Messages in this thread | | | From | Balbir Singh <> | Subject | [PATCH v1 0/3] Fixes to L1D flushing (on top of linux-next and | Date | Wed, 18 Nov 2020 10:49:31 +1100 |
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There were concerns with the current interface (checking for the state of SMT of the core at opt-in time [1]). These patches change the interface to send a SIGBUS to the task if
a. It opts into L1D flushing b. Runs on a core with SMT enabled
There are also documentation fixes. I've tested the patches at my end, but would appreciate a broad review of the change in functionality and/or any recommended doc updates.
[1] http://lkml.iu.edu/hypermail/linux/kernel/2009.3/09310.html [2] http://lkml.iu.edu/hypermail/linux/kernel/2009.3/09613.html
NOTE: For testing these patches, specifically the SIGBUS behaviour, there needs to be contention on the CPU where the task that opts into L1D flushing is running to see the SIGBUS being sent to it (the deterministic bit is that if there is scope of data leak the task will get killed)
Balbir Singh (3): x86/mm: change l1d flush runtime prctl behaviour Documentation: Update the new SIGBUS behaviour for tasks Documentation/l1d_flush: Fix up warning with labels
.../admin-guide/hw-vuln/l1d_flush.rst | 12 +++--- arch/Kconfig | 4 ++ arch/x86/Kconfig | 1 + arch/x86/mm/tlb.c | 37 +++++++++++-------- include/linux/sched.h | 10 +++++ 5 files changed, 42 insertions(+), 22 deletions(-)
-- 2.17.1
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