msan.h revision 1.1.8.3 1 1.1.8.2 martin /* $NetBSD: msan.h,v 1.1.8.3 2020/04/21 18:42:03 martin Exp $ */
2 1.1.8.2 martin
3 1.1.8.2 martin /*
4 1.1.8.2 martin * Copyright (c) 2019 The NetBSD Foundation, Inc.
5 1.1.8.2 martin * All rights reserved.
6 1.1.8.2 martin *
7 1.1.8.2 martin * This code is derived from software contributed to The NetBSD Foundation
8 1.1.8.2 martin * by Maxime Villard.
9 1.1.8.2 martin *
10 1.1.8.2 martin * Redistribution and use in source and binary forms, with or without
11 1.1.8.2 martin * modification, are permitted provided that the following conditions
12 1.1.8.2 martin * are met:
13 1.1.8.2 martin * 1. Redistributions of source code must retain the above copyright
14 1.1.8.2 martin * notice, this list of conditions and the following disclaimer.
15 1.1.8.2 martin * 2. Redistributions in binary form must reproduce the above copyright
16 1.1.8.2 martin * notice, this list of conditions and the following disclaimer in the
17 1.1.8.2 martin * documentation and/or other materials provided with the distribution.
18 1.1.8.2 martin *
19 1.1.8.2 martin * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 1.1.8.2 martin * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 1.1.8.2 martin * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 1.1.8.2 martin * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 1.1.8.2 martin * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 1.1.8.2 martin * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 1.1.8.2 martin * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 1.1.8.2 martin * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 1.1.8.2 martin * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 1.1.8.2 martin * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 1.1.8.2 martin * POSSIBILITY OF SUCH DAMAGE.
30 1.1.8.2 martin */
31 1.1.8.2 martin
32 1.1.8.2 martin #include <sys/ksyms.h>
33 1.1.8.2 martin
34 1.1.8.2 martin #include <amd64/pmap.h>
35 1.1.8.2 martin #include <amd64/vmparam.h>
36 1.1.8.2 martin
37 1.1.8.2 martin #ifdef __HAVE_PCPU_AREA
38 1.1.8.2 martin #error "PCPU area not allowed with KMSAN"
39 1.1.8.2 martin #endif
40 1.1.8.2 martin #ifdef __HAVE_DIRECT_MAP
41 1.1.8.2 martin #error "DMAP not allowed with KMSAN"
42 1.1.8.2 martin #endif
43 1.1.8.2 martin
44 1.1.8.2 martin /*
45 1.1.8.2 martin * One big shadow, divided in two sub-shadows (SHAD and ORIG), themselves
46 1.1.8.2 martin * divided in two regions (MAIN and KERN).
47 1.1.8.2 martin */
48 1.1.8.2 martin
49 1.1.8.2 martin #define __MD_SHADOW_SIZE 0x20000000000ULL /* 4 * NBPD_L4 */
50 1.1.8.2 martin #define __MD_SHADOW_START (VA_SIGN_NEG((L4_SLOT_KMSAN * NBPD_L4)))
51 1.1.8.2 martin #define __MD_SHADOW_END (__MD_SHADOW_START + __MD_SHADOW_SIZE)
52 1.1.8.2 martin
53 1.1.8.2 martin #define __MD_SHAD_MAIN_START (__MD_SHADOW_START)
54 1.1.8.2 martin #define __MD_SHAD_KERN_START (__MD_SHADOW_START + 0x8000000000ULL)
