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iov_iter: Kunit tests for copying to/from an iterator
authorDavid Howells <dhowells@redhat.com>
Fri, 8 Sep 2023 16:03:21 +0000 (17:03 +0100)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 9 Sep 2023 22:11:49 +0000 (15:11 -0700)
Add some kunit tests for page extraction for ITER_BVEC, ITER_KVEC and
ITER_XARRAY type iterators.  ITER_UBUF and ITER_IOVEC aren't dealt with
as they require userspace VM interaction.  ITER_DISCARD isn't dealt with
either as that does nothing.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/Kconfig.debug
lib/Makefile
lib/kunit_iov_iter.c [new file with mode: 0644]

index 319cfbe..fa307f9 100644 (file)
@@ -2237,6 +2237,17 @@ config TEST_DIV64
 
          If unsure, say N.
 
+config TEST_IOV_ITER
+       tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
+       depends on KUNIT
+       default KUNIT_ALL_TESTS
+       help
+         Enable this to turn on testing of the operation of the I/O iterator
+         (iov_iter). This test is executed only once during system boot (so
+         affects only boot time), or at module load time.
+
+         If unsure, say N.
+
 config KPROBES_SANITY_TEST
        tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
        depends on DEBUG_KERNEL
index 2e08397..740109b 100644 (file)
@@ -64,6 +64,7 @@ obj-$(CONFIG_TEST_BITOPS) += test_bitops.o
 CFLAGS_test_bitops.o += -Werror
 obj-$(CONFIG_CPUMASK_KUNIT_TEST) += cpumask_kunit.o
 obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o
+obj-$(CONFIG_TEST_IOV_ITER) += kunit_iov_iter.o
 obj-$(CONFIG_HASH_KUNIT_TEST) += test_hash.o
 obj-$(CONFIG_TEST_IDA) += test_ida.o
 obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o
diff --git a/lib/kunit_iov_iter.c b/lib/kunit_iov_iter.c
new file mode 100644 (file)
index 0000000..25a9101
--- /dev/null
@@ -0,0 +1,537 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* I/O iterator tests.  This can only test kernel-backed iterator types.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/uio.h>
+#include <linux/bvec.h>
+#include <kunit/test.h>
+
+MODULE_DESCRIPTION("iov_iter testing");
+MODULE_AUTHOR("David Howells <dhowells@redhat.com>");
+MODULE_LICENSE("GPL");
+
+struct kvec_test_range {
+       int     from, to;
+};
+
+static const struct kvec_test_range kvec_test_ranges[] = {
+       { 0x00002, 0x00002 },
+       { 0x00027, 0x03000 },
+       { 0x05193, 0x18794 },
+       { 0x20000, 0x20000 },
+       { 0x20000, 0x24000 },
+       { 0x24000, 0x27001 },
+       { 0x29000, 0xffffb },
+       { 0xffffd, 0xffffe },
+       { -1 }
+};
+
+static inline u8 pattern(unsigned long x)
+{
+       return x & 0xff;
+}
+
+static void iov_kunit_unmap(void *data)
+{
+       vunmap(data);
+}
+
+static void *__init iov_kunit_create_buffer(struct kunit *test,
+                                           struct page ***ppages,
+                                           size_t npages)
+{
+       struct page **pages;
+       unsigned long got;
+       void *buffer;
+
+       pages = kunit_kcalloc(test, npages, sizeof(struct page *), GFP_KERNEL);
+        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pages);
+       *ppages = pages;
+
+       got = alloc_pages_bulk_array(GFP_KERNEL, npages, pages);
+       if (got != npages) {
+               release_pages(pages, got);
+               KUNIT_ASSERT_EQ(test, got, npages);
+       }
+
+       buffer = vmap(pages, npages, VM_MAP | VM_MAP_PUT_PAGES, PAGE_KERNEL);
+        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buffer);
+
+       kunit_add_action_or_reset(test, iov_kunit_unmap, buffer);
+       return buffer;
+}
+
+static void __init iov_kunit_load_kvec(struct kunit *test,
+                                      struct iov_iter *iter, int dir,
+                                      struct kvec *kvec, unsigned int kvmax,
+                                      void *buffer, size_t bufsize,
+                                      const struct kvec_test_range *pr)
+{
+       size_t size = 0;
+       int i;
+
+       for (i = 0; i < kvmax; i++, pr++) {
+               if (pr->from < 0)
+                       break;
+               KUNIT_ASSERT_GE(test, pr->to, pr->from);
+               KUNIT_ASSERT_LE(test, pr->to, bufsize);
+               kvec[i].iov_base = buffer + pr->from;
+               kvec[i].iov_len = pr->to - pr->from;
+               size += pr->to - pr->from;
+       }
+       KUNIT_ASSERT_LE(test, size, bufsize);
+
+       iov_iter_kvec(iter, dir, kvec, i, size);
+}
+
+/*
+ * Test copying to a ITER_KVEC-type iterator.
