Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...

19 files changed, 902 insertions, 217 deletions

diff --git a/tools/testing/selftests/cgroup/test_zswap.c b/tools/testing/selftests/cgroup/test_zswap.c
index 8418a8d7439f..cfaa94e0a175 100644
--- a/tools/testing/selftests/cgroup/test_zswap.c
+++ b/tools/testing/selftests/cgroup/test_zswap.c
@@ -48,7 +48,7 @@ static int get_zswap_stored_pages(size_t *value)
 	return read_int("/sys/kernel/debug/zswap/stored_pages", value);
 }
 
-static int get_cg_wb_count(const char *cg)
+static long get_cg_wb_count(const char *cg)
 {
 	return cg_read_key_long(cg, "memory.stat", "zswpwb");
 }
@@ -247,6 +247,132 @@ out:
 }
 
 /*
+ * Attempt writeback with the following steps:
+ * 1. Allocate memory.
+ * 2. Reclaim memory equal to the amount that was allocated in step 1.
+      This will move it into zswap.
+ * 3. Save current zswap usage.
+ * 4. Move the memory allocated in step 1 back in from zswap.
+ * 5. Set zswap.max to half the amount that was recorded in step 3.
+ * 6. Attempt to reclaim memory equal to the amount that was allocated,
+      this will either trigger writeback if it's enabled, or reclamation
+      will fail if writeback is disabled as there isn't enough zswap space.
+ */
+static int attempt_writeback(const char *cgroup, void *arg)
+{
+	long pagesize = sysconf(_SC_PAGESIZE);
+	char *test_group = arg;
+	size_t memsize = MB(4);
+	char buf[pagesize];
+	long zswap_usage;
+	bool wb_enabled;
+	int ret = -1;
+	char *mem;
+
+	wb_enabled = cg_read_long(test_group, "memory.zswap.writeback");
+	mem = (char *)malloc(memsize);
+	if (!mem)
+		return ret;
+
+	/*
+	 * Fill half of each page with increasing data, and keep other
+	 * half empty, this will result in data that is still compressible
+	 * and ends up in zswap, with material zswap usage.
+	 */
+	for (int i = 0; i < pagesize; i++)
+		buf[i] = i < pagesize/2 ? (char) i : 0;
+
+	for (int i = 0; i < memsize; i += pagesize)
+		memcpy(&mem[i], buf, pagesize);
+
+	/* Try and reclaim allocated memory */
+	if (cg_write_numeric(test_group, "memory.reclaim", memsize)) {
+		ksft_print_msg("Failed to reclaim all of the requested memory\n");
+		goto out;
+	}
+
+	zswap_usage = cg_read_long(test_group, "memory.zswap.current");
+
+	/* zswpin */
+	for (int i = 0; i < memsize; i += pagesize) {
+		if (memcmp(&mem[i], buf, pagesize)) {
+			ksft_print_msg("invalid memory\n");
+			goto out;
+		}
+	}
+
+	if (cg_write_numeric(test_group, "memory.zswap.max", zswap_usage/2))
+		goto out;
+
+	/*
+	 * If writeback is enabled, trying to reclaim memory now will trigger a
+	 * writeback as zswap.max is half of what was needed when reclaim ran the first time.
+	 * If writeback is disabled, memory reclaim will fail as zswap is limited and
+	 * it can't writeback to swap.
+	 */
+	ret = cg_write_numeric(test_group, "memory.reclaim", memsize);
+	if (!wb_enabled)
+		ret = (ret == -EAGAIN) ? 0 : -1;
+
+out:
+	free(mem);
+	return ret;
+}
+
+/* Test to verify the zswap writeback path */
+static int test_zswap_writeback(const char *root, bool wb)
+{
+	long zswpwb_before, zswpwb_after;
+	int ret = KSFT_FAIL;
+	char *test_group;
+
+	test_group = cg_name(root, "zswap_writeback_test");
+	if (!test_group)
+		goto out;
+	if (cg_create(test_group))
+		goto out;
+	if (cg_write(test_group, "memory.zswap.writeback", wb ? "1" : "0"))
+		goto out;
+
+	zswpwb_before = get_cg_wb_count(test_group);
+	if (zswpwb_before != 0) {
+		ksft_print_msg("zswpwb_before = %ld instead of 0\n", zswpwb_before);
+		goto out;
+	}
+
+	if (cg_run(test_group, attempt_writeback, (void *) test_group))
+		goto out;
+
+	/* Verify that zswap writeback occurred only if writeback was enabled */
+	zswpwb_after = get_cg_wb_count(test_group);
+	if (zswpwb_after < 0)
+		goto out;
+
+	if (wb != !!zswpwb_after) {
+		ksft_print_msg("zswpwb_after is %ld while wb is %s",
+				zswpwb_after, wb ? "enabled" : "disabled");
+		goto out;
+	}
+
+	ret = KSFT_PASS;
+
+out:
+	cg_destroy(test_group);
+	free(test_group);
+	return ret;
+}
+
+static int test_zswap_writeback_enabled(const char *root)
+{
+	return test_zswap_writeback(root, true);
+}
+
+static int test_zswap_writeback_disabled(const char *root)
+{
+	return test_zswap_writeback(root, false);
+}
+
+/*
  * When trying to store a memcg page in zswap, if the memcg hits its memory
  * limit in zswap, writeback should affect only the zswapped pages of that
  * memcg.
@@ -362,8 +488,6 @@ static int test_no_kmem_bypass(const char *root)
 	trigger_allocation_size = sys_info.totalram / 20;
 
 	/* Set up test memcg */
-	if (cg_write(root, "cgroup.subtree_control", "+memory"))
-		goto out;
 	test_group = cg_name(root, "kmem_bypass_test");
 	if (!test_group)
 		goto out;
@@ -423,6 +547,8 @@ struct zswap_test {
 	T(test_zswap_usage),
 	T(test_swapin_nozswap),
 	T(test_zswapin),
+	T(test_zswap_writeback_enabled),
+	T(test_zswap_writeback_disabled),
 	T(test_no_kmem_bypass),
 	T(test_no_invasive_cgroup_shrink),
 };
diff --git a/tools/testing/selftests/damon/Makefile b/tools/testing/selftests/damon/Makefile
index 789d6949c247..29a22f50e762 100644
--- a/tools/testing/selftests/damon/Makefile
+++ b/tools/testing/selftests/damon/Makefile
@@ -7,16 +7,21 @@ TEST_GEN_FILES += debugfs_target_ids_pid_leak
 TEST_GEN_FILES += access_memory
 
 TEST_FILES = _chk_dependency.sh _debugfs_common.sh
+
+# functionality tests
 TEST_PROGS = debugfs_attrs.sh debugfs_schemes.sh debugfs_target_ids.sh
+TEST_PROGS += sysfs.sh
+TEST_PROGS += sysfs_update_schemes_tried_regions_wss_estimation.py
+TEST_PROGS += damos_quota.py damos_quota_goal.py damos_apply_interval.py
+TEST_PROGS += reclaim.sh lru_sort.sh
+
+# regression tests (reproducers of previously found bugs)
 TEST_PROGS += debugfs_empty_targets.sh debugfs_huge_count_read_write.sh
 TEST_PROGS += debugfs_duplicate_context_creation.sh
 TEST_PROGS += debugfs_rm_non_contexts.sh
 TEST_PROGS += debugfs_target_ids_read_before_terminate_race.sh
 TEST_PROGS += debugfs_target_ids_pid_leak.sh
-TEST_PROGS += sysfs.sh sysfs_update_removed_scheme_dir.sh
+TEST_PROGS += sysfs_update_removed_scheme_dir.sh
 TEST_PROGS += sysfs_update_schemes_tried_regions_hang.py
-TEST_PROGS += sysfs_update_schemes_tried_regions_wss_estimation.py
-TEST_PROGS += damos_quota.py damos_apply_interval.py
-TEST_PROGS += reclaim.sh lru_sort.sh
 
 include ../lib.mk
diff --git a/tools/testing/selftests/damon/_damon_sysfs.py b/tools/testing/selftests/damon/_damon_sysfs.py
index d23d7398a27a..2bd44c32be1b 100644
--- a/tools/testing/selftests/damon/_damon_sysfs.py
+++ b/tools/testing/selftests/damon/_damon_sysfs.py
@@ -2,7 +2,18 @@
 
 import os
 
-sysfs_root = '/sys/kernel/mm/damon/admin'
+ksft_skip=4
+
+sysfs_root = None
+with open('/proc/mounts', 'r') as f:
+    for line in f:
+        dev_name, mount_point, dev_fs = line.split()[:3]
+        if dev_fs == 'sysfs':
+            sysfs_root = '%s/kernel/mm/damon/admin' % mount_point
+            break
+if sysfs_root is None:
+    print('Seems sysfs not mounted?')
+    exit(ksft_skip)
 
 def write_file(path, string):
     "Returns error string if failed, or None otherwise"
@@ -34,11 +45,11 @@ class DamosAccessPattern:
         self.nr_accesses = nr_accesses
         self.age = age
 
-        if self.size == None:
+        if self.size is None:
             self.size = [0, 2**64 - 1]
-        if self.nr_accesses == None:
+        if self.nr_accesses is None:
             self.nr_accesses = [0, 2**64 - 1]
-        if self.age == None:
+        if self.age is None:
             self.age = [0, 2**64 - 1]
 
     def sysfs_dir(self):
@@ -47,55 +58,109 @@ class DamosAccessPattern:
     def stage(self):
         err = write_file(
                 os.path.join(self.sysfs_dir(), 'sz', 'min'), self.size[0])
-        if err != None:
+        if err is not None:
             return err
         err = write_file(
                 os.path.join(self.sysfs_dir(), 'sz', 'max'), self.size[1])
-        if err != None:
+        if err is not None:
             return err
         err = write_file(os.path.join(self.sysfs_dir(), 'nr_accesses', 'min'),
                 self.nr_accesses[0])
-        if err != None:
+        if err is not None:
             return err
         err = write_file(os.path.join(self.sysfs_dir(), 'nr_accesses', 'max'),
                 self.nr_accesses[1])
-        if err != None:
+        if err is not None:
             return err
         err = write_file(
                 os.path.join(self.sysfs_dir(), 'age', 'min'), self.age[0])
-        if err != None:
+        if err is not None:
             return err
         err = write_file(
                 os.path.join(self.sysfs_dir(), 'age', 'max'), self.age[1])
-        if err != None:
+        if err is not None:
             return err
 
