powerpc/bpf: Emit stf barrier instruction sequences for BPF_NOSPEC
upstream commit
b7540d62509453263604a155bf2d5f0ed450cba2
Emit similar instruction sequences to commit
a048a07d7f4535
("powerpc/64s: Add support for a store forwarding barrier at kernel
entry/exit") when encountering BPF_NOSPEC.
Mitigations are enabled depending on what the firmware advertises. In
particular, we do not gate these mitigations based on current settings,
just like in x86. Due to this, we don't need to take any action if
mitigations are enabled or disabled at runtime.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/956570cbc191cd41f8274bed48ee757a86dac62a.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
[adjust macros to account for commits
1c9debbc2eb539 and
ef909ba954145e.
adjust security feature checks to account for commit
84ed26fd00c514]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>