diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h
index 611fa41..eccc75b 100644
--- a/arch/x86/include/asm/fpu/signal.h
+++ b/arch/x86/include/asm/fpu/signal.h
@@ -29,7 +29,7 @@ fpu__alloc_mathframe(unsigned long sp, int ia32_frame,
 
 unsigned long fpu__get_fpstate_size(void);
 
-extern bool copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size);
+extern bool copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size, u32 pkru);
 extern void fpu__clear_user_states(struct fpu *fpu);
 extern bool fpu__restore_sig(void __user *buf, int ia32_frame);
 
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 8dac45a..19091eb 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -88,7 +88,13 @@ static inline void switch_ldt(struct mm_struct *prev, struct mm_struct *next)
 #ifdef CONFIG_ADDRESS_MASKING
 static inline unsigned long mm_lam_cr3_mask(struct mm_struct *mm)
 {
-	return mm->context.lam_cr3_mask;
+	/*
+	 * When switch_mm_irqs_off() is called for a kthread, it may race with
+	 * LAM enablement. switch_mm_irqs_off() uses the LAM mask to do two
+	 * things: populate CR3 and populate 'cpu_tlbstate.lam'. Make sure it
+	 * reads a single value for both.
+	 */
+	return READ_ONCE(mm->context.lam_cr3_mask);
 }
 
 static inline void dup_lam(struct mm_struct *oldmm, struct mm_struct *mm)
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 2f32113..6f82e75 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -517,8 +517,6 @@ typedef struct page *pgtable_t;
 
 extern pteval_t __supported_pte_mask;
 extern pteval_t __default_kernel_pte_mask;
-extern void set_nx(void);
-extern int nx_enabled;
 
 #define pgprot_writecombine	pgprot_writecombine
 extern pgprot_t pgprot_writecombine(pgprot_t prot);
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 2572689..69e79ff 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -399,11 +399,10 @@ static inline  u64 tlbstate_lam_cr3_mask(void)
 	return lam << X86_CR3_LAM_U57_BIT;
 }
 
-static inline void set_tlbstate_lam_mode(struct mm_struct *mm)
+static inline void cpu_tlbstate_update_lam(unsigned long lam, u64 untag_mask)
 {
-	this_cpu_write(cpu_tlbstate.lam,
-		       mm->context.lam_cr3_mask >> X86_CR3_LAM_U57_BIT);
-	this_cpu_write(tlbstate_untag_mask, mm->context.untag_mask);
+	this_cpu_write(cpu_tlbstate.lam, lam >> X86_CR3_LAM_U57_BIT);
+	this_cpu_write(tlbstate_untag_mask, untag_mask);
 }
 
 #else
@@ -413,7 +412,7 @@ static inline u64 tlbstate_lam_cr3_mask(void)
 	return 0;
 }
 
-static inline void set_tlbstate_lam_mode(struct mm_struct *mm)
+static inline void cpu_tlbstate_update_lam(unsigned long lam, u64 untag_mask)
 {
 }
 #endif
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 247f222..1065ab9 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -64,6 +64,16 @@ static inline bool check_xstate_in_sigframe(struct fxregs_state __user *fxbuf,
 }
 
 /*
+ * Update the value of PKRU register that was already pushed onto the signal frame.
+ */
+static inline int update_pkru_in_sigframe(struct xregs_state __user *buf, u32 pkru)
+{
+	if (unlikely(!cpu_feature_enabled(X86_FEATURE_OSPKE)))
+		return 0;
+	return __put_user(pkru, (unsigned int __user *)get_xsave_addr_user(buf, XFEATURE_PKRU));
+}
+
+/*
  * Signal frame handlers.
  */
 static inline bool save_fsave_header(struct task_struct *tsk, void __user *buf)
@@ -156,10 +166,17 @@ static inline bool save_xstate_epilog(void __user *buf, int ia32_frame,
 	return !err;
 }
 
-static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf)
+static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf, u32 pkru)
 {
-	if (use_xsave())
-		return xsave_to_user_sigframe(buf);
+	int err = 0;
+
+	if (use_xsave()) {
+		err = xsave_to_user_sigframe(buf);
+		if (!err)
+			err = update_pkru_in_sigframe(buf, pkru);
+		return err;
+	}
+
 	if (use_fxsr())
 		return fxsave_to_user_sigframe((struct fxregs_state __user *) buf);
 	else
@@ -185,7 +202,7 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf)
  * For [f]xsave state, update the SW reserved fields in the [f]xsave frame
  * indicating the absence/presence of the extended state to the user.
  */
-bool copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
+bool copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size, u32 pkru)
 {
 	struct task_struct *tsk = current;
 	struct fpstate *fpstate = tsk->thread.fpu.fpstate;
@@ -228,7 +245,7 @@ bool copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
 		fpregs_restore_userregs();
 
 	pagefault_disable();
-	ret = copy_fpregs_to_sigframe(buf_fx);
+	ret = copy_fpregs_to_sigframe(buf_fx, pkru);
 	pagefault_enable();
 	fpregs_unlock();
 
