linux/tools/testing/radix-tree/idr-test.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* idr-test.c: Test the IDR API
* Copyright (c) 2016 Matthew Wilcox <willy@infradead.org>
*/
#include <linux/bitmap.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include "test.h"
#define DUMMY_PTR ((void *)0x10)
int item_idr_free(int id, void *p, void *data)
{
struct item *item = p;
assert(item->index == id);
free(p);
return 0;
}
void item_idr_remove(struct idr *idr, int id)
{
struct item *item = idr_find(idr, id);
assert(item->index == id);
idr_remove(idr, id);
free(item);
}
void idr_alloc_test(void)
{
unsigned long i;
DEFINE_IDR(idr);
assert(idr_alloc_cyclic(&idr, DUMMY_PTR, 0, 0x4000, GFP_KERNEL) == 0);
assert(idr_alloc_cyclic(&idr, DUMMY_PTR, 0x3ffd, 0x4000, GFP_KERNEL) == 0x3ffd);
idr_remove(&idr, 0x3ffd);
idr_remove(&idr, 0);
for (i = 0x3ffe; i < 0x4003; i++) {
int id;
struct item *item;
if (i < 0x4000)
item = item_create(i, 0);
else
item = item_create(i - 0x3fff, 0);
id = idr_alloc_cyclic(&idr, item, 1, 0x4000, GFP_KERNEL);
assert(id == item->index);
}
idr_for_each(&idr, item_idr_free, &idr);
idr_destroy(&idr);
}
void idr_replace_test(void)
{
DEFINE_IDR(idr);
idr_alloc(&idr, (void *)-1, 10, 11, GFP_KERNEL);
idr_replace(&idr, &idr, 10);
idr_destroy(&idr);
}
/*
* Unlike the radix tree, you can put a NULL pointer -- with care -- into
* the IDR. Some interfaces, like idr_find() do not distinguish between
* "present, value is NULL" and "not present", but that's exactly what some
* users want.
*/
void idr_null_test(void)
{
int i;
DEFINE_IDR(idr);
assert(idr_is_empty(&idr));
assert(idr_alloc(&idr, NULL, 0, 0, GFP_KERNEL) == 0);
assert(!idr_is_empty(&idr));
idr_remove(&idr, 0);
assert(idr_is_empty(&idr));
assert(idr_alloc(&idr, NULL, 0, 0, GFP_KERNEL) == 0);
assert(!idr_is_empty(&idr));
idr_destroy(&idr);
assert(idr_is_empty(&idr));
for (i = 0; i < 10; i++) {
assert(idr_alloc(&idr, NULL, 0, 0, GFP_KERNEL) == i);
}
assert(idr_replace(&idr, DUMMY_PTR, 3) == NULL);
assert(idr_replace(&idr, DUMMY_PTR, 4) == NULL);
assert(idr_replace(&idr, NULL, 4) == DUMMY_PTR);
assert(idr_replace(&idr, DUMMY_PTR, 11) == ERR_PTR(-ENOENT));
idr_remove(&idr, 5);
assert(idr_alloc(&idr, NULL, 0, 0, GFP_KERNEL) == 5);
idr_remove(&idr, 5);
for (i = 0; i < 9; i++) {
idr_remove(&idr, i);
assert(!idr_is_empty(&idr));
}
idr_remove(&idr, 8);
assert(!idr_is_empty(&idr));
idr_remove(&idr, 9);
assert(idr_is_empty(&idr));
assert(idr_alloc(&idr, NULL, 0, 0, GFP_KERNEL) == 0);
assert(idr_replace(&idr, DUMMY_PTR, 3) == ERR_PTR(-ENOENT));
assert(idr_replace(&idr, DUMMY_PTR, 0) == NULL);
assert(idr_replace(&idr, NULL, 0) == DUMMY_PTR);
idr_destroy(&idr);
assert(idr_is_empty(&idr));
for (i = 1; i < 10; i++) {
assert(idr_alloc(&idr, NULL, 1, 0, GFP_KERNEL) == i);
}
idr_destroy(&idr);
assert(idr_is_empty(&idr));
}
void idr_nowait_test(void)
{
unsigned int i;
DEFINE_IDR(idr);
idr_preload(GFP_KERNEL);
for (i = 0; i < 3; i++) {
struct item *item = item_create(i, 0);
assert(idr_alloc(&idr, item, i, i + 1, GFP_NOWAIT) == i);
}
idr_preload_end();
idr_for_each(&idr, item_idr_free, &idr);
idr_destroy(&idr);
}
void idr_get_next_test(int base)
{
unsigned long i;
int nextid;
DEFINE_IDR(idr);
idr_init_base(&idr, base);
int indices[] = {4, 7, 9, 15, 65, 128, 1000, 99999, 0};
for(i = 0; indices[i]; i++) {
struct item *item = item_create(indices[i], 0);
assert(idr_alloc(&idr, item, indices[i], indices[i+1],
GFP_KERNEL) == indices[i]);
}
for(i = 0, nextid = 0; indices[i]; i++) {
idr_get_next(&idr, &nextid);
