if (src == MAP_FAILED) {
+ if (errno == ENOMEM) {
+ ksft_test_result_skip("%s test.\n", test_name);
+ goto unmap_dst;
+ }
+ perror("mmap");
+ abort();
+ }
+
+ /* Read/write from/to huge zero pages. */
+ for (i = 0; i < NR_HUGE_ARRAY; i++) {
+ ret = test_memcpy_op(dst + (i * PF_ARRAY_LEN / sizeof(int)),
+ src + (i * PF_ARRAY_LEN / sizeof(int)),
+ PF_ARRAY_LEN);
+ if (ret) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return ret;
+ }
+ }
+ for (i = 0; i < NR_HUGE_ARRAY * (PF_ARRAY_LEN / sizeof(int)); i++)
+ src[i] = i;
+
+ for (i = 0; i < NR_HUGE_ARRAY; i++) {
+ ret = test_memcpy_op(dst + (i * PF_ARRAY_LEN / sizeof(int)),
+ src + (i * PF_ARRAY_LEN / sizeof(int)),
+ PF_ARRAY_LEN);
+ if (ret) {
+ ksft_test_result_fail("%s test: ret = %d, errno = %s\n",
+ test_name, ret, strerror(errno));
+ return ret;
+ }
+ }
+
+ for (i = 0; i < NR_HUGE_ARRAY * (PF_ARRAY_LEN / sizeof(int)); i++) {
+ if (dst[i] != i) {
+ ksft_test_result_fail("%s mismatch, expect %d, got %d\n",
+ test_name, i, dst[i]);
+ return ret;
+ }
+ }
+
+ ksft_test_result_pass("%s test\n", test_name);
+
+ if (munmap(src, HUGEMAPLEN)) {
+ perror("munmap");
+ abort();
+ }
+unmap_dst:
+ if (munmap(dst, HUGEMAPLEN)) {
+ perror("munmap");
+ abort();
+ }
+end:
+ return 0;
+}
+
+static int test_cmpxchg_op_cpu(void *v, void *expect, void *old, void *n,
+ size_t len, int cpu)
+{
+ int ret;
+
+ do {
+ ret = cpu_op_cmpxchg(v, expect, old, n, len, cpu);
+ } while (ret == -1 && errno == EAGAIN);
+
+ return ret;
+}
+
+static int test_over_possible_cpu(void)
+{
+ int ret;
+ uint64_t orig_v = 1, v, expect = 1, old = 0, n = 3;
+ const char *test_name = "test_over_possible_cpu";
+
+ v = orig_v;
+ ret = test_cmpxchg_op_cpu(&v, &expect, &old, &n, sizeof(uint64_t),
+ 0xFFFFFFFF);
+ if (ret == 0) {
+ ksft_test_result_fail("%s test: ret = %d\n",
+ test_name, ret);
+ return -1;
+ }
+ if (ret < 0 && errno == EINVAL) {
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+ }
+ ksft_test_result_fail("%s returned %d, errno %s, expecting %d, errno %s\n",
+ test_name, ret, strerror(errno),
+ 0, strerror(EINVAL));
+ return -1;
+}
+
+static int test_allowed_affinity(void)
+{
+ int ret;
+ uint64_t orig_v = 1, v, expect = 1, old = 0, n = 3;
+ const char *test_name = "test_allowed_affinity";
+ cpu_set_t allowed_cpus, cpuset;
+
+ ret = sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
+ if (ret) {
+ ksft_test_result_fail("%s returned %d, errno %s\n",
+ test_name, ret, strerror(errno));
+ return -1;
+ }
+ if (!(CPU_ISSET(0, &allowed_cpus) && CPU_ISSET(1, &allowed_cpus))) {
+ ksft_test_result_skip("%s test. Requiring allowed CPUs 0 and 1.\n",
+ test_name);
+ return 0;
+ }
+ CPU_ZERO(&cpuset);
+ CPU_SET(0, &cpuset);
+ if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
+ ksft_test_result_fail("%s test. Unable to set affinity. errno = %s\n",
+ test_name, strerror(errno));
+ return -1;
+ }
+ v = orig_v;
+ ret = test_cmpxchg_op_cpu(&v, &expect, &old, &n, sizeof(uint64_t),
+ 1);
+ if (sched_setaffinity(0, sizeof(allowed_cpus), &allowed_cpus) != 0) {
+ ksft_test_result_fail("%s test. Unable to set affinity. errno = %s\n",
+ test_name, strerror(errno));
+ return -1;
+ }
+ if (ret == 0) {
+ ksft_test_result_fail("%s test: ret = %d\n",
+ test_name, ret);
+ return -1;
+ }
+
+ if (ret < 0 && errno == EINVAL) {
+ ksft_test_result_pass("%s test\n", test_name);
+ return 0;
+ }
+ ksft_test_result_fail("%s returned %d, errno %s, expecting %d, errno %s\n",
+ test_name, ret, strerror(errno),
+ 0, strerror(EINVAL));
+ return -1;
+}
+
+int main(int argc, char **argv)
+{
+ ksft_print_header();
+
+ test_ops_supported();
+ test_compare_eq_same();
+ test_compare_eq_diff();
+ test_compare_ne_same();
+ test_compare_ne_diff();
+ test_2compare_eq_index();
+ test_2compare_ne_index();
