diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst
index 334df758dce3..dae90c21aed3 100644
--- a/Documentation/kbuild/llvm.rst
+++ b/Documentation/kbuild/llvm.rst
@@ -39,10 +39,10 @@ which can help simplify cross compiling. ::
 	ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make CC=clang
 
 ``CROSS_COMPILE`` is not used to prefix the Clang compiler binary, instead
-``CROSS_COMPILE`` is used to set a command line flag: ``--target <triple>``. For
+``CROSS_COMPILE`` is used to set a command line flag: ``--target=<triple>``. For
 example: ::
 
-	clang --target aarch64-linux-gnu foo.c
+	clang --target=aarch64-linux-gnu foo.c
 
 LLVM Utilities
 --------------
diff --git a/Makefile b/Makefile
index 3663fe2dfb32..f364c34b49e8 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 VERSION = 5
 PATCHLEVEL = 9
 SUBLEVEL = 0
-EXTRAVERSION = -rc6
+EXTRAVERSION = -rc7
 NAME = Kleptomaniac Octopus
 
 # *DOCUMENTATION*
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 2f84c7ca74ea..870efeec8bda 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -299,7 +299,7 @@ __visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs)
 	old_regs = set_irq_regs(regs);
 
 	instrumentation_begin();
-	run_on_irqstack_cond(__xen_pv_evtchn_do_upcall, NULL, regs);
+	run_on_irqstack_cond(__xen_pv_evtchn_do_upcall, regs);
 	instrumentation_begin();
 
 	set_irq_regs(old_regs);
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 70dea9337816..d977079a7d02 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -682,6 +682,8 @@ SYM_CODE_END(.Lbad_gs)
  * rdx: Function argument (can be NULL if none)
  */
 SYM_FUNC_START(asm_call_on_stack)
+SYM_INNER_LABEL(asm_call_sysvec_on_stack, SYM_L_GLOBAL)
+SYM_INNER_LABEL(asm_call_irq_on_stack, SYM_L_GLOBAL)
 	/*
 	 * Save the frame pointer unconditionally. This allows the ORC
 	 * unwinder to handle the stack switch.
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index a43366191212..a0638640f1ed 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -242,7 +242,7 @@ __visible noinstr void func(struct pt_regs *regs)			\
 	instrumentation_begin();					\
 	irq_enter_rcu();						\
 	kvm_set_cpu_l1tf_flush_l1d();					\
-	run_on_irqstack_cond(__##func, regs, regs);			\
+	run_sysvec_on_irqstack_cond(__##func, regs);			\
 	irq_exit_rcu();							\
 	instrumentation_end();						\
 	irqentry_exit(regs, state);					\
diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h
index 4ae66f097101..775816965c6a 100644
--- a/arch/x86/include/asm/irq_stack.h
+++ b/arch/x86/include/asm/irq_stack.h
@@ -12,20 +12,50 @@ static __always_inline bool irqstack_active(void)
 	return __this_cpu_read(irq_count) != -1;
 }
 
-void asm_call_on_stack(void *sp, void *func, void *arg);
+void asm_call_on_stack(void *sp, void (*func)(void), void *arg);
+void asm_call_sysvec_on_stack(void *sp, void (*func)(struct pt_regs *regs),
+			      struct pt_regs *regs);
+void asm_call_irq_on_stack(void *sp, void (*func)(struct irq_desc *desc),
+			   struct irq_desc *desc);
 
-static __always_inline void __run_on_irqstack(void *func, void *arg)
+static __always_inline void __run_on_irqstack(void (*func)(void))
 {
 	void *tos = __this_cpu_read(hardirq_stack_ptr);
 
 	__this_cpu_add(irq_count, 1);
-	asm_call_on_stack(tos - 8, func, arg);
+	asm_call_on_stack(tos - 8, func, NULL);
+	__this_cpu_sub(irq_count, 1);
+}
+
+static __always_inline void
+__run_sysvec_on_irqstack(void (*func)(struct pt_regs *regs),
+			 struct pt_regs *regs)
+{
+	void *tos = __this_cpu_read(hardirq_stack_ptr);
+
+	__this_cpu_add(irq_count, 1);
+	asm_call_sysvec_on_stack(tos - 8, func, regs);
+	__this_cpu_sub(irq_count, 1);
+}
+
+static __always_inline void
+__run_irq_on_irqstack(void (*func)(struct irq_desc *desc),
+		      struct irq_desc *desc)
+{
+	void *tos = __this_cpu_read(hardirq_stack_ptr);
+
+	__this_cpu_add(irq_count, 1);
+	asm_call_irq_on_stack(tos - 8, func, desc);
 	__this_cpu_sub(irq_count, 1);
 }
 
