From: Jeremy Linton <jlinton@xxxxxxxxxx> redhat/configs: For aarch64/RT, default kstack randomization off Unlike other architectures which use their cycles counters to seed the kstack randomization (which is sketchy) aarch64 uses the kernel random number generator. For a list of reasons starting with the lack of an enabled/fast cycle counter, a ubiquitous high frequency timer, nor machines which have the v8.5 FEAT_RNG. Using the kernel rng is largely an acceptable solution except for RT workloads which can experience quite large latency spikes as a result. So, lets invert the default kstack randomization for RT kernels on aarch64 until FEAT_RNG is common or a better solution is found. Signed-off-by: Jeremy Linton <jlinton@xxxxxxxxxx> diff --git a/redhat/configs/common/rt/generic/arm/aarch64/CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT b/redhat/configs/common/rt/generic/arm/aarch64/CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/rt/generic/arm/aarch64/CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT @@ -0,0 +1 @@ +# CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT is not set -- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/2933 -- _______________________________________________ kernel mailing list -- kernel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to kernel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
