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

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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>
This commit is contained in:
Andy Lutomirski 2017-09-17 09:03:50 -07:00 committed by Greg Kroah-Hartman
parent 91b7e5cdc8
commit 00bcb5ada6
2 changed files with 8 additions and 8 deletions
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8
arch/x86/kernel/cpu/bugs.c
View File

@ -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)) {

8
arch/x86/kernel/cpu/common.c
View File

@ -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)