On Thu, Jan 18, 2024 at 12:02:26PM +0000, Will Deacon wrote:
On Tue, 16 Jan 2024 11:02:19 +0000, Mark Rutland wrote:
While testing an unrelated patch on the arm64 for-next/core branch, I spotted an issue in the ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD workaround. The first patch fixes that issue, and the second patch cleans up the remaining logic.
The issue has existed since the workaround was introduced in commit:
[...]
Cheers, I picked these up, but you might need to shepherd them through -stable, so please keep an eye out for any "failed to apply" mails.
Talking of which, the original workaround didn't make it to any kernels before 6.1:
[5.15] https://lore.kernel.org/r/2023100743-evasion-figment-fbcc@gregkh [5.10] https://lore.kernel.org/r/2023100745-statute-component-dd0f@gregkh
From a quick look, these failed because we forgot to backport some prior errata workarounds (which are still missing from stable), and backported others out-of-order relative to mainline, so every subsequent backport is likely to hit a massive text conflict in the diff.
I'll have a go at backorting the missing pieces in-order to get this closer to mainline. I suspect that'll take a short while...
Going forwards, we should check that errata patches are CC'd to stable appropriately when we merge them in the arm64 tree, and we should make sure those are successfully backported in-order.
Mark.
Please can you or Rob have a crack at that?
[1/2] arm64: entry: fix ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD https://git.kernel.org/arm64/c/832dd634bd1b [2/2] arm64: entry: simplify kernel_exit logic https://git.kernel.org/arm64/c/da59f1d051d5
Cheers,
Will
https://fixes.arm64.dev https://next.arm64.dev https://will.arm64.dev