diff options
Diffstat (limited to 'lib/test_ida.c')
| -rw-r--r-- | lib/test_ida.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/lib/test_ida.c b/lib/test_ida.c new file mode 100644 index 000000000..b06880625 --- /dev/null +++ b/lib/test_ida.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * test_ida.c: Test the IDA API + * Copyright (c) 2016-2018 Microsoft Corporation + * Copyright (c) 2018 Oracle Corporation + * Author: Matthew Wilcox <willy@infradead.org> + */ + +#include <linux/idr.h> +#include <linux/module.h> + +static unsigned int tests_run; +static unsigned int tests_passed; + +#ifdef __KERNEL__ +void ida_dump(struct ida *ida) { } +#endif +#define IDA_BUG_ON(ida, x) do { \ + tests_run++; \ + if (x) { \ + ida_dump(ida); \ + dump_stack(); \ + } else { \ + tests_passed++; \ + } \ +} while (0) + +/* + * Straightforward checks that allocating and freeing IDs work. + */ +static void ida_check_alloc(struct ida *ida) +{ + int i, id; + + for (i = 0; i < 10000; i++) + IDA_BUG_ON(ida, ida_alloc(ida, GFP_KERNEL) != i); + + ida_free(ida, 20); + ida_free(ida, 21); + for (i = 0; i < 3; i++) { + id = ida_alloc(ida, GFP_KERNEL); + IDA_BUG_ON(ida, id < 0); + if (i == 2) + IDA_BUG_ON(ida, id != 10000); + } + + for (i = 0; i < 5000; i++) + ida_free(ida, i); + + IDA_BUG_ON(ida, ida_alloc_min(ida, 5000, GFP_KERNEL) != 10001); + ida_destroy(ida); + + IDA_BUG_ON(ida, !ida_is_empty(ida)); +} + +/* Destroy an IDA with a single entry at @base */ +static void ida_check_destroy_1(struct ida *ida, unsigned int base) +{ + IDA_BUG_ON(ida, ida_alloc_min(ida, base, GFP_KERNEL) != base); + IDA_BUG_ON(ida, ida_is_empty(ida)); + ida_destroy(ida); + IDA_BUG_ON(ida, !ida_is_empty(ida)); +} + +/* Check that ida_destroy and ida_is_empty work */ +static void ida_check_destroy(struct ida *ida) +{ + /* Destroy an already-empty IDA */ + IDA_BUG_ON(ida, !ida_is_empty(ida)); + ida_destroy(ida); + IDA_BUG_ON(ida, !ida_is_empty(ida)); + + ida_check_destroy_1(ida, 0); + ida_check_destroy_1(ida, 1); + ida_check_destroy_1(ida, 1023); + ida_check_destroy_1(ida, 1024); + ida_check_destroy_1(ida, 12345678); +} + +/* + * Check what happens when we fill a leaf and then delete it. This may + * discover mishandling of IDR_FREE. + */ +static void ida_check_leaf(struct ida *ida, unsigned int base) +{ + unsigned long i; + + for (i = 0; i < IDA_BITMAP_BITS; i++) { + IDA_BUG_ON(ida, ida_alloc_min(ida, base, GFP_KERNEL) != + base + i); + } + + ida_destroy(ida); + IDA_BUG_ON(ida, !ida_is_empty(ida)); + + IDA_BUG_ON(ida, ida_alloc(ida, GFP_KERNEL) != 0); + IDA_BUG_ON(ida, ida_is_empty(ida)); + ida_free(ida, 0); + IDA_BUG_ON(ida, !ida_is_empty(ida)); +} + +/* + * Check allocations up to and slightly above the maximum allowed (2^31-1) ID. + * Allocating up to 2^31-1 should succeed, and then allocating the next one + * should fail. + */ +static void ida_check_max(struct ida *ida) +{ + unsigned long i, j; + + for (j = 1; j < 65537; j *= 2) { + unsigned long base = (1UL << 31) - j; + for (i = 0; i < j; i++) { + IDA_BUG_ON(ida, ida_alloc_min(ida, base, GFP_KERNEL) != + base + i); + } + IDA_BUG_ON(ida, ida_alloc_min(ida, base, GFP_KERNEL) != + -ENOSPC); + ida_destroy(ida); + IDA_BUG_ON(ida, !ida_is_empty(ida)); + } +} + +/* + * Check handling of conversions between exceptional entries and full bitmaps. + */ +static void ida_check_conv(struct ida *ida) +{ + unsigned long i; + + for (i = 0; i < IDA_BITMAP_BITS * 2; i += IDA_BITMAP_BITS) { + IDA_BUG_ON(ida, ida_alloc_min(ida, i + 1, GFP_KERNEL) != i + 1); + IDA_BUG_ON(ida, ida_alloc_min(ida, i + BITS_PER_LONG, + GFP_KERNEL) != i + BITS_PER_LONG); + ida_free(ida, i + 1); + ida_free(ida, i + BITS_PER_LONG); + IDA_BUG_ON(ida, !ida_is_empty(ida)); + } + + for (i = 0; i < IDA_BITMAP_BITS * 2; i++) + IDA_BUG_ON(ida, ida_alloc(ida, GFP_KERNEL) != i); + for (i = IDA_BITMAP_BITS * 2; i > 0; i--) + ida_free(ida, i - 1); + IDA_BUG_ON(ida, !ida_is_empty(ida)); + + for (i = 0; i < IDA_BITMAP_BITS + BITS_PER_LONG - 4; i++) + IDA_BUG_ON(ida, ida_alloc(ida, GFP_KERNEL) != i); + for (i = IDA_BITMAP_BITS + BITS_PER_LONG - 4; i > 0; i--) + ida_free(ida, i - 1); + IDA_BUG_ON(ida, !ida_is_empty(ida)); +} + +static DEFINE_IDA(ida); + +static int ida_checks(void) +{ + IDA_BUG_ON(&ida, !ida_is_empty(&ida)); + ida_check_alloc(&ida); + ida_check_destroy(&ida); + ida_check_leaf(&ida, 0); + ida_check_leaf(&ida, 1024); + ida_check_leaf(&ida, 1024 * 64); + ida_check_max(&ida); + ida_check_conv(&ida); + + printk("IDA: %u of %u tests passed\n", tests_passed, tests_run); + return (tests_run != tests_passed) ? 0 : -EINVAL; +} + +static void ida_exit(void) +{ +} + +module_init(ida_checks); +module_exit(ida_exit); +MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>"); +MODULE_LICENSE("GPL"); |