55 1.1.8.2 martin
56 1.1.8.2 martin #define __MD_ORIG_MAIN_START (__MD_SHAD_KERN_START + 0x8000000000ULL)
57 1.1.8.2 martin #define __MD_ORIG_KERN_START (__MD_ORIG_MAIN_START + 0x8000000000ULL)
58 1.1.8.2 martin
59 1.1.8.2 martin #define __MD_PTR_BASE 0xFFFFFFFF80000000ULL
60 1.1.8.2 martin #define __MD_ORIG_TYPE __BITS(31,28)
61 1.1.8.2 martin
62 1.1.8.2 martin static inline int8_t *
63 1.1.8.2 martin kmsan_md_addr_to_shad(const void *addr)
64 1.1.8.2 martin {
65 1.1.8.2 martin vaddr_t va = (vaddr_t)addr;
66 1.1.8.2 martin
67 1.1.8.2 martin if (va >= vm_min_kernel_address && va < vm_max_kernel_address) {
68 1.1.8.2 martin return (int8_t *)(__MD_SHAD_MAIN_START + (va - vm_min_kernel_address));
69 1.1.8.2 martin } else if (va >= KERNBASE) {
70 1.1.8.2 martin return (int8_t *)(__MD_SHAD_KERN_START + (va - KERNBASE));
71 1.1.8.2 martin } else {
72 1.1.8.2 martin panic("%s: impossible, va=%p", __func__, (void *)va);
73 1.1.8.2 martin }
74 1.1.8.2 martin }
75 1.1.8.2 martin
76 1.1.8.2 martin static inline int8_t *
77 1.1.8.2 martin kmsan_md_addr_to_orig(const void *addr)
78 1.1.8.2 martin {
79 1.1.8.2 martin vaddr_t va = (vaddr_t)addr;
80 1.1.8.2 martin
81 1.1.8.2 martin if (va >= vm_min_kernel_address && va < vm_max_kernel_address) {
82 1.1.8.2 martin return (int8_t *)(__MD_ORIG_MAIN_START + (va - vm_min_kernel_address));
83 1.1.8.2 martin } else if (va >= KERNBASE) {
84 1.1.8.2 martin return (int8_t *)(__MD_ORIG_KERN_START + (va - KERNBASE));
85 1.1.8.2 martin } else {
86 1.1.8.2 martin panic("%s: impossible, va=%p", __func__, (void *)va);
87 1.1.8.2 martin }
88 1.1.8.2 martin }
89 1.1.8.2 martin
90 1.1.8.2 martin static inline bool
91 1.1.8.2 martin kmsan_md_unsupported(vaddr_t addr)
92 1.1.8.2 martin {
93 1.1.8.2 martin return (addr >= (vaddr_t)PTE_BASE &&
94 1.1.8.2 martin addr < ((vaddr_t)PTE_BASE + NBPD_L4));
95 1.1.8.2 martin }
96 1.1.8.2 martin
97 1.1.8.2 martin static inline paddr_t
98 1.1.8.2 martin __md_palloc(void)
99 1.1.8.2 martin {
100 1.1.8.3 martin /* The page is zeroed. */
101 1.1.8.2 martin return pmap_get_physpage();
102 1.1.8.2 martin }
103 1.1.8.2 martin
104 1.1.8.3 martin static inline paddr_t
105 1.1.8.3 martin __md_palloc_large(void)
106 1.1.8.3 martin {
107 1.1.8.3 martin struct pglist pglist;
108 1.1.8.3 martin int ret;
109 1.1.8.3 martin
110 1.1.8.3 martin if (!uvm.page_init_done)
111 1.1.8.3 martin return 0;
112 1.1.8.3 martin
113 1.1.8.3 martin kmsan_init_arg(sizeof(psize_t) + 4 * sizeof(paddr_t) +
114 1.1.8.3 martin sizeof(struct pglist *) + 2 * sizeof(int));
115 1.1.8.3 martin ret = uvm_pglistalloc(NBPD_L2, 0, ~0UL, NBPD_L2, 0,
116 1.1.8.3 martin &pglist, 1, 0);
117 1.1.8.3 martin if (ret != 0)
118 1.1.8.3 martin return 0;
119 1.1.8.3 martin
120 1.1.8.3 martin /* The page may not be zeroed. */
121 1.1.8.3 martin return VM_PAGE_TO_PHYS(TAILQ_FIRST(&pglist));
122 1.1.8.3 martin }
