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    Subject[patch 04/24] x86/speculation: Reorganize cpu_show_common()
    From: Tim Chen <tim.c.chen@linux.intel.com>

    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>
    Signed-off-by: Thomas Gleixner <tglx@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());


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