Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/l…

…inux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "The accumulated fixes from this and last week:

   - Fix vmalloc TLB flush and map range calculations which lead to
     stale TLBs, spurious faults and other hard to diagnose issues.

   - Use fault_in_pages_writable() for prefaulting the user stack in the
     FPU code as it's less fragile than the current solution

   - Use the PF_KTHREAD flag when checking for a kernel thread instead
     of current->mm as the latter can give the wrong answer due to
     use_mm()

   - Compute the vmemmap size correctly for KASLR and 5-Level paging.
     Otherwise this can end up with a way too small vmemmap area.

   - Make KASAN and 5-level paging work again by making sure that all
     invalid bits are masked out when computing the P4D offset. This
     worked before but got broken recently when the LDT remap area was
     moved.

   - Prevent a NULL pointer dereference in the resource control code
     which can be triggered with certain mount options when the
     requested resource is not available.

   - Enforce ordering of microcode loading vs. perf initialization on
     secondary CPUs. Otherwise perf tries to access a non-existing MSR
     as the boot CPU marked it as available.

   - Don't stop the resource control group walk early otherwise the
     control bitmaps are not updated correctly and become inconsistent.

   - Unbreak kgdb by returning 0 on success from
     kgdb_arch_set_breakpoint() instead of an error code.

   - Add more Icelake CPU model defines so depending changes can be
     queued in other trees"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback
  x86/kasan: Fix boot with 5-level paging and KASAN
  x86/fpu: Don't use current->mm to check for a kthread
  x86/kgdb: Return 0 from kgdb_arch_set_breakpoint()
  x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled
  x86/resctrl: Don't stop walking closids when a locksetup group is found
  x86/fpu: Update kernel's FPU state before using for the fsave header
  x86/mm/KASLR: Compute the size of the vmemmap section properly
  x86/fpu: Use fault_in_pages_writeable() for pre-faulting
  x86/CPU: Add more Icelake model numbers
  mm/vmalloc: Avoid rare case of flushing TLB with weird arguments
  mm/vmalloc: Fix calculation of direct map addr range

arch/x86/include/asm/fpu/internal.h

@@ -536,7 +536,7 @@ static inline void __fpregs_load_activate(void)
 	struct fpu *fpu = &current->thread.fpu;
 	int cpu = smp_processor_id();
 
-	if (WARN_ON_ONCE(current->mm == NULL))
+	if (WARN_ON_ONCE(current->flags & PF_KTHREAD))
 		return;
 
 	if (!fpregs_state_valid(fpu, cpu)) {
@@ -567,11 +567,11 @@ static inline void __fpregs_load_activate(void)
  * otherwise.
  *
  * The FPU context is only stored/restored for a user task and
- * ->mm is used to distinguish between kernel and user threads.
+ * PF_KTHREAD is used to distinguish between kernel and user threads.
  */
 static inline void switch_fpu_prepare(struct fpu *old_fpu, int cpu)
 {
-	if (static_cpu_has(X86_FEATURE_FPU) && current->mm) {
+	if (static_cpu_has(X86_FEATURE_FPU) && !(current->flags & PF_KTHREAD)) {
 		if (!copy_fpregs_to_fpstate(old_fpu))
 			old_fpu->last_cpu = -1;
 		else

arch/x86/include/asm/intel-family.h

@@ -52,6 +52,9 @@
 
 #define INTEL_FAM6_CANNONLAKE_MOBILE	0x66
 
+#define INTEL_FAM6_ICELAKE_X		0x6A
+#define INTEL_FAM6_ICELAKE_XEON_D	0x6C
+#define INTEL_FAM6_ICELAKE_DESKTOP	0x7D
 #define INTEL_FAM6_ICELAKE_MOBILE	0x7E
 
