On Fri, Nov 8, 2019 at 1:36 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > This is a backport to v4.4 of the Spectre v1 and v2 mitigations for 32-bit > ARM that have already been backported to v4.9. > > Patches #17 and up were cherry-picked from the v4.9 tree, and applied cleanly. > The first 16 patches are prerequisites that were introduced between v4.4 and > v4.9, and some needed minor massaging to apply. Some notable issues: > - the 32-bit KVM host parts were omitted, given the lack of demand and the > fact that those pieces saw significantly more churn during the v4.4-v4.9 > timeframe due to the fact that the code is shared with arm64 > - some other changes are shared between ARM and arm64 (notably, the ARM SMCCCC > changes), so the backport affects both architectures. > > Patches can be found at [0]. They were build and boot tested using a variety > of ARM and arm64 configs and platforms, both locally and on KernelCI. > > An RFC of this series was sent out to the linux-arm-kernel mailing list > and cc'ed to the maintainer, and no objections were raised. (The only > difference between the RFC and this submission is that I have dropped > a couple of mostly unrelated patches that were only there to make patch #8 > match its context more closely in the file include/linux/arm-smccc.h) > > Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> > Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> I felt responsible so I took it for a ride on a number of physical systems (no QEMU!). It works flawlessly on: - Ux500 ARMv7 A9 x 2 - Versatile AB ARMv5 ARM926EJ-S - Integrator CP ARMv4t ARM920T It bombs on RealView PB11MPCore but it's not your fault, it also hangs on v4.4.186 and a clean v4.4. However it boots fine with v5.6-rc1 and -next, anything using ARM11 in MPcore configurations (such as the Oxnas routers) should use a newer kernel and stay away from v4.4. Anyways: Tested-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Yours, Linus Walleij
