[PATCH 5.4 02/33] x86,bugs: Unconditionally allow spectre_v2=retpoline,amd

Greg Kroah-Hartman
2022-03-10T14:41:56Z

From: Peter Zijlstra <peterz@infradead.org>

commit f8a66d608a3e471e1202778c2a36cbdc96bae73b upstream.

Currently Linux prevents usage of retpoline,amd on !AMD hardware, this
is unfriendly and gets in the way of testing. Remove this restriction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120310.487348118@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/cpu/bugs.c | 7 -------
1 file changed, 7 deletions(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -839,13 +839,6 @@ static enum spectre_v2_mitigation_cmd __
return SPECTRE_V2_CMD_AUTO;
}

- if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD &&
- boot_cpu_data.x86_vendor != X86_VENDOR_HYGON &&
- boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
- pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n");
- return SPECTRE_V2_CMD_AUTO;
- }
-
spec_v2_print_cond(mitigation_options[i].option,
mitigation_options[i].secure);
return cmd;