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 53d9f01..22abb5e 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -999,6 +999,19 @@ void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr)
 }
 EXPORT_SYMBOL_GPL(get_xsave_addr);
 
+/*
+ * Given an xstate feature nr, calculate where in the xsave buffer the state is.
+ * The xsave buffer should be in standard format, not compacted (e.g. user mode
+ * signal frames).
+ */
+void __user *get_xsave_addr_user(struct xregs_state __user *xsave, int xfeature_nr)
+{
+	if (WARN_ON_ONCE(!xfeature_enabled(xfeature_nr)))
+		return NULL;
+
+	return (void __user *)xsave + xstate_offsets[xfeature_nr];
+}
+
 #ifdef CONFIG_ARCH_HAS_PKEYS
 
 /*
diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h
index afb404c..0b86a50 100644
--- a/arch/x86/kernel/fpu/xstate.h
+++ b/arch/x86/kernel/fpu/xstate.h
@@ -54,6 +54,8 @@ extern int copy_sigframe_from_user_to_xstate(struct task_struct *tsk, const void
 extern void fpu__init_cpu_xstate(void);
 extern void fpu__init_system_xstate(unsigned int legacy_size);
 
+extern void __user *get_xsave_addr_user(struct xregs_state __user *xsave, int xfeature_nr);
+
 static inline u64 xfeatures_mask_supervisor(void)
 {
 	return fpu_kernel_cfg.max_features & XFEATURE_MASK_SUPERVISOR_SUPPORTED;
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index cc0f7f7..9c9ac60 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -28,6 +28,7 @@
 #include <asm/setup.h>
 #include <asm/set_memory.h>
 #include <asm/cpu.h>
+#include <asm/efi.h>
 
 #ifdef CONFIG_ACPI
 /*
@@ -87,6 +88,8 @@ map_efi_systab(struct x86_mapping_info *info, pgd_t *level4p)
 {
 #ifdef CONFIG_EFI
 	unsigned long mstart, mend;
+	void *kaddr;
+	int ret;
 
 	if (!efi_enabled(EFI_BOOT))
 		return 0;
@@ -102,6 +105,30 @@ map_efi_systab(struct x86_mapping_info *info, pgd_t *level4p)
 	if (!mstart)
 		return 0;
 
+	ret = kernel_ident_mapping_init(info, level4p, mstart, mend);
+	if (ret)
+		return ret;
+
+	kaddr = memremap(mstart, mend - mstart, MEMREMAP_WB);
+	if (!kaddr) {
+		pr_err("Could not map UEFI system table\n");
+		return -ENOMEM;
+	}
+
+	mstart = efi_config_table;
+
+	if (efi_enabled(EFI_64BIT)) {
+		efi_system_table_64_t *stbl = (efi_system_table_64_t *)kaddr;
+
+		mend = mstart + sizeof(efi_config_table_64_t) * stbl->nr_tables;
+	} else {
+		efi_system_table_32_t *stbl = (efi_system_table_32_t *)kaddr;
+
+		mend = mstart + sizeof(efi_config_table_32_t) * stbl->nr_tables;
+	}
+
+	memunmap(kaddr);
+
 	return kernel_ident_mapping_init(info, level4p, mstart, mend);
 #endif
 	return 0;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 6d3d20e..2264723 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -798,6 +798,32 @@ static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr)
 
 #define LAM_U57_BITS 6
 
+static void enable_lam_func(void *__mm)
+{
+	struct mm_struct *mm = __mm;
+	unsigned long lam;
+
+	if (this_cpu_read(cpu_tlbstate.loaded_mm) == mm) {
+		lam = mm_lam_cr3_mask(mm);
+		write_cr3(__read_cr3() | lam);
+		cpu_tlbstate_update_lam(lam, mm_untag_mask(mm));
+	}
+}
+
+static void mm_enable_lam(struct mm_struct *mm)
+{
+	mm->context.lam_cr3_mask = X86_CR3_LAM_U57;
+	mm->context.untag_mask =  ~GENMASK(62, 57);
+
+	/*
+	 * Even though the process must still be single-threaded at this
+	 * point, kernel threads may be using the mm.  IPI those kernel
+	 * threads if they exist.
+	 */
+	on_each_cpu_mask(mm_cpumask(mm), enable_lam_func, mm, true);
+	set_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags);
+}
+
 static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits)
 {
 	if (!cpu_feature_enabled(X86_FEATURE_LAM))
@@ -814,25 +840,21 @@ static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits)
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
+	/*
+	 * MM_CONTEXT_LOCK_LAM is set on clone.  Prevent LAM from
+	 * being enabled unless the process is single threaded:
+	 */
 	if (test_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags)) {
 		mmap_write_unlock(mm);
 		return -EBUSY;
 	}
 
