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| author | Andy Lutomirski <luto@kernel.org> | 2017-07-26 16:16:30 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-07-27 09:12:57 +0200 |
| commit | a632375764aa25c97b78beb56c71b0ba59d1cf83 (patch) | |
| tree | 367b9197b23b4010591750bff661656f7bce7a6e /tools/objtool/arch | |
| parent | x86/kconfig: Consolidate unwinders into multiple choice selection (diff) | |
| download | linux-a632375764aa25c97b78beb56c71b0ba59d1cf83.tar.xz linux-a632375764aa25c97b78beb56c71b0ba59d1cf83.zip | |
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 <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Chang Seok <chang.seok.bae@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/objtool/arch')
0 files changed, 0 insertions, 0 deletions