 #else /* CONFIG_X86_64 */
 static inline bool irqstack_active(void) { return false; }
-static inline void __run_on_irqstack(void *func, void *arg) { }
+static inline void __run_on_irqstack(void (*func)(void)) { }
+static inline void __run_sysvec_on_irqstack(void (*func)(struct pt_regs *regs),
+					    struct pt_regs *regs) { }
+static inline void __run_irq_on_irqstack(void (*func)(struct irq_desc *desc),
+					 struct irq_desc *desc) { }
 #endif /* !CONFIG_X86_64 */
 
 static __always_inline bool irq_needs_irq_stack(struct pt_regs *regs)
@@ -37,17 +67,40 @@ static __always_inline bool irq_needs_irq_stack(struct pt_regs *regs)
 	return !user_mode(regs) && !irqstack_active();
 }
 
-static __always_inline void run_on_irqstack_cond(void *func, void *arg,
+
+static __always_inline void run_on_irqstack_cond(void (*func)(void),
 						 struct pt_regs *regs)
 {
-	void (*__func)(void *arg) = func;
-
 	lockdep_assert_irqs_disabled();
 
 	if (irq_needs_irq_stack(regs))
-		__run_on_irqstack(__func, arg);
+		__run_on_irqstack(func);
 	else
-		__func(arg);
+		func();
+}
+
+static __always_inline void
+run_sysvec_on_irqstack_cond(void (*func)(struct pt_regs *regs),
+			    struct pt_regs *regs)
+{
+	lockdep_assert_irqs_disabled();
+
+	if (irq_needs_irq_stack(regs))
+		__run_sysvec_on_irqstack(func, regs);
+	else
+		func(regs);
+}
+
+static __always_inline void
+run_irq_on_irqstack_cond(void (*func)(struct irq_desc *desc), struct irq_desc *desc,
+			 struct pt_regs *regs)
+{
+	lockdep_assert_irqs_disabled();
+
+	if (irq_needs_irq_stack(regs))
+		__run_irq_on_irqstack(func, desc);
+	else
+		func(desc);
 }
 
 #endif
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 779a89e31c4c..21f9c7f11779 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2243,6 +2243,7 @@ static inline void __init check_timer(void)
 	legacy_pic->init(0);
 	legacy_pic->make_irq(0);
 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
+	legacy_pic->unmask(0);
 
 	unlock_ExtINT_logic();
 
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 181060247e3c..c5dd50369e2f 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -227,7 +227,7 @@ static __always_inline void handle_irq(struct irq_desc *desc,
 				       struct pt_regs *regs)
 {
 	if (IS_ENABLED(CONFIG_X86_64))
-		run_on_irqstack_cond(desc->handle_irq, desc, regs);
+		run_irq_on_irqstack_cond(desc->handle_irq, desc, regs);
 	else
 		__handle_irq(desc, regs);
 }
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 1b4fe93a86c5..440eed558558 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -74,5 +74,5 @@ int irq_init_percpu_irqstack(unsigned int cpu)
 
 void do_softirq_own_stack(void)
 {
-	run_on_irqstack_cond(__do_softirq, NULL, NULL);
+	run_on_irqstack_cond(__do_softirq, NULL);
 }
diff --git a/drivers/clocksource/h8300_timer8.c b/drivers/clocksource/h8300_timer8.c
index 1d740a8c42ab..47114c2a7cb5 100644
--- a/drivers/clocksource/h8300_timer8.c
+++ b/drivers/clocksource/h8300_timer8.c
@@ -169,7 +169,7 @@ static int __init h8300_8timer_init(struct device_node *node)
 		return PTR_ERR(clk);
 	}
 