123 1.1.8.3 martin
124 1.1.8.2 martin static void
125 1.1.8.2 martin kmsan_md_shadow_map_page(vaddr_t va)
126 1.1.8.2 martin {
127 1.1.8.3 martin const pt_entry_t pteflags = PTE_W | pmap_pg_nx | PTE_P;
128 1.1.8.2 martin paddr_t pa;
129 1.1.8.2 martin
130 1.1.8.2 martin KASSERT(va >= __MD_SHADOW_START && va < __MD_SHADOW_END);
131 1.1.8.2 martin
132 1.1.8.2 martin if (!pmap_valid_entry(L4_BASE[pl4_i(va)])) {
133 1.1.8.2 martin pa = __md_palloc();
134 1.1.8.3 martin L4_BASE[pl4_i(va)] = pa | pteflags;
135 1.1.8.2 martin }
136 1.1.8.2 martin if (!pmap_valid_entry(L3_BASE[pl3_i(va)])) {
137 1.1.8.2 martin pa = __md_palloc();
138 1.1.8.3 martin L3_BASE[pl3_i(va)] = pa | pteflags;
139 1.1.8.2 martin }
140 1.1.8.2 martin if (!pmap_valid_entry(L2_BASE[pl2_i(va)])) {
141 1.1.8.3 martin if ((pa = __md_palloc_large()) != 0) {
142 1.1.8.3 martin L2_BASE[pl2_i(va)] = pa | pteflags | PTE_PS |
143 1.1.8.3 martin pmap_pg_g;
144 1.1.8.3 martin __insn_barrier();
145 1.1.8.3 martin __builtin_memset(va, 0, NBPD_L2);
146 1.1.8.3 martin return;
147 1.1.8.3 martin }
148 1.1.8.2 martin pa = __md_palloc();
149 1.1.8.3 martin L2_BASE[pl2_i(va)] = pa | pteflags;
150 1.1.8.3 martin } else if (L2_BASE[pl2_i(va)] & PTE_PS) {
151 1.1.8.3 martin return;
152 1.1.8.2 martin }
153 1.1.8.2 martin if (!pmap_valid_entry(L1_BASE[pl1_i(va)])) {
154 1.1.8.2 martin pa = __md_palloc();
155 1.1.8.3 martin L1_BASE[pl1_i(va)] = pa | pteflags | pmap_pg_g;
156 1.1.8.2 martin }
157 1.1.8.2 martin }
158 1.1.8.2 martin
159 1.1.8.2 martin static void
160 1.1.8.2 martin kmsan_md_init(void)
161 1.1.8.2 martin {
162 1.1.8.2 martin extern struct bootspace bootspace;
163 1.1.8.2 martin size_t i;
164 1.1.8.2 martin
165 1.1.8.2 martin CTASSERT((__MD_SHADOW_SIZE / NBPD_L4) == NL4_SLOT_KMSAN);
166 1.1.8.2 martin
167 1.1.8.2 martin /* Kernel. */
168 1.1.8.2 martin for (i = 0; i < BTSPACE_NSEGS; i++) {
169 1.1.8.2 martin if (bootspace.segs[i].type == BTSEG_NONE) {
170 1.1.8.2 martin continue;
171 1.1.8.2 martin }
172 1.1.8.2 martin kmsan_shadow_map((void *)bootspace.segs[i].va,
173 1.1.8.2 martin bootspace.segs[i].sz);
174 1.1.8.2 martin }
175 1.1.8.2 martin
176 1.1.8.2 martin /* Boot region. */
177 1.1.8.2 martin kmsan_shadow_map((void *)bootspace.boot.va, bootspace.boot.sz);
178 1.1.8.2 martin
179 1.1.8.2 martin /* Module map. */
180 1.1.8.2 martin kmsan_shadow_map((void *)bootspace.smodule,
181 1.1.8.2 martin (size_t)(bootspace.emodule - bootspace.smodule));
182 1.1.8.2 martin
183 1.1.8.2 martin /* The bootstrap spare va. */
184 1.1.8.2 martin kmsan_shadow_map((void *)bootspace.spareva, PAGE_SIZE);
185 1.1.8.2 martin }
186 1.1.8.2 martin
187 1.1.8.2 martin static inline msan_orig_t
188 1.1.8.2 martin kmsan_md_orig_encode(int type, uintptr_t ptr)
189 1.1.8.2 martin {
190 1.1.8.2 martin msan_orig_t ret;
191 1.1.8.2 martin
192 1.1.8.2 martin ret = (ptr & 0xFFFFFFFF) & ~__MD_ORIG_TYPE;
