Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "zram: optimal post-processing target selection" from
   Sergey Senozhatsky improves zram's post-processing selection
   algorithm. This leads to improved memory savings.

 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
	- "refine mas_mab_cp()"
	- "Reduce the space to be cleared for maple_big_node"
	- "maple_tree: simplify mas_push_node()"
	- "Following cleanup after introduce mas_wr_store_type()"
	- "refine storing null"

 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.

 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping
   code.

 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of
   shadow entries.

 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.

 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in
   the hugetlb code.

 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page
   into small pages. Instead we replace the whole thing with a THP. More
   consistent cleaner and potentiall saves a large number of pagefaults.

 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.

 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to
   do.

 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio
   size rather than as individual pages. A 20% speedup was observed.

 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
   splitting.

 - The series "memcg-v1: fully deprecate charge moving" from Shakeel
   Butt removes the long-deprecated memcgv2 charge moving feature.

 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.

 - The series "x86/module: use large ROX pages for text allocations"
   from Mike Rapoport teaches x86 to use large pages for
   read-only-execute module text.

 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.

 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/. A slow march towards shrinking
   struct page.

 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.

 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression. It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.

 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
   tests over to the KUnit framework.

 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a
   single VMA, rather than requiring that multiple VMAs be created for
   this. Improved efficiencies for userspace memory allocators are
   expected.

 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.

 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.

 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP
   from the kernel boot command line.

 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.

 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep
   is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...

1 files changed, 344 insertions, 8 deletions

diff --git a/mm/execmem.c b/mm/execmem.c
index 0c4b36bc6d10..317b6a8d35be 100644
--- a/mm/execmem.c
+++ b/mm/execmem.c
@@ -6,28 +6,41 @@
  * Copyright (C) 2024 Mike Rapoport IBM.
  */
 
+#define pr_fmt(fmt) "execmem: " fmt
+
 #include <linux/mm.h>
+#include <linux/mutex.h>
 #include <linux/vmalloc.h>
 #include <linux/execmem.h>
+#include <linux/maple_tree.h>
+#include <linux/set_memory.h>
 #include <linux/moduleloader.h>
+#include <linux/text-patching.h>
+
+#include <asm/tlbflush.h>
+
+#include "internal.h"
 
 static struct execmem_info *execmem_info __ro_after_init;
 static struct execmem_info default_execmem_info __ro_after_init;
 
-static void *__execmem_alloc(struct execmem_range *range, size_t size)
+#ifdef CONFIG_MMU
+static void *execmem_vmalloc(struct execmem_range *range, size_t size,
+			     pgprot_t pgprot, unsigned long vm_flags)
 {
 	bool kasan = range->flags & EXECMEM_KASAN_SHADOW;
-	unsigned long vm_flags  = VM_FLUSH_RESET_PERMS;
 	gfp_t gfp_flags = GFP_KERNEL | __GFP_NOWARN;
+	unsigned int align = range->alignment;
 	unsigned long start = range->start;
 	unsigned long end = range->end;
-	unsigned int align = range->alignment;
-	pgprot_t pgprot = range->pgprot;
 	void *p;
 
 	if (kasan)
 		vm_flags |= VM_DEFER_KMEMLEAK;
 
+	if (vm_flags & VM_ALLOW_HUGE_VMAP)
+		align = PMD_SIZE;
+
 	p = __vmalloc_node_range(size, align, start, end, gfp_flags,
 				 pgprot, vm_flags, NUMA_NO_NODE,
 				 __builtin_return_address(0));
@@ -40,7 +53,7 @@ static void *__execmem_alloc(struct execmem_range *range, size_t size)
 	}
 
 	if (!p) {
-		pr_warn_ratelimited("execmem: unable to allocate memory\n");
+		pr_warn_ratelimited("unable to allocate memory\n");
 		return NULL;
 	}
 
@@ -49,14 +62,314 @@ static void *__execmem_alloc(struct execmem_range *range, size_t size)
 		return NULL;
 	}
 
