static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
{
char arg[20];
int ret, i;
enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO;
if (cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
return SPECTRE_V2_CMD_NONE;
else {
ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, sizeof(arg));
if (ret < 0)
return SPECTRE_V2_CMD_AUTO;
for (i = 0; i < ARRAY_SIZE(mitigation_options); i++) {
if (!match_option(arg, ret, mitigation_options[i].option))
continue;
cmd = mitigation_options[i].cmd;
break;
}
if (i >= ARRAY_SIZE(mitigation_options)) {
pr_err("unknown option (%s). Switching to AUTO select\n", arg);
return SPECTRE_V2_CMD_AUTO;
}
}
if ((cmd == SPECTRE_V2_CMD_RETPOLINE ||
cmd == SPECTRE_V2_CMD_RETPOLINE_AMD ||
cmd == SPECTRE_V2_CMD_RETPOLINE_GENERIC) &&
!IS_ENABLED(CONFIG_RETPOLINE)) {
pr_err("%s selected but not compiled in. Switching to AUTO select\n", mitigation_options[i].option);
return SPECTRE_V2_CMD_AUTO;
}
if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD &&
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;
}
if (mitigation_options[i].secure)
spec2_print_if_secure(mitigation_options[i].option);
else
spec2_print_if_insecure(mitigation_options[i].option);
return cmd;
}
static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
{
char arg[20];
int ret;
ret = cmdline_find_option(boot_command_line, "spectre_v2", arg,
sizeof(arg));
if (ret > 0) {
if (match_option(arg, ret, "off")) {
goto disable;
} else if (match_option(arg, ret, "on")) {
spec2_print_if_secure("force enabled on command line.");
return SPECTRE_V2_CMD_FORCE;
} else if (match_option(arg, ret, "retpoline")) {
spec2_print_if_insecure("retpoline selected on command line.");
return SPECTRE_V2_CMD_RETPOLINE;
} else if (match_option(arg, ret, "retpoline,amd")) {
if (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;
}
spec2_print_if_insecure("AMD retpoline selected on command line.");
return SPECTRE_V2_CMD_RETPOLINE_AMD;
} else if (match_option(arg, ret, "retpoline,generic")) {
spec2_print_if_insecure("generic retpoline selected on command line.");
return SPECTRE_V2_CMD_RETPOLINE_GENERIC;
} else if (match_option(arg, ret, "auto")) {
return SPECTRE_V2_CMD_AUTO;
}
}
if (!cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
return SPECTRE_V2_CMD_AUTO;
disable:
spec2_print_if_insecure("disabled on command line.");
return SPECTRE_V2_CMD_NONE;
}
