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| author | Andy Lutomirski <luto@kernel.org> | 2017-09-17 09:03:51 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-09-17 18:59:09 +0200 |
| commit | 4ba55e65f471d011d3ba2ac2022180ea0877d68e (patch) | |
| tree | 1f2760ddbd6d5e8b97f824206b506ee9a892e2c4 | |
| parent | b8b7abaed7a49b350f8ba659ddc264b04931d581 (diff) | |
| download | linux-4ba55e65f471d011d3ba2ac2022180ea0877d68e.tar.bz2 | |
x86/mm/32: Load a sane CR3 before cpu_init() on secondary CPUs
For unknown historical reasons (i.e. Borislav doesn't recall),
32-bit kernels invoke cpu_init() on secondary CPUs with
initial_page_table loaded into CR3. Then they set
current->active_mm to &init_mm and call enter_lazy_tlb() before
fixing CR3. This means that the x86 TLB code gets invoked while CR3
is inconsistent, and, with the improved PCID sanity checks I added,
we warn.
Fix it by loading swapper_pg_dir (i.e. init_mm.pgd) earlier.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
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: 72c0098d92ce ("x86/mm: Reinitialize TLB state on hotplug and resume")
Link: http://lkml.kernel.org/r/30cdfea504682ba3b9012e77717800a91c22097f.1505663533.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 0854ff169274..ad59edd84de7 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -232,12 +232,6 @@ static void notrace start_secondary(void *unused) */ if (boot_cpu_has(X86_FEATURE_PCID)) __write_cr4(__read_cr4() | X86_CR4_PCIDE); - cpu_init(); - x86_cpuinit.early_percpu_clock_init(); - preempt_disable(); - smp_callin(); - - enable_start_cpu0 = 0; #ifdef CONFIG_X86_32 /* switch away from the initial page table */ @@ -245,6 +239,13 @@ static void notrace start_secondary(void *unused) __flush_tlb_all(); #endif + cpu_init(); + x86_cpuinit.early_percpu_clock_init(); + preempt_disable(); + smp_callin(); + + enable_start_cpu0 = 0; + /* otherwise gcc will move up smp_processor_id before the cpu_init */ barrier(); /* |