-	ret = ENXIO;
+	ret = -ENXIO;
 	base = of_iomap(node, 0);
 	if (!base) {
 		pr_err("failed to map registers for clockevent\n");
diff --git a/drivers/clocksource/timer-gx6605s.c b/drivers/clocksource/timer-gx6605s.c
index 80d0939d040b..8d386adbe800 100644
--- a/drivers/clocksource/timer-gx6605s.c
+++ b/drivers/clocksource/timer-gx6605s.c
@@ -28,6 +28,7 @@ static irqreturn_t gx6605s_timer_interrupt(int irq, void *dev)
 	void __iomem *base = timer_of_base(to_timer_of(ce));
 
 	writel_relaxed(GX6605S_STATUS_CLR, base + TIMER_STATUS);
+	writel_relaxed(0, base + TIMER_INI);
 
 	ce->event_handler(ce);
 
diff --git a/drivers/clocksource/timer-ti-dm-systimer.c b/drivers/clocksource/timer-ti-dm-systimer.c
index f6fd1c1cc527..33b3e8aa2cc5 100644
--- a/drivers/clocksource/timer-ti-dm-systimer.c
+++ b/drivers/clocksource/timer-ti-dm-systimer.c
@@ -69,12 +69,33 @@ static bool dmtimer_systimer_revision1(struct dmtimer_systimer *t)
 	return !(tidr >> 16);
 }
 
+static void dmtimer_systimer_enable(struct dmtimer_systimer *t)
+{
+	u32 val;
+
+	if (dmtimer_systimer_revision1(t))
+		val = DMTIMER_TYPE1_ENABLE;
+	else
+		val = DMTIMER_TYPE2_ENABLE;
+
+	writel_relaxed(val, t->base + t->sysc);
+}
+
+static void dmtimer_systimer_disable(struct dmtimer_systimer *t)
+{
+	if (!dmtimer_systimer_revision1(t))
+		return;
+
+	writel_relaxed(DMTIMER_TYPE1_DISABLE, t->base + t->sysc);
+}
+
 static int __init dmtimer_systimer_type1_reset(struct dmtimer_systimer *t)
 {
 	void __iomem *syss = t->base + OMAP_TIMER_V1_SYS_STAT_OFFSET;
 	int ret;
 	u32 l;
 
+	dmtimer_systimer_enable(t);
 	writel_relaxed(BIT(1) | BIT(2), t->base + t->ifctrl);
 	ret = readl_poll_timeout_atomic(syss, l, l & BIT(0), 100,
 					DMTIMER_RESET_WAIT);
@@ -88,6 +109,7 @@ static int __init dmtimer_systimer_type2_reset(struct dmtimer_systimer *t)
 	void __iomem *sysc = t->base + t->sysc;
 	u32 l;
 
+	dmtimer_systimer_enable(t);
 	l = readl_relaxed(sysc);
 	l |= BIT(0);
 	writel_relaxed(l, sysc);
@@ -336,26 +358,6 @@ static int __init dmtimer_systimer_init_clock(struct dmtimer_systimer *t,
 	return 0;
 }
 
-static void dmtimer_systimer_enable(struct dmtimer_systimer *t)
-{
-	u32 val;
-
-	if (dmtimer_systimer_revision1(t))
-		val = DMTIMER_TYPE1_ENABLE;
-	else
-		val = DMTIMER_TYPE2_ENABLE;
-
-	writel_relaxed(val, t->base + t->sysc);
-}
-
-static void dmtimer_systimer_disable(struct dmtimer_systimer *t)
-{
-	if (!dmtimer_systimer_revision1(t))
-		return;
-
-	writel_relaxed(DMTIMER_TYPE1_DISABLE, t->base + t->sysc);
-}
-
 static int __init dmtimer_systimer_setup(struct device_node *np,
 					 struct dmtimer_systimer *t)
 {
@@ -409,8 +411,8 @@ static int __init dmtimer_systimer_setup(struct device_node *np,
 	t->wakeup = regbase + _OMAP_TIMER_WAKEUP_EN_OFFSET;
 	t->ifctrl = regbase + _OMAP_TIMER_IF_CTRL_OFFSET;
 
-	dmtimer_systimer_enable(t);
 	dmtimer_systimer_reset(t);
+	dmtimer_systimer_enable(t);
 	pr_debug("dmtimer rev %08x sysc %08x\n", readl_relaxed(t->base),
 		 readl_relaxed(t->base + t->sysc));
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5d0c0388480c..901cca87957f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1646,7 +1646,7 @@ struct mmu_notifier_range;
 void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
 		unsigned long end, unsigned long floor, unsigned long ceiling);
 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
-			struct vm_area_struct *vma);
+		    struct vm_area_struct *vma, struct vm_area_struct *new);
 int follow_pte_pmd(struct mm_struct *mm, unsigned long address,
 		   struct mmu_notifier_range *range,
 		   pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 9103b83eb1b0..2e58e45d867f 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -443,6 +443,16 @@ struct mm_struct {
 		 */
 		atomic_t mm_count;
 