+qgoal_metric_user_input = 'user_input'
+qgoal_metric_some_mem_psi_us = 'some_mem_psi_us'
+qgoal_metrics = [qgoal_metric_user_input, qgoal_metric_some_mem_psi_us]
+
+class DamosQuotaGoal:
+    metric = None
+    target_value = None
+    current_value = None
+    effective_bytes = None
+    quota = None            # owner quota
+    idx = None
+
+    def __init__(self, metric, target_value=10000, current_value=0):
+        self.metric = metric
+        self.target_value = target_value
+        self.current_value = current_value
+
+    def sysfs_dir(self):
+        return os.path.join(self.quota.sysfs_dir(), 'goals', '%d' % self.idx)
+
+    def stage(self):
+        err = write_file(os.path.join(self.sysfs_dir(), 'target_metric'),
+                         self.metric)
+        if err is not None:
+            return err
+        err = write_file(os.path.join(self.sysfs_dir(), 'target_value'),
+                         self.target_value)
+        if err is not None:
+            return err
+        err = write_file(os.path.join(self.sysfs_dir(), 'current_value'),
+                         self.current_value)
+        if err is not None:
+            return err
+        return None
+
 class DamosQuota:
     sz = None                   # size quota, in bytes
     ms = None                   # time quota
+    goals = None                # quota goals
     reset_interval_ms = None    # quota reset interval
     scheme = None               # owner scheme
 
-    def __init__(self, sz=0, ms=0, reset_interval_ms=0):
+    def __init__(self, sz=0, ms=0, goals=None, reset_interval_ms=0):
         self.sz = sz
         self.ms = ms
         self.reset_interval_ms = reset_interval_ms
+        self.goals = goals if goals is not None else []
+        for idx, goal in enumerate(self.goals):
+            goal.idx = idx
+            goal.quota = self
 
     def sysfs_dir(self):
         return os.path.join(self.scheme.sysfs_dir(), 'quotas')
 
     def stage(self):
         err = write_file(os.path.join(self.sysfs_dir(), 'bytes'), self.sz)
-        if err != None:
+        if err is not None:
             return err
         err = write_file(os.path.join(self.sysfs_dir(), 'ms'), self.ms)
-        if err != None:
+        if err is not None:
             return err
         err = write_file(os.path.join(self.sysfs_dir(), 'reset_interval_ms'),
                          self.reset_interval_ms)
-        if err != None:
+        if err is not None:
             return err
 
+        nr_goals_file = os.path.join(self.sysfs_dir(), 'goals', 'nr_goals')
+        content, err = read_file(nr_goals_file)
+        if err is not None:
+            return err
+        if int(content) != len(self.goals):
+            err = write_file(nr_goals_file, len(self.goals))
+            if err is not None:
+                return err
+        for goal in self.goals:
+            err = goal.stage()
+            if err is not None:
+                return err
+        return None
+
 class DamosStats:
     nr_tried = None
     sz_tried = None
@@ -136,30 +201,30 @@ class Damos:
 
     def stage(self):
         err = write_file(os.path.join(self.sysfs_dir(), 'action'), self.action)
-        if err != None:
+        if err is not None:
             return err
         err = self.access_pattern.stage()
-        if err != None:
+        if err is not None:
             return err
         err = write_file(os.path.join(self.sysfs_dir(), 'apply_interval_us'),
                          '%d' % self.apply_interval_us)
-        if err != None:
+        if err is not None:
             return err
 
         err = self.quota.stage()
-        if err != None:
+        if err is not None:
             return err
 
         # disable watermarks
         err = write_file(
                 os.path.join(self.sysfs_dir(), 'watermarks', 'metric'), 'none')
-        if err != None:
+        if err is not None:
             return err
 
         # disable filters
         err = write_file(
                 os.path.join(self.sysfs_dir(), 'filters', 'nr_filters'), '0')
-        if err != None:
+        if err is not None:
             return err
 
 class DamonTarget:
@@ -178,7 +243,7 @@ class DamonTarget:
     def stage(self):
         err = write_file(
                 os.path.join(self.sysfs_dir(), 'regions', 'nr_regions'), '0')
-        if err != None:
+        if err is not None:
             return err
         return write_file(
                 os.path.join(self.sysfs_dir(), 'pid_target'), self.pid)
@@ -210,27 +275,27 @@ class DamonAttrs:
     def stage(self):
         err = write_file(os.path.join(self.interval_sysfs_dir(), 'sample_us'),
                 self.sample_us)
-        if err != None:
+        if err is not None:
             return err
         err = write_file(os.path.join(self.interval_sysfs_dir(), 'aggr_us'),
                 self.aggr_us)
-        if err != None:
+        if err is not None:
             return err
         err = write_file(os.path.join(self.interval_sysfs_dir(), 'update_us'),
                 self.update_us)
-        if err != None:
+        if err is not None:
             return err
 
         err = write_file(
                 os.path.join(self.nr_regions_range_sysfs_dir(), 'min'),
                 self.min_nr_regions)
-        if err != None:
+        if err is not None:
             return err
 
         err = write_file(
                 os.path.join(self.nr_regions_range_sysfs_dir(), 'max'),
                 self.max_nr_regions)
-        if err != None:
+        if err is not None:
             return err
 
 class DamonCtx:
@@ -264,36 +329,38 @@ class DamonCtx:
     def stage(self):
         err = write_file(
                 os.path.join(self.sysfs_dir(), 'operations'), self.ops)
-        if err != None:
+        if err is not None:
             return err
         err = self.monitoring_attrs.stage()
-        if err != None:
+        if err is not None:
             return err
 
         nr_targets_file = os.path.join(
                 self.sysfs_dir(), 'targets', 'nr_targets')
         content, err = read_file(nr_targets_file)
-        if err != None:
+        if err is not None:
             return err
         if int(content) != len(self.targets):
             err = write_file(nr_targets_file, '%d' % len(self.targets))
-            if err != None:
+            if err is not None:
                 return err
         for target in self.targets:
             err = target.stage()
-            if err != None:
+            if err is not None:
                 return err
 
         nr_schemes_file = os.path.join(
                 self.sysfs_dir(), 'schemes', 'nr_schemes')
         content, err = read_file(nr_schemes_file)
+        if err is not None:
+            return err
         if int(content) != len(self.schemes):
             err = write_file(nr_schemes_file, '%d' % len(self.schemes))
-            if err != None:
+            if err is not None:
                 return err
         for scheme in self.schemes:
             err = scheme.stage()
-            if err != None:
+            if err is not None:
                 return err
         return None
 
@@ -317,16 +384,16 @@ class Kdamond:
         nr_contexts_file = os.path.join(self.sysfs_dir(),
                 'contexts', 'nr_contexts')
         content, err = read_file(nr_contexts_file)
-        if err != None:
+        if err is not None:
             return err
         if int(content) != len(self.contexts):
             err = write_file(nr_contexts_file, '%d' % len(self.contexts))
-            if err != None:
+            if err is not None:
                 return err
 
         for context in self.contexts:
             err = context.stage()
-            if err != None:
+            if err is not None:
                 return err
         err = write_file(os.path.join(self.sysfs_dir(), 'state'), 'on')
         return err
@@ -334,20 +401,20 @@ class Kdamond:
     def update_schemes_tried_bytes(self):
         err = write_file(os.path.join(self.sysfs_dir(), 'state'),
                 'update_schemes_tried_bytes')
-        if err != None:
+        if err is not None:
             return err
         for context in self.contexts:
             for scheme in context.schemes:
                 content, err = read_file(os.path.join(scheme.sysfs_dir(),
                     'tried_regions', 'total_bytes'))
-                if err != None:
+                if err is not None:
                     return err
                 scheme.tried_bytes = int(content)
 
     def update_schemes_stats(self):
         err = write_file(os.path.join(self.sysfs_dir(), 'state'),
                 'update_schemes_stats')
-        if err != None:
+        if err is not None:
             return err
         for context in self.contexts:
             for scheme in context.schemes:
@@ -356,11 +423,39 @@ class Kdamond:
                              'sz_applied', 'qt_exceeds']:
                     content, err = read_file(
                             os.path.join(scheme.sysfs_dir(), 'stats', stat))
-                    if err != None:
+                    if err is not None:
                         return err
                     stat_values.append(int(content))
                 scheme.stats = DamosStats(*stat_values)
 
+    def update_schemes_effective_quotas(self):
+        err = write_file(os.path.join(self.sysfs_dir(), 'state'),
+                         'update_schemes_effective_quotas')
+        if err is not None:
+            return err
+        for context in self.contexts:
+            for scheme in context.schemes:
+                for goal in scheme.quota.goals:
+                    content, err = read_file(
+                            os.path.join(scheme.quota.sysfs_dir(),
+                                         'effective_bytes'))
+                    if err is not None:
+                        return err
+                    goal.effective_bytes = int(content)
+        return None
+
+    def commit_schemes_quota_goals(self):
+        for context in self.contexts:
+            for scheme in context.schemes:
+                for goal in scheme.quota.goals:
+                    err = goal.stage()
+                    if err is not None:
+                        print('commit_schemes_quota_goals failed stagign: %s'%
+                              err)
+                        exit(1)
+        return write_file(os.path.join(self.sysfs_dir(), 'state'),
+                         'commit_schemes_quota_goals')
+
 class Kdamonds:
     kdamonds = []
 