 /* "Small Core" Processors (Atom) */

arch/x86/kernel/cpu/microcode/core.c

@@ -872,7 +872,7 @@ int __init microcode_init(void)
 		goto out_ucode_group;
 
 	register_syscore_ops(&mc_syscore_ops);
-	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
+	cpuhp_setup_state_nocalls(CPUHP_AP_MICROCODE_LOADER, "x86/microcode:online",
 				  mc_cpu_online, mc_cpu_down_prep);
 
 	pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION);

arch/x86/kernel/cpu/resctrl/monitor.c

@@ -360,6 +360,9 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
 	struct list_head *head;
 	struct rdtgroup *entry;
 
+	if (!is_mbm_local_enabled())
+		return;
+
 	r_mba = &rdt_resources_all[RDT_RESOURCE_MBA];
 	closid = rgrp->closid;
 	rmid = rgrp->mon.rmid;

arch/x86/kernel/cpu/resctrl/rdtgroup.c

@@ -2534,7 +2534,12 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct rdt_resource *r,
 		if (closid_allocated(i) && i != closid) {
 			mode = rdtgroup_mode_by_closid(i);
 			if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
-				break;
+				/*
+				 * ctrl values for locksetup aren't relevant
+				 * until the schemata is written, and the mode
+				 * becomes RDT_MODE_PSEUDO_LOCKED.
+				 */
+				continue;
 			/*
 			 * If CDP is active include peer domain's
 			 * usage to ensure there is no overlap

arch/x86/kernel/fpu/core.c

@@ -102,7 +102,7 @@ static void __kernel_fpu_begin(void)
 
 	kernel_fpu_disable();
 
-	if (current->mm) {
+	if (!(current->flags & PF_KTHREAD)) {
 		if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {
 			set_thread_flag(TIF_NEED_FPU_LOAD);
 			/*

arch/x86/kernel/fpu/signal.c

@@ -5,6 +5,7 @@
 
 #include <linux/compat.h>
 #include <linux/cpu.h>
+#include <linux/pagemap.h>
 
 #include <asm/fpu/internal.h>
 #include <asm/fpu/signal.h>
@@ -61,6 +62,11 @@ static inline int save_fsave_header(struct task_struct *tsk, void __user *buf)
 		struct user_i387_ia32_struct env;
 		struct _fpstate_32 __user *fp = buf;
 
+		fpregs_lock();
+		if (!test_thread_flag(TIF_NEED_FPU_LOAD))
+			copy_fxregs_to_kernel(&tsk->thread.fpu);
+		fpregs_unlock();
+
 		convert_from_fxsr(&env, tsk);
 
 		if (__copy_to_user(buf, &env, sizeof(env)) ||
@@ -189,15 +195,7 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
 	fpregs_unlock();
 
 	if (ret) {
-		int aligned_size;
-		int nr_pages;
-
-		aligned_size = offset_in_page(buf_fx) + fpu_user_xstate_size;
-		nr_pages = DIV_ROUND_UP(aligned_size, PAGE_SIZE);
-
-		ret = get_user_pages_unlocked((unsigned long)buf_fx, nr_pages,
-					      NULL, FOLL_WRITE);
-		if (ret == nr_pages)
+		if (!fault_in_pages_writeable(buf_fx, fpu_user_xstate_size))
 			goto retry;
 		return -EFAULT;
 	}

arch/x86/kernel/kgdb.c

@@ -758,7 +758,7 @@ int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
 		       BREAK_INSTR_SIZE);
 	bpt->type = BP_POKE_BREAKPOINT;
 
-	return err;
+	return 0;
 }
 
 int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)

arch/x86/mm/kasan_init_64.c

@@ -199,7 +199,7 @@ static inline p4d_t *early_p4d_offset(pgd_t *pgd, unsigned long addr)
 	if (!pgtable_l5_enabled())
 		return (p4d_t *)pgd;
 