+ test_memcpy();
+ test_memcpy_u32();
+ test_memcpy_memcpy_release();
+ test_add();
+ test_add_release();
+ test_two_add();
+ test_cmpxchg_success();
+ test_cmpxchg_fail();
+ test_memcpy_fault();
+ test_unknown_op();
+ test_max_ops();
+ test_too_many_ops();
+ test_memcpy_single_too_large();
+ test_memcpy_single_ok_sum_too_large();
+ test_page_fault();
+ test_hugetlb();
+ test_over_possible_cpu();
+ test_allowed_affinity();
+
+ return ksft_exit_pass();
+}
--
2.11.0
^ permalink raw reply related
* [RFC PATCH for 4.21 11/16] cpu-opv/selftests: Provide cpu-op library
From: Mathieu Desnoyers @ 2018-11-01 9:58 UTC (permalink / raw)
To: Peter Zijlstra, Paul E . McKenney, Boqun Feng
Cc: linux-kernel, linux-api, Thomas Gleixner, Andy Lutomirski,
Dave Watson, Paul Turner, Andrew Morton, Russell King,
Ingo Molnar, H . Peter Anvin, Andi Kleen, Chris Lameter,
Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes,
Mathieu Desnoyers
In-Reply-To: <20181101095844.24462-1-mathieu.desnoyers@efficios.com>
This cpu-op helper library provides a user-space API to the cpu_opv()
system call.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
tools/testing/selftests/cpu-opv/cpu-op.c | 362 +++++++++++++++++++++++++++++++
tools/testing/selftests/cpu-opv/cpu-op.h | 43 ++++
2 files changed, 405 insertions(+)
create mode 100644 tools/testing/selftests/cpu-opv/cpu-op.c
create mode 100644 tools/testing/selftests/cpu-opv/cpu-op.h
diff --git a/tools/testing/selftests/cpu-opv/cpu-op.c b/tools/testing/selftests/cpu-opv/cpu-op.c
new file mode 100644
index 000000000000..0cdc39bffbbf
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/cpu-op.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * cpu-op.c
+ *
+ * Copyright (C) 2017 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <syscall.h>
+#include <assert.h>
+#include <signal.h>
+
+#include "cpu-op.h"
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+#define ACCESS_ONCE(x) (*(__volatile__ __typeof__(x) *)&(x))
+#define WRITE_ONCE(x, v) __extension__ ({ ACCESS_ONCE(x) = (v); })
+#define READ_ONCE(x) ACCESS_ONCE(x)
+
+int cpu_opv(struct cpu_op *cpu_opv, int cpuopcnt, int cpu, int flags)
+{
+ return syscall(__NR_cpu_opv, cpu_opv, cpuopcnt, cpu, flags);
+}
+
+int cpu_op_get_current_cpu(void)
+{
+ int cpu;
+
+ cpu = sched_getcpu();
+ if (cpu < 0) {
+ perror("sched_getcpu()");
+ abort();
+ }
+ return cpu;
+}
+
+int cpu_op_cmpxchg(void *v, void *expect, void *old, void *n, size_t len,
+ int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)old,
+ .u.memcpy_op.src = (unsigned long)v,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ [1] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = len,
+ .u.compare_op.a = (unsigned long)v,
+ .u.compare_op.b = (unsigned long)expect,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [2] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)v,
+ .u.memcpy_op.src = (unsigned long)n,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_add(void *v, int64_t count, size_t len, int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_ADD_OP,
+ .len = len,
+ .u.arithmetic_op.p = (unsigned long)v,
+ .u.arithmetic_op.count = count,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_add_release(void *v, int64_t count, size_t len, int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_ADD_RELEASE_OP,
+ .len = len,
+ .u.arithmetic_op.p = (unsigned long)v,
+ .u.arithmetic_op.count = count,
+ .u.arithmetic_op.expect_fault_p = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv,
+ int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = sizeof(intptr_t),
+ .u.compare_op.a = (unsigned long)v,
+ .u.compare_op.b = (unsigned long)&expect,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_MEMCPY_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v,