@@ -376,10 +471,10 @@ class Kdamonds:
     def start(self):
         err = write_file(os.path.join(self.sysfs_dir(),  'nr_kdamonds'),
                 '%s' % len(self.kdamonds))
-        if err != None:
+        if err is not None:
             return err
         for kdamond in self.kdamonds:
             err = kdamond.start()
-            if err != None:
+            if err is not None:
                 return err
         return None
diff --git a/tools/testing/selftests/damon/damos_quota_goal.py b/tools/testing/selftests/damon/damos_quota_goal.py
new file mode 100644
index 000000000000..18246f3b62f7
--- /dev/null
+++ b/tools/testing/selftests/damon/damos_quota_goal.py
@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import subprocess
+import time
+
+import _damon_sysfs
+
+def main():
+    # access two 10 MiB memory regions, 2 second per each
+    sz_region = 10 * 1024 * 1024
+    proc = subprocess.Popen(['./access_memory', '2', '%d' % sz_region, '2000'])
+
+    goal = _damon_sysfs.DamosQuotaGoal(
+            metric=_damon_sysfs.qgoal_metric_user_input, target_value=10000)
+    kdamonds = _damon_sysfs.Kdamonds([_damon_sysfs.Kdamond(
+            contexts=[_damon_sysfs.DamonCtx(
+                ops='vaddr',
+                targets=[_damon_sysfs.DamonTarget(pid=proc.pid)],
+                schemes=[_damon_sysfs.Damos(
+                    action='stat',
+                    quota=_damon_sysfs.DamosQuota(
+                        goals=[goal], reset_interval_ms=100),
+                    )] # schemes
+                )] # contexts
+            )]) # kdamonds
+
+    err = kdamonds.start()
+    if err != None:
+        print('kdamond start failed: %s' % err)
+        exit(1)
+
+    score_values_to_test = [0, 15000, 5000, 18000]
+    while proc.poll() == None:
+        if len(score_values_to_test) == 0:
+            time.sleep(0.1)
+            continue
+
+        goal.current_value = score_values_to_test.pop(0)
+        expect_increase = goal.current_value < goal.target_value
+
+        err = kdamonds.kdamonds[0].commit_schemes_quota_goals()
+        if err is not None:
+            print('commit_schemes_quota_goals failed: %s' % err)
+            exit(1)
+
+        err = kdamonds.kdamonds[0].update_schemes_effective_quotas()
+        if err is not None:
+            print('before-update_schemes_effective_quotas failed: %s' % err)
+            exit(1)
+        last_effective_bytes = goal.effective_bytes
+
+        time.sleep(0.5)
+
+        err = kdamonds.kdamonds[0].update_schemes_effective_quotas()
+        if err is not None:
+            print('after-update_schemes_effective_quotas failed: %s' % err)
+            exit(1)
+
+        print('score: %s, effective quota: %d -> %d (%.3fx)' % (
+            goal.current_value, last_effective_bytes, goal.effective_bytes,
+            goal.effective_bytes / last_effective_bytes
+            if last_effective_bytes != 0 else -1.0))
+
+        if last_effective_bytes == goal.effective_bytes:
+            print('efective bytes not changed: %d' % goal.effective_bytes)
+            exit(1)
+
+        increased = last_effective_bytes < goal.effective_bytes
+        if expect_increase != increased:
+            print('expectation of increase (%s) != increased (%s)' %
+                  (expect_increase, increased))
+            exit(1)
+        last_effective_bytes = goal.effective_bytes
+
+if __name__ == '__main__':
+    main()
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 33c24ceddfb7..3023e0e2f58f 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -70,6 +70,15 @@ ifeq ($(KHDR_INCLUDES),)
 KHDR_INCLUDES := -D_GNU_SOURCE -isystem $(top_srcdir)/usr/include
 endif
 
+# In order to use newer items that haven't yet been added to the user's system
+# header files, add $(TOOLS_INCLUDES) to the compiler invocation in each
+# each selftest.
+# You may need to add files to that location, or to refresh an existing file. In
+# order to do that, run "make headers" from $(top_srcdir), then copy the
+# header file that you want from $(top_srcdir)/usr/include/... , to the matching
+# subdir in $(TOOLS_INCLUDE).
+TOOLS_INCLUDES := -isystem $(top_srcdir)/tools/include/uapi
+
 # The following are built by lib.mk common compile rules.
 # TEST_CUSTOM_PROGS should be used by tests that require
 # custom build rule and prevent common build rule use.
diff --git a/tools/testing/selftests/memfd/fuse_test.c b/tools/testing/selftests/memfd/fuse_test.c
index 93798c8c5d54..dbc171a3806d 100644
--- a/tools/testing/selftests/memfd/fuse_test.c
+++ b/tools/testing/selftests/memfd/fuse_test.c
@@ -306,7 +306,7 @@ int main(int argc, char **argv)
 	 * then the kernel did a page-replacement or canceled the read() (or
 	 * whatever magic it did..). In that case, the memfd object is still
 	 * all zero.
-	 * In case the memfd-object was *not* sealed, the read() was successfull
+	 * In case the memfd-object was *not* sealed, the read() was successful
 	 * and the memfd object must *not* be all zero.
 	 * Note that in real scenarios, there might be a mixture of both, but
 	 * in this test-cases, we have explicit 200ms delays which should be
diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c
index 18f585684e20..95af2d78fd31 100644
--- a/tools/testing/selftests/memfd/memfd_test.c
+++ b/tools/testing/selftests/memfd/memfd_test.c
@@ -1528,7 +1528,7 @@ static void test_share_open(char *banner, char *b_suffix)
 
 /*
  * Test sharing via fork()
- * Test whether seal-modifications work as expected with forked childs.
+ * Test whether seal-modifications work as expected with forked children.
  */
 static void test_share_fork(char *banner, char *b_suffix)
 {
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 410495e0a611..60b8feb6a5ec 100644
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -32,7 +32,7 @@ endif
 # LDLIBS.
 MAKEFLAGS += --no-builtin-rules
 
-CFLAGS = -Wall -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES)
+CFLAGS = -Wall -I $(top_srcdir) $(EXTRA_CFLAGS) $(KHDR_INCLUDES) $(TOOLS_INCLUDES)
 LDLIBS = -lrt -lpthread -lm
 
 TEST_GEN_FILES = cow
diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index fe078d6e1806..32c6ccc2a6be 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -199,7 +199,7 @@ static int child_vmsplice_memcmp_fn(char *mem, size_t size,
 typedef int (*child_fn)(char *mem, size_t size, struct comm_pipes *comm_pipes);
 
 static void do_test_cow_in_parent(char *mem, size_t size, bool do_mprotect,
-				  child_fn fn)
+		child_fn fn, bool xfail)
 {
 	struct comm_pipes comm_pipes;
 	char buf;
@@ -247,33 +247,47 @@ static void do_test_cow_in_parent(char *mem, size_t size, bool do_mprotect,
 	else
 		ret = -EINVAL;
 
-	ksft_test_result(!ret, "No leak from parent into child\n");
+	if (!ret) {
+		ksft_test_result_pass("No leak from parent into child\n");
+	} else if (xfail) {
+		/*
+		 * With hugetlb, some vmsplice() tests are currently expected to
+		 * fail because (a) harder to fix and (b) nobody really cares.
+		 * Flag them as expected failure for now.
+		 */
+		ksft_test_result_xfail("Leak from parent into child\n");
+	} else {
+		ksft_test_result_fail("Leak from parent into child\n");
+	}
 close_comm_pipes:
 	close_comm_pipes(&comm_pipes);
 }
 
-static void test_cow_in_parent(char *mem, size_t size)
+static void test_cow_in_parent(char *mem, size_t size, bool is_hugetlb)
 {
-	do_test_cow_in_parent(mem, size, false, child_memcmp_fn);
+	do_test_cow_in_parent(mem, size, false, child_memcmp_fn, false);
 }
 
-static void test_cow_in_parent_mprotect(char *mem, size_t size)
+static void test_cow_in_parent_mprotect(char *mem, size_t size, bool is_hugetlb)
 {
-	do_test_cow_in_parent(mem, size, true, child_memcmp_fn);
+	do_test_cow_in_parent(mem, size, true, child_memcmp_fn, false);
 }
 
-static void test_vmsplice_in_child(char *mem, size_t size)
+static void test_vmsplice_in_child(char *mem, size_t size, bool is_hugetlb)
 {
-	do_test_cow_in_parent(mem, size, false, child_vmsplice_memcmp_fn);
+	do_test_cow_in_parent(mem, size, false, child_vmsplice_memcmp_fn,
+			      is_hugetlb);
 }
 
-static void test_vmsplice_in_child_mprotect(char *mem, size_t size)
+static void test_vmsplice_in_child_mprotect(char *mem, size_t size,
+		bool is_hugetlb)
 {
-	do_test_cow_in_parent(mem, size, true, child_vmsplice_memcmp_fn);
+	do_test_cow_in_parent(mem, size, true, child_vmsplice_memcmp_fn,
+			      is_hugetlb);
 }
 
 static void do_test_vmsplice_in_parent(char *mem, size_t size,
-				       bool before_fork)
+				       bool before_fork, bool xfail)
 {
 	struct iovec iov = {
 		.iov_base = mem,
@@ -355,8 +369,18 @@ static void do_test_vmsplice_in_parent(char *mem, size_t size,
 		}
 	}
 
-	ksft_test_result(!memcmp(old, new, transferred),
-			 "No leak from child into parent\n");
+	if (!memcmp(old, new, transferred)) {
+		ksft_test_result_pass("No leak from child into parent\n");
+	} else if (xfail) {
+		/*
+		 * With hugetlb, some vmsplice() tests are currently expected to
+		 * fail because (a) harder to fix and (b) nobody really cares.
+		 * Flag them as expected failure for now.
+		 */
+		ksft_test_result_xfail("Leak from child into parent\n");
+	} else {
+		ksft_test_result_fail("Leak from child into parent\n");
+	}
 close_pipe:
 	close(fds[0]);
 	close(fds[1]);
@@ -367,14 +391,14 @@ free:
 	free(new);
 }
 
