Revision 32ffa4f71e10009498ae6b54da65ab316db967bd authored by Axel Rasmussen on 19 May 2021, 20:03:33 UTC, committed by Paolo Bonzini on 27 May 2021, 11:45:55 UTC
This is a preparatory commit needed before we can use different kinds of backing pages for guest memory. Previously, we used perf_test_args.host_page_size, which is the host's native page size (commonly 4K). For VM_MEM_SRC_ANONYMOUS this turns out to be okay, but in a follow-up commit we want to allow using different kinds of backing memory. Take VM_MEM_SRC_ANONYMOUS_HUGETLB for example. Without this change, if we used that backing page type, when we issued a UFFDIO_COPY ioctl we'd only do so with 4K, rather than the full 2M of a backing hugepage. In this case, UFFDIO_COPY returns -EINVAL (__mcopy_atomic_hugetlb checks the size). Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Message-Id: <20210519200339.829146-5-axelrasmussen@google.com> Reviewed-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 parent 25408e5
test_ubsan.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
typedef void(*test_ubsan_fp)(void);
#define UBSAN_TEST(config, ...) do { \
pr_info("%s " __VA_ARGS__ "%s(%s=%s)\n", __func__, \
sizeof(" " __VA_ARGS__) > 2 ? " " : "", \
#config, IS_ENABLED(config) ? "y" : "n"); \
} while (0)
static void test_ubsan_divrem_overflow(void)
{
volatile int val = 16;
volatile int val2 = 0;
UBSAN_TEST(CONFIG_UBSAN_DIV_ZERO);
val /= val2;
}
static void test_ubsan_shift_out_of_bounds(void)
{
volatile int neg = -1, wrap = 4;
int val1 = 10;
int val2 = INT_MAX;
UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent");
val1 <<= neg;
UBSAN_TEST(CONFIG_UBSAN_SHIFT, "left overflow");
val2 <<= wrap;
}
static void test_ubsan_out_of_bounds(void)
{
volatile int i = 4, j = 5, k = -1;
volatile char above[4] = { }; /* Protect surrounding memory. */
volatile int arr[4];
volatile char below[4] = { }; /* Protect surrounding memory. */
above[0] = below[0];
UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "above");
arr[j] = i;
UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "below");
arr[k] = i;
}
enum ubsan_test_enum {
UBSAN_TEST_ZERO = 0,
UBSAN_TEST_ONE,
UBSAN_TEST_MAX,
};
static void test_ubsan_load_invalid_value(void)
{
volatile char *dst, *src;
bool val, val2, *ptr;
enum ubsan_test_enum eval, eval2, *eptr;
unsigned char c = 0xff;
UBSAN_TEST(CONFIG_UBSAN_BOOL, "bool");
dst = (char *)&val;
src = &c;
*dst = *src;
ptr = &val2;
val2 = val;
UBSAN_TEST(CONFIG_UBSAN_ENUM, "enum");
dst = (char *)&eval;
src = &c;
*dst = *src;
eptr = &eval2;
eval2 = eval;
}
static void test_ubsan_null_ptr_deref(void)
{
volatile int *ptr = NULL;
int val;
UBSAN_TEST(CONFIG_UBSAN_OBJECT_SIZE);
val = *ptr;
}
static void test_ubsan_misaligned_access(void)
{
volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
volatile int *ptr, val = 6;
UBSAN_TEST(CONFIG_UBSAN_ALIGNMENT);
ptr = (int *)(arr + 1);
*ptr = val;
}
static void test_ubsan_object_size_mismatch(void)
{
/* "((aligned(8)))" helps this not into be misaligned for ptr-access. */
volatile int val __aligned(8) = 4;
volatile long long *ptr, val2;
UBSAN_TEST(CONFIG_UBSAN_OBJECT_SIZE);
ptr = (long long *)&val;
val2 = *ptr;
}
static const test_ubsan_fp test_ubsan_array[] = {
test_ubsan_shift_out_of_bounds,
test_ubsan_out_of_bounds,
test_ubsan_load_invalid_value,
test_ubsan_misaligned_access,
test_ubsan_object_size_mismatch,
};
/* Excluded because they Oops the module. */
static const test_ubsan_fp skip_ubsan_array[] = {
test_ubsan_divrem_overflow,
test_ubsan_null_ptr_deref,
};
static int __init test_ubsan_init(void)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
test_ubsan_array[i]();
return 0;
}
module_init(test_ubsan_init);
static void __exit test_ubsan_exit(void)
{
/* do nothing */
}
module_exit(test_ubsan_exit);
MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>");
MODULE_LICENSE("GPL v2");
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