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Commit 52c90f2d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 page table isolation fixes from Thomas Gleixner:
 "Four patches addressing the PTI fallout as discussed and debugged
  yesterday:

   - Remove stale and pointless TLB flush invocations from the hotplug
     code

   - Remove stale preempt_disable/enable from __native_flush_tlb()

   - Plug the memory leak in the write_ldt() error path"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ldt: Make LDT pgtable free conditional
  x86/ldt: Plug memory leak in error path
  x86/mm: Remove preempt_disable/enable() from __native_flush_tlb()
  x86/smpboot: Remove stale TLB flush invocations
parents cea92e84 7f414195

arch/x86/include/asm/tlbflush.h

+8 −6
Original line number Diff line number Diff line
@@ -348,15 +348,17 @@ static inline void invalidate_user_asid(u16 asid) 
 */

static inline void __native_flush_tlb(void)

{

	invalidate_user_asid(this_cpu_read(cpu_tlbstate.loaded_mm_asid));

	/*

	 * If current->mm == NULL then we borrow a mm which may change

	 * during a task switch and therefore we must not be preempted

	 * while we write CR3 back:

	 * Preemption or interrupts must be disabled to protect the access

	 * to the per CPU variable and to prevent being preempted between

	 * read_cr3() and write_cr3().

	 */

	preempt_disable();

	WARN_ON_ONCE(preemptible());



	invalidate_user_asid(this_cpu_read(cpu_tlbstate.loaded_mm_asid));



	/* If current->mm == NULL then the read_cr3() "borrows" an mm */

	native_write_cr3(__native_read_cr3());

	preempt_enable();

}



/*

arch/x86/kernel/ldt.c

+8 −1
Original line number Diff line number Diff line
@@ -421,7 +421,14 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) 
	 */

	error = map_ldt_struct(mm, new_ldt, old_ldt ? !old_ldt->slot : 0);

	if (error) {

		free_ldt_struct(old_ldt);

		/*

		 * This only can fail for the first LDT setup. If an LDT is

		 * already installed then the PTE page is already

		 * populated. Mop up a half populated page table.

		 */

		if (!WARN_ON_ONCE(old_ldt))

			free_ldt_pgtables(mm);

		free_ldt_struct(new_ldt);

		goto out_unlock;

	}

arch/x86/kernel/smpboot.c

+0 −9
Original line number Diff line number Diff line
@@ -126,25 +126,16 @@ static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip) 
	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)

{

	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.