+ .u.memcpy_op.src = (unsigned long)&newv,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+static int cpu_op_cmpeqv_storep_expect_fault(intptr_t *v, intptr_t expect,
+ intptr_t *newp, int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = sizeof(intptr_t),
+ .u.compare_op.a = (unsigned long)v,
+ .u.compare_op.b = (unsigned long)&expect,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_MEMCPY_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v,
+ .u.memcpy_op.src = (unsigned long)newp,
+ .u.memcpy_op.expect_fault_dst = 0,
+ /* Return EAGAIN on src fault. */
+ .u.memcpy_op.expect_fault_src = 1,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
+ off_t voffp, intptr_t *load, int cpu)
+{
+ int ret;
+
+ do {
+ intptr_t oldv = READ_ONCE(*v);
+ intptr_t *newp = (intptr_t *)(oldv + voffp);
+
+ if (oldv == expectnot)
+ return 1;
+ ret = cpu_op_cmpeqv_storep_expect_fault(v, oldv, newp, cpu);
+ if (!ret) {
+ *load = oldv;
+ return 0;
+ }
+ } while (ret > 0);
+
+ return -1;
+}
+
+int cpu_op_cmpeqv_storev_storev(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t newv2,
+ intptr_t newv, int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = sizeof(intptr_t),
+ .u.compare_op.a = (unsigned long)v,
+ .u.compare_op.b = (unsigned long)&expect,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_MEMCPY_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v2,
+ .u.memcpy_op.src = (unsigned long)&newv2,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ [2] = {
+ .op = CPU_MEMCPY_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v,
+ .u.memcpy_op.src = (unsigned long)&newv,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_cmpeqv_storev_storev_release(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t newv2,
+ intptr_t newv, int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = sizeof(intptr_t),
+ .u.compare_op.a = (unsigned long)v,
+ .u.compare_op.b = (unsigned long)&expect,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_MEMCPY_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v2,
+ .u.memcpy_op.src = (unsigned long)&newv2,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ [2] = {
+ .op = CPU_MEMCPY_RELEASE_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v,
+ .u.memcpy_op.src = (unsigned long)&newv,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t expect2,
+ intptr_t newv, int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = sizeof(intptr_t),
+ .u.compare_op.a = (unsigned long)v,
+ .u.compare_op.b = (unsigned long)&expect,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = sizeof(intptr_t),
+ .u.compare_op.a = (unsigned long)v2,
+ .u.compare_op.b = (unsigned long)&expect2,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [2] = {
+ .op = CPU_MEMCPY_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v,
+ .u.memcpy_op.src = (unsigned long)&newv,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_cmpeqv_memcpy_storev(intptr_t *v, intptr_t expect,
+ void *dst, void *src, size_t len,
+ intptr_t newv, int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = sizeof(intptr_t),
+ .u.compare_op.a = (unsigned long)v,
+ .u.compare_op.b = (unsigned long)&expect,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)dst,
+ .u.memcpy_op.src = (unsigned long)src,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ [2] = {
+ .op = CPU_MEMCPY_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v,
+ .u.memcpy_op.src = (unsigned long)&newv,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_cmpeqv_memcpy_storev_release(intptr_t *v, intptr_t expect,
+ void *dst, void *src, size_t len,
+ intptr_t newv, int cpu)
+{
+ struct cpu_op opvec[] = {
+ [0] = {
+ .op = CPU_COMPARE_EQ_OP,