+		/**
+		 * @has_pinned: Whether this mm has pinned any pages.  This can
+		 * be either replaced in the future by @pinned_vm when it
+		 * becomes stable, or grow into a counter on its own. We're
+		 * aggresive on this bit now - even if the pinned pages were
+		 * unpinned later on, we'll still keep this bit set for the
+		 * lifecycle of this mm just for simplicity.
+		 */
+		atomic_t has_pinned;
+
 #ifdef CONFIG_MMU
 		atomic_long_t pgtables_bytes;	/* PTE page table pages */
 #endif
diff --git a/kernel/fork.c b/kernel/fork.c
index f4db5653594f..c9dc66faf1be 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -591,7 +591,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
 
 		mm->map_count++;
 		if (!(tmp->vm_flags & VM_WIPEONFORK))
-			retval = copy_page_range(mm, oldmm, mpnt);
+			retval = copy_page_range(mm, oldmm, mpnt, tmp);
 
 		if (tmp->vm_ops && tmp->vm_ops->open)
 			tmp->vm_ops->open(tmp);
@@ -1013,6 +1013,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
 	mm_pgtables_bytes_init(mm);
 	mm->map_count = 0;
 	mm->locked_vm = 0;
+	atomic_set(&mm->has_pinned, 0);
 	atomic64_set(&mm->pinned_vm, 0);
 	memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
 	spin_lock_init(&mm->page_table_lock);
diff --git a/mm/gup.c b/mm/gup.c
index 578bf5bd8bf8..dfe781d2ad4c 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1255,6 +1255,9 @@ static __always_inline long __get_user_pages_locked(struct mm_struct *mm,
 		BUG_ON(*locked != 1);
 	}
 
+	if (flags & FOLL_PIN)
+		atomic_set(&current->mm->has_pinned, 1);
+
 	/*
 	 * FOLL_PIN and FOLL_GET are mutually exclusive. Traditional behavior
 	 * is to set FOLL_GET if the caller wants pages[] filled in (but has
@@ -2660,6 +2663,9 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages,
 				       FOLL_FAST_ONLY)))
 		return -EINVAL;
 
+	if (gup_flags & FOLL_PIN)
+		atomic_set(&current->mm->has_pinned, 1);
+
 	if (!(gup_flags & FOLL_FAST_ONLY))
 		might_lock_read(&current->mm->mmap_lock);
 
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index faadc449cca5..da397779a6d4 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1074,6 +1074,24 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 
 	src_page = pmd_page(pmd);
 	VM_BUG_ON_PAGE(!PageHead(src_page), src_page);
+
+	/*
+	 * If this page is a potentially pinned page, split and retry the fault
+	 * with smaller page size.  Normally this should not happen because the
+	 * userspace should use MADV_DONTFORK upon pinned regions.  This is a
+	 * best effort that the pinned pages won't be replaced by another
+	 * random page during the coming copy-on-write.
+	 */
+	if (unlikely(is_cow_mapping(vma->vm_flags) &&
+		     atomic_read(&src_mm->has_pinned) &&
+		     page_maybe_dma_pinned(src_page))) {
+		pte_free(dst_mm, pgtable);
+		spin_unlock(src_ptl);
+		spin_unlock(dst_ptl);
+		__split_huge_pmd(vma, src_pmd, addr, false, NULL);
+		return -EAGAIN;
+	}
+
 	get_page(src_page);
 	page_dup_rmap(src_page, true);
 	add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
@@ -1177,6 +1195,16 @@ int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		/* No huge zero pud yet */
 	}
 
+	/* Please refer to comments in copy_huge_pmd() */
+	if (unlikely(is_cow_mapping(vma->vm_flags) &&
+		     atomic_read(&src_mm->has_pinned) &&
+		     page_maybe_dma_pinned(pud_page(pud)))) {
+		spin_unlock(src_ptl);
+		spin_unlock(dst_ptl);
+		__split_huge_pud(vma, src_pud, addr);
+		return -EAGAIN;
+	}
+
 	pudp_set_wrprotect(src_mm, addr, src_pud);
 	pud = pud_mkold(pud_wrprotect(pud));
 	set_pud_at(dst_mm, addr, dst_pud, pud);
diff --git a/mm/memory.c b/mm/memory.c
index 983b08f8dfb7..0fb7eba2dc6e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -786,15 +786,142 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	return 0;
 }
 