-	if (!nr_bits) {
-		mmap_write_unlock(mm);
-		return -EINVAL;
-	} else if (nr_bits <= LAM_U57_BITS) {
-		mm->context.lam_cr3_mask = X86_CR3_LAM_U57;
-		mm->context.untag_mask =  ~GENMASK(62, 57);
-	} else {
+	if (!nr_bits || nr_bits > LAM_U57_BITS) {
 		mmap_write_unlock(mm);
 		return -EINVAL;
 	}
 
-	write_cr3(__read_cr3() | mm->context.lam_cr3_mask);
-	set_tlbstate_lam_mode(mm);
-	set_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags);
+	mm_enable_lam(mm);
 
 	mmap_write_unlock(mm);
 
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 31b6f5d..5f44103 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -61,6 +61,24 @@ static inline int is_x32_frame(struct ksignal *ksig)
 }
 
 /*
+ * Enable all pkeys temporarily, so as to ensure that both the current
+ * execution stack as well as the alternate signal stack are writeable.
+ * The application can use any of the available pkeys to protect the
+ * alternate signal stack, and we don't know which one it is, so enable
+ * all. The PKRU register will be reset to init_pkru later in the flow,
+ * in fpu__clear_user_states(), and it is the application's responsibility
+ * to enable the appropriate pkey as the first step in the signal handler
+ * so that the handler does not segfault.
+ */
+static inline u32 sig_prepare_pkru(void)
+{
+	u32 orig_pkru = read_pkru();
+
+	write_pkru(0);
+	return orig_pkru;
+}
+
+/*
  * Set up a signal frame.
  */
 
@@ -84,6 +102,7 @@ get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 	unsigned long math_size = 0;
 	unsigned long sp = regs->sp;
 	unsigned long buf_fx = 0;
+	u32 pkru;
 
 	/* redzone */
 	if (!ia32_frame)
@@ -138,9 +157,17 @@ get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
 		return (void __user *)-1L;
 	}
 
+	/* Update PKRU to enable access to the alternate signal stack. */
+	pkru = sig_prepare_pkru();
 	/* save i387 and extended state */
-	if (!copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size))
+	if (!copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size, pkru)) {
+		/*
+		 * Restore PKRU to the original, user-defined value; disable
+		 * extra pkeys enabled for the alternate signal stack, if any.
+		 */
+		write_pkru(pkru);
 		return (void __user *)-1L;
+	}
 
 	return (void __user *)sp;
 }
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index 8a94053..ee94538 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -260,15 +260,15 @@ SYSCALL_DEFINE0(rt_sigreturn)
 
 	set_current_blocked(&set);
 
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
 	if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
 		goto badframe;
 
 	if (restore_signal_shadow_stack())
 		goto badframe;
 
-	if (restore_altstack(&frame->uc.uc_stack))
-		goto badframe;
-
 	return regs->ax;
 
 badframe:
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c
index c451272..437e96f 100644
--- a/arch/x86/mm/ident_map.c
+++ b/arch/x86/mm/ident_map.c
@@ -99,18 +99,31 @@ static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
 	for (; addr < end; addr = next) {
 		pud_t *pud = pud_page + pud_index(addr);
 		pmd_t *pmd;
+		bool use_gbpage;
 
 		next = (addr & PUD_MASK) + PUD_SIZE;
 		if (next > end)
 			next = end;
 
-		if (info->direct_gbpages) {
+		/* if this is already a gbpage, this portion is already mapped */
+		if (pud_leaf(*pud))
+			continue;
+
+		/* Is using a gbpage allowed? */
+		use_gbpage = info->direct_gbpages;
+
+		/* Don't use gbpage if it maps more than the requested region. */
+		/* at the begining: */
+		use_gbpage &= ((addr & ~PUD_MASK) == 0);
+		/* ... or at the end: */
+		use_gbpage &= ((next & ~PUD_MASK) == 0);
+
+		/* Never overwrite existing mappings */
+		use_gbpage &= !pud_present(*pud);
+
+		if (use_gbpage) {
 			pud_t pudval;
 
-			if (pud_present(*pud))
-				continue;
-
-			addr &= PUD_MASK;
 			pudval = __pud((addr - info->offset) | info->page_flag);
 			set_pud(pud, pudval);
 			continue;
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index aa7d279..70b02fc 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -11,6 +11,7 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
+#include <linux/ioremap.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/mmiotrace.h>
@@ -457,7 +458,7 @@ void iounmap(volatile void __iomem *addr)
 {
 	struct vm_struct *p, *o;
 
-	if ((void __force *)addr <= high_memory)
+	if (WARN_ON_ONCE(!is_ioremap_addr((void __force *)addr)))
 		return;
 