193 1.1.8.2 martin ret |= __SHIFTIN(type, __MD_ORIG_TYPE);
194 1.1.8.2 martin
195 1.1.8.2 martin return ret;
196 1.1.8.2 martin }
197 1.1.8.2 martin
198 1.1.8.2 martin static inline void
199 1.1.8.2 martin kmsan_md_orig_decode(msan_orig_t orig, int *type, uintptr_t *ptr)
200 1.1.8.2 martin {
201 1.1.8.2 martin *type = __SHIFTOUT(orig, __MD_ORIG_TYPE);
202 1.1.8.2 martin *ptr = (uintptr_t)(orig & ~__MD_ORIG_TYPE) | __MD_PTR_BASE;
203 1.1.8.2 martin }
204 1.1.8.2 martin
205 1.1.8.2 martin static inline bool
206 1.1.8.2 martin kmsan_md_is_pc(uintptr_t ptr)
207 1.1.8.2 martin {
208 1.1.8.2 martin extern uint8_t __rodata_start;
209 1.1.8.2 martin
210 1.1.8.2 martin return (ptr < (uintptr_t)&__rodata_start);
211 1.1.8.2 martin }
212 1.1.8.2 martin
213 1.1.8.2 martin static inline bool
214 1.1.8.2 martin __md_unwind_end(const char *name)
215 1.1.8.2 martin {
216 1.1.8.2 martin if (!strcmp(name, "syscall") ||
217 1.1.8.2 martin !strcmp(name, "alltraps") ||
218 1.1.8.2 martin !strcmp(name, "handle_syscall") ||
219 1.1.8.2 martin !strncmp(name, "Xtrap", 5) ||
220 1.1.8.2 martin !strncmp(name, "Xintr", 5) ||
221 1.1.8.2 martin !strncmp(name, "Xhandle", 7) ||
222 1.1.8.2 martin !strncmp(name, "Xresume", 7) ||
223 1.1.8.2 martin !strncmp(name, "Xstray", 6) ||
224 1.1.8.2 martin !strncmp(name, "Xhold", 5) ||
225 1.1.8.2 martin !strncmp(name, "Xrecurse", 8) ||
226 1.1.8.2 martin !strcmp(name, "Xdoreti") ||
227 1.1.8.2 martin !strncmp(name, "Xsoft", 5)) {
228 1.1.8.2 martin return true;
229 1.1.8.2 martin }
230 1.1.8.2 martin
231 1.1.8.2 martin return false;
232 1.1.8.2 martin }
233 1.1.8.2 martin
234 1.1.8.2 martin static void
235 1.1.8.2 martin kmsan_md_unwind(void)
236 1.1.8.2 martin {
237 1.1.8.2 martin uint64_t *rbp, rip;
238 1.1.8.2 martin const char *mod;
239 1.1.8.2 martin const char *sym;
240 1.1.8.2 martin size_t nsym;
241 1.1.8.2 martin int error;
242 1.1.8.2 martin
243 1.1.8.2 martin rbp = (uint64_t *)__builtin_frame_address(0);
244 1.1.8.2 martin nsym = 0;
245 1.1.8.2 martin
246 1.1.8.2 martin while (1) {
247 1.1.8.2 martin /* 8(%rbp) contains the saved %rip. */
248 1.1.8.2 martin rip = *(rbp + 1);
249 1.1.8.2 martin
250 1.1.8.2 martin if (rip < KERNBASE) {
251 1.1.8.2 martin break;
252 1.1.8.2 martin }
253 1.1.8.2 martin error = ksyms_getname(&mod, &sym, (vaddr_t)rip, KSYMS_PROC);
254 1.1.8.2 martin if (error) {
255 1.1.8.2 martin break;
256 1.1.8.2 martin }
257 1.1.8.2 martin kmsan_printf("#%zu %p in %s <%s>\n", nsym, (void *)rip, sym, mod);
258 1.1.8.2 martin if (__md_unwind_end(sym)) {
259 1.1.8.2 martin break;
260 1.1.8.2 martin }
261 1.1.8.2 martin
262 1.1.8.2 martin rbp = (uint64_t *)*(rbp);
263 1.1.8.2 martin if (rbp == 0) {
264 1.1.8.2 martin break;
265 1.1.8.2 martin }
266 1.1.8.2 martin nsym++;
267 1.1.8.2 martin
268 1.1.8.2 martin if (nsym >= 15) {
269 1.1.8.2 martin break;
270 1.1.8.2 martin }
271 1.1.8.2 martin }
272 1.1.8.2 martin }
273