assert(nextid == indices[i]);
nextid++;
}
idr_for_each(&idr, item_idr_free, &idr);
idr_destroy(&idr);
}
int idr_u32_cb(int id, void *ptr, void *data)
{
BUG_ON(id < 0);
BUG_ON(ptr != DUMMY_PTR);
return 0;
}
void idr_u32_test1(struct idr *idr, u32 handle)
{
static bool warned = false;
u32 id = handle;
int sid = 0;
void *ptr;
BUG_ON(idr_alloc_u32(idr, DUMMY_PTR, &id, id, GFP_KERNEL));
BUG_ON(id != handle);
BUG_ON(idr_alloc_u32(idr, DUMMY_PTR, &id, id, GFP_KERNEL) != -ENOSPC);
BUG_ON(id != handle);
if (!warned && id > INT_MAX)
printk("vvv Ignore these warnings\n");
ptr = idr_get_next(idr, &sid);
if (id > INT_MAX) {
BUG_ON(ptr != NULL);
BUG_ON(sid != 0);
} else {
BUG_ON(ptr != DUMMY_PTR);
BUG_ON(sid != id);
}
idr_for_each(idr, idr_u32_cb, NULL);
if (!warned && id > INT_MAX) {
printk("^^^ Warnings over\n");
warned = true;
}
BUG_ON(idr_remove(idr, id) != DUMMY_PTR);
BUG_ON(!idr_is_empty(idr));
}
void idr_u32_test(int base)
{
DEFINE_IDR(idr);
idr_init_base(&idr, base);
idr_u32_test1(&idr, 10);
idr_u32_test1(&idr, 0x7fffffff);
idr_u32_test1(&idr, 0x80000000);
idr_u32_test1(&idr, 0x80000001);
idr_u32_test1(&idr, 0xffe00000);
idr_u32_test1(&idr, 0xffffffff);
}
idr: Permit any valid kernel pointer to be stored An upcoming change to the encoding of internal entries will set the bottom two bits to 0b10. Unfortunately, m68k only aligns some data structures to 2 bytes, so the IDR will interpret them as internal entries and things will go badly wrong. Change the radix tree so that it stops either when the node indicates that it's the bottom of the tree (shift == 0) or when the entry is not an internal entry. This means we cannot insert an arbitrary kernel pointer as a multiorder entry, but the IDR does not permit multiorder entries. Annoyingly, this means the IDR can no longer take advantage of the radix tree's ability to store a single entry at offset 0 without allocating memory. A pointer which is 2-byte aligned cannot be stored directly in the root as it would be indistinguishable from a node, so we must allocate a node in order to store a 2-byte pointer at index 0. The idr_replace() function does not take a GFP flags argument, so cannot allocate memory. If a user inserts a 4-byte aligned pointer at index 0 and then replaces it with a 2-byte aligned pointer, we must be able to store it. Arbitrary pointer values are still not permitted; pointers of the form 2 + (i * 4) for values of i between 0 and 1023 are reserved for the implementation. These are not valid kernel pointers as they would point into the zero page. This change does cause a runtime memory consumption regression for the IDA. I will recover that later. Signed-off-by: Matthew Wilcox <willy@infradead.org> Tested-by: Guenter Roeck <linux@roeck-us.net>
2018-06-25 18:56:50 +08:00
static void idr_align_test(struct idr *idr)
{
char name[] = "Motorola 68000";
int i, id;
void *entry;
for (i = 0; i < 9; i++) {
BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != i);
idr_for_each_entry(idr, entry, id);
}
idr_destroy(idr);
for (i = 1; i < 10; i++) {
BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != i - 1);
idr_for_each_entry(idr, entry, id);
}
idr_destroy(idr);
for (i = 2; i < 11; i++) {
BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != i - 2);
idr_for_each_entry(idr, entry, id);
}
idr_destroy(idr);
for (i = 3; i < 12; i++) {
BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != i - 3);
idr_for_each_entry(idr, entry, id);
}
idr_destroy(idr);
for (i = 0; i < 8; i++) {
BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != 0);
