diff options
| author | Andy Lutomirski <[email protected]> | 2017-07-26 07:16:30 -0700 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2017-07-27 09:12:57 +0200 |
| commit | a632375764aa25c97b78beb56c71b0ba59d1cf83 (patch) | |
| tree | 367b9197b23b4010591750bff661656f7bce7a6e /tools/perf/scripts/python/intel-pt-events.py | |
| parent | 81d387190039c14edac8de2b3ec789beb899afd9 (diff) | |
x86/ldt/64: Refresh DS and ES when modify_ldt changes an entry
On x86_32, modify_ldt() implicitly refreshes the cached DS and ES
segments because they are refreshed on return to usermode.
On x86_64, they're not refreshed on return to usermode. To improve
determinism and match x86_32's behavior, refresh them when we update
the LDT.
This avoids a situation in which the DS points to a descriptor that is
changed but the old cached segment persists until the next reschedule.
If this happens, then the user-visible state will change
nondeterministically some time after modify_ldt() returns, which is
unfortunate.
Signed-off-by: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Chang Seok <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'tools/perf/scripts/python/intel-pt-events.py')
0 files changed, 0 insertions, 0 deletions