-static inline void
+/*
+ * Copy a present and normal page if necessary.
+ *
+ * NOTE! The usual case is that this doesn't need to do
+ * anything, and can just return a positive value. That
+ * will let the caller know that it can just increase
+ * the page refcount and re-use the pte the traditional
+ * way.
+ *
+ * But _if_ we need to copy it because it needs to be
+ * pinned in the parent (and the child should get its own
+ * copy rather than just a reference to the same page),
+ * we'll do that here and return zero to let the caller
+ * know we're done.
+ *
+ * And if we need a pre-allocated page but don't yet have
+ * one, return a negative error to let the preallocation
+ * code know so that it can do so outside the page table
+ * lock.
+ */
+static inline int
+copy_present_page(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+		pte_t *dst_pte, pte_t *src_pte,
+		struct vm_area_struct *vma, struct vm_area_struct *new,
+		unsigned long addr, int *rss, struct page **prealloc,
+		pte_t pte, struct page *page)
+{
+	struct page *new_page;
+
+	if (!is_cow_mapping(vma->vm_flags))
+		return 1;
+
+	/*
+	 * The trick starts.
+	 *
+	 * What we want to do is to check whether this page may
+	 * have been pinned by the parent process.  If so,
+	 * instead of wrprotect the pte on both sides, we copy
+	 * the page immediately so that we'll always guarantee
+	 * the pinned page won't be randomly replaced in the
+	 * future.
+	 *
+	 * To achieve this, we do the following:
+	 *
+	 * 1. Write-protect the pte if it's writable.  This is
+	 *    to protect concurrent write fast-gup with
+	 *    FOLL_PIN, so that we'll fail the fast-gup with
+	 *    the write bit removed.
+	 *
+	 * 2. Check page_maybe_dma_pinned() to see whether this
+	 *    page may have been pinned.
+	 *
+	 * The order of these steps is important to serialize
+	 * against the fast-gup code (gup_pte_range()) on the
+	 * pte check and try_grab_compound_head(), so that
+	 * we'll make sure either we'll capture that fast-gup
+	 * so we'll copy the pinned page here, or we'll fail
+	 * that fast-gup.
+	 *
+	 * NOTE! Even if we don't end up copying the page,
+	 * we won't undo this wrprotect(), because the normal
+	 * reference copy will need it anyway.
+	 */
+	if (pte_write(pte))
+		ptep_set_wrprotect(src_mm, addr, src_pte);
+
+	/*
+	 * These are the "normally we can just copy by reference"
+	 * checks.
+	 */
+	if (likely(!atomic_read(&src_mm->has_pinned)))
+		return 1;
+	if (likely(!page_maybe_dma_pinned(page)))
+		return 1;
+
+	/*
+	 * Uhhuh. It looks like the page might be a pinned page,
+	 * and we actually need to copy it. Now we can set the
+	 * source pte back to being writable.
+	 */
+	if (pte_write(pte))
+		set_pte_at(src_mm, addr, src_pte, pte);
+
+	new_page = *prealloc;
+	if (!new_page)
+		return -EAGAIN;
+
+	/*
+	 * We have a prealloc page, all good!  Take it
+	 * over and copy the page & arm it.
+	 */
+	*prealloc = NULL;
+	copy_user_highpage(new_page, page, addr, vma);
+	__SetPageUptodate(new_page);
+	page_add_new_anon_rmap(new_page, new, addr, false);
+	lru_cache_add_inactive_or_unevictable(new_page, new);
+	rss[mm_counter(new_page)]++;
+
+	/* All done, just insert the new page copy in the child */
+	pte = mk_pte(new_page, new->vm_page_prot);
+	pte = maybe_mkwrite(pte_mkdirty(pte), new);
+	set_pte_at(dst_mm, addr, dst_pte, pte);
+	return 0;
+}
+
+/*
+ * Copy one pte.  Returns 0 if succeeded, or -EAGAIN if one preallocated page
+ * is required to copy this pte.
+ */
+static inline int
 copy_present_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
-		unsigned long addr, int *rss)
+		struct vm_area_struct *new,
+		unsigned long addr, int *rss, struct page **prealloc)
 {
 	unsigned long vm_flags = vma->vm_flags;
 	pte_t pte = *src_pte;
 	struct page *page;
 