-static void test_vmsplice_before_fork(char *mem, size_t size)
+static void test_vmsplice_before_fork(char *mem, size_t size, bool is_hugetlb)
 {
-	do_test_vmsplice_in_parent(mem, size, true);
+	do_test_vmsplice_in_parent(mem, size, true, is_hugetlb);
 }
 
-static void test_vmsplice_after_fork(char *mem, size_t size)
+static void test_vmsplice_after_fork(char *mem, size_t size, bool is_hugetlb)
 {
-	do_test_vmsplice_in_parent(mem, size, false);
+	do_test_vmsplice_in_parent(mem, size, false, is_hugetlb);
 }
 
 #ifdef LOCAL_CONFIG_HAVE_LIBURING
@@ -529,12 +553,12 @@ close_comm_pipes:
 	close_comm_pipes(&comm_pipes);
 }
 
-static void test_iouring_ro(char *mem, size_t size)
+static void test_iouring_ro(char *mem, size_t size, bool is_hugetlb)
 {
 	do_test_iouring(mem, size, false);
 }
 
-static void test_iouring_fork(char *mem, size_t size)
+static void test_iouring_fork(char *mem, size_t size, bool is_hugetlb)
 {
 	do_test_iouring(mem, size, true);
 }
@@ -678,37 +702,41 @@ free_tmp:
 	free(tmp);
 }
 
-static void test_ro_pin_on_shared(char *mem, size_t size)
+static void test_ro_pin_on_shared(char *mem, size_t size, bool is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_SHARED, false);
 }
 
-static void test_ro_fast_pin_on_shared(char *mem, size_t size)
+static void test_ro_fast_pin_on_shared(char *mem, size_t size, bool is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_SHARED, true);
 }
 
-static void test_ro_pin_on_ro_previously_shared(char *mem, size_t size)
+static void test_ro_pin_on_ro_previously_shared(char *mem, size_t size,
+		bool is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_PREVIOUSLY_SHARED, false);
 }
 
-static void test_ro_fast_pin_on_ro_previously_shared(char *mem, size_t size)
+static void test_ro_fast_pin_on_ro_previously_shared(char *mem, size_t size,
+		bool is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_PREVIOUSLY_SHARED, true);
 }
 
-static void test_ro_pin_on_ro_exclusive(char *mem, size_t size)
+static void test_ro_pin_on_ro_exclusive(char *mem, size_t size,
+		bool is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_RO_EXCLUSIVE, false);
 }
 
-static void test_ro_fast_pin_on_ro_exclusive(char *mem, size_t size)
+static void test_ro_fast_pin_on_ro_exclusive(char *mem, size_t size,
+		bool is_hugetlb)
 {
 	do_test_ro_pin(mem, size, RO_PIN_TEST_RO_EXCLUSIVE, true);
 }
 
-typedef void (*test_fn)(char *mem, size_t size);
+typedef void (*test_fn)(char *mem, size_t size, bool hugetlb);
 
 static void do_run_with_base_page(test_fn fn, bool swapout)
 {
@@ -740,7 +768,7 @@ static void do_run_with_base_page(test_fn fn, bool swapout)
 		}
 	}
 
-	fn(mem, pagesize);
+	fn(mem, pagesize, false);
 munmap:
 	munmap(mem, pagesize);
 }
@@ -904,7 +932,7 @@ static void do_run_with_thp(test_fn fn, enum thp_run thp_run, size_t thpsize)
 		break;
 	}
 
-	fn(mem, size);
+	fn(mem, size, false);
 munmap:
 	munmap(mmap_mem, mmap_size);
 	if (mremap_mem != MAP_FAILED)
@@ -997,7 +1025,7 @@ static void run_with_hugetlb(test_fn fn, const char *desc, size_t hugetlbsize)
 	}
 	munmap(dummy, hugetlbsize);
 
-	fn(mem, hugetlbsize);
+	fn(mem, hugetlbsize, true);
 munmap:
 	munmap(mem, hugetlbsize);
 }
@@ -1036,7 +1064,7 @@ static const struct test_case anon_test_cases[] = {
 	 */
 	{
 		"vmsplice() + unmap in child",
-		test_vmsplice_in_child
+		test_vmsplice_in_child,
 	},
 	/*
 	 * vmsplice() test, but do an additional mprotect(PROT_READ)+
@@ -1044,7 +1072,7 @@ static const struct test_case anon_test_cases[] = {
 	 */
 	{
 		"vmsplice() + unmap in child with mprotect() optimization",
-		test_vmsplice_in_child_mprotect
+		test_vmsplice_in_child_mprotect,
 	},
 	/*
 	 * vmsplice() [R/O GUP] in parent before fork(), unmap in parent after
@@ -1322,23 +1350,31 @@ close_comm_pipes:
 	close_comm_pipes(&comm_pipes);
 }
 
-static void test_anon_thp_collapse_unshared(char *mem, size_t size)
+static void test_anon_thp_collapse_unshared(char *mem, size_t size,
+		bool is_hugetlb)
 {
+	assert(!is_hugetlb);
 	do_test_anon_thp_collapse(mem, size, ANON_THP_COLLAPSE_UNSHARED);
 }
 
-static void test_anon_thp_collapse_fully_shared(char *mem, size_t size)
+static void test_anon_thp_collapse_fully_shared(char *mem, size_t size,
+		bool is_hugetlb)
 {
+	assert(!is_hugetlb);
 	do_test_anon_thp_collapse(mem, size, ANON_THP_COLLAPSE_FULLY_SHARED);
 }
 
-static void test_anon_thp_collapse_lower_shared(char *mem, size_t size)
+static void test_anon_thp_collapse_lower_shared(char *mem, size_t size,
+		bool is_hugetlb)
 {
+	assert(!is_hugetlb);
 	do_test_anon_thp_collapse(mem, size, ANON_THP_COLLAPSE_LOWER_SHARED);
 }
 
-static void test_anon_thp_collapse_upper_shared(char *mem, size_t size)
+static void test_anon_thp_collapse_upper_shared(char *mem, size_t size,
+		bool is_hugetlb)
 {
+	assert(!is_hugetlb);
 	do_test_anon_thp_collapse(mem, size, ANON_THP_COLLAPSE_UPPER_SHARED);
 }
 
diff --git a/tools/testing/selftests/mm/gup_longterm.c b/tools/testing/selftests/mm/gup_longterm.c
index d7eaca5bbe9b..9423ad439a61 100644
--- a/tools/testing/selftests/mm/gup_longterm.c
+++ b/tools/testing/selftests/mm/gup_longterm.c
@@ -118,15 +118,22 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared)
 		return;
 	}
 
-	/*
-	 * Fault in the page writable such that GUP-fast can eventually pin
-	 * it immediately.
-	 */
+	/* Fault in the page such that GUP-fast can pin it directly. */
 	memset(mem, 0, size);
 
 	switch (type) {
 	case TEST_TYPE_RO:
 	case TEST_TYPE_RO_FAST:
+		/*
+		 * Cover more cases regarding unsharing decisions when
+		 * long-term R/O pinning by mapping the page R/O.
+		 */
+		ret = mprotect(mem, size, PROT_READ);
+		if (ret) {
+			ksft_test_result_fail("mprotect() failed\n");
+			goto munmap;
+		}
+		/* FALLTHROUGH */
 	case TEST_TYPE_RW:
 	case TEST_TYPE_RW_FAST: {
 		struct pin_longterm_test args;
@@ -228,6 +235,7 @@ static void do_test(int fd, size_t size, enum test_type type, bool shared)
 		assert(false);
 	}
 
+munmap:
 	munmap(mem, size);
 }
 
diff --git a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
index d01e8d4901d0..8f122a0f0828 100644
--- a/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
+++ b/tools/testing/selftests/mm/hugetlb_madv_vs_map.c
@@ -27,9 +27,9 @@
 #include "vm_util.h"
 #include "../kselftest.h"
 
-#define MMAP_SIZE (1 << 21)
 #define INLOOP_ITER 100
 
+size_t mmap_size;
 char *huge_ptr;
 
 /* Touch the memory while it is being madvised() */
@@ -44,7 +44,7 @@ void *touch(void *unused)
 void *madv(void *unused)
 {
 	for (int i = 0; i < INLOOP_ITER; i++)
-		madvise(huge_ptr, MMAP_SIZE, MADV_DONTNEED);
+		madvise(huge_ptr, mmap_size, MADV_DONTNEED);
 
 	return NULL;
 }
@@ -59,7 +59,7 @@ void *map_extra(void *unused)
 	void *ptr;
 
 	for (int i = 0; i < INLOOP_ITER; i++) {
-		ptr = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE,
+		ptr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
 			   MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
 			   -1, 0);
 
@@ -93,14 +93,16 @@ int main(void)
 			       free_hugepages);
 	}
 
+	mmap_size = default_huge_page_size();
+
 	while (max--) {
-		huge_ptr = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE,
+		huge_ptr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
 				MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
 				-1, 0);
 
 		if ((unsigned long)huge_ptr == -1) {
-			ksft_exit_skip("Failed to allocated huge page\n");
-			return KSFT_SKIP;
+			ksft_test_result_fail("Failed to allocate huge page\n");
+			return KSFT_FAIL;
 		}
 
 		pthread_create(&thread1, NULL, madv, NULL);
@@ -117,7 +119,7 @@ int main(void)
 		}
 
