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authorLinus Torvalds <torvalds@linux-foundation.org>2021-08-30 15:00:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-08-30 15:00:33 -0700
commit0a096f240aa1992ddac65f8e704f7b0c0795fe1c (patch)
tree04c64aca17b94b0862214e09784fc23b413df578 /include/uapi/linux
parent7d6e3fa87e732ec1e7761bf325c0907685c8571b (diff)
parentb7fe54f6c2d437082dcbecfbd832f38edd9caaf4 (diff)
Merge tag 'x86-cpu-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cache flush updates from Thomas Gleixner: "A reworked version of the opt-in L1D flush mechanism. This is a stop gap for potential future speculation related hardware vulnerabilities and a mechanism for truly security paranoid applications. It allows a task to request that the L1D cache is flushed when the kernel switches to a different mm. This can be requested via prctl(). Changes vs the previous versions: - Get rid of the software flush fallback - Make the handling consistent with other mitigations - Kill the task when it ends up on a SMT enabled core which defeats the purpose of L1D flushing obviously" * tag 'x86-cpu-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation: Add L1D flushing Documentation x86, prctl: Hook L1D flushing in via prctl x86/mm: Prepare for opt-in based L1D flush in switch_mm() x86/process: Make room for TIF_SPEC_L1D_FLUSH sched: Add task_work callback for paranoid L1D flush x86/mm: Refactor cond_ibpb() to support other use cases x86/smp: Add a per-cpu view of SMT state
Diffstat (limited to 'include/uapi/linux')
-rw-r--r--include/uapi/linux/prctl.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index 967d9c55323d..964c41ed303e 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h
@@ -213,6 +213,7 @@ struct prctl_mm_map {
/* Speculation control variants */
# define PR_SPEC_STORE_BYPASS 0
# define PR_SPEC_INDIRECT_BRANCH 1
+# define PR_SPEC_L1D_FLUSH 2
/* Return and control values for PR_SET/GET_SPECULATION_CTRL */
# define PR_SPEC_NOT_AFFECTED 0
# define PR_SPEC_PRCTL (1UL << 0)