 	/*
diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index 9c52a95..6f8e0f2 100644
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -57,8 +57,7 @@ acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
 	}
 	set_apicid_to_node(apic_id, node);
 	node_set(node, numa_nodes_parsed);
-	printk(KERN_INFO "SRAT: PXM %u -> APIC 0x%04x -> Node %u\n",
-	       pxm, apic_id, node);
+	pr_debug("SRAT: PXM %u -> APIC 0x%04x -> Node %u\n", pxm, apic_id, node);
 }
 
 /* Callback for Proximity Domain -> LAPIC mapping */
@@ -98,8 +97,7 @@ acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *pa)
 
 	set_apicid_to_node(apic_id, node);
 	node_set(node, numa_nodes_parsed);
-	printk(KERN_INFO "SRAT: PXM %u -> APIC 0x%02x -> Node %u\n",
-	       pxm, apic_id, node);
+	pr_debug("SRAT: PXM %u -> APIC 0x%02x -> Node %u\n", pxm, apic_id, node);
 }
 
 int __init x86_acpi_numa_init(void)
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 44ac64f..86593d1 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -11,6 +11,7 @@
 #include <linux/sched/smt.h>
 #include <linux/task_work.h>
 #include <linux/mmu_notifier.h>
+#include <linux/mmu_context.h>
 
 #include <asm/tlbflush.h>
 #include <asm/mmu_context.h>
@@ -85,9 +86,6 @@
  *
  */
 
-/* There are 12 bits of space for ASIDS in CR3 */
-#define CR3_HW_ASID_BITS		12
-
 /*
  * When enabled, MITIGATION_PAGE_TABLE_ISOLATION consumes a single bit for
  * user/kernel switches
@@ -160,7 +158,6 @@ static inline unsigned long build_cr3(pgd_t *pgd, u16 asid, unsigned long lam)
 	unsigned long cr3 = __sme_pa(pgd) | lam;
 
 	if (static_cpu_has(X86_FEATURE_PCID)) {
-		VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE);
 		cr3 |= kern_pcid(asid);
 	} else {
 		VM_WARN_ON_ONCE(asid != 0);
@@ -503,9 +500,9 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next,
 {
 	struct mm_struct *prev = this_cpu_read(cpu_tlbstate.loaded_mm);
 	u16 prev_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
-	unsigned long new_lam = mm_lam_cr3_mask(next);
 	bool was_lazy = this_cpu_read(cpu_tlbstate_shared.is_lazy);
 	unsigned cpu = smp_processor_id();
+	unsigned long new_lam;
 	u64 next_tlb_gen;
 	bool need_flush;
 	u16 new_asid;
@@ -619,9 +616,7 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next,
 			cpumask_clear_cpu(cpu, mm_cpumask(prev));
 		}
 
-		/*
-		 * Start remote flushes and then read tlb_gen.
-		 */
+		/* Start receiving IPIs and then read tlb_gen (and LAM below) */
 		if (next != &init_mm)
 			cpumask_set_cpu(cpu, mm_cpumask(next));
 		next_tlb_gen = atomic64_read(&next->context.tlb_gen);
@@ -633,7 +628,7 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next,
 		barrier();
 	}
 
-	set_tlbstate_lam_mode(next);
+	new_lam = mm_lam_cr3_mask(next);
 	if (need_flush) {
 		this_cpu_write(cpu_tlbstate.ctxs[new_asid].ctx_id, next->context.ctx_id);
 		this_cpu_write(cpu_tlbstate.ctxs[new_asid].tlb_gen, next_tlb_gen);
@@ -652,6 +647,7 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next,
 
 	this_cpu_write(cpu_tlbstate.loaded_mm, next);
 	this_cpu_write(cpu_tlbstate.loaded_mm_asid, new_asid);
+	cpu_tlbstate_update_lam(new_lam, mm_untag_mask(next));
 
 	if (next != prev) {
 		cr4_update_pce_mm(next);
@@ -698,6 +694,7 @@ void initialize_tlbstate_and_flush(void)
 	int i;
 	struct mm_struct *mm = this_cpu_read(cpu_tlbstate.loaded_mm);
 	u64 tlb_gen = atomic64_read(&init_mm.context.tlb_gen);
+	unsigned long lam = mm_lam_cr3_mask(mm);
 	unsigned long cr3 = __read_cr3();
 
 	/* Assert that CR3 already references the right mm. */
@@ -705,7 +702,7 @@ void initialize_tlbstate_and_flush(void)
 
 	/* LAM expected to be disabled */
 	WARN_ON(cr3 & (X86_CR3_LAM_U48 | X86_CR3_LAM_U57));
-	WARN_ON(mm_lam_cr3_mask(mm));
+	WARN_ON(lam);
 
