Hi Greg,
On 09/03/2022 12:05, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
------------------ original commit in Linus's tree ------------------
From 58c9a5060cb7cd529d49c93954cdafe81c1d642a Mon Sep 17 00:00:00 2001 From: James Morse james.morse@arm.com Date: Thu, 3 Mar 2022 16:53:56 +0000 Subject: [PATCH] arm64: proton-pack: Include unprivileged eBPF status in Spectre v2 mitigation reporting
The mitigations for Spectre-BHB are only applied when an exception is taken from user-space. The mitigation status is reported via the spectre_v2 sysfs vulnerabilities file.
When unprivileged eBPF is enabled the mitigation in the exception vectors can be avoided by an eBPF program.
When unprivileged eBPF is enabled, print a warning and report vulnerable via the sysfs vulnerabilities file.
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c index d3fbff00993d..6d45c63c6454 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c
Yup, this far back the code lives in cpu_errata.c, as it hadn't been centralised. I'll look at what is involved in backporting the whole lot...
Thanks,
James