BUG_ON(idr_alloc(idr, &name[i + 1], 0, 0, GFP_KERNEL) != 1);
idr_for_each_entry(idr, entry, id);
idr_remove(idr, 1);
idr_for_each_entry(idr, entry, id);
idr_remove(idr, 0);
BUG_ON(!idr_is_empty(idr));
}
for (i = 0; i < 8; i++) {
BUG_ON(idr_alloc(idr, NULL, 0, 0, GFP_KERNEL) != 0);
idr_for_each_entry(idr, entry, id);
idr_replace(idr, &name[i], 0);
idr_for_each_entry(idr, entry, id);
BUG_ON(idr_find(idr, 0) != &name[i]);
idr_remove(idr, 0);
}
for (i = 0; i < 8; i++) {
BUG_ON(idr_alloc(idr, &name[i], 0, 0, GFP_KERNEL) != 0);
BUG_ON(idr_alloc(idr, NULL, 0, 0, GFP_KERNEL) != 1);
idr_remove(idr, 1);
idr_for_each_entry(idr, entry, id);
idr_replace(idr, &name[i + 1], 0);
idr_for_each_entry(idr, entry, id);
idr_remove(idr, 0);
}
}
DEFINE_IDR(find_idr);
static void *idr_throbber(void *arg)
{
time_t start = time(NULL);
int id = *(int *)arg;
rcu_register_thread();
do {
idr_alloc(&find_idr, xa_mk_value(id), id, id + 1, GFP_KERNEL);
idr_remove(&find_idr, id);
} while (time(NULL) < start + 10);
rcu_unregister_thread();
return NULL;
}
void idr_find_test_1(int anchor_id, int throbber_id)
{
pthread_t throbber;
time_t start = time(NULL);
pthread_create(&throbber, NULL, idr_throbber, &throbber_id);
BUG_ON(idr_alloc(&find_idr, xa_mk_value(anchor_id), anchor_id,
anchor_id + 1, GFP_KERNEL) != anchor_id);
do {
int id = 0;
void *entry = idr_get_next(&find_idr, &id);
BUG_ON(entry != xa_mk_value(id));
} while (time(NULL) < start + 11);
pthread_join(throbber, NULL);
idr_remove(&find_idr, anchor_id);
BUG_ON(!idr_is_empty(&find_idr));
}
void idr_find_test(void)
{
idr_find_test_1(100000, 0);
idr_find_test_1(0, 100000);
}
void idr_checks(void)
{
unsigned long i;
DEFINE_IDR(idr);
for (i = 0; i < 10000; i++) {
struct item *item = item_create(i, 0);
assert(idr_alloc(&idr, item, 0, 20000, GFP_KERNEL) == i);
}
assert(idr_alloc(&idr, DUMMY_PTR, 5, 30, GFP_KERNEL) < 0);
for (i = 0; i < 5000; i++)
item_idr_remove(&idr, i);
idr_remove(&idr, 3);
idr_for_each(&idr, item_idr_free, &idr);
idr_destroy(&idr);
assert(idr_is_empty(&idr));
idr_remove(&idr, 3);
idr_remove(&idr, 0);
idr: fix invalid ptr dereference on item delete If the radix tree underlying the IDR happens to be full and we attempt to remove an id which is larger than any id in the IDR, we will call __radix_tree_delete() with an uninitialised 'slot' pointer, at which point anything could happen. This was easiest to hit with a single entry at id 0 and attempting to remove a non-0 id, but it could have happened with 64 entries and attempting to remove an id >= 64. Roman said: The syzcaller test boils down to opening /dev/kvm, creating an eventfd, and calling a couple of KVM ioctls. None of this requires superuser. And the result is dereferencing an uninitialized pointer which is likely a crash. The specific path caught by syzbot is via KVM_HYPERV_EVENTD ioctl which is new in 4.17. But I guess there are other user-triggerable paths, so cc:stable is probably justified. Matthew added: We have around 250 calls to idr_remove() in the kernel today. Many of them pass an ID which is embedded in the object they're removing, so they're safe. Picking a few likely candidates: drivers/firewire/core-cdev.c looks unsafe; the ID comes from an ioctl. drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c is similar drivers/atm/nicstar.c could be taken down by a handcrafted packet Link: http://lkml.kernel.org/r/20180518175025.GD6361@bombadil.infradead.org Fixes: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree") Reported-by: <syzbot+35666cba7f0a337e2e79@syzkaller.appspotmail.com> Debugged-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-26 05:47:24 +08:00
