On Sun, Nov 25, 2018 at 07:33:32PM +0100, Thomas Gleixner wrote:
> 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.
>
Yeeey!
Reviewed-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Thank you!
> Signed-off-by: Tim Chen <tim.c.c...@linux.intel.com>
> Signed-off-by: Thomas Gleixner <t...@linutronix.de>
>
> ---
> arch/x86/kernel/cpu/bugs.c | 20 ++++++++++++++++++--
> 1 file changed, 18 insertions(+), 2 deletions(-)
>
> --- a/arch/x86/kernel/cpu/bugs.c
> +++ b/arch/x86/kernel/cpu/bugs.c
> @@ -844,6 +844,22 @@ 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)
> {
> @@ -865,9 +881,9 @@ static ssize_t cpu_show_common(struct de
>
> 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());
>
>
>