+	page = vm_normal_page(vma, addr, pte);
+	if (page) {
+		int retval;
+
+		retval = copy_present_page(dst_mm, src_mm,
+			dst_pte, src_pte,
+			vma, new,
+			addr, rss, prealloc,
+			pte, page);
+		if (retval <= 0)
+			return retval;
+
+		get_page(page);
+		page_dup_rmap(page, false);
+		rss[mm_counter(page)]++;
+	}
+
 	/*
 	 * If it's a COW mapping, write protect it both
 	 * in the parent and the child
@@ -820,33 +947,51 @@ copy_present_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	if (!(vm_flags & VM_UFFD_WP))
 		pte = pte_clear_uffd_wp(pte);
 
-	page = vm_normal_page(vma, addr, pte);
-	if (page) {
-		get_page(page);
-		page_dup_rmap(page, false);
-		rss[mm_counter(page)]++;
-	}
-
 	set_pte_at(dst_mm, addr, dst_pte, pte);
+	return 0;
+}
+
+static inline struct page *
+page_copy_prealloc(struct mm_struct *src_mm, struct vm_area_struct *vma,
+		   unsigned long addr)
+{
+	struct page *new_page;
+
+	new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, addr);
+	if (!new_page)
+		return NULL;
+
+	if (mem_cgroup_charge(new_page, src_mm, GFP_KERNEL)) {
+		put_page(new_page);
+		return NULL;
+	}
+	cgroup_throttle_swaprate(new_page, GFP_KERNEL);
+
+	return new_page;
 }
 
 static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		   pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma,
+		   struct vm_area_struct *new,
 		   unsigned long addr, unsigned long end)
 {
 	pte_t *orig_src_pte, *orig_dst_pte;
 	pte_t *src_pte, *dst_pte;
 	spinlock_t *src_ptl, *dst_ptl;
-	int progress = 0;
+	int progress, ret = 0;
 	int rss[NR_MM_COUNTERS];
 	swp_entry_t entry = (swp_entry_t){0};
+	struct page *prealloc = NULL;
 
 again:
+	progress = 0;
 	init_rss_vec(rss);
 
 	dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl);
-	if (!dst_pte)
-		return -ENOMEM;
+	if (!dst_pte) {
+		ret = -ENOMEM;
+		goto out;
+	}
 	src_pte = pte_offset_map(src_pmd, addr);
 	src_ptl = pte_lockptr(src_mm, src_pmd);
 	spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
@@ -878,8 +1023,25 @@ static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 			progress += 8;
 			continue;
 		}
-		copy_present_pte(dst_mm, src_mm, dst_pte, src_pte,
-				 vma, addr, rss);
+		/* copy_present_pte() will clear `*prealloc' if consumed */
+		ret = copy_present_pte(dst_mm, src_mm, dst_pte, src_pte,
+				       vma, new, addr, rss, &prealloc);
+		/*
+		 * If we need a pre-allocated page for this pte, drop the
+		 * locks, allocate, and try again.
+		 */
+		if (unlikely(ret == -EAGAIN))
+			break;
+		if (unlikely(prealloc)) {
+			/*
+			 * pre-alloc page cannot be reused by next time so as
+			 * to strictly follow mempolicy (e.g., alloc_page_vma()
+			 * will allocate page according to address).  This
+			 * could only happen if one pinned pte changed.
+			 */
+			put_page(prealloc);
+			prealloc = NULL;
+		}
 		progress += 8;
 	} while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end);
 
@@ -891,17 +1053,30 @@ static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	cond_resched();
 
 	if (entry.val) {
-		if (add_swap_count_continuation(entry, GFP_KERNEL) < 0)
+		if (add_swap_count_continuation(entry, GFP_KERNEL) < 0) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		entry.val = 0;
+	} else if (ret) {
+		WARN_ON_ONCE(ret != -EAGAIN);
+		prealloc = page_copy_prealloc(src_mm, vma, addr);
+		if (!prealloc)
 			return -ENOMEM;
-		progress = 0;
+		/* We've captured and resolved the error. Reset, try again. */
+		ret = 0;
 	}
 	if (addr != end)
 		goto again;
-	return 0;
+out:
+	if (unlikely(prealloc))
+		put_page(prealloc);
+	return ret;
 }
 