 		/* Unmap and restart */
-		munmap(huge_ptr, MMAP_SIZE);
+		munmap(huge_ptr, mmap_size);
 	}
 
 	return KSFT_PASS;
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c
index 508287560c45..37de82da9be7 100644
--- a/tools/testing/selftests/mm/ksm_functional_tests.c
+++ b/tools/testing/selftests/mm/ksm_functional_tests.c
@@ -28,6 +28,15 @@
 #define MiB (1024 * KiB)
 #define FORK_EXEC_CHILD_PRG_NAME "ksm_fork_exec_child"
 
+#define MAP_MERGE_FAIL ((void *)-1)
+#define MAP_MERGE_SKIP ((void *)-2)
+
+enum ksm_merge_mode {
+	KSM_MERGE_PRCTL,
+	KSM_MERGE_MADVISE,
+	KSM_MERGE_NONE, /* PRCTL already set */
+};
+
 static int mem_fd;
 static int ksm_fd;
 static int ksm_full_scans_fd;
@@ -146,33 +155,34 @@ static int ksm_unmerge(void)
 	return 0;
 }
 
-static char *mmap_and_merge_range(char val, unsigned long size, int prot,
-				  bool use_prctl)
+static char *__mmap_and_merge_range(char val, unsigned long size, int prot,
+				  enum ksm_merge_mode mode)
 {
 	char *map;
+	char *err_map = MAP_MERGE_FAIL;
 	int ret;
 
 	/* Stabilize accounting by disabling KSM completely. */
 	if (ksm_unmerge()) {
-		ksft_test_result_fail("Disabling (unmerging) KSM failed\n");
-		return MAP_FAILED;
+		ksft_print_msg("Disabling (unmerging) KSM failed\n");
+		return err_map;
 	}
 
 	if (get_my_merging_pages() > 0) {
-		ksft_test_result_fail("Still pages merged\n");
-		return MAP_FAILED;
+		ksft_print_msg("Still pages merged\n");
+		return err_map;
 	}
 
 	map = mmap(NULL, size, PROT_READ|PROT_WRITE,
 		   MAP_PRIVATE|MAP_ANON, -1, 0);
 	if (map == MAP_FAILED) {
-		ksft_test_result_fail("mmap() failed\n");
-		return MAP_FAILED;
+		ksft_print_msg("mmap() failed\n");
+		return err_map;
 	}
 
 	/* Don't use THP. Ignore if THP are not around on a kernel. */
 	if (madvise(map, size, MADV_NOHUGEPAGE) && errno != EINVAL) {
-		ksft_test_result_fail("MADV_NOHUGEPAGE failed\n");
+		ksft_print_msg("MADV_NOHUGEPAGE failed\n");
 		goto unmap;
 	}
 
@@ -180,27 +190,36 @@ static char *mmap_and_merge_range(char val, unsigned long size, int prot,
 	memset(map, val, size);
 
 	if (mprotect(map, size, prot)) {
-		ksft_test_result_skip("mprotect() failed\n");
+		ksft_print_msg("mprotect() failed\n");
+		err_map = MAP_MERGE_SKIP;
 		goto unmap;
 	}
 
-	if (use_prctl) {
+	switch (mode) {
+	case KSM_MERGE_PRCTL:
 		ret = prctl(PR_SET_MEMORY_MERGE, 1, 0, 0, 0);
 		if (ret < 0 && errno == EINVAL) {
-			ksft_test_result_skip("PR_SET_MEMORY_MERGE not supported\n");
+			ksft_print_msg("PR_SET_MEMORY_MERGE not supported\n");
+			err_map = MAP_MERGE_SKIP;
 			goto unmap;
 		} else if (ret) {
-			ksft_test_result_fail("PR_SET_MEMORY_MERGE=1 failed\n");
+			ksft_print_msg("PR_SET_MEMORY_MERGE=1 failed\n");
 			goto unmap;
 		}
-	} else if (madvise(map, size, MADV_MERGEABLE)) {
-		ksft_test_result_fail("MADV_MERGEABLE failed\n");
-		goto unmap;
+		break;
+	case KSM_MERGE_MADVISE:
+		if (madvise(map, size, MADV_MERGEABLE)) {
+			ksft_print_msg("MADV_MERGEABLE failed\n");
+			goto unmap;
+		}
+		break;
+	case KSM_MERGE_NONE:
+		break;
 	}
 
 	/* Run KSM to trigger merging and wait. */
 	if (ksm_merge()) {
-		ksft_test_result_fail("Running KSM failed\n");
+		ksft_print_msg("Running KSM failed\n");
 		goto unmap;
 	}
 
@@ -209,14 +228,31 @@ static char *mmap_and_merge_range(char val, unsigned long size, int prot,
 	 * accounted differently (depending on kernel support).
 	 */
 	if (val && !get_my_merging_pages()) {
-		ksft_test_result_fail("No pages got merged\n");
+		ksft_print_msg("No pages got merged\n");
 		goto unmap;
 	}
 
 	return map;
 unmap:
 	munmap(map, size);
-	return MAP_FAILED;
+	return err_map;
+}
+
+static char *mmap_and_merge_range(char val, unsigned long size, int prot,
+				  enum ksm_merge_mode mode)
+{
+	char *map;
+	char *ret = MAP_FAILED;
+
+	map = __mmap_and_merge_range(val, size, prot, mode);
+	if (map == MAP_MERGE_FAIL)
+		ksft_test_result_fail("Merging memory failed");
+	else if (map == MAP_MERGE_SKIP)
+		ksft_test_result_skip("Merging memory skipped");
+	else
+		ret = map;
+
+	return ret;
 }
 
 static void test_unmerge(void)
@@ -226,7 +262,7 @@ static void test_unmerge(void)
 
 	ksft_print_msg("[RUN] %s\n", __func__);
 
-	map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+	map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
 	if (map == MAP_FAILED)
 		return;
 
@@ -264,7 +300,7 @@ static void test_unmerge_zero_pages(void)
 	}
 
 	/* Let KSM deduplicate zero pages. */
-	map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, false);
+	map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
 	if (map == MAP_FAILED)
 		return;
 
@@ -312,7 +348,7 @@ static void test_unmerge_discarded(void)
 
 	ksft_print_msg("[RUN] %s\n", __func__);
 
-	map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+	map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
 	if (map == MAP_FAILED)
 		return;
 
@@ -344,7 +380,7 @@ static void test_unmerge_uffd_wp(void)
 
 	ksft_print_msg("[RUN] %s\n", __func__);
 
-	map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+	map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
 	if (map == MAP_FAILED)
 		return;
 
@@ -439,6 +475,36 @@ static void test_prctl(void)
 	ksft_test_result_pass("Setting/clearing PR_SET_MEMORY_MERGE works\n");
 }
 
+static int test_child_ksm(void)
+{
+	const unsigned int size = 2 * MiB;
+	char *map;
+
+	/* Test if KSM is enabled for the process. */
+	if (prctl(PR_GET_MEMORY_MERGE, 0, 0, 0, 0) != 1)
+		return -1;
+
+	/* Test if merge could really happen. */
+	map = __mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_NONE);
+	if (map == MAP_MERGE_FAIL)
+		return -2;
+	else if (map == MAP_MERGE_SKIP)
+		return -3;
+
+	munmap(map, size);
+	return 0;
+}
+
+static void test_child_ksm_err(int status)
+{
+	if (status == -1)
+		ksft_test_result_fail("unexpected PR_GET_MEMORY_MERGE result in child\n");
+	else if (status == -2)
+		ksft_test_result_fail("Merge in child failed\n");
+	else if (status == -3)
+		ksft_test_result_skip("Merge in child skipped\n");
+}
+
 /* Verify that prctl ksm flag is inherited. */
 static void test_prctl_fork(void)
 {
@@ -458,7 +524,7 @@ static void test_prctl_fork(void)
 
 	child_pid = fork();
 	if (!child_pid) {
-		exit(prctl(PR_GET_MEMORY_MERGE, 0, 0, 0, 0));
+		exit(test_child_ksm());
 	} else if (child_pid < 0) {
 		ksft_test_result_fail("fork() failed\n");
 		return;
@@ -467,8 +533,11 @@ static void test_prctl_fork(void)
 	if (waitpid(child_pid, &status, 0) < 0) {
 		ksft_test_result_fail("waitpid() failed\n");
 		return;
-	} else if (WEXITSTATUS(status) != 1) {
-		ksft_test_result_fail("unexpected PR_GET_MEMORY_MERGE result in child\n");
+	}
+
+	status = WEXITSTATUS(status);
+	if (status) {
+		test_child_ksm_err(status);
 		return;
 	}
 
@@ -480,12 +549,6 @@ static void test_prctl_fork(void)
 	ksft_test_result_pass("PR_SET_MEMORY_MERGE value is inherited\n");
 }
 
-static int ksm_fork_exec_child(void)
-{
-	/* Test if KSM is enabled for the process. */
-	return prctl(PR_GET_MEMORY_MERGE, 0, 0, 0, 0) == 1;
-}
-
 static void test_prctl_fork_exec(void)
 {
 	int ret, status;
@@ -518,7 +581,7 @@ static void test_prctl_fork_exec(void)
 		if (WIFEXITED(status)) {
 			status = WEXITSTATUS(status);
 			if (status) {
-				ksft_test_result_fail("KSM not enabled\n");
+				test_child_ksm_err(status);
 				return;
 			}
 		} else {
@@ -545,7 +608,7 @@ static void test_prctl_unmerge(void)
 
 	ksft_print_msg("[RUN] %s\n", __func__);
 
-	map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, true);
+	map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_PRCTL);
 	if (map == MAP_FAILED)
 		return;
 
@@ -568,7 +631,7 @@ static void test_prot_none(void)
 
 	ksft_print_msg("[RUN] %s\n", __func__);
 
-	map = mmap_and_merge_range(0x11, size, PROT_NONE, false);
+	map = mmap_and_merge_range(0x11, size, PROT_NONE, KSM_MERGE_MADVISE);
 	if (map == MAP_FAILED)
 		goto unmap;
 