+ */
+static void __init iov_kunit_copy_to_kvec(struct kunit *test)
+{
+       const struct kvec_test_range *pr;
+       struct iov_iter iter;
+       struct page **spages, **bpages;
+       struct kvec kvec[8];
+       u8 *scratch, *buffer;
+       size_t bufsize, npages, size, copied;
+       int i, patt;
+
+       bufsize = 0x100000;
+       npages = bufsize / PAGE_SIZE;
+
+       scratch = iov_kunit_create_buffer(test, &spages, npages);
+       for (i = 0; i < bufsize; i++)
+               scratch[i] = pattern(i);
+
+       buffer = iov_kunit_create_buffer(test, &bpages, npages);
+       memset(buffer, 0, bufsize);
+
+       iov_kunit_load_kvec(test, &iter, READ, kvec, ARRAY_SIZE(kvec),
+                           buffer, bufsize, kvec_test_ranges);
+       size = iter.count;
+
+       copied = copy_to_iter(scratch, size, &iter);
+
+       KUNIT_EXPECT_EQ(test, copied, size);
+       KUNIT_EXPECT_EQ(test, iter.count, 0);
+       KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
+
+       /* Build the expected image in the scratch buffer. */
+       patt = 0;
+       memset(scratch, 0, bufsize);
+       for (pr = kvec_test_ranges; pr->from >= 0; pr++)
+               for (i = pr->from; i < pr->to; i++)
+                       scratch[i] = pattern(patt++);
+
+       /* Compare the images */
+       for (i = 0; i < bufsize; i++) {
+               KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
+               if (buffer[i] != scratch[i])
+                       return;
+       }
+
+       KUNIT_SUCCEED();
+}
+
+/*
+ * Test copying from a ITER_KVEC-type iterator.
+ */
+static void __init iov_kunit_copy_from_kvec(struct kunit *test)
+{
+       const struct kvec_test_range *pr;
+       struct iov_iter iter;
+       struct page **spages, **bpages;
+       struct kvec kvec[8];
+       u8 *scratch, *buffer;
+       size_t bufsize, npages, size, copied;
+       int i, j;
+
+       bufsize = 0x100000;
+       npages = bufsize / PAGE_SIZE;
+
+       buffer = iov_kunit_create_buffer(test, &bpages, npages);
+       for (i = 0; i < bufsize; i++)
+               buffer[i] = pattern(i);
+
+       scratch = iov_kunit_create_buffer(test, &spages, npages);
+       memset(scratch, 0, bufsize);
+
+       iov_kunit_load_kvec(test, &iter, WRITE, kvec, ARRAY_SIZE(kvec),
+                           buffer, bufsize, kvec_test_ranges);
+       size = min(iter.count, bufsize);
+
+       copied = copy_from_iter(scratch, size, &iter);
+
+       KUNIT_EXPECT_EQ(test, copied, size);
+       KUNIT_EXPECT_EQ(test, iter.count, 0);
+       KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
+
+       /* Build the expected image in the main buffer. */
+       i = 0;
+       memset(buffer, 0, bufsize);
+       for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
+               for (j = pr->from; j < pr->to; j++) {
+                       buffer[i++] = pattern(j);
+                       if (i >= bufsize)
+                               goto stop;
+               }
+       }
+stop:
+
+       /* Compare the images */
+       for (i = 0; i < bufsize; i++) {
+               KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
+               if (scratch[i] != buffer[i])
+                       return;
+       }
+
+       KUNIT_SUCCEED();
+}
+
+struct bvec_test_range {
+       int     page, from, to;
+};
+
+static const struct bvec_test_range bvec_test_ranges[] = {
+       { 0, 0x0002, 0x0002 },
+       { 1, 0x0027, 0x0893 },