-	return kasan_reset_tag(p);
+	return p;
+}
+
+struct vm_struct *execmem_vmap(size_t size)
+{
+	struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
+	struct vm_struct *area;
+
+	area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
+				  range->start, range->end, NUMA_NO_NODE,
+				  GFP_KERNEL, __builtin_return_address(0));
+	if (!area && range->fallback_start)
+		area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
+					  range->fallback_start, range->fallback_end,
+					  NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
+
+	return area;
+}
+#else
+static void *execmem_vmalloc(struct execmem_range *range, size_t size,
+			     pgprot_t pgprot, unsigned long vm_flags)
+{
+	return vmalloc(size);
+}
+#endif /* CONFIG_MMU */
+
+#ifdef CONFIG_ARCH_HAS_EXECMEM_ROX
+struct execmem_cache {
+	struct mutex mutex;
+	struct maple_tree busy_areas;
+	struct maple_tree free_areas;
+};
+
+static struct execmem_cache execmem_cache = {
+	.mutex = __MUTEX_INITIALIZER(execmem_cache.mutex),
+	.busy_areas = MTREE_INIT_EXT(busy_areas, MT_FLAGS_LOCK_EXTERN,
+				     execmem_cache.mutex),
+	.free_areas = MTREE_INIT_EXT(free_areas, MT_FLAGS_LOCK_EXTERN,
+				     execmem_cache.mutex),
+};
+
+static inline unsigned long mas_range_len(struct ma_state *mas)
+{
+	return mas->last - mas->index + 1;
+}
+
+static int execmem_set_direct_map_valid(struct vm_struct *vm, bool valid)
+{
+	unsigned int nr = (1 << get_vm_area_page_order(vm));
+	unsigned int updated = 0;
+	int err = 0;
+
+	for (int i = 0; i < vm->nr_pages; i += nr) {
+		err = set_direct_map_valid_noflush(vm->pages[i], nr, valid);
+		if (err)
+			goto err_restore;
+		updated += nr;
+	}
+
+	return 0;
+
+err_restore:
+	for (int i = 0; i < updated; i += nr)
+		set_direct_map_valid_noflush(vm->pages[i], nr, !valid);
+
+	return err;
+}
+
+static void execmem_cache_clean(struct work_struct *work)
+{
+	struct maple_tree *free_areas = &execmem_cache.free_areas;
+	struct mutex *mutex = &execmem_cache.mutex;
+	MA_STATE(mas, free_areas, 0, ULONG_MAX);
+	void *area;
+
+	mutex_lock(mutex);
+	mas_for_each(&mas, area, ULONG_MAX) {
+		size_t size = mas_range_len(&mas);
+
+		if (IS_ALIGNED(size, PMD_SIZE) &&
+		    IS_ALIGNED(mas.index, PMD_SIZE)) {
+			struct vm_struct *vm = find_vm_area(area);
+
+			execmem_set_direct_map_valid(vm, true);
+			mas_store_gfp(&mas, NULL, GFP_KERNEL);
+			vfree(area);
+		}
+	}
+	mutex_unlock(mutex);
+}
+
+static DECLARE_WORK(execmem_cache_clean_work, execmem_cache_clean);
+
+static int execmem_cache_add(void *ptr, size_t size)
+{
+	struct maple_tree *free_areas = &execmem_cache.free_areas;
+	struct mutex *mutex = &execmem_cache.mutex;
+	unsigned long addr = (unsigned long)ptr;
+	MA_STATE(mas, free_areas, addr - 1, addr + 1);
+	unsigned long lower, upper;
+	void *area = NULL;
+	int err;
+
+	lower = addr;
+	upper = addr + size - 1;
+
+	mutex_lock(mutex);
+	area = mas_walk(&mas);
+	if (area && mas.last == addr - 1)
+		lower = mas.index;
+
+	area = mas_next(&mas, ULONG_MAX);
+	if (area && mas.index == addr + size)
+		upper = mas.last;
+
+	mas_set_range(&mas, lower, upper);
+	err = mas_store_gfp(&mas, (void *)lower, GFP_KERNEL);
+	mutex_unlock(mutex);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static bool within_range(struct execmem_range *range, struct ma_state *mas,
+			 size_t size)
+{
+	unsigned long addr = mas->index;
+
+	if (addr >= range->start && addr + size < range->end)
+		return true;
+
+	if (range->fallback_start &&
+	    addr >= range->fallback_start && addr + size < range->fallback_end)
+		return true;
+
+	return false;
+}
+
+static void *__execmem_cache_alloc(struct execmem_range *range, size_t size)
+{
+	struct maple_tree *free_areas = &execmem_cache.free_areas;
+	struct maple_tree *busy_areas = &execmem_cache.busy_areas;
+	MA_STATE(mas_free, free_areas, 0, ULONG_MAX);
+	MA_STATE(mas_busy, busy_areas, 0, ULONG_MAX);
+	struct mutex *mutex = &execmem_cache.mutex;
+	unsigned long addr, last, area_size = 0;
+	void *area, *ptr = NULL;
+	int err;
+
+	mutex_lock(mutex);
+	mas_for_each(&mas_free, area, ULONG_MAX) {
+		area_size = mas_range_len(&mas_free);
+
+		if (area_size >= size && within_range(range, &mas_free, size))
+			break;
+	}
+
+	if (area_size < size)
+		goto out_unlock;
+
+	addr = mas_free.index;
+	last = mas_free.last;
+
+	/* insert allocated size to busy_areas at range [addr, addr + size) */
+	mas_set_range(&mas_busy, addr, addr + size - 1);
+	err = mas_store_gfp(&mas_busy, (void *)addr, GFP_KERNEL);
+	if (err)
+		goto out_unlock;
+
+	mas_store_gfp(&mas_free, NULL, GFP_KERNEL);
+	if (area_size > size) {
+		void *ptr = (void *)(addr + size);
+
+		/*
+		 * re-insert remaining free size to free_areas at range
+		 * [addr + size, last]
+		 */
+		mas_set_range(&mas_free, addr + size, last);
+		err = mas_store_gfp(&mas_free, ptr, GFP_KERNEL);
+		if (err) {
+			mas_store_gfp(&mas_busy, NULL, GFP_KERNEL);
+			goto out_unlock;
+		}
+	}
+	ptr = (void *)addr;
+
+out_unlock:
+	mutex_unlock(mutex);
+	return ptr;
+}
+
+static int execmem_cache_populate(struct execmem_range *range, size_t size)
+{
+	unsigned long vm_flags = VM_ALLOW_HUGE_VMAP;
+	unsigned long start, end;
+	struct vm_struct *vm;
+	size_t alloc_size;
+	int err = -ENOMEM;
+	void *p;
+
+	alloc_size = round_up(size, PMD_SIZE);
+	p = execmem_vmalloc(range, alloc_size, PAGE_KERNEL, vm_flags);
+	if (!p)
+		return err;
+
+	vm = find_vm_area(p);
+	if (!vm)
+		goto err_free_mem;
+
+	/* fill memory with instructions that will trap */
+	execmem_fill_trapping_insns(p, alloc_size, /* writable = */ true);
+
+	start = (unsigned long)p;
+	end = start + alloc_size;
+
+	vunmap_range(start, end);
+
+	err = execmem_set_direct_map_valid(vm, false);
+	if (err)
+		goto err_free_mem;
+
+	err = vmap_pages_range_noflush(start, end, range->pgprot, vm->pages,
+				       PMD_SHIFT);
+	if (err)
+		goto err_free_mem;
+
+	err = execmem_cache_add(p, alloc_size);
+	if (err)
+		goto err_free_mem;
+
+	return 0;
+
+err_free_mem:
+	vfree(p);
+	return err;
+}
+
+static void *execmem_cache_alloc(struct execmem_range *range, size_t size)
+{
+	void *p;
+	int err;
+
+	p = __execmem_cache_alloc(range, size);
+	if (p)
+		return p;
+
+	err = execmem_cache_populate(range, size);
+	if (err)
+		return NULL;
+
+	return __execmem_cache_alloc(range, size);
+}
+
+static bool execmem_cache_free(void *ptr)
+{
+	struct maple_tree *busy_areas = &execmem_cache.busy_areas;
+	struct mutex *mutex = &execmem_cache.mutex;
+	unsigned long addr = (unsigned long)ptr;
+	MA_STATE(mas, busy_areas, addr, addr);
+	size_t size;
+	void *area;
+
+	mutex_lock(mutex);
+	area = mas_walk(&mas);
+	if (!area) {
+		mutex_unlock(mutex);
+		return false;
+	}
+	size = mas_range_len(&mas);
+
+	mas_store_gfp(&mas, NULL, GFP_KERNEL);
+	mutex_unlock(mutex);
+
+	execmem_fill_trapping_insns(ptr, size, /* writable = */ false);
+
+	execmem_cache_add(ptr, size);
+
+	schedule_work(&execmem_cache_clean_work);
+
+	return true;
+}
+#else /* CONFIG_ARCH_HAS_EXECMEM_ROX */
+static void *execmem_cache_alloc(struct execmem_range *range, size_t size)
+{
+	return NULL;
+}
+
+static bool execmem_cache_free(void *ptr)
+{
+	return false;
 }
+#endif /* CONFIG_ARCH_HAS_EXECMEM_ROX */
 