@@ -599,7 +662,7 @@ int main(int argc, char **argv)
 	int err;
 
 	if (argc > 1 && !strcmp(argv[1], FORK_EXEC_CHILD_PRG_NAME)) {
-		exit(ksm_fork_exec_child() == 1 ? 0 : 1);
+		exit(test_child_ksm());
 	}
 
 #ifdef __NR_userfaultfd
diff --git a/tools/testing/selftests/mm/memfd_secret.c b/tools/testing/selftests/mm/memfd_secret.c
index 9b298f6a04b3..9a0597310a76 100644
--- a/tools/testing/selftests/mm/memfd_secret.c
+++ b/tools/testing/selftests/mm/memfd_secret.c
@@ -20,6 +20,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <stdio.h>
+#include <fcntl.h>
 
 #include "../kselftest.h"
 
@@ -83,6 +84,45 @@ static void test_mlock_limit(int fd)
 	pass("mlock limit is respected\n");
 }
 
+static void test_vmsplice(int fd, const char *desc)
+{
+	ssize_t transferred;
+	struct iovec iov;
+	int pipefd[2];
+	char *mem;
+
+	if (pipe(pipefd)) {
+		fail("pipe failed: %s\n", strerror(errno));
+		return;
+	}
+
+	mem = mmap(NULL, page_size, prot, mode, fd, 0);
+	if (mem == MAP_FAILED) {
+		fail("Unable to mmap secret memory\n");
+		goto close_pipe;
+	}
+
+	/*
+	 * vmsplice() may use GUP-fast, which must also fail. Prefault the
+	 * page table, so GUP-fast could find it.
+	 */
+	memset(mem, PATTERN, page_size);
+
+	iov.iov_base = mem;
+	iov.iov_len = page_size;
+	transferred = vmsplice(pipefd[1], &iov, 1, 0);
+
+	if (transferred < 0 && errno == EFAULT)
+		pass("vmsplice is blocked as expected with %s\n", desc);
+	else
+		fail("vmsplice: unexpected memory access with %s\n", desc);
+
+	munmap(mem, page_size);
+close_pipe:
+	close(pipefd[0]);
+	close(pipefd[1]);
+}
+
 static void try_process_vm_read(int fd, int pipefd[2])
 {
 	struct iovec liov, riov;
@@ -187,7 +227,6 @@ static void test_remote_access(int fd, const char *name,
 		return;
 	}
 
-	ftruncate(fd, page_size);
 	memset(mem, PATTERN, page_size);
 
 	if (write(pipefd[1], &mem, sizeof(mem)) < 0) {
@@ -258,7 +297,7 @@ static void prepare(void)
 				   strerror(errno));
 }
 
-#define NUM_TESTS 4
+#define NUM_TESTS 6
 
 int main(int argc, char *argv[])
 {
@@ -277,9 +316,17 @@ int main(int argc, char *argv[])
 			ksft_exit_fail_msg("memfd_secret failed: %s\n",
 					   strerror(errno));
 	}
+	if (ftruncate(fd, page_size))
+		ksft_exit_fail_msg("ftruncate failed: %s\n", strerror(errno));
 
 	test_mlock_limit(fd);
 	test_file_apis(fd);
+	/*
+	 * We have to run the first vmsplice test before any secretmem page was
+	 * allocated for this fd.
+	 */
+	test_vmsplice(fd, "fresh page");
+	test_vmsplice(fd, "existing page");
 	test_process_vm_read(fd);
 	test_ptrace(fd);
 
diff --git a/tools/testing/selftests/mm/mlock2-tests.c b/tools/testing/selftests/mm/mlock2-tests.c
index 26f744188ad0..7f0d50fa361d 100644
--- a/tools/testing/selftests/mm/mlock2-tests.c
+++ b/tools/testing/selftests/mm/mlock2-tests.c
@@ -20,8 +20,6 @@ static int get_vm_area(unsigned long addr, struct vm_boundaries *area)
 	FILE *file;
 	int ret = 1;
 	char line[1024] = {0};
-	char *end_addr;
-	char *stop;
 	unsigned long start;
 	unsigned long end;
 
@@ -37,21 +35,10 @@ static int get_vm_area(unsigned long addr, struct vm_boundaries *area)
 	memset(area, 0, sizeof(struct vm_boundaries));
 
 	while(fgets(line, 1024, file)) {
-		end_addr = strchr(line, '-');
-		if (!end_addr) {
+		if (sscanf(line, "%lx-%lx", &start, &end) != 2) {
 			ksft_print_msg("cannot parse /proc/self/maps\n");
 			goto out;
 		}
-		*end_addr = '\0';
-		end_addr++;
-		stop = strchr(end_addr, ' ');
-		if (!stop) {
-			ksft_print_msg("cannot parse /proc/self/maps\n");
-			goto out;
-		}
-
-		sscanf(line, "%lx", &start);
-		sscanf(end_addr, "%lx", &end);
 
 		if (start <= addr && end > addr) {
 			area->start = start;
diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c
index 2f8b991f78cb..1b03bcfaefdf 100644
--- a/tools/testing/selftests/mm/mremap_test.c
+++ b/tools/testing/selftests/mm/mremap_test.c
@@ -23,6 +23,7 @@
 #define VALIDATION_NO_THRESHOLD 0	/* Verify the entire region */
 
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+#define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
 #define SIZE_MB(m) ((size_t)m * (1024 * 1024))
 #define SIZE_KB(k) ((size_t)k * 1024)
 
@@ -69,6 +70,27 @@ enum {
 	.expect_failure = should_fail				\
 }
 
+/* compute square root using binary search */
+static unsigned long get_sqrt(unsigned long val)
+{
+	unsigned long low = 1;
+
+	/* assuming rand_size is less than 1TB */
+	unsigned long high = (1UL << 20);
+
+	while (low <= high) {
+		unsigned long mid = low + (high - low) / 2;
+		unsigned long temp = mid * mid;
+
+		if (temp == val)
+			return mid;
+		if (temp < val)
+			low = mid + 1;
+		high = mid - 1;
+	}
+	return low;
+}
+
 /*
  * Returns false if the requested remap region overlaps with an
  * existing mapping (e.g text, stack) else returns true.
@@ -126,19 +148,21 @@ static unsigned long long get_mmap_min_addr(void)
  * Using /proc/self/maps, assert that the specified address range is contained
  * within a single mapping.
  */
-static bool is_range_mapped(FILE *maps_fp, void *start, void *end)
+static bool is_range_mapped(FILE *maps_fp, unsigned long start,
+			    unsigned long end)
 {
 	char *line = NULL;
 	size_t len = 0;
 	bool success = false;
+	unsigned long first_val, second_val;
 
 	rewind(maps_fp);
 
 	while (getline(&line, &len, maps_fp) != -1) {
-		char *first = strtok(line, "- ");
-		void *first_val = (void *)strtol(first, NULL, 16);
-		char *second = strtok(NULL, "- ");
-		void *second_val = (void *) strtol(second, NULL, 16);
+		if (sscanf(line, "%lx-%lx", &first_val, &second_val) != 2) {
+			ksft_exit_fail_msg("cannot parse /proc/self/maps\n");
+			break;
+		}
 
 		if (first_val <= start && second_val >= end) {
 			success = true;
@@ -233,7 +257,8 @@ static void mremap_expand_merge(FILE *maps_fp, unsigned long page_size)
 		goto out;
 	}
 
-	success = is_range_mapped(maps_fp, start, start + 3 * page_size);
+	success = is_range_mapped(maps_fp, (unsigned long)start,
+				  (unsigned long)(start + 3 * page_size));
 	munmap(start, 3 * page_size);
 
 out:
@@ -272,7 +297,8 @@ static void mremap_expand_merge_offset(FILE *maps_fp, unsigned long page_size)
 		goto out;
 	}
 
-	success = is_range_mapped(maps_fp, start, start + 3 * page_size);
+	success = is_range_mapped(maps_fp, (unsigned long)start,
+				  (unsigned long)(start + 3 * page_size));
 	munmap(start, 3 * page_size);
 
 out:
@@ -296,7 +322,7 @@ out:
  *
  * |DDDDddddSSSSssss|
  */
-static void mremap_move_within_range(char pattern_seed)
+static void mremap_move_within_range(unsigned int pattern_seed, char *rand_addr)
 {
 	char *test_name = "mremap mremap move within range";
 	void *src, *dest;
@@ -316,10 +342,7 @@ static void mremap_move_within_range(char pattern_seed)
 	src = (void *)((unsigned long)src & ~(SIZE_MB(2) - 1));
 
 	/* Set byte pattern for source block. */
-	srand(pattern_seed);
-	for (i = 0; i < SIZE_MB(2); i++) {
-		((char *)src)[i] = (char) rand();
-	}
+	memcpy(src, rand_addr, SIZE_MB(2));
 
 	dest = src - SIZE_MB(2);
 
@@ -357,14 +380,14 @@ out:
 
 /* Returns the time taken for the remap on success else returns -1. */
 static long long remap_region(struct config c, unsigned int threshold_mb,
-			      char pattern_seed)
+			      char *rand_addr)
 {
 	void *addr, *src_addr, *dest_addr, *dest_preamble_addr;
-	int d;
-	unsigned long long t;
+	unsigned long long t, d;
 	struct timespec t_start = {0, 0}, t_end = {0, 0};
 	long long  start_ns, end_ns, align_mask, ret, offset;
 	unsigned long long threshold;
+	unsigned long num_chunks;
 
 	if (threshold_mb == VALIDATION_NO_THRESHOLD)
 		threshold = c.region_size;
@@ -378,9 +401,7 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 	}
 
 	/* Set byte pattern for source block. */
-	srand(pattern_seed);
-	for (t = 0; t < threshold; t++)
-		memset((char *) src_addr + t, (char) rand(), 1);
+	memcpy(src_addr, rand_addr, threshold);
 