 static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma,
+		struct vm_area_struct *new,
 		unsigned long addr, unsigned long end)
 {
 	pmd_t *src_pmd, *dst_pmd;
@@ -928,7 +1103,7 @@ static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src
 		if (pmd_none_or_clear_bad(src_pmd))
 			continue;
 		if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd,
-						vma, addr, next))
+				   vma, new, addr, next))
 			return -ENOMEM;
 	} while (dst_pmd++, src_pmd++, addr = next, addr != end);
 	return 0;
@@ -936,6 +1111,7 @@ static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src
 
 static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		p4d_t *dst_p4d, p4d_t *src_p4d, struct vm_area_struct *vma,
+		struct vm_area_struct *new,
 		unsigned long addr, unsigned long end)
 {
 	pud_t *src_pud, *dst_pud;
@@ -962,7 +1138,7 @@ static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src
 		if (pud_none_or_clear_bad(src_pud))
 			continue;
 		if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud,
-						vma, addr, next))
+				   vma, new, addr, next))
 			return -ENOMEM;
 	} while (dst_pud++, src_pud++, addr = next, addr != end);
 	return 0;
@@ -970,6 +1146,7 @@ static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src
 
 static inline int copy_p4d_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma,
+		struct vm_area_struct *new,
 		unsigned long addr, unsigned long end)
 {
 	p4d_t *src_p4d, *dst_p4d;
@@ -984,14 +1161,14 @@ static inline int copy_p4d_range(struct mm_struct *dst_mm, struct mm_struct *src
 		if (p4d_none_or_clear_bad(src_p4d))
 			continue;
 		if (copy_pud_range(dst_mm, src_mm, dst_p4d, src_p4d,
-						vma, addr, next))
+				   vma, new, addr, next))
 			return -ENOMEM;
 	} while (dst_p4d++, src_p4d++, addr = next, addr != end);
 	return 0;
 }
 
 int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
-		struct vm_area_struct *vma)
+		    struct vm_area_struct *vma, struct vm_area_struct *new)
 {
 	pgd_t *src_pgd, *dst_pgd;
 	unsigned long next;
@@ -1046,7 +1223,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 		if (pgd_none_or_clear_bad(src_pgd))
 			continue;
 		if (unlikely(copy_p4d_range(dst_mm, src_mm, dst_pgd, src_pgd,
-					    vma, addr, next))) {
+					    vma, new, addr, next))) {
 			ret = -ENOMEM;
 			break;
 		}
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 0096cd965332..7ecd2ccba531 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -82,6 +82,7 @@ static char *sym_name(const struct sym_entry *s)
 
 static bool is_ignored_symbol(const char *name, char type)
 {
+	/* Symbol names that exactly match to the following are ignored.*/
 	static const char * const ignored_symbols[] = {
 		/*
 		 * Symbols which vary between passes. Passes 1 and 2 must have
@@ -104,6 +105,7 @@ static bool is_ignored_symbol(const char *name, char type)
 		NULL
 	};
 
+	/* Symbol names that begin with the following are ignored.*/
 	static const char * const ignored_prefixes[] = {
 		"$",			/* local symbols for ARM, MIPS, etc. */
 		".LASANPC",		/* s390 kasan local symbols */
@@ -113,6 +115,7 @@ static bool is_ignored_symbol(const char *name, char type)
 		NULL
 	};
 
+	/* Symbol names that end with the following are ignored.*/
 	static const char * const ignored_suffixes[] = {
 		"_from_arm",		/* arm */
 		"_from_thumb",		/* arm */
@@ -120,9 +123,15 @@ static bool is_ignored_symbol(const char *name, char type)
 		NULL
 	};
 
+	/* Symbol names that contain the following are ignored.*/
+	static const char * const ignored_matches[] = {
+		".long_branch.",	/* ppc stub */
+		".plt_branch.",		/* ppc stub */
+		NULL
+	};
+
 	const char * const *p;
 
-	/* Exclude symbols which vary between passes. */
 	for (p = ignored_symbols; *p; p++)
 		if (!strcmp(name, *p))
 			return true;
@@ -138,6 +147,11 @@ static bool is_ignored_symbol(const char *name, char type)
 			return true;
 	}
 
+	for (p = ignored_matches; *p; p++) {
+		if (strstr(name, *p))
+			return true;
+	}
+
 	if (type == 'U' || type == 'u')
 		return true;
 	/* exclude debugging symbols */