 void *execmem_alloc(enum execmem_type type, size_t size)
 {
 	struct execmem_range *range = &execmem_info->ranges[type];
+	bool use_cache = range->flags & EXECMEM_ROX_CACHE;
+	unsigned long vm_flags = VM_FLUSH_RESET_PERMS;
+	pgprot_t pgprot = range->pgprot;
+	void *p;
 
-	return __execmem_alloc(range, size);
+	if (use_cache)
+		p = execmem_cache_alloc(range, size);
+	else
+		p = execmem_vmalloc(range, size, pgprot, vm_flags);
+
+	return kasan_reset_tag(p);
 }
 
 void execmem_free(void *ptr)
@@ -66,7 +379,19 @@ void execmem_free(void *ptr)
 	 * supported by vmalloc.
 	 */
 	WARN_ON(in_interrupt());
-	vfree(ptr);
+
+	if (!execmem_cache_free(ptr))
+		vfree(ptr);
+}
+
+void *execmem_update_copy(void *dst, const void *src, size_t size)
+{
+	return text_poke_copy(dst, src, size);
+}
+
+bool execmem_is_rox(enum execmem_type type)
+{
+	return !!(execmem_info->ranges[type].flags & EXECMEM_ROX_CACHE);
 }
 
 static bool execmem_validate(struct execmem_info *info)
@@ -78,6 +403,17 @@ static bool execmem_validate(struct execmem_info *info)
 		return false;
 	}
 
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_EXECMEM_ROX)) {
+		for (int i = EXECMEM_DEFAULT; i < EXECMEM_TYPE_MAX; i++) {
+			r = &info->ranges[i];
+
+			if (r->flags & EXECMEM_ROX_CACHE) {
+				pr_warn_once("ROX cache is not supported\n");
+				r->flags &= ~EXECMEM_ROX_CACHE;
+			}
+		}
+	}
+
 	return true;
 }