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Reply-To: Gavin Shan <gshan@redhat.com>
Subject: Re: [PATCH v2 1/2] KVM: selftests: Make rseq compatible with
 glibc-2.35
To:     Paolo Bonzini <pbonzini@redhat.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc:     kvmarm <kvmarm@lists.cs.columbia.edu>,
        KVM list <kvm@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-kselftest <linux-kselftest@vger.kernel.org>,
        Florian Weimer <fweimer@redhat.com>,
        shan gavin <shan.gavin@gmail.com>, maz <maz@kernel.org>,
        andrew jones <andrew.jones@linux.dev>,
        yihyu <yihyu@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        oliver upton <oliver.upton@linux.dev>
References: <20220810104114.6838-1-gshan@redhat.com>
 <20220810104114.6838-2-gshan@redhat.com>
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 <1e41a634-0419-e0a8-364c-2e30ed2dbe4d@redhat.com>
From:   Gavin Shan <gshan@redhat.com>
Message-ID: <234b81a0-d7eb-ee92-3ed3-ce2abf566b63@redhat.com>
Date:   Thu, 11 Aug 2022 09:57:32 +1000
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On 8/10/22 10:29 PM, Paolo Bonzini wrote:
> On 8/10/22 14:22, Mathieu Desnoyers wrote:
>>>
>>>     /*
>>>      * Create and run a dummy VM that immediately exits to userspace via
>>> @@ -256,7 +244,7 @@ int main(int argc, char *argv[])
>>>              */
>>>             smp_rmb();
>>>             cpu = sched_getcpu();
>>> -            rseq_cpu = READ_ONCE(__rseq.cpu_id);
>>> +            rseq_cpu = READ_ONCE(__rseq->cpu_id);
>> #include <rseq.h>
>>
>> and use
>>
>> rseq_current_cpu_raw().
> 
> Thanks, I squashed it and queued it for -rc1 (tested on both
> glibc 2.34 and 2.35).
> 

Paolo, Thanks for the makeup, which looks good to me :)

> diff --git a/tools/testing/selftests/kvm/rseq_test.c b/tools/testing/selftests/kvm/rseq_test.c
> index 84e8425edc2c..987a76674f4f 100644
> --- a/tools/testing/selftests/kvm/rseq_test.c
> +++ b/tools/testing/selftests/kvm/rseq_test.c
> @@ -29,7 +29,6 @@
>   #define NR_TASK_MIGRATIONS 100000
> 
>   static pthread_t migration_thread;
> -static struct rseq_abi *__rseq;
>   static cpu_set_t possible_mask;
>   static int min_cpu, max_cpu;
>   static bool done;
> @@ -218,7 +217,6 @@ int main(int argc, char *argv[])
>       r = rseq_register_current_thread();
>       TEST_ASSERT(!r, "rseq_register_current_thread failed, errno = %d (%s)",
>               errno, strerror(errno));
> -    __rseq = rseq_get_abi();
> 
>       /*
>        * Create and run a dummy VM that immediately exits to userspace via
> @@ -256,7 +254,7 @@ int main(int argc, char *argv[])
>                */
>               smp_rmb();
>               cpu = sched_getcpu();
> -            rseq_cpu = READ_ONCE(__rseq->cpu_id);
> +            rseq_cpu = rseq_current_cpu_raw();
>               smp_rmb();
>           } while (snapshot != atomic_read(&seq_cnt));
>