This is a note to let you know that I've just added the patch titled

x86/smpboot: Remove stale TLB flush invocations

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: x86-smpboot-remove-stale-tlb-flush-invocations.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 322f8b8b340c824aef891342b0f5795d15e11562 Mon Sep 17 00:00:00 2001

From: Thomas Gleixner tglx@linutronix.de Date: Sat, 30 Dec 2017 22:13:53 +0100 Subject: x86/smpboot: Remove stale TLB flush invocations

From: Thomas Gleixner tglx@linutronix.de

commit 322f8b8b340c824aef891342b0f5795d15e11562 upstream.

smpboot_setup_warm_reset_vector() and smpboot_restore_warm_reset_vector() invoke local_flush_tlb() for no obvious reason.

Digging in history revealed that the original code in the 2.1 era added those because the code manipulated a swapper_pg_dir pagetable entry. The pagetable manipulation was removed long ago in the 2.3 timeframe, but the TLB flush invocations stayed around forever.

Remove them along with the pointless pr_debug()s which come from the same 2.1 change.

Reported-by: Dominik Brodowski linux@dominikbrodowski.net Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Andy Lutomirski luto@kernel.org Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Linus Torvalds torvalds@linuxfoundation.org Cc: Peter Zijlstra peterz@infradead.org Link: http://lkml.kernel.org/r/20171230211829.586548655@linutronix.de Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/x86/kernel/smpboot.c | 9 --------- 1 file changed, 9 deletions(-)

--- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -115,14 +115,10 @@ static inline void smpboot_setup_warm_re spin_lock_irqsave(&rtc_lock, flags); CMOS_WRITE(0xa, 0xf); spin_unlock_irqrestore(&rtc_lock, flags); - local_flush_tlb(); - pr_debug("1.\n"); *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = start_eip >> 4; - pr_debug("2.\n"); *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = start_eip & 0xf; - pr_debug("3.\n"); }

static inline void smpboot_restore_warm_reset_vector(void) @@ -130,11 +126,6 @@ static inline void smpboot_restore_warm_ unsigned long flags;

/* - * Install writable page 0 entry to set BIOS data area. - */ - local_flush_tlb(); - - /* * Paranoid: Set warm reset code and vector here back * to default values. */

Patches currently in stable-queue which might be from tglx@linutronix.de are

queue-4.9/nohz-prevent-a-timer-interrupt-storm-in-tick_nohz_stop_sched_tick.patch queue-4.9/timers-invoke-timer_start_debug-where-it-makes-sense.patch queue-4.9/x86-vm86-32-switch-to-flush_tlb_mm_range-in-mark_screen_rdonly.patch queue-4.9/x86-mm-add-the-nopcid-boot-option-to-turn-off-pcid.patch queue-4.9/x86-mm-enable-cr4.pcide-on-supported-systems.patch queue-4.9/sync-objtool-s-copy-of-x86-opcode-map.txt.patch queue-4.9/x86-smpboot-remove-stale-tlb-flush-invocations.patch queue-4.9/timers-use-deferrable-base-independent-of-base-nohz_active.patch queue-4.9/x86-mm-remove-the-up-asm-tlbflush.h-code-always-use-the-formerly-smp-code.patch queue-4.9/x86-mm-reimplement-flush_tlb_page-using-flush_tlb_mm_range.patch queue-4.9/x86-mm-make-flush_tlb_mm_range-more-predictable.patch queue-4.9/x86-mm-remove-flush_tlb-and-flush_tlb_current_task.patch queue-4.9/x86-mm-disable-pcid-on-32-bit-kernels.patch queue-4.9/timers-reinitialize-per-cpu-bases-on-hotplug.patch queue-4.9/x86-mm-64-fix-reboot-interaction-with-cr4.pcide.patch