assert(idr_alloc(&idr, DUMMY_PTR, 0, 0, GFP_KERNEL) == 0);
idr_remove(&idr, 1);
for (i = 1; i < RADIX_TREE_MAP_SIZE; i++)
assert(idr_alloc(&idr, DUMMY_PTR, 0, 0, GFP_KERNEL) == i);
idr_remove(&idr, 1 << 30);
idr_destroy(&idr);
for (i = INT_MAX - 3UL; i < INT_MAX + 1UL; i++) {
struct item *item = item_create(i, 0);
assert(idr_alloc(&idr, item, i, i + 10, GFP_KERNEL) == i);
}
assert(idr_alloc(&idr, DUMMY_PTR, i - 2, i, GFP_KERNEL) == -ENOSPC);
assert(idr_alloc(&idr, DUMMY_PTR, i - 2, i + 10, GFP_KERNEL) == -ENOSPC);
idr_for_each(&idr, item_idr_free, &idr);
idr_destroy(&idr);
idr_destroy(&idr);
assert(idr_is_empty(&idr));
idr_set_cursor(&idr, INT_MAX - 3UL);
for (i = INT_MAX - 3UL; i < INT_MAX + 3UL; i++) {
struct item *item;
unsigned int id;
if (i <= INT_MAX)
item = item_create(i, 0);
else
item = item_create(i - INT_MAX - 1, 0);
id = idr_alloc_cyclic(&idr, item, 0, 0, GFP_KERNEL);
assert(id == item->index);
}
idr_for_each(&idr, item_idr_free, &idr);
idr_destroy(&idr);
assert(idr_is_empty(&idr));
for (i = 1; i < 10000; i++) {
struct item *item = item_create(i, 0);
assert(idr_alloc(&idr, item, 1, 20000, GFP_KERNEL) == i);
}
idr_for_each(&idr, item_idr_free, &idr);
idr_destroy(&idr);
idr_replace_test();
idr_alloc_test();
idr_null_test();
idr_nowait_test();
idr_get_next_test(0);
idr_get_next_test(1);
idr_get_next_test(4);
idr_u32_test(4);
idr_u32_test(1);
idr_u32_test(0);
idr: Permit any valid kernel pointer to be stored An upcoming change to the encoding of internal entries will set the bottom two bits to 0b10. Unfortunately, m68k only aligns some data structures to 2 bytes, so the IDR will interpret them as internal entries and things will go badly wrong. Change the radix tree so that it stops either when the node indicates that it's the bottom of the tree (shift == 0) or when the entry is not an internal entry. This means we cannot insert an arbitrary kernel pointer as a multiorder entry, but the IDR does not permit multiorder entries. Annoyingly, this means the IDR can no longer take advantage of the radix tree's ability to store a single entry at offset 0 without allocating memory. A pointer which is 2-byte aligned cannot be stored directly in the root as it would be indistinguishable from a node, so we must allocate a node in order to store a 2-byte pointer at index 0. The idr_replace() function does not take a GFP flags argument, so cannot allocate memory. If a user inserts a 4-byte aligned pointer at index 0 and then replaces it with a 2-byte aligned pointer, we must be able to store it. Arbitrary pointer values are still not permitted; pointers of the form 2 + (i * 4) for values of i between 0 and 1023 are reserved for the implementation. These are not valid kernel pointers as they would point into the zero page. This change does cause a runtime memory consumption regression for the IDA. I will recover that later. Signed-off-by: Matthew Wilcox <willy@infradead.org> Tested-by: Guenter Roeck <linux@roeck-us.net>
2018-06-25 18:56:50 +08:00
idr_align_test(&idr);
idr_find_test();
}
#define module_init(x)
#define module_exit(x)
#define MODULE_AUTHOR(x)
#define MODULE_LICENSE(x)
#define dump_stack() assert(0)
void ida_dump(struct ida *);
#include "../../../lib/test_ida.c"
/*
* Check that we get the correct error when we run out of memory doing
* allocations. In userspace, GFP_NOWAIT will always fail an allocation.
