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| author | Kristina Martsenko <kristina.martsenko@arm.com> | 2022-06-22 13:54:24 +0200 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2022-06-23 19:40:38 +0200 |
| commit | 3a46b352a3e6721db02f60827bdb974d48825bfe (patch) | |
| tree | 77bf81560d0a7adc014b955afbdbda72c395434f /arch/arm64/tools | |
| parent | Linux 5.19-rc3 (diff) | |
| download | linux-3a46b352a3e6721db02f60827bdb974d48825bfe.tar.xz linux-3a46b352a3e6721db02f60827bdb974d48825bfe.zip | |
arm64: trap implementation defined functionality in userspace
The Arm v8.8 extension adds a new control FEAT_TIDCP1 that allows the
kernel to disable all implementation-defined system registers and
instructions in userspace. This can improve robustness against covert
channels between processes, for example in cases where the firmware or
hardware didn't disable that functionality by default.
The kernel does not currently support any implementation-defined
features, as there are no hwcaps for any such features, so disable all
imp-def features unconditionally. Any use of imp-def instructions will
result in a SIGILL being delivered to the process (same as for undefined
instructions).
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220622115424.683520-1-kristina.martsenko@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/tools')
| -rw-r--r-- | arch/arm64/tools/cpucaps | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 507b20373953..e491d89913c2 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -36,6 +36,7 @@ HAS_RNG HAS_SB HAS_STAGE2_FWB HAS_SYSREG_GIC_CPUIF +HAS_TIDCP1 HAS_TLB_RANGE HAS_VIRT_HOST_EXTN HAS_WFXT |