 	/*
 	 * Assert that CR4.PCIDE is set if needed.  (CR4.PCIDE initialization
@@ -724,7 +721,7 @@ void initialize_tlbstate_and_flush(void)
 	this_cpu_write(cpu_tlbstate.next_asid, 1);
 	this_cpu_write(cpu_tlbstate.ctxs[0].ctx_id, mm->context.ctx_id);
 	this_cpu_write(cpu_tlbstate.ctxs[0].tlb_gen, tlb_gen);
-	set_tlbstate_lam_mode(mm);
+	cpu_tlbstate_update_lam(lam, mm_untag_mask(mm));
 
 	for (i = 1; i < TLB_NR_DYN_ASIDS; i++)
 		this_cpu_write(cpu_tlbstate.ctxs[i].ctx_id, 0);
diff --git a/include/linux/ioremap.h b/include/linux/ioremap.h
index f0e99fc..2bd1661 100644
--- a/include/linux/ioremap.h
+++ b/include/linux/ioremap.h
@@ -4,6 +4,7 @@
 
 #include <linux/kasan.h>
 #include <asm/pgtable.h>
+#include <asm/vmalloc.h>
 
 #if defined(CONFIG_HAS_IOMEM) || defined(CONFIG_GENERIC_IOREMAP)
 /*
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 5f2ca59..e10b873 100644
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -90,6 +90,7 @@
 CAN_BUILD_WITH_NOPIE := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_program.c -no-pie)
 
 VMTARGETS := protection_keys
+VMTARGETS += pkey_sighandler_tests
 BINARIES_32 := $(VMTARGETS:%=%_32)
 BINARIES_64 := $(VMTARGETS:%=%_64)
 
diff --git a/tools/testing/selftests/mm/pkey-helpers.h b/tools/testing/selftests/mm/pkey-helpers.h
index 1560835..9ab6a3e 100644
--- a/tools/testing/selftests/mm/pkey-helpers.h
+++ b/tools/testing/selftests/mm/pkey-helpers.h
@@ -79,7 +79,18 @@ extern void abort_hooks(void);
 	}					\
 } while (0)
 
