The Spectre V2 printout in cpu_show_common() handles conditionals for the various mitigation methods directly in the sprintf() argument list. That's hard to read and will become unreadable if more complex decisions need to be made for a particular method.
Move the conditionals for STIBP and IBPB string selection into helper functions, so they can be extended later on.
Signed-off-by: Tim Chen tim.c.chen@linux.intel.com --- arch/x86/kernel/cpu/bugs.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 84e3579..91a754a 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -853,6 +853,22 @@ static ssize_t l1tf_show_state(char *buf) } #endif
+static char *stibp_state(void) +{ + if (x86_spec_ctrl_base & SPEC_CTRL_STIBP) + return ", STIBP"; + else + return ""; +} + +static char *ibpb_state(void) +{ + if (boot_cpu_has(X86_FEATURE_USE_IBPB)) + return ", IBPB"; + else + return ""; +} + static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr, char *buf, unsigned int bug) { @@ -874,9 +890,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
case X86_BUG_SPECTRE_V2: return sprintf(buf, "%s%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled], - boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "", + ibpb_state(), boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "", - (x86_spec_ctrl_base & SPEC_CTRL_STIBP) ? ", STIBP" : "", + stibp_state(), boot_cpu_has(X86_FEATURE_RSB_CTXSW) ? ", RSB filling" : "", spectre_v2_module_string());