+       { 2, 0x0193, 0x0794 },
+       { 3, 0x0000, 0x1000 },
+       { 4, 0x0000, 0x1000 },
+       { 5, 0x0000, 0x1000 },
+       { 6, 0x0000, 0x0ffb },
+       { 6, 0x0ffd, 0x0ffe },
+       { -1, -1, -1 }
+};
+
+static void __init iov_kunit_load_bvec(struct kunit *test,
+                                      struct iov_iter *iter, int dir,
+                                      struct bio_vec *bvec, unsigned int bvmax,
+                                      struct page **pages, size_t npages,
+                                      size_t bufsize,
+                                      const struct bvec_test_range *pr)
+{
+       struct page *can_merge = NULL, *page;
+       size_t size = 0;
+       int i;
+
+       for (i = 0; i < bvmax; i++, pr++) {
+               if (pr->from < 0)
+                       break;
+               KUNIT_ASSERT_LT(test, pr->page, npages);
+               KUNIT_ASSERT_LT(test, pr->page * PAGE_SIZE, bufsize);
+               KUNIT_ASSERT_GE(test, pr->from, 0);
+               KUNIT_ASSERT_GE(test, pr->to, pr->from);
+               KUNIT_ASSERT_LE(test, pr->to, PAGE_SIZE);
+
+               page = pages[pr->page];
+               if (pr->from == 0 && pr->from != pr->to && page == can_merge) {
+                       i--;
+                       bvec[i].bv_len += pr->to;
+               } else {
+                       bvec_set_page(&bvec[i], page, pr->to - pr->from, pr->from);
+               }
+
+               size += pr->to - pr->from;
+               if ((pr->to & ~PAGE_MASK) == 0)
+                       can_merge = page + pr->to / PAGE_SIZE;
+               else
+                       can_merge = NULL;
+       }
+
+       iov_iter_bvec(iter, dir, bvec, i, size);
+}
+
+/*
+ * Test copying to a ITER_BVEC-type iterator.
+ */
+static void __init iov_kunit_copy_to_bvec(struct kunit *test)
+{
+       const struct bvec_test_range *pr;
+       struct iov_iter iter;
+       struct bio_vec bvec[8];
+       struct page **spages, **bpages;
+       u8 *scratch, *buffer;
+       size_t bufsize, npages, size, copied;
+       int i, b, patt;
+
+       bufsize = 0x100000;
+       npages = bufsize / PAGE_SIZE;
+
+       scratch = iov_kunit_create_buffer(test, &spages, npages);
+       for (i = 0; i < bufsize; i++)
+               scratch[i] = pattern(i);
+
+       buffer = iov_kunit_create_buffer(test, &bpages, npages);
+       memset(buffer, 0, bufsize);
+
+       iov_kunit_load_bvec(test, &iter, READ, bvec, ARRAY_SIZE(bvec),
+                           bpages, npages, bufsize, bvec_test_ranges);
+       size = iter.count;
+
+       copied = copy_to_iter(scratch, size, &iter);
+
+       KUNIT_EXPECT_EQ(test, copied, size);
+       KUNIT_EXPECT_EQ(test, iter.count, 0);
+       KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
+
+       /* Build the expected image in the scratch buffer. */
+       b = 0;
+       patt = 0;
+       memset(scratch, 0, bufsize);
+       for (pr = bvec_test_ranges; pr->from >= 0; pr++, b++) {
+               u8 *p = scratch + pr->page * PAGE_SIZE;
+
+               for (i = pr->from; i < pr->to; i++)
+                       p[i] = pattern(patt++);
+       }
+
+       /* Compare the images */
+       for (i = 0; i < bufsize; i++) {
+               KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
+               if (buffer[i] != scratch[i])
+                       return;
+       }
+
+       KUNIT_SUCCEED();
+}
+
+/*
+ * Test copying from a ITER_BVEC-type iterator.
