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From:   tedheadster <tedheadster@gmail.com>
Date:   Fri, 2 Feb 2018 23:52:30 -0500
Message-ID: <CAP8WD_YnJnQW9o+t2jn6HRrY3kKQMRD44joP=thPYO5vS4ev7Q@mail.gmail.com>
Subject: [BUG] x86 : i486 reporting to be vulnerable to Meltdown/Spectre_V1/Spectre_V2
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>, hughd@google.com,
        dave.hansen@linux.intel.com, jikos@kernel.org, bp@alien8.de,
        linux@roeck-us.net, Kees Cook <keescook@chromium.org>,
        jamie@jamieiles.com, dwmw2@infradead.org, eduval@amazon.com,
        labbott@redhat.com, riel@surriel.com,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org
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I just tested the 4.15 kernel and it is reporting that my old i486
(non-cpuid capable) cpu is vulnerable to all three issues: Meltdown,
Spectre V1, and Spectre V2.

I find this to be _unlikely_.

/sys/devices/system/cpu/vulnerabilities/* reports the following:

meltdown: "Vulnerable"
spectre_v1: "Vulnerable"
spectre_v2: "Vulnerable: Minimal generic ASM retpoline"

The output of dmesg includes:

"Spectre V2 mitigation: Vulnerable: Minimal generic ASM retpoline"
"Spectre V2 mitigation: Filling RSB on context switch"

Also, /proc/cpuinfo reports the following:

cpuid level: -1
flags: fpu retpoline rsb_ctxsw
bugs: cpu_meltdown spectre_v1 spectre_v2

I have the hardware to test on. Send me your patches.

- Matthew Whitehead