Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "VM:
   - z3fold fixes and enhancements by Henry Burns and Vitaly Wool

   - more accurate reclaimed slab caches calculations by Yafang Shao

   - fix MAP_UNINITIALIZED UAPI symbol to not depend on config, by
     Christoph Hellwig

   - !CONFIG_MMU fixes by Christoph Hellwig

   - new novmcoredd parameter to omit device dumps from vmcore, by
     Kairui Song

   - new test_meminit module for testing heap and pagealloc
     initialization, by Alexander Potapenko

   - ioremap improvements for huge mappings, by Anshuman Khandual

   - generalize kprobe page fault handling, by Anshuman Khandual

   - device-dax hotplug fixes and improvements, by Pavel Tatashin

   - enable synchronous DAX fault on powerpc, by Aneesh Kumar K.V

   - add pte_devmap() support for arm64, by Robin Murphy

   - unify locked_vm accounting with a helper, by Daniel Jordan

   - several misc fixes

  core/lib:
   - new typeof_member() macro including some users, by Alexey Dobriyan

   - make BIT() and GENMASK() available in asm, by Masahiro Yamada

   - changed LIST_POISON2 on x86_64 to 0xdead000000000122 for better
     code generation, by Alexey Dobriyan

   - rbtree code size optimizations, by Michel Lespinasse

   - convert struct pid count to refcount_t, by Joel Fernandes

  get_maintainer.pl:
   - add --no-moderated switch to skip moderated ML's, by Joe Perches

  misc:
   - ptrace PTRACE_GET_SYSCALL_INFO interface

   - coda updates

   - gdb scripts, various"

[ Using merge message suggestion from Vlastimil Babka, with some editing - Linus ]

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits)
  fs/select.c: use struct_size() in kmalloc()
  mm: add account_locked_vm utility function
  arm64: mm: implement pte_devmap support
  mm: introduce ARCH_HAS_PTE_DEVMAP
  mm: clean up is_device_*_page() definitions
  mm/mmap: move common defines to mman-common.h
  mm: move MAP_SYNC to asm-generic/mman-common.h
  device-dax: "Hotremove" persistent memory that is used like normal RAM
  mm/hotplug: make remove_memory() interface usable
  device-dax: fix memory and resource leak if hotplug fails
  include/linux/lz4.h: fix spelling and copy-paste errors in documentation
  ipc/mqueue.c: only perform resource calculation if user valid
  include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures
  scripts/gdb: add helpers to find and list devices
  scripts/gdb: add lx-genpd-summary command
  drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl
  kernel/pid.c: convert struct pid count to refcount_t
  drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings
  select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining()
  select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR
  ...

