blob: d2a1f7757d5d797fa4890739ca6da15eb7583b13 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
From c496ed83a15de9cbad1ee25f6fc55fc7b9136f43 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@kernel.org>
Date: Sun, 17 Sep 2017 09:03:50 -0700
Subject: [PATCH 060/102] 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>
---
arch/x86/kernel/cpu/common.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8339b43..7b9ae04 100644
--- 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)
--
2.7.4
|