x86/speculation: Fill RSB on vmexit for IBRS
authorJosh Poimboeuf <jpoimboe@kernel.org>
Tue, 14 Jun 2022 21:16:15 +0000 (23:16 +0200)
committerBorislav Petkov <bp@suse.de>
Mon, 27 Jun 2022 08:34:00 +0000 (10:34 +0200)
commit9756bba28470722dacb79ffce554336dd1f6a6cd
tree2de4396bfa550c400fe8380e435fb28169733cd9
parentbea7e31a5caccb6fe8ed989c065072354f0ecb52
x86/speculation: Fill RSB on vmexit for IBRS

Prevent RSB underflow/poisoning attacks with RSB.  While at it, add a
bunch of comments to attempt to document the current state of tribal
knowledge about RSB attacks and what exactly is being mitigated.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
arch/x86/include/asm/cpufeatures.h
arch/x86/kernel/cpu/bugs.c
arch/x86/kvm/vmx/vmenter.S