[PATCH 4.4 049/107] x86/bugs: Concentrate bug detection into a separate function

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>

commit 4a28bfe3267b68e22c663ac26185aa16c9b879ef upstream

Combine the various logic which goes through all those
x86_cpu_id matching structures in one function.

Suggested-by: Borislav Petkov <b...@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Reviewed-by: Borislav Petkov <b...@suse.de>
Reviewed-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Srivatsa S. Bhat <sriva...@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.hels...@gmail.com>
Reviewed-by: Alexey Makhalov <amakha...@vmware.com>
Reviewed-by: Bo Gan <g...@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---

 arch/x86/kernel/cpu/common.c |   21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -835,21 +835,27 @@ static const __initconst struct x86_cpu_
        {}
 };
 
-static bool __init cpu_vulnerable_to_meltdown(struct cpuinfo_x86 *c)
+static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 {
        u64 ia32_cap = 0;
 
+       if (x86_match_cpu(cpu_no_speculation))
+               return;
+
+       setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
+       setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
        if (x86_match_cpu(cpu_no_meltdown))
-               return false;
+               return;
 
        if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
                rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
 
        /* Rogue Data Cache Load? No! */
        if (ia32_cap & ARCH_CAP_RDCL_NO)
-               return false;
+               return;
 
-       return true;
+       setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
 }
 
 /*
@@ -898,12 +904,7 @@ static void __init early_identify_cpu(st
 
        setup_force_cpu_cap(X86_FEATURE_ALWAYS);
 
-       if (!x86_match_cpu(cpu_no_speculation)) {
-               if (cpu_vulnerable_to_meltdown(c))
-                       setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
-               setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
-               setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
-       }
+       cpu_set_bug_bits(c);
 
        fpu__init_system(c);