+ */
+static void __init iov_kunit_copy_from_bvec(struct kunit *test)
+{
+       const struct bvec_test_range *pr;
+       struct iov_iter iter;
+       struct bio_vec bvec[8];
+       struct page **spages, **bpages;
+       u8 *scratch, *buffer;
+       size_t bufsize, npages, size, copied;
+       int i, j;
+
+       bufsize = 0x100000;
+       npages = bufsize / PAGE_SIZE;
+
+       buffer = iov_kunit_create_buffer(test, &bpages, npages);
+       for (i = 0; i < bufsize; i++)
+               buffer[i] = pattern(i);
+
+       scratch = iov_kunit_create_buffer(test, &spages, npages);
+       memset(scratch, 0, bufsize);
+
+       iov_kunit_load_bvec(test, &iter, WRITE, bvec, ARRAY_SIZE(bvec),
+                           bpages, npages, bufsize, bvec_test_ranges);
+       size = iter.count;
+
+       copied = copy_from_iter(scratch, size, &iter);
+
+       KUNIT_EXPECT_EQ(test, copied, size);
+       KUNIT_EXPECT_EQ(test, iter.count, 0);
+       KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
+
+       /* Build the expected image in the main buffer. */
+       i = 0;
+       memset(buffer, 0, bufsize);
+       for (pr = bvec_test_ranges; pr->from >= 0; pr++) {
+               size_t patt = pr->page * PAGE_SIZE;
+
+               for (j = pr->from; j < pr->to; j++) {
+                       buffer[i++] = pattern(patt + j);
+                       if (i >= bufsize)
+                               goto stop;
+               }
+       }
+stop:
+
+       /* Compare the images */
+       for (i = 0; i < bufsize; i++) {
+               KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
+               if (scratch[i] != buffer[i])
+                       return;
+       }
+
+       KUNIT_SUCCEED();
+}
+
+static void iov_kunit_destroy_xarray(void *data)
+{
+       struct xarray *xarray = data;
+
+       xa_destroy(xarray);
+       kfree(xarray);
+}
+
+static void __init iov_kunit_load_xarray(struct kunit *test,
+                                        struct iov_iter *iter, int dir,
+                                        struct xarray *xarray,
+                                        struct page **pages, size_t npages)
+{
+       size_t size = 0;
+       int i;
+
+       for (i = 0; i < npages; i++) {
+               void *x = xa_store(xarray, i, pages[i], GFP_KERNEL);
+
+               KUNIT_ASSERT_FALSE(test, xa_is_err(x));
+               size += PAGE_SIZE;
+       }
+       iov_iter_xarray(iter, dir, xarray, 0, size);
+}
+
+static struct xarray *iov_kunit_create_xarray(struct kunit *test)
+{
+       struct xarray *xarray;
+
+       xarray = kzalloc(sizeof(struct xarray), GFP_KERNEL);
+       xa_init(xarray);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xarray);
+       kunit_add_action_or_reset(test, iov_kunit_destroy_xarray, xarray);
+       return xarray;
+}
+
+/*
+ * Test copying to a ITER_XARRAY-type iterator.
