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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * KUnit userspace memory allocation resource management.
4 */
5#include <kunit/resource.h>
6#include <kunit/test.h>
7#include <linux/kthread.h>
8#include <linux/mm.h>
9
10struct kunit_vm_mmap_resource {
11 unsigned long addr;
12 size_t size;
13};
14
15/* vm_mmap() arguments */
16struct kunit_vm_mmap_params {
17 struct file *file;
18 unsigned long addr;
19 unsigned long len;
20 unsigned long prot;
21 unsigned long flag;
22 unsigned long offset;
23};
24
25int kunit_attach_mm(void)
26{
27 struct mm_struct *mm;
28
29 if (current->mm)
30 return 0;
31
32 /* arch_pick_mmap_layout() is only sane with MMU systems. */
33 if (!IS_ENABLED(CONFIG_MMU))
34 return -EINVAL;
35
36 mm = mm_alloc();
37 if (!mm)
38 return -ENOMEM;
39
40 /* Define the task size. */
41 mm->task_size = TASK_SIZE;
42
43 /* Make sure we can allocate new VMAs. */
44 arch_pick_mmap_layout(mm, &current->signal->rlim[RLIMIT_STACK]);
45
46 /* Attach the mm. It will be cleaned up when the process dies. */
47 kthread_use_mm(mm);
48
49 return 0;
50}
51EXPORT_SYMBOL_GPL(kunit_attach_mm);
52
53static int kunit_vm_mmap_init(struct kunit_resource *res, void *context)
54{
55 struct kunit_vm_mmap_params *p = context;
56 struct kunit_vm_mmap_resource vres;
57 int ret;
58
59 ret = kunit_attach_mm();
60 if (ret)
61 return ret;
62
63 vres.size = p->len;
64 vres.addr = vm_mmap(p->file, p->addr, p->len, p->prot, p->flag, p->offset);
65 if (!vres.addr)
66 return -ENOMEM;
67 res->data = kmemdup(&vres, sizeof(vres), GFP_KERNEL);
68 if (!res->data) {
69 vm_munmap(vres.addr, vres.size);
70 return -ENOMEM;
71 }
72
73 return 0;
74}
75
76static void kunit_vm_mmap_free(struct kunit_resource *res)
77{
78 struct kunit_vm_mmap_resource *vres = res->data;
79
80 /*
81 * Since this is executed from the test monitoring process,
82 * the test's mm has already been torn down. We don't need
83 * to run vm_munmap(vres->addr, vres->size), only clean up
84 * the vres.
85 */
86
87 kfree(vres);
88 res->data = NULL;
89}
90
91unsigned long kunit_vm_mmap(struct kunit *test, struct file *file,
92 unsigned long addr, unsigned long len,
93 unsigned long prot, unsigned long flag,
94 unsigned long offset)
95{
96 struct kunit_vm_mmap_params params = {
97 .file = file,
98 .addr = addr,
99 .len = len,
100 .prot = prot,
101 .flag = flag,
102 .offset = offset,
103 };
104 struct kunit_vm_mmap_resource *vres;
105
106 vres = kunit_alloc_resource(test,
107 kunit_vm_mmap_init,
108 kunit_vm_mmap_free,
109 GFP_KERNEL,
110 &params);
111 if (vres)
112 return vres->addr;
113 return 0;
114}
115EXPORT_SYMBOL_GPL(kunit_vm_mmap);
116
117MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");