-__attribute__((noinline)) int read_ptr(int *ptr);
+#define barrier() __asm__ __volatile__("": : :"memory")
+#ifndef noinline
+# define noinline __attribute__((noinline))
+#endif
+
+noinline int read_ptr(int *ptr)
+{
+	/* Keep GCC from optimizing this away somehow */
+	barrier();
+	return *ptr;
+}
+
 void expected_pkey_fault(int pkey);
 int sys_pkey_alloc(unsigned long flags, unsigned long init_val);
 int sys_pkey_free(unsigned long pkey);
diff --git a/tools/testing/selftests/mm/pkey_sighandler_tests.c b/tools/testing/selftests/mm/pkey_sighandler_tests.c
new file mode 100644
index 0000000..a8088b64
--- /dev/null
+++ b/tools/testing/selftests/mm/pkey_sighandler_tests.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tests Memory Protection Keys (see Documentation/core-api/protection-keys.rst)
+ *
+ * The testcases in this file exercise various flows related to signal handling,
+ * using an alternate signal stack, with the default pkey (pkey 0) disabled.
+ *
+ * Compile with:
+ * gcc -mxsave      -o pkey_sighandler_tests -O2 -g -std=gnu99 -pthread -Wall pkey_sighandler_tests.c -I../../../../tools/include -lrt -ldl -lm
+ * gcc -mxsave -m32 -o pkey_sighandler_tests -O2 -g -std=gnu99 -pthread -Wall pkey_sighandler_tests.c -I../../../../tools/include -lrt -ldl -lm
+ */
+#define _GNU_SOURCE
+#define __SANE_USERSPACE_TYPES__
+#include <errno.h>
+#include <sys/syscall.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <signal.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <limits.h>
+
+#include "pkey-helpers.h"
+
+#define STACK_SIZE PTHREAD_STACK_MIN
+
+void expected_pkey_fault(int pkey) {}
+
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+siginfo_t siginfo = {0};
+
+/*
+ * We need to use inline assembly instead of glibc's syscall because glibc's
+ * syscall will attempt to access the PLT in order to call a library function
+ * which is protected by MPK 0 which we don't have access to.
+ */
+static inline __always_inline
+long syscall_raw(long n, long a1, long a2, long a3, long a4, long a5, long a6)
+{
+	unsigned long ret;
+#ifdef __x86_64__
+	register long r10 asm("r10") = a4;
+	register long r8 asm("r8") = a5;
+	register long r9 asm("r9") = a6;
+	asm volatile ("syscall"
+		      : "=a"(ret)
+		      : "a"(n), "D"(a1), "S"(a2), "d"(a3), "r"(r10), "r"(r8), "r"(r9)
+		      : "rcx", "r11", "memory");
+#elif defined __i386__
+	asm volatile ("int $0x80"
+		      : "=a"(ret)
+		      : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5)
+		      : "memory");
+#else
+# error syscall_raw() not implemented
+#endif
+	return ret;
+}
+
+static void sigsegv_handler(int signo, siginfo_t *info, void *ucontext)
+{
+	pthread_mutex_lock(&mutex);
+
+	memcpy(&siginfo, info, sizeof(siginfo_t));
+
+	pthread_cond_signal(&cond);
+	pthread_mutex_unlock(&mutex);
+
+	syscall_raw(SYS_exit, 0, 0, 0, 0, 0, 0);
+}
+
+static void sigusr1_handler(int signo, siginfo_t *info, void *ucontext)
+{
+	pthread_mutex_lock(&mutex);
+
+	memcpy(&siginfo, info, sizeof(siginfo_t));
+
+	pthread_cond_signal(&cond);
+	pthread_mutex_unlock(&mutex);
+}
+
+static void sigusr2_handler(int signo, siginfo_t *info, void *ucontext)
+{
+	/*
+	 * pkru should be the init_pkru value which enabled MPK 0 so
+	 * we can use library functions.
+	 */
+	printf("%s invoked.\n", __func__);
+}
+
+static void raise_sigusr2(void)
+{
+	pid_t tid = 0;
+
+	tid = syscall_raw(SYS_gettid, 0, 0, 0, 0, 0, 0);
+
+	syscall_raw(SYS_tkill, tid, SIGUSR2, 0, 0, 0, 0);
+
+	/*
+	 * We should return from the signal handler here and be able to
+	 * return to the interrupted thread.
+	 */
+}
+
+static void *thread_segv_with_pkey0_disabled(void *ptr)
+{
+	/* Disable MPK 0 (and all others too) */
+	__write_pkey_reg(0x55555555);
+
+	/* Segfault (with SEGV_MAPERR) */
+	*(int *) (0x1) = 1;
+	return NULL;
+}
+
+static void *thread_segv_pkuerr_stack(void *ptr)
+{
+	/* Disable MPK 0 (and all others too) */
+	__write_pkey_reg(0x55555555);
+
+	/* After we disable MPK 0, we can't access the stack to return */
+	return NULL;
+}
+
+static void *thread_segv_maperr_ptr(void *ptr)
+{
+	stack_t *stack = ptr;
+	int *bad = (int *)1;
+
+	/*
+	 * Setup alternate signal stack, which should be pkey_mprotect()ed by
+	 * MPK 0. The thread's stack cannot be used for signals because it is
+	 * not accessible by the default init_pkru value of 0x55555554.
+	 */
+	syscall_raw(SYS_sigaltstack, (long)stack, 0, 0, 0, 0, 0);
+
+	/* Disable MPK 0.  Only MPK 1 is enabled. */
+	__write_pkey_reg(0x55555551);
+
+	/* Segfault */
+	*bad = 1;
+	syscall_raw(SYS_exit, 0, 0, 0, 0, 0, 0);
+	return NULL;
+}
+
+/*
+ * Verify that the sigsegv handler is invoked when pkey 0 is disabled.
+ * Note that the new thread stack and the alternate signal stack is
+ * protected by MPK 0.
+ */