* The first test is for not having a bitmap available, and the second test
* is for not being able to allocate a level of the radix tree.
*/
void ida_check_nomem(void)
{
DEFINE_IDA(ida);
int id;
id = ida_alloc_min(&ida, 256, GFP_NOWAIT);
IDA_BUG_ON(&ida, id != -ENOMEM);
id = ida_alloc_min(&ida, 1UL << 30, GFP_NOWAIT);
IDA_BUG_ON(&ida, id != -ENOMEM);
IDA_BUG_ON(&ida, !ida_is_empty(&ida));
}
/*
* Check handling of conversions between exceptional entries and full bitmaps.
*/
void ida_check_conv_user(void)
{
DEFINE_IDA(ida);
unsigned long i;
for (i = 0; i < 1000000; i++) {
int id = ida_alloc(&ida, GFP_NOWAIT);
if (id == -ENOMEM) {
IDA_BUG_ON(&ida, ((i % IDA_BITMAP_BITS) !=
BITS_PER_XA_VALUE) &&
((i % IDA_BITMAP_BITS) != 0));
id = ida_alloc(&ida, GFP_KERNEL);
} else {
IDA_BUG_ON(&ida, (i % IDA_BITMAP_BITS) ==
BITS_PER_XA_VALUE);
}
IDA_BUG_ON(&ida, id != i);
}
ida_destroy(&ida);
}
void ida_check_random(void)
{
DEFINE_IDA(ida);
DECLARE_BITMAP(bitmap, 2048);
unsigned int i;
time_t s = time(NULL);
repeat:
memset(bitmap, 0, sizeof(bitmap));
for (i = 0; i < 100000; i++) {
int i = rand();
int bit = i & 2047;
if (test_bit(bit, bitmap)) {
__clear_bit(bit, bitmap);
ida_free(&ida, bit);
} else {
__set_bit(bit, bitmap);
IDA_BUG_ON(&ida, ida_alloc_min(&ida, bit, GFP_KERNEL)
!= bit);
}
}
ida_destroy(&ida);
if (time(NULL) < s + 10)
goto repeat;
}
void ida_simple_get_remove_test(void)
{
DEFINE_IDA(ida);
unsigned long i;
for (i = 0; i < 10000; i++) {
assert(ida_simple_get(&ida, 0, 20000, GFP_KERNEL) == i);
}
assert(ida_simple_get(&ida, 5, 30, GFP_KERNEL) < 0);
for (i = 0; i < 10000; i++) {
ida_simple_remove(&ida, i);
}
assert(ida_is_empty(&ida));
ida_destroy(&ida);
}
void user_ida_checks(void)
{
radix_tree_cpu_dead(1);
ida_check_nomem();
ida_check_conv_user();
ida_check_random();
ida_simple_get_remove_test();
radix_tree_cpu_dead(1);
}
static void *ida_random_fn(void *arg)
{
rcu_register_thread();
ida_check_random();
rcu_unregister_thread();
return NULL;
}
static void *ida_leak_fn(void *arg)
{
struct ida *ida = arg;
time_t s = time(NULL);
int i, ret;
rcu_register_thread();
do for (i = 0; i < 1000; i++) {
ret = ida_alloc_range(ida, 128, 128, GFP_KERNEL);
if (ret >= 0)
ida_free(ida, 128);
} while (time(NULL) < s + 2);
rcu_unregister_thread();
return NULL;
}
void ida_thread_tests(void)
{
DEFINE_IDA(ida);
pthread_t threads[20];
int i;
for (i = 0; i < ARRAY_SIZE(threads); i++)
if (pthread_create(&threads[i], NULL, ida_random_fn, NULL)) {
perror("creating ida thread");
exit(1);
}
while (i--)
pthread_join(threads[i], NULL);
for (i = 0; i < ARRAY_SIZE(threads); i++)
if (pthread_create(&threads[i], NULL, ida_leak_fn, &ida)) {
perror("creating ida thread");
exit(1);
}
while (i--)
pthread_join(threads[i], NULL);
assert(ida_is_empty(&ida));
}
void ida_tests(void)
{
user_ida_checks();
ida_checks();
ida_exit();
ida_thread_tests();
}
int __weak main(void)
{
radix_tree_init();
idr_checks();
ida_tests();
radix_tree_cpu_dead(1);
rcu_barrier();
if (nr_allocated)
printf("nr_allocated = %d\n", nr_allocated);
return 0;
}