 	/* Mask to zero out lower bits of address for alignment */
 	align_mask = ~(c.dest_alignment - 1);
@@ -420,9 +441,7 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 		}
 
 		/* Set byte pattern for the dest preamble block. */
-		srand(pattern_seed);
-		for (d = 0; d < c.dest_preamble_size; d++)
-			memset((char *) dest_preamble_addr + d, (char) rand(), 1);
+		memcpy(dest_preamble_addr, rand_addr, c.dest_preamble_size);
 	}
 
 	clock_gettime(CLOCK_MONOTONIC, &t_start);
@@ -436,15 +455,42 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 		goto clean_up_dest_preamble;
 	}
 
-	/* Verify byte pattern after remapping */
-	srand(pattern_seed);
-	for (t = 0; t < threshold; t++) {
-		char c = (char) rand();
+	/*
+	 * Verify byte pattern after remapping. Employ an algorithm with a
+	 * square root time complexity in threshold: divide the range into
+	 * chunks, if memcmp() returns non-zero, only then perform an
+	 * iteration in that chunk to find the mismatch index.
+	 */
+	num_chunks = get_sqrt(threshold);
+	for (unsigned long i = 0; i < num_chunks; ++i) {
+		size_t chunk_size = threshold / num_chunks;
+		unsigned long shift = i * chunk_size;
+
+		if (!memcmp(dest_addr + shift, rand_addr + shift, chunk_size))
+			continue;
+
+		/* brute force iteration only over mismatch segment */
+		for (t = shift; t < shift + chunk_size; ++t) {
+			if (((char *) dest_addr)[t] != rand_addr[t]) {
+				ksft_print_msg("Data after remap doesn't match at offset %llu\n",
+						t);
+				ksft_print_msg("Expected: %#x\t Got: %#x\n", rand_addr[t] & 0xff,
+						((char *) dest_addr)[t] & 0xff);
+				ret = -1;
+				goto clean_up_dest;
+			}
+		}
+	}
 
-		if (((char *) dest_addr)[t] != c) {
+	/*
+	 * if threshold is not divisible by num_chunks, then check the
+	 * last chunk
+	 */
+	for (t = num_chunks * (threshold / num_chunks); t < threshold; ++t) {
+		if (((char *) dest_addr)[t] != rand_addr[t]) {
 			ksft_print_msg("Data after remap doesn't match at offset %llu\n",
-				       t);
-			ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
+					t);
+			ksft_print_msg("Expected: %#x\t Got: %#x\n", rand_addr[t] & 0xff,
 					((char *) dest_addr)[t] & 0xff);
 			ret = -1;
 			goto clean_up_dest;
@@ -452,22 +498,44 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 	}
 
 	/* Verify the dest preamble byte pattern after remapping */
-	if (c.dest_preamble_size) {
-		srand(pattern_seed);
-		for (d = 0; d < c.dest_preamble_size; d++) {
-			char c = (char) rand();
-
-			if (((char *) dest_preamble_addr)[d] != c) {
-				ksft_print_msg("Preamble data after remap doesn't match at offset %d\n",
-					       d);
-				ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
-					       ((char *) dest_preamble_addr)[d] & 0xff);
+	if (!c.dest_preamble_size)
+		goto no_preamble;
+
+	num_chunks = get_sqrt(c.dest_preamble_size);
+
+	for (unsigned long i = 0; i < num_chunks; ++i) {
+		size_t chunk_size = c.dest_preamble_size / num_chunks;
+		unsigned long shift = i * chunk_size;
+
+		if (!memcmp(dest_preamble_addr + shift, rand_addr + shift,
+			    chunk_size))
+			continue;
+
+		/* brute force iteration only over mismatched segment */
+		for (d = shift; d < shift + chunk_size; ++d) {
+			if (((char *) dest_preamble_addr)[d] != rand_addr[d]) {
+				ksft_print_msg("Preamble data after remap doesn't match at offset %llu\n",
+						d);
+				ksft_print_msg("Expected: %#x\t Got: %#x\n", rand_addr[d] & 0xff,
+						((char *) dest_preamble_addr)[d] & 0xff);
 				ret = -1;
 				goto clean_up_dest;
 			}
 		}
 	}
 
+	for (d = num_chunks * (c.dest_preamble_size / num_chunks); d < c.dest_preamble_size; ++d) {
+		if (((char *) dest_preamble_addr)[d] != rand_addr[d]) {
+			ksft_print_msg("Preamble data after remap doesn't match at offset %llu\n",
+					d);
+			ksft_print_msg("Expected: %#x\t Got: %#x\n", rand_addr[d] & 0xff,
+					((char *) dest_preamble_addr)[d] & 0xff);
+			ret = -1;
+			goto clean_up_dest;
+		}
+	}
+
+no_preamble:
 	start_ns = t_start.tv_sec * NS_PER_SEC + t_start.tv_nsec;
 	end_ns = t_end.tv_sec * NS_PER_SEC + t_end.tv_nsec;
 	ret = end_ns - start_ns;
@@ -494,7 +562,8 @@ out:
  * the beginning of the mapping just because the aligned
  * down address landed on a mapping that maybe does not exist.
  */
-static void mremap_move_1mb_from_start(char pattern_seed)
+static void mremap_move_1mb_from_start(unsigned int pattern_seed,
+				       char *rand_addr)
 {
 	char *test_name = "mremap move 1mb from start at 1MB+256KB aligned src";
 	void *src = NULL, *dest = NULL;
@@ -520,10 +589,7 @@ static void mremap_move_1mb_from_start(char pattern_seed)
 	}
 
 	/* Set byte pattern for source block. */
-	srand(pattern_seed);
-	for (i = 0; i < SIZE_MB(2); i++) {
-		((char *)src)[i] = (char) rand();
-	}
+	memcpy(src, rand_addr, SIZE_MB(2));
 
 	/*
 	 * Unmap the beginning of dest so that the aligned address
@@ -568,10 +634,10 @@ out:
 
 static void run_mremap_test_case(struct test test_case, int *failures,
 				 unsigned int threshold_mb,
-				 unsigned int pattern_seed)
+				 unsigned int pattern_seed, char *rand_addr)
 {
 	long long remap_time = remap_region(test_case.config, threshold_mb,
-					    pattern_seed);
+					    rand_addr);
 
 	if (remap_time < 0) {
 		if (test_case.expect_failure)
@@ -642,7 +708,15 @@ int main(int argc, char **argv)
 	int failures = 0;
 	int i, run_perf_tests;
 	unsigned int threshold_mb = VALIDATION_DEFAULT_THRESHOLD;
+
+	/* hard-coded test configs */
+	size_t max_test_variable_region_size = _2GB;
+	size_t max_test_constant_region_size = _2MB;
+	size_t dest_preamble_size = 10 * _4MB;
+
 	unsigned int pattern_seed;
+	char *rand_addr;
+	size_t rand_size;
 	int num_expand_tests = 2;
 	int num_misc_tests = 2;
 	struct test test_cases[MAX_TEST] = {};
@@ -659,6 +733,31 @@ int main(int argc, char **argv)
 	ksft_print_msg("Test configs:\n\tthreshold_mb=%u\n\tpattern_seed=%u\n\n",
 		       threshold_mb, pattern_seed);
 
+	/*
+	 * set preallocated random array according to test configs; see the
+	 * functions for the logic of setting the size
+	 */
+	if (!threshold_mb)
+		rand_size = MAX(max_test_variable_region_size,
+				max_test_constant_region_size);
+	else
+		rand_size = MAX(MIN(threshold_mb * _1MB,
+				    max_test_variable_region_size),
+				max_test_constant_region_size);
+	rand_size = MAX(dest_preamble_size, rand_size);
+
+	rand_addr = (char *)mmap(NULL, rand_size, PROT_READ | PROT_WRITE,
+				 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if (rand_addr == MAP_FAILED) {
+		perror("mmap");
+		ksft_exit_fail_msg("cannot mmap rand_addr\n");
+	}
+
+	/* fill stream of random bytes */
+	srand(pattern_seed);
+	for (unsigned long i = 0; i < rand_size; ++i)
+		rand_addr[i] = (char) rand();
+
 	page_size = sysconf(_SC_PAGESIZE);
 
 	/* Expected mremap failures */
@@ -730,13 +829,13 @@ int main(int argc, char **argv)
 
 	for (i = 0; i < ARRAY_SIZE(test_cases); i++)
 		run_mremap_test_case(test_cases[i], &failures, threshold_mb,
-				     pattern_seed);
+				     pattern_seed, rand_addr);
 
 	maps_fp = fopen("/proc/self/maps", "r");
 
 	if (maps_fp == NULL) {
-		ksft_print_msg("Failed to read /proc/self/maps: %s\n", strerror(errno));
-		exit(KSFT_FAIL);
+		munmap(rand_addr, rand_size);
+		ksft_exit_fail_msg("Failed to read /proc/self/maps: %s\n", strerror(errno));
 	}
 
 	mremap_expand_merge(maps_fp, page_size);
@@ -744,17 +843,20 @@ int main(int argc, char **argv)
 
 	fclose(maps_fp);
 
-	mremap_move_within_range(pattern_seed);
-	mremap_move_1mb_from_start(pattern_seed);
+	mremap_move_within_range(pattern_seed, rand_addr);
+	mremap_move_1mb_from_start(pattern_seed, rand_addr);
 
 	if (run_perf_tests) {
 		ksft_print_msg("\n%s\n",
 		 "mremap HAVE_MOVE_PMD/PUD optimization time comparison for 1GB region:");
 		for (i = 0; i < ARRAY_SIZE(perf_test_cases); i++)
 			run_mremap_test_case(perf_test_cases[i], &failures,
-					     threshold_mb, pattern_seed);
+					     threshold_mb, pattern_seed,
+					     rand_addr);
 	}
 
