x86/mm/32: Move setup_clear_cpu_cap(X86_FEATURE_PCID) earlier

commit b8b7abaed7a49b350f8ba659ddc264b04931d581 upstream.

Otherwise we might have the PCID feature bit set during cpu_init().

This is just for robustness.  I haven't seen any actual bugs here.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: cba4671af755 ("x86/mm: Disable PCID on 32-bit kernels")
Link: http://lkml.kernel.org/r/b16dae9d6b0db5d9801ddbebbfd83384097c61f3.1505663533.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index cd46f90..cb6b4f9 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -22,14 +22,6 @@
 
 void __init check_bugs(void)
 {
-#ifdef CONFIG_X86_32
-       /*
-        * Regardless of whether PCID is enumerated, the SDM says
-        * that it can't be enabled in 32-bit mode.
-        */
-       setup_clear_cpu_cap(X86_FEATURE_PCID);
-#endif
-
        identify_boot_cpu();
 
        if (!IS_ENABLED(CONFIG_SMP)) {

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8339b43..7b9ae04 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -890,6 +890,14 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
        setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
 
        fpu__init_system(c);
+
+#ifdef CONFIG_X86_32
+       /*
+        * Regardless of whether PCID is enumerated, the SDM says
+        * that it can't be enabled in 32-bit mode.
+        */
+       setup_clear_cpu_cap(X86_FEATURE_PCID);
+#endif
 }
 
 void __init early_cpu_init(void)