+ .len = sizeof(intptr_t),
+ .u.compare_op.a = (unsigned long)v,
+ .u.compare_op.b = (unsigned long)&expect,
+ .u.compare_op.expect_fault_a = 0,
+ .u.compare_op.expect_fault_b = 0,
+ },
+ [1] = {
+ .op = CPU_MEMCPY_OP,
+ .len = len,
+ .u.memcpy_op.dst = (unsigned long)dst,
+ .u.memcpy_op.src = (unsigned long)src,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ [2] = {
+ .op = CPU_MEMCPY_RELEASE_OP,
+ .len = sizeof(intptr_t),
+ .u.memcpy_op.dst = (unsigned long)v,
+ .u.memcpy_op.src = (unsigned long)&newv,
+ .u.memcpy_op.expect_fault_dst = 0,
+ .u.memcpy_op.expect_fault_src = 0,
+ },
+ };
+
+ return cpu_opv(opvec, ARRAY_SIZE(opvec), cpu, 0);
+}
+
+int cpu_op_addv(intptr_t *v, int64_t count, int cpu)
+{
+ return cpu_op_add(v, count, sizeof(intptr_t), cpu);
+}
diff --git a/tools/testing/selftests/cpu-opv/cpu-op.h b/tools/testing/selftests/cpu-opv/cpu-op.h
new file mode 100644
index 000000000000..853fcb302516
--- /dev/null
+++ b/tools/testing/selftests/cpu-opv/cpu-op.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * cpu-op.h
+ *
+ * (C) Copyright 2017-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef CPU_OPV_H
+#define CPU_OPV_H
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <linux/cpu_opv.h>
+
+int cpu_opv(struct cpu_op *cpuopv, int cpuopcnt, int cpu, int flags);
+int cpu_op_get_current_cpu(void);
+
+int cpu_op_cmpxchg(void *v, void *expect, void *old, void *_new, size_t len,
+ int cpu);
+int cpu_op_add(void *v, int64_t count, size_t len, int cpu);
+int cpu_op_add_release(void *v, int64_t count, size_t len, int cpu);
+
+int cpu_op_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu);
+int cpu_op_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
+ off_t voffp, intptr_t *load, int cpu);
+int cpu_op_cmpeqv_storev_storev(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t newv2,
+ intptr_t newv, int cpu);
+int cpu_op_cmpeqv_storev_storev_release(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t newv2,
+ intptr_t newv, int cpu);
+int cpu_op_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t expect2,
+ intptr_t newv, int cpu);
+int cpu_op_cmpeqv_memcpy_storev(intptr_t *v, intptr_t expect,
+ void *dst, void *src, size_t len,
+ intptr_t newv, int cpu);
+int cpu_op_cmpeqv_memcpy_storev_release(intptr_t *v, intptr_t expect,
+ void *dst, void *src, size_t len,
+ intptr_t newv, int cpu);
+int cpu_op_addv(intptr_t *v, int64_t count, int cpu);
+
+#endif /* CPU_OPV_H_ */
--
2.11.0
^ permalink raw reply related
* [RFC PATCH for 4.21 10/16] arm: Wire up cpu_opv system call
From: Mathieu Desnoyers @ 2018-11-01 9:58 UTC (permalink / raw)
To: Peter Zijlstra, Paul E . McKenney, Boqun Feng
Cc: linux-kernel, linux-api, Thomas Gleixner, Andy Lutomirski,
Dave Watson, Paul Turner, Andrew Morton, Russell King,
Ingo Molnar, H . Peter Anvin, Andi Kleen, Chris Lameter,
Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes,
Mathieu Desnoyers
In-Reply-To: <20181101095844.24462-1-mathieu.desnoyers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Paul Turner <pjt@google.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andi Kleen <andi@firstfloor.org>
CC: Dave Watson <davejwatson@fb.com>
CC: Chris Lameter <cl@linux.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Ben Maurer <bmaurer@fb.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: linux-api@vger.kernel.org
---
arch/arm/tools/syscall.tbl | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 8edf93b4490f..da2cb7a12644 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -414,3 +414,4 @@
397 common statx sys_statx
398 common rseq sys_rseq
399 common io_pgetevents sys_io_pgetevents
+400 common cpu_opv sys_cpu_opv
--
2.11.0
^ permalink raw reply related
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