+	munmap(rand_addr, rand_size);
+
 	if (failures > 0)
 		ksft_exit_fail();
 	else
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index 4bdb3a0c7a60..3157204b9047 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -152,9 +152,13 @@ done < /proc/meminfo
 # both of these requirements into account and attempt to increase
 # number of huge pages available.
 nr_cpus=$(nproc)
-hpgsize_MB=$((hpgsize_KB / 1024))
-half_ufd_size_MB=$((((nr_cpus * hpgsize_MB + 127) / 128) * 128))
-needmem_KB=$((half_ufd_size_MB * 2 * 1024))
+uffd_min_KB=$((hpgsize_KB * nr_cpus * 2))
+hugetlb_min_KB=$((256 * 1024))
+if [[ $uffd_min_KB -gt $hugetlb_min_KB ]]; then
+	needmem_KB=$uffd_min_KB
+else
+	needmem_KB=$hugetlb_min_KB
+fi
 
 # set proper nr_hugepages
 if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then
@@ -294,7 +298,8 @@ CATEGORY="userfaultfd" run_test ./uffd-unit-tests
 uffd_stress_bin=./uffd-stress
 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} anon 20 16
 # Hugetlb tests require source and destination huge pages. Pass in half
-# the size ($half_ufd_size_MB), which is used for *each*.
+# the size of the free pages we have, which is used for *each*.
+half_ufd_size_MB=$((freepgs / 2))
 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb "$half_ufd_size_MB" 32
 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} hugetlb-private "$half_ufd_size_MB" 32
 CATEGORY="userfaultfd" run_test ${uffd_stress_bin} shmem 20 16
diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c
index d9dbf879748b..bdfa5d085f00 100644
--- a/tools/testing/selftests/mm/soft-dirty.c
+++ b/tools/testing/selftests/mm/soft-dirty.c
@@ -209,5 +209,5 @@ int main(int argc, char **argv)
 
 	close(pagemap_fd);
 
-	ksft_exit_pass();
+	ksft_finished();
 }
diff --git a/tools/testing/selftests/mm/virtual_address_range.c b/tools/testing/selftests/mm/virtual_address_range.c
index 7bcf8d48256a..4e4c1e311247 100644
--- a/tools/testing/selftests/mm/virtual_address_range.c
+++ b/tools/testing/selftests/mm/virtual_address_range.c
@@ -12,6 +12,8 @@
 #include <errno.h>
 #include <sys/mman.h>
 #include <sys/time.h>
+#include <fcntl.h>
+
 #include "../kselftest.h"
 
 /*
@@ -85,7 +87,7 @@ static int validate_lower_address_hint(void)
 	char *ptr;
 
 	ptr = mmap((void *) (1UL << 45), MAP_CHUNK_SIZE, PROT_READ |
-			PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+		   PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
 	if (ptr == MAP_FAILED)
 		return 0;
@@ -93,6 +95,66 @@ static int validate_lower_address_hint(void)
 	return 1;
 }
 
+static int validate_complete_va_space(void)
+{
+	unsigned long start_addr, end_addr, prev_end_addr;
+	char line[400];
+	char prot[6];
+	FILE *file;
+	int fd;
+
+	fd = open("va_dump", O_CREAT | O_WRONLY, 0600);
+	unlink("va_dump");
+	if (fd < 0) {
+		ksft_test_result_skip("cannot create or open dump file\n");
+		ksft_finished();
+	}
+
+	file = fopen("/proc/self/maps", "r");
+	if (file == NULL)
+		ksft_exit_fail_msg("cannot open /proc/self/maps\n");
+
+	prev_end_addr = 0;
+	while (fgets(line, sizeof(line), file)) {
+		unsigned long hop;
+
+		if (sscanf(line, "%lx-%lx %s[rwxp-]",
+			   &start_addr, &end_addr, prot) != 3)
+			ksft_exit_fail_msg("cannot parse /proc/self/maps\n");
+
+		/* end of userspace mappings; ignore vsyscall mapping */
+		if (start_addr & (1UL << 63))
+			return 0;
+
+		/* /proc/self/maps must have gaps less than MAP_CHUNK_SIZE */
+		if (start_addr - prev_end_addr >= MAP_CHUNK_SIZE)
+			return 1;
+
+		prev_end_addr = end_addr;
+
+		if (prot[0] != 'r')
+			continue;
+
+		/*
+		 * Confirm whether MAP_CHUNK_SIZE chunk can be found or not.
+		 * If write succeeds, no need to check MAP_CHUNK_SIZE - 1
+		 * addresses after that. If the address was not held by this
+		 * process, write would fail with errno set to EFAULT.
+		 * Anyways, if write returns anything apart from 1, exit the
+		 * program since that would mean a bug in /proc/self/maps.
+		 */
+		hop = 0;
+		while (start_addr + hop < end_addr) {
+			if (write(fd, (void *)(start_addr + hop), 1) != 1)
+				return 1;
+			lseek(fd, 0, SEEK_SET);
+
+			hop += MAP_CHUNK_SIZE;
+		}
+	}
+	return 0;
+}
+
 int main(int argc, char *argv[])
 {
 	char *ptr[NR_CHUNKS_LOW];
@@ -105,13 +167,11 @@ int main(int argc, char *argv[])
 
 	for (i = 0; i < NR_CHUNKS_LOW; i++) {
 		ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,
-					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
 		if (ptr[i] == MAP_FAILED) {
-			if (validate_lower_address_hint()) {
-				ksft_test_result_skip("Memory constraint not fulfilled\n");
-				ksft_finished();
-			}
+			if (validate_lower_address_hint())
+				ksft_exit_fail_msg("mmap unexpectedly succeeded with hint\n");
 			break;
 		}
 
@@ -127,7 +187,7 @@ int main(int argc, char *argv[])
 	for (i = 0; i < NR_CHUNKS_HIGH; i++) {
 		hint = hind_addr();
 		hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,
-					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+			       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
 		if (hptr[i] == MAP_FAILED)
 			break;
@@ -135,6 +195,10 @@ int main(int argc, char *argv[])
 		validate_addr(hptr[i], 1);
 	}
 	hchunks = i;
+	if (validate_complete_va_space()) {
+		ksft_test_result_fail("BUG in mmap() or /proc/self/maps\n");
+		ksft_finished();
+	}
 
 	for (i = 0; i < lchunks; i++)
 		munmap(ptr[i], MAP_CHUNK_SIZE);
diff --git a/tools/testing/selftests/x86/test_shadow_stack.c b/tools/testing/selftests/x86/test_shadow_stack.c
index 757e6527f67e..ee909a7927f9 100644
--- a/tools/testing/selftests/x86/test_shadow_stack.c
+++ b/tools/testing/selftests/x86/test_shadow_stack.c
@@ -556,7 +556,7 @@ struct node {
  *      looked at the shadow stack gaps.
  *   5. See if it landed in the gap.
  */
-int test_guard_gap(void)
+int test_guard_gap_other_gaps(void)
 {
 	void *free_area, *shstk, *test_map = (void *)0xFFFFFFFFFFFFFFFF;
 	struct node *head = NULL, *cur;
@@ -593,11 +593,64 @@ int test_guard_gap(void)
 	if (shstk - test_map - PAGE_SIZE != PAGE_SIZE)
 		return 1;
 
-	printf("[OK]\tGuard gap test\n");
+	printf("[OK]\tGuard gap test, other mapping's gaps\n");
 
 	return 0;
 }
 
+/* Tests respecting the guard gap of the mapping getting placed */
+int test_guard_gap_new_mappings_gaps(void)
+{
+	void *free_area, *shstk_start, *test_map = (void *)0xFFFFFFFFFFFFFFFF;
+	struct node *head = NULL, *cur;
+	int ret = 0;
+
+	free_area = mmap(0, PAGE_SIZE * 4, PROT_READ | PROT_WRITE,
+			 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	munmap(free_area, PAGE_SIZE * 4);
+
+	/* Test letting map_shadow_stack find a free space */
+	shstk_start = mmap(free_area, PAGE_SIZE, PROT_READ | PROT_WRITE,
+			   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if (shstk_start == MAP_FAILED || shstk_start != free_area)
+		return 1;
+
+	while (test_map > shstk_start) {
+		test_map = (void *)syscall(__NR_map_shadow_stack, 0, PAGE_SIZE, 0);
+		if (test_map == MAP_FAILED) {
+			printf("[INFO]\tmap_shadow_stack MAP_FAILED\n");
+			ret = 1;
+			break;
+		}
+
+		cur = malloc(sizeof(*cur));
+		cur->mapping = test_map;
+
+		cur->next = head;
+		head = cur;
+
+		if (test_map == free_area + PAGE_SIZE) {
+			printf("[INFO]\tNew mapping has other mapping in guard gap!\n");
+			ret = 1;
+			break;
+		}
+	}
+
+	while (head) {
+		cur = head;
+		head = cur->next;
+		munmap(cur->mapping, PAGE_SIZE);
+		free(cur);
+	}
+
+	munmap(shstk_start, PAGE_SIZE);
+
+	if (!ret)
+		printf("[OK]\tGuard gap test, placement mapping's gaps\n");
+
+	return ret;
+}
+
 /*
  * Too complicated to pull it out of the 32 bit header, but also get the
  * 64 bit one needed above. Just define a copy here.
@@ -850,9 +903,15 @@ int main(int argc, char *argv[])
 		goto out;
 	}
 
-	if (test_guard_gap()) {
+	if (test_guard_gap_other_gaps()) {
+		ret = 1;
+		printf("[FAIL]\tGuard gap test, other mappings' gaps\n");
+		goto out;
+	}
+
+	if (test_guard_gap_new_mappings_gaps()) {
 		ret = 1;
-		printf("[FAIL]\tGuard gap test\n");
+		printf("[FAIL]\tGuard gap test, placement mapping's gaps\n");
 		goto out;
 	}