Lines Matching +full:d +full:- +full:tlb +full:- +full:sets

1 .. SPDX-License-Identifier: GPL-2.0
27 This approach helps to ensure that side-channel attacks leveraging
30 time.  Once enabled at compile-time, it can be disabled at boot with
31 the 'nopti' or 'pti=' kernel parameters (see kernel-parameters.txt).
36 When PTI is enabled, the kernel manages two sets of page tables.
43 that any missed kernel->user CR3 switch will immediately crash
49 each CPU's copy of the area a compile-time-fixed virtual address.
65 Protection against side-channel attacks is important.  But,
70   a. Each process now needs an order-1 PGD instead of order-0.
89      feature of the MMU allows different processes to share TLB
91      TLB misses after a context switch.  The actual loss of
93   d. Process Context IDentifiers (PCID) is a CPU feature that
94      allows us to skip flushing the entire TLB when switching page
99      and kernel entries out of the TLB.  The user PCID TLB flush is
104      are created by copying top-level (PGD) entries into each
109   f. In addition to the fork()-time copying, there must also
115      the entire TLB.  That means that each syscall, interrupt
116      or exception flushes the TLB.
117   h. INVPCID is a TLB-flushing instruction which allows flushing
118      of TLB entries for non-current PCIDs.  Some systems support
120      can only be flushed from the TLB for the current PCID.  When
122      single kernel address flush will require a TLB-flushing CR3
130    boot-time switching.
145    frequent performance monitoring non-maskable interrupts (see "NMI"
148    interrupted, including nested NMIs.  Using "-c" boosts the rate of
149    NMIs, and using two -c with separate counters encourages nested NMIs
153 	while true; do perf record -c 10000 -e instructions,cycles -a sleep 10; done
156 5. Run 32-bit binaries on systems supporting the SYSCALL instruction.
157    This has been a lightly-tested code path and needs extra scrutiny.
184    faults upon page faults.  Caused by touching non-pti-mapped
186    CR3 before calling into C functions which are not pti-mapped.
189    tended to be TLB invalidation issues.  Usually invalidating