lkml.org 
[lkml]   [2017]   [Sep]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/urgent] x86/mm/32: Move setup_clear_cpu_cap(X86_FEATURE_PCID) earlier
Commit-ID:  b8b7abaed7a49b350f8ba659ddc264b04931d581
Gitweb: http://git.kernel.org/tip/b8b7abaed7a49b350f8ba659ddc264b04931d581
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Sun, 17 Sep 2017 09:03:50 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 17 Sep 2017 18:59:08 +0200

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

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>
---
arch/x86/kernel/cpu/bugs.c | 8 --------
arch/x86/kernel/cpu/common.c | 8 ++++++++
2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index db68488..0af86d9 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -21,14 +21,6 @@

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 775f101..c9176ba 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -904,6 +904,14 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)

setup_force_cpu_cap(X86_FEATURE_ALWAYS);
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)
\
 
 \ /
  Last update: 2017-09-17 20:24    [W:0.063 / U:1.888 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site