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References: <20190621095252.32307-11-vincenzo.frascino@arm.com> <20190710140119.23417-1-vincenzo.frascino@arm.com>
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From:   John Stultz <john.stultz@linaro.org>
Date:   Wed, 10 Jul 2019 08:44:43 -0700
Message-ID: <CALAqxLVnf_hyxxmx72F360PbJUTZowuD3wJx0nJ=dCTyW+w-Tw@mail.gmail.com>
Subject: Re: [PATCH v2] arm64: vdso: Fix ABI regression in compat vdso
To:     Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc:     linux-arch@vger.kernel.org,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        lkml <linux-kernel@vger.kernel.org>, linux-mips@vger.kernel.org,
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        Catalin Marinas <catalin.marinas@arm.com>,
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        Arnd Bergmann <arnd@arndb.de>,
        Russell King - ARM Linux <linux@armlinux.org.uk>,
        Ralf Baechle <ralf@linux-mips.org>,
        Paul Burton <paul.burton@mips.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
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        Shuah Khan <shuah@kernel.org>,
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On Wed, Jul 10, 2019 at 7:01 AM Vincenzo Frascino
<vincenzo.frascino@arm.com> wrote:
>
> Prior to the introduction of Unified vDSO support and compat layer for
> vDSO on arm64, AT_SYSINFO_EHDR was not defined for compat tasks.
> In the current implementation, AT_SYSINFO_EHDR is defined even if the
> compat vdso layer is not built and this causes a regression in the
> expected behavior of the ABI.
>
> Restore the ABI behavior making sure that AT_SYSINFO_EHDR for compat
> tasks is defined only when CONFIG_COMPAT_VDSO is enabled.
>
> Reported-by: John Stultz <john.stultz@linaro.org>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

This seems to solve it for me!
Thanks so much for the quick turnaround on a fix. I really appreciate it!

Tested-by: John Stultz <john.stultz@linaro.org>

thanks
-john