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authorAndy Lutomirski <luto@kernel.org>2017-09-17 09:03:51 -0700
committerIngo Molnar <mingo@kernel.org>2017-09-17 18:59:09 +0200
commit4ba55e65f471d011d3ba2ac2022180ea0877d68e (patch)
tree1f2760ddbd6d5e8b97f824206b506ee9a892e2c4
parentb8b7abaed7a49b350f8ba659ddc264b04931d581 (diff)
downloadlinux-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.c13
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();
/*