1 files changed, 364 insertions, 0 deletions

diff --git a/lib/test_meminit.c b/lib/test_meminit.c
new file mode 100644
index 000000000000..62d19f270cad
--- /dev/null
+++ b/lib/test_meminit.c
@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test cases for SL[AOU]B/page initialization at alloc/free time.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+
+#define GARBAGE_INT (0x09A7BA9E)
+#define GARBAGE_BYTE (0x9E)
+
+#define REPORT_FAILURES_IN_FN() \
+        do {    \
+                if (failures)   \
+                        pr_info("%s failed %d out of %d times\n",       \
+                                __func__, failures, num_tests);         \
+                else            \
+                        pr_info("all %d tests in %s passed\n",          \
+                                num_tests, __func__);                   \
+        } while (0)
+
+/* Calculate the number of uninitialized bytes in the buffer. */
+static int __init count_nonzero_bytes(void *ptr, size_t size)
+{
+        int i, ret = 0;
+        unsigned char *p = (unsigned char *)ptr;
+
+        for (i = 0; i < size; i++)
+                if (p[i])
+                        ret++;
+        return ret;
+}
+
+/* Fill a buffer with garbage, skipping |skip| first bytes. */
+static void __init fill_with_garbage_skip(void *ptr, int size, size_t skip)
+{
+        unsigned int *p = (unsigned int *)((char *)ptr + skip);
+        int i = 0;
+
+        WARN_ON(skip > size);
+        size -= skip;
+
+        while (size >= sizeof(*p)) {
+                p[i] = GARBAGE_INT;
+                i++;
+                size -= sizeof(*p);
+        }
+        if (size)
+                memset(&p[i], GARBAGE_BYTE, size);
+}
+
+static void __init fill_with_garbage(void *ptr, size_t size)
+{
+        fill_with_garbage_skip(ptr, size, 0);
+}
+
+static int __init do_alloc_pages_order(int order, int *total_failures)
+{
+        struct page *page;
+        void *buf;
+        size_t size = PAGE_SIZE << order;
+
+        page = alloc_pages(GFP_KERNEL, order);
+        buf = page_address(page);
+        fill_with_garbage(buf, size);
+        __free_pages(page, order);
+
+        page = alloc_pages(GFP_KERNEL, order);
+        buf = page_address(page);
+        if (count_nonzero_bytes(buf, size))
+                (*total_failures)++;
+        fill_with_garbage(buf, size);
+        __free_pages(page, order);
+        return 1;
+}
+
+/* Test the page allocator by calling alloc_pages with different orders. */
+static int __init test_pages(int *total_failures)
+{
+        int failures = 0, num_tests = 0;
+        int i;
+
+        for (i = 0; i < 10; i++)
+                num_tests += do_alloc_pages_order(i, &failures);
+
+        REPORT_FAILURES_IN_FN();
+        *total_failures += failures;
+        return num_tests;
+}
+
+/* Test kmalloc() with given parameters. */
+static int __init do_kmalloc_size(size_t size, int *total_failures)
+{
+        void *buf;
+
+        buf = kmalloc(size, GFP_KERNEL);
+        fill_with_garbage(buf, size);
+        kfree(buf);
+
+        buf = kmalloc(size, GFP_KERNEL);
+        if (count_nonzero_bytes(buf, size))
+                (*total_failures)++;
+        fill_with_garbage(buf, size);
+        kfree(buf);
+        return 1;
+}
+
+/* Test vmalloc() with given parameters. */
+static int __init do_vmalloc_size(size_t size, int *total_failures)
+{
+        void *buf;
+
+        buf = vmalloc(size);
+        fill_with_garbage(buf, size);
+        vfree(buf);
+
+        buf = vmalloc(size);
+        if (count_nonzero_bytes(buf, size))
+                (*total_failures)++;
+        fill_with_garbage(buf, size);
+        vfree(buf);
+        return 1;
+}
+
+/* Test kmalloc()/vmalloc() by allocating objects of different sizes. */
+static int __init test_kvmalloc(int *total_failures)
+{
+        int failures = 0, num_tests = 0;
+        int i, size;
+
+        for (i = 0; i < 20; i++) {
+                size = 1 << i;
+                num_tests += do_kmalloc_size(size, &failures);
+                num_tests += do_vmalloc_size(size, &failures);
+        }
+
+        REPORT_FAILURES_IN_FN();
+        *total_failures += failures;
+        return num_tests;
+}
+
+#define CTOR_BYTES (sizeof(unsigned int))
+#define CTOR_PATTERN (0x41414141)
+/* Initialize the first 4 bytes of the object. */
+static void test_ctor(void *obj)
+{
+        *(unsigned int *)obj = CTOR_PATTERN;
+}
+
+/*
+ * Check the invariants for the buffer allocated from a slab cache.
+ * If the cache has a test constructor, the first 4 bytes of the object must
+ * always remain equal to CTOR_PATTERN.
+ * If the cache isn't an RCU-typesafe one, or if the allocation is done with
+ * __GFP_ZERO, then the object contents must be zeroed after allocation.
+ * If the cache is an RCU-typesafe one, the object contents must never be
+ * zeroed after the first use. This is checked by memcmp() in
+ * do_kmem_cache_size().
+ */
+static bool __init check_buf(void *buf, int size, bool want_ctor,
+                             bool want_rcu, bool want_zero)
+{
+        int bytes;
+        bool fail = false;
+
+        bytes = count_nonzero_bytes(buf, size);
+        WARN_ON(want_ctor && want_zero);
+        if (want_zero)
+                return bytes;
+        if (want_ctor) {
+                if (*(unsigned int *)buf != CTOR_PATTERN)
+                        fail = 1;
+        } else {
+                if (bytes)
+                        fail = !want_rcu;
+        }
+        return fail;
+}
+
+/*
+ * Test kmem_cache with given parameters:
+ *  want_ctor - use a constructor;
+ *  want_rcu - use SLAB_TYPESAFE_BY_RCU;
+ *  want_zero - use __GFP_ZERO.
+ */
+static int __init do_kmem_cache_size(size_t size, bool want_ctor,
+                                     bool want_rcu, bool want_zero,
+                                     int *total_failures)