+ */
+static void __init iov_kunit_copy_to_xarray(struct kunit *test)
+{
+       const struct kvec_test_range *pr;
+       struct iov_iter iter;
+       struct xarray *xarray;
+       struct page **spages, **bpages;
+       u8 *scratch, *buffer;
+       size_t bufsize, npages, size, copied;
+       int i, patt;
+
+       bufsize = 0x100000;
+       npages = bufsize / PAGE_SIZE;
+
+       xarray = iov_kunit_create_xarray(test);
+
+       scratch = iov_kunit_create_buffer(test, &spages, npages);
+       for (i = 0; i < bufsize; i++)
+               scratch[i] = pattern(i);
+
+       buffer = iov_kunit_create_buffer(test, &bpages, npages);
+       memset(buffer, 0, bufsize);
+
+       iov_kunit_load_xarray(test, &iter, READ, xarray, bpages, npages);
+
+       i = 0;
+       for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
+               size = pr->to - pr->from;
+               KUNIT_ASSERT_LE(test, pr->to, bufsize);
+
+               iov_iter_xarray(&iter, READ, xarray, pr->from, size);
+               copied = copy_to_iter(scratch + i, size, &iter);
+
+               KUNIT_EXPECT_EQ(test, copied, size);
+               KUNIT_EXPECT_EQ(test, iter.count, 0);
+               KUNIT_EXPECT_EQ(test, iter.iov_offset, size);
+               i += size;
+       }
+
+       /* Build the expected image in the scratch buffer. */
+       patt = 0;
+       memset(scratch, 0, bufsize);
+       for (pr = kvec_test_ranges; pr->from >= 0; pr++)
+               for (i = pr->from; i < pr->to; i++)
+                       scratch[i] = pattern(patt++);
+
+       /* Compare the images */
+       for (i = 0; i < bufsize; i++) {
+               KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
+               if (buffer[i] != scratch[i])
+                       return;
+       }
+
+       KUNIT_SUCCEED();
+}
+
+/*
+ * Test copying from a ITER_XARRAY-type iterator.
+ */
+static void __init iov_kunit_copy_from_xarray(struct kunit *test)
+{
+       const struct kvec_test_range *pr;
+       struct iov_iter iter;
+       struct xarray *xarray;
+       struct page **spages, **bpages;
+       u8 *scratch, *buffer;
+       size_t bufsize, npages, size, copied;
+       int i, j;
+
+       bufsize = 0x100000;
+       npages = bufsize / PAGE_SIZE;
+
+       xarray = iov_kunit_create_xarray(test);
+
+       buffer = iov_kunit_create_buffer(test, &bpages, npages);
+       for (i = 0; i < bufsize; i++)
+               buffer[i] = pattern(i);
+
+       scratch = iov_kunit_create_buffer(test, &spages, npages);
+       memset(scratch, 0, bufsize);
+
+       iov_kunit_load_xarray(test, &iter, READ, xarray, bpages, npages);
+
+       i = 0;
+       for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
+               size = pr->to - pr->from;
+               KUNIT_ASSERT_LE(test, pr->to, bufsize);
+
+               iov_iter_xarray(&iter, WRITE, xarray, pr->from, size);
+               copied = copy_from_iter(scratch + i, size, &iter);
+
+               KUNIT_EXPECT_EQ(test, copied, size);
+               KUNIT_EXPECT_EQ(test, iter.count, 0);
+               KUNIT_EXPECT_EQ(test, iter.iov_offset, size);
+               i += size;
+       }
+
+       /* Build the expected image in the main buffer. */
+       i = 0;
+       memset(buffer, 0, bufsize);
+       for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
+               for (j = pr->from; j < pr->to; j++) {
+                       buffer[i++] = pattern(j);
+                       if (i >= bufsize)
+                               goto stop;
+               }
+       }
+stop:
+
+       /* Compare the images */
+       for (i = 0; i < bufsize; i++) {
+               KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
+               if (scratch[i] != buffer[i])
+                       return;
+       }
+
+       KUNIT_SUCCEED();
+}
+
+static struct kunit_case __refdata iov_kunit_cases[] = {
+       KUNIT_CASE(iov_kunit_copy_to_kvec),
+       KUNIT_CASE(iov_kunit_copy_from_kvec),
+       KUNIT_CASE(iov_kunit_copy_to_bvec),
+       KUNIT_CASE(iov_kunit_copy_from_bvec),
+       KUNIT_CASE(iov_kunit_copy_to_xarray),
+       KUNIT_CASE(iov_kunit_copy_from_xarray),
+       {}
+};
+
+static struct kunit_suite iov_kunit_suite = {
+       .name = "iov_iter",
+       .test_cases = iov_kunit_cases,
+};
+
+kunit_test_suites(&iov_kunit_suite);