Messages in this thread | | | Date | Fri, 20 Oct 2023 16:49:34 -0700 | From | Andi Kleen <> | Subject | Re: [PATCH 3/6] x86/entry_32: Add VERW just before userspace transition |
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On Fri, Oct 20, 2023 at 01:45:09PM -0700, Pawan Gupta wrote: > As done for entry_64, add support for executing VERW late in exit to > user path for 32-bit mode. > > Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> > --- > arch/x86/entry/entry_32.S | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S > index 6e6af42e044a..bbf77d2aab2e 100644 > --- a/arch/x86/entry/entry_32.S > +++ b/arch/x86/entry/entry_32.S > @@ -886,6 +886,9 @@ SYM_FUNC_START(entry_SYSENTER_32) > popfl > popl %eax > > + /* Mitigate CPU data sampling attacks .e.g. MDS */ > + USER_CLEAR_CPU_BUFFERS > + > /* > * Return back to the vDSO, which will pop ecx and edx. > * Don't bother with DS and ES (they already contain __USER_DS).
Did you forget the INT 0x80 entry point?
-Andi
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