+static void test_sigsegv_handler_with_pkey0_disabled(void)
+{
+	struct sigaction sa;
+	pthread_attr_t attr;
+	pthread_t thr;
+
+	sa.sa_flags = SA_SIGINFO;
+
+	sa.sa_sigaction = sigsegv_handler;
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
+		perror("sigaction");
+		exit(EXIT_FAILURE);
+	}
+
+	memset(&siginfo, 0, sizeof(siginfo));
+
+	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+
+	pthread_create(&thr, &attr, thread_segv_with_pkey0_disabled, NULL);
+
+	pthread_mutex_lock(&mutex);
+	while (siginfo.si_signo == 0)
+		pthread_cond_wait(&cond, &mutex);
+	pthread_mutex_unlock(&mutex);
+
+	ksft_test_result(siginfo.si_signo == SIGSEGV &&
+			 siginfo.si_code == SEGV_MAPERR &&
+			 siginfo.si_addr == (void *)1,
+			 "%s\n", __func__);
+}
+
+/*
+ * Verify that the sigsegv handler is invoked when pkey 0 is disabled.
+ * Note that the new thread stack and the alternate signal stack is
+ * protected by MPK 0, which renders them inaccessible when MPK 0
+ * is disabled. So just the return from the thread should cause a
+ * segfault with SEGV_PKUERR.
+ */
+static void test_sigsegv_handler_cannot_access_stack(void)
+{
+	struct sigaction sa;
+	pthread_attr_t attr;
+	pthread_t thr;
+
+	sa.sa_flags = SA_SIGINFO;
+
+	sa.sa_sigaction = sigsegv_handler;
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
+		perror("sigaction");
+		exit(EXIT_FAILURE);
+	}
+
+	memset(&siginfo, 0, sizeof(siginfo));
+
+	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+
+	pthread_create(&thr, &attr, thread_segv_pkuerr_stack, NULL);
+
+	pthread_mutex_lock(&mutex);
+	while (siginfo.si_signo == 0)
+		pthread_cond_wait(&cond, &mutex);
+	pthread_mutex_unlock(&mutex);
+
+	ksft_test_result(siginfo.si_signo == SIGSEGV &&
+			 siginfo.si_code == SEGV_PKUERR,
+			 "%s\n", __func__);
+}
+
+/*
+ * Verify that the sigsegv handler that uses an alternate signal stack
+ * is correctly invoked for a thread which uses a non-zero MPK to protect
+ * its own stack, and disables all other MPKs (including 0).
+ */
+static void test_sigsegv_handler_with_different_pkey_for_stack(void)
+{
+	struct sigaction sa;
+	static stack_t sigstack;
+	void *stack;
+	int pkey;
+	int parent_pid = 0;
+	int child_pid = 0;
+
+	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
+
+	sa.sa_sigaction = sigsegv_handler;
+
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
+		perror("sigaction");
+		exit(EXIT_FAILURE);
+	}
+
+	stack = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
+		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+	assert(stack != MAP_FAILED);
+
+	/* Allow access to MPK 0 and MPK 1 */
+	__write_pkey_reg(0x55555550);
+
+	/* Protect the new stack with MPK 1 */
+	pkey = pkey_alloc(0, 0);
+	pkey_mprotect(stack, STACK_SIZE, PROT_READ | PROT_WRITE, pkey);
+
+	/* Set up alternate signal stack that will use the default MPK */
+	sigstack.ss_sp = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
+			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	sigstack.ss_flags = 0;
+	sigstack.ss_size = STACK_SIZE;
+
+	memset(&siginfo, 0, sizeof(siginfo));
+
+	/* Use clone to avoid newer glibcs using rseq on new threads */
+	long ret = syscall_raw(SYS_clone,
+			       CLONE_VM | CLONE_FS | CLONE_FILES |
+			       CLONE_SIGHAND | CLONE_THREAD | CLONE_SYSVSEM |
+			       CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID |
+			       CLONE_DETACHED,
+			       (long) ((char *)(stack) + STACK_SIZE),
+			       (long) &parent_pid,
+			       (long) &child_pid, 0, 0);
+
+	if (ret < 0) {
+		errno = -ret;
+		perror("clone");
+	} else if (ret == 0) {
+		thread_segv_maperr_ptr(&sigstack);
+		syscall_raw(SYS_exit, 0, 0, 0, 0, 0, 0);
+	}
+
+	pthread_mutex_lock(&mutex);
+	while (siginfo.si_signo == 0)
+		pthread_cond_wait(&cond, &mutex);
+	pthread_mutex_unlock(&mutex);
+
+	ksft_test_result(siginfo.si_signo == SIGSEGV &&
+			 siginfo.si_code == SEGV_MAPERR &&
+			 siginfo.si_addr == (void *)1,
+			 "%s\n", __func__);
+}
+
+/*
+ * Verify that the PKRU value set by the application is correctly
+ * restored upon return from signal handling.
+ */
+static void test_pkru_preserved_after_sigusr1(void)
+{
+	struct sigaction sa;
+	unsigned long pkru = 0x45454544;
+
+	sa.sa_flags = SA_SIGINFO;
+
+	sa.sa_sigaction = sigusr1_handler;
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(SIGUSR1, &sa, NULL) == -1) {
+		perror("sigaction");
+		exit(EXIT_FAILURE);
+	}
+
+	memset(&siginfo, 0, sizeof(siginfo));
+
+	__write_pkey_reg(pkru);
+
+	raise(SIGUSR1);
+
+	pthread_mutex_lock(&mutex);
+	while (siginfo.si_signo == 0)
+		pthread_cond_wait(&cond, &mutex);
+	pthread_mutex_unlock(&mutex);
+
+	/* Ensure the pkru value is the same after returning from signal. */
+	ksft_test_result(pkru == __read_pkey_reg() &&
+			 siginfo.si_signo == SIGUSR1,