-	p4d = __pa_nodebug(pgd_val(*pgd)) & PTE_PFN_MASK;
+	p4d = pgd_val(*pgd) & PTE_PFN_MASK;
 	p4d += __START_KERNEL_map - phys_base;
 	return (p4d_t *)p4d + p4d_index(addr);
 }

arch/x86/mm/kaslr.c

@@ -52,7 +52,7 @@ static __initdata struct kaslr_memory_region {
 } kaslr_regions[] = {
 	{ &page_offset_base, 0 },
 	{ &vmalloc_base, 0 },
-	{ &vmemmap_base, 1 },
+	{ &vmemmap_base, 0 },
 };
 
 /* Get size in bytes used by the memory region */
@@ -78,6 +78,7 @@ void __init kernel_randomize_memory(void)
 	unsigned long rand, memory_tb;
 	struct rnd_state rand_state;
 	unsigned long remain_entropy;
+	unsigned long vmemmap_size;
 
 	vaddr_start = pgtable_l5_enabled() ? __PAGE_OFFSET_BASE_L5 : __PAGE_OFFSET_BASE_L4;
 	vaddr = vaddr_start;
@@ -109,6 +110,14 @@ void __init kernel_randomize_memory(void)
 	if (memory_tb < kaslr_regions[0].size_tb)
 		kaslr_regions[0].size_tb = memory_tb;
 
+	/*
+	 * Calculate the vmemmap region size in TBs, aligned to a TB
+	 * boundary.
+	 */
+	vmemmap_size = (kaslr_regions[0].size_tb << (TB_SHIFT - PAGE_SHIFT)) *
+			sizeof(struct page);
+	kaslr_regions[2].size_tb = DIV_ROUND_UP(vmemmap_size, 1UL << TB_SHIFT);
+
 	/* Calculate entropy available between regions */
 	remain_entropy = vaddr_end - vaddr_start;
 	for (i = 0; i < ARRAY_SIZE(kaslr_regions); i++)

include/linux/cpuhotplug.h

@@ -101,6 +101,7 @@ enum cpuhp_state {
 	CPUHP_AP_IRQ_BCM2836_STARTING,
 	CPUHP_AP_IRQ_MIPS_GIC_STARTING,
 	CPUHP_AP_ARM_MVEBU_COHERENCY,
+	CPUHP_AP_MICROCODE_LOADER,
 	CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
 	CPUHP_AP_PERF_X86_STARTING,
 	CPUHP_AP_PERF_X86_AMD_IBS_STARTING,

mm/vmalloc.c

@@ -2123,9 +2123,9 @@ static inline void set_area_direct_map(const struct vm_struct *area,
 /* Handle removing and resetting vm mappings related to the vm_struct. */
 static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
 {
-	unsigned long addr = (unsigned long)area->addr;
 	unsigned long start = ULONG_MAX, end = 0;
 	int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;
+	int flush_dmap = 0;
 	int i;
 
 	/*
@@ -2135,8 +2135,8 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
 	 * execute permissions, without leaving a RW+X window.
 	 */
 	if (flush_reset && !IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
-		set_memory_nx(addr, area->nr_pages);
-		set_memory_rw(addr, area->nr_pages);
+		set_memory_nx((unsigned long)area->addr, area->nr_pages);
+		set_memory_rw((unsigned long)area->addr, area->nr_pages);
 	}
 
 	remove_vm_area(area->addr);
@@ -2160,9 +2160,11 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
 	 * the vm_unmap_aliases() flush includes the direct map.
 	 */
 	for (i = 0; i < area->nr_pages; i++) {
-		if (page_address(area->pages[i])) {
+		unsigned long addr = (unsigned long)page_address(area->pages[i]);
+		if (addr) {
 			start = min(addr, start);
-			end = max(addr, end);
+			end = max(addr + PAGE_SIZE, end);
+			flush_dmap = 1;
 		}
 	}
 
@@ -2172,7 +2174,7 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
 	 * reset the direct map permissions to the default.
 	 */
 	set_area_direct_map(area, set_direct_map_invalid_noflush);
-	_vm_unmap_aliases(start, end, 1);
+	_vm_unmap_aliases(start, end, flush_dmap);
 	set_area_direct_map(area, set_direct_map_default_noflush);
 }