+{
+        struct kmem_cache *c;
+        int iter;
+        bool fail = false;
+        gfp_t alloc_mask = GFP_KERNEL | (want_zero ? __GFP_ZERO : 0);
+        void *buf, *buf_copy;
+
+        c = kmem_cache_create("test_cache", size, 1,
+                              want_rcu ? SLAB_TYPESAFE_BY_RCU : 0,
+                              want_ctor ? test_ctor : NULL);
+        for (iter = 0; iter < 10; iter++) {
+                buf = kmem_cache_alloc(c, alloc_mask);
+                /* Check that buf is zeroed, if it must be. */
+                fail = check_buf(buf, size, want_ctor, want_rcu, want_zero);
+                fill_with_garbage_skip(buf, size, want_ctor ? CTOR_BYTES : 0);
+
+                if (!want_rcu) {
+                        kmem_cache_free(c, buf);
+                        continue;
+                }
+
+                /*
+                 * If this is an RCU cache, use a critical section to ensure we
+                 * can touch objects after they're freed.
+                 */
+                rcu_read_lock();
+                /*
+                 * Copy the buffer to check that it's not wiped on
+                 * free().
+                 */
+                buf_copy = kmalloc(size, GFP_KERNEL);
+                if (buf_copy)
+                        memcpy(buf_copy, buf, size);
+
+                kmem_cache_free(c, buf);
+                /*
+                 * Check that |buf| is intact after kmem_cache_free().
+                 * |want_zero| is false, because we wrote garbage to
+                 * the buffer already.
+                 */
+                fail |= check_buf(buf, size, want_ctor, want_rcu,
+                                  false);
+                if (buf_copy) {
+                        fail |= (bool)memcmp(buf, buf_copy, size);
+                        kfree(buf_copy);
+                }
+                rcu_read_unlock();
+        }
+        kmem_cache_destroy(c);
+
+        *total_failures += fail;
+        return 1;
+}
+
+/*
+ * Check that the data written to an RCU-allocated object survives
+ * reallocation.
+ */
+static int __init do_kmem_cache_rcu_persistent(int size, int *total_failures)
+{
+        struct kmem_cache *c;
+        void *buf, *buf_contents, *saved_ptr;
+        void **used_objects;
+        int i, iter, maxiter = 1024;
+        bool fail = false;
+
+        c = kmem_cache_create("test_cache", size, size, SLAB_TYPESAFE_BY_RCU,
+                              NULL);
+        buf = kmem_cache_alloc(c, GFP_KERNEL);
+        saved_ptr = buf;
+        fill_with_garbage(buf, size);
+        buf_contents = kmalloc(size, GFP_KERNEL);
+        if (!buf_contents)
+                goto out;
+        used_objects = kmalloc_array(maxiter, sizeof(void *), GFP_KERNEL);
+        if (!used_objects) {
+                kfree(buf_contents);
+                goto out;
+        }
+        memcpy(buf_contents, buf, size);
+        kmem_cache_free(c, buf);
+        /*
+         * Run for a fixed number of iterations. If we never hit saved_ptr,
+         * assume the test passes.
+         */
+        for (iter = 0; iter < maxiter; iter++) {
+                buf = kmem_cache_alloc(c, GFP_KERNEL);
+                used_objects[iter] = buf;
+                if (buf == saved_ptr) {
+                        fail = memcmp(buf_contents, buf, size);
+                        for (i = 0; i <= iter; i++)
+                                kmem_cache_free(c, used_objects[i]);
+                        goto free_out;
+                }
+        }
+
+free_out:
+        kmem_cache_destroy(c);
+        kfree(buf_contents);
+        kfree(used_objects);
+out:
+        *total_failures += fail;
+        return 1;
+}
+
+/*
+ * Test kmem_cache allocation by creating caches of different sizes, with and
+ * without constructors, with and without SLAB_TYPESAFE_BY_RCU.
+ */
+static int __init test_kmemcache(int *total_failures)
+{
+        int failures = 0, num_tests = 0;
+        int i, flags, size;
+        bool ctor, rcu, zero;
+
+        for (i = 0; i < 10; i++) {
+                size = 8 << i;
+                for (flags = 0; flags < 8; flags++) {
+                        ctor = flags & 1;
+                        rcu = flags & 2;
+                        zero = flags & 4;
+                        if (ctor & zero)
+                                continue;
+                        num_tests += do_kmem_cache_size(size, ctor, rcu, zero,
+                                                        &failures);
+                }
+        }
+        REPORT_FAILURES_IN_FN();
+        *total_failures += failures;
+        return num_tests;
+}
+
+/* Test the behavior of SLAB_TYPESAFE_BY_RCU caches of different sizes. */
+static int __init test_rcu_persistent(int *total_failures)
+{
+        int failures = 0, num_tests = 0;
+        int i, size;
+
+        for (i = 0; i < 10; i++) {
+                size = 8 << i;
+                num_tests += do_kmem_cache_rcu_persistent(size, &failures);
+        }
+        REPORT_FAILURES_IN_FN();
+        *total_failures += failures;
+        return num_tests;
+}
+
+/*
+ * Run the tests. Each test function returns the number of executed tests and
+ * updates |failures| with the number of failed tests.
+ */
+static int __init test_meminit_init(void)
+{
+        int failures = 0, num_tests = 0;
+
+        num_tests += test_pages(&failures);
+        num_tests += test_kvmalloc(&failures);
+        num_tests += test_kmemcache(&failures);
+        num_tests += test_rcu_persistent(&failures);
+
+        if (failures == 0)
+                pr_info("all %d tests passed!\n", num_tests);
+        else
+                pr_info("failures: %d out of %d\n", failures, num_tests);
+
+        return failures ? -EINVAL : 0;
+}
+module_init(test_meminit_init);
+
+MODULE_LICENSE("GPL");