+			 "%s\n", __func__);
+}
+
+static noinline void *thread_sigusr2_self(void *ptr)
+{
+	/*
+	 * A const char array like "Resuming after SIGUSR2" won't be stored on
+	 * the stack and the code could access it via an offset from the program
+	 * counter. This makes sure it's on the function's stack frame.
+	 */
+	char str[] = {'R', 'e', 's', 'u', 'm', 'i', 'n', 'g', ' ',
+		'a', 'f', 't', 'e', 'r', ' ',
+		'S', 'I', 'G', 'U', 'S', 'R', '2',
+		'.', '.', '.', '\n', '\0'};
+	stack_t *stack = ptr;
+
+	/*
+	 * Setup alternate signal stack, which should be pkey_mprotect()ed by
+	 * MPK 0. The thread's stack cannot be used for signals because it is
+	 * not accessible by the default init_pkru value of 0x55555554.
+	 */
+	syscall(SYS_sigaltstack, (long)stack, 0, 0, 0, 0, 0);
+
+	/* Disable MPK 0.  Only MPK 2 is enabled. */
+	__write_pkey_reg(0x55555545);
+
+	raise_sigusr2();
+
+	/* Do something, to show the thread resumed execution after the signal */
+	syscall_raw(SYS_write, 1, (long) str, sizeof(str) - 1, 0, 0, 0);
+
+	/*
+	 * We can't return to test_pkru_sigreturn because it
+	 * will attempt to use a %rbp value which is on the stack
+	 * of the main thread.
+	 */
+	syscall_raw(SYS_exit, 0, 0, 0, 0, 0, 0);
+	return NULL;
+}
+
+/*
+ * Verify that sigreturn is able to restore altstack even if the thread had
+ * disabled pkey 0.
+ */
+static void test_pkru_sigreturn(void)
+{
+	struct sigaction sa = {0};
+	static stack_t sigstack;
+	void *stack;
+	int pkey;
+	int parent_pid = 0;
+	int child_pid = 0;
+
+	sa.sa_handler = SIG_DFL;
+	sa.sa_flags = 0;
+	sigemptyset(&sa.sa_mask);
+
+	/*
+	 * For this testcase, we do not want to handle SIGSEGV. Reset handler
+	 * to default so that the application can crash if it receives SIGSEGV.
+	 */
+	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
+		perror("sigaction");
+		exit(EXIT_FAILURE);
+	}
+
+	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
+	sa.sa_sigaction = sigusr2_handler;
+	sigemptyset(&sa.sa_mask);
+
+	if (sigaction(SIGUSR2, &sa, NULL) == -1) {
+		perror("sigaction");
+		exit(EXIT_FAILURE);
+	}
+
+	stack = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE,
+		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+	assert(stack != MAP_FAILED);
+
+	/*
+	 * Allow access to MPK 0 and MPK 2. The child thread (to be created
+	 * later in this flow) will have its stack protected by MPK 2, whereas
+	 * the current thread's stack is protected by the default MPK 0. Hence
+	 * both need to be enabled.
+	 */
+	__write_pkey_reg(0x55555544);
+
+	/* Protect the stack with MPK 2 */
+	pkey = pkey_alloc(0, 0);
+	pkey_mprotect(stack, STACK_SIZE, PROT_READ | PROT_WRITE, pkey);
+
+	/* Set up alternate signal stack that will use the default MPK */
+	sigstack.ss_sp = mmap(0, STACK_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
+			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	sigstack.ss_flags = 0;
+	sigstack.ss_size = STACK_SIZE;
+
+	/* Use clone to avoid newer glibcs using rseq on new threads */
+	long ret = syscall_raw(SYS_clone,
+			       CLONE_VM | CLONE_FS | CLONE_FILES |
+			       CLONE_SIGHAND | CLONE_THREAD | CLONE_SYSVSEM |
+			       CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID |
+			       CLONE_DETACHED,
+			       (long) ((char *)(stack) + STACK_SIZE),
+			       (long) &parent_pid,
+			       (long) &child_pid, 0, 0);
+
+	if (ret < 0) {
+		errno = -ret;
+		perror("clone");
+	}  else if (ret == 0) {
+		thread_sigusr2_self(&sigstack);
+		syscall_raw(SYS_exit, 0, 0, 0, 0, 0, 0);
+	}
+
+	child_pid =  ret;
+	/* Check that thread exited */
+	do {
+		sched_yield();
+		ret = syscall_raw(SYS_tkill, child_pid, 0, 0, 0, 0, 0);
+	} while (ret != -ESRCH && ret != -EINVAL);
+
+	ksft_test_result_pass("%s\n", __func__);
+}
+
+static void (*pkey_tests[])(void) = {
+	test_sigsegv_handler_with_pkey0_disabled,
+	test_sigsegv_handler_cannot_access_stack,
+	test_sigsegv_handler_with_different_pkey_for_stack,
+	test_pkru_preserved_after_sigusr1,
+	test_pkru_sigreturn
+};
+
+int main(int argc, char *argv[])
+{
+	int i;
+
+	ksft_print_header();
+	ksft_set_plan(ARRAY_SIZE(pkey_tests));
+
+	for (i = 0; i < ARRAY_SIZE(pkey_tests); i++)
+		(*pkey_tests[i])();
+
+	ksft_finished();
+	return 0;
+}
diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c
index 0789981..4990f7a 100644
--- a/tools/testing/selftests/mm/protection_keys.c
+++ b/tools/testing/selftests/mm/protection_keys.c
@@ -954,16 +954,6 @@ void close_test_fds(void)
 	nr_test_fds = 0;
 }
 
-#define barrier() __asm__ __volatile__("": : :"memory")
-__attribute__((noinline)) int read_ptr(int *ptr)
-{
-	/*
-	 * Keep GCC from optimizing this away somehow
-	 */
-	barrier();
-	return *ptr;
-}
-
 void test_pkey_alloc_free_attach_pkey0(int *ptr, u16 pkey)
 {
 	int i, err;