1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2019 ARM Limited */
3 #include "testcases.h"
4
get_header(struct _aarch64_ctx * head,uint32_t magic,size_t resv_sz,size_t * offset)5 struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic,
6 size_t resv_sz, size_t *offset)
7 {
8 size_t offs = 0;
9 struct _aarch64_ctx *found = NULL;
10
11 if (!head || resv_sz < HDR_SZ)
12 return found;
13
14 while (offs <= resv_sz - HDR_SZ &&
15 head->magic != magic && head->magic) {
16 offs += head->size;
17 head = GET_RESV_NEXT_HEAD(head);
18 }
19 if (head->magic == magic) {
20 found = head;
21 if (offset)
22 *offset = offs;
23 }
24
25 return found;
26 }
27
validate_extra_context(struct extra_context * extra,char ** err)28 bool validate_extra_context(struct extra_context *extra, char **err)
29 {
30 struct _aarch64_ctx *term;
31
32 if (!extra || !err)
33 return false;
34
35 fprintf(stderr, "Validating EXTRA...\n");
36 term = GET_RESV_NEXT_HEAD(extra);
37 if (!term || term->magic || term->size) {
38 *err = "Missing terminator after EXTRA context";
39 return false;
40 }
41 if (extra->datap & 0x0fUL)
42 *err = "Extra DATAP misaligned";
43 else if (extra->size & 0x0fUL)
44 *err = "Extra SIZE misaligned";
45 else if (extra->datap != (uint64_t)term + sizeof(*term))
46 *err = "Extra DATAP misplaced (not contiguous)";
47 if (*err)
48 return false;
49
50 return true;
51 }
52
validate_sve_context(struct sve_context * sve,char ** err)53 bool validate_sve_context(struct sve_context *sve, char **err)
54 {
55 /* Size will be rounded up to a multiple of 16 bytes */
56 size_t regs_size
57 = ((SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve->vl)) + 15) / 16) * 16;
58
59 if (!sve || !err)
60 return false;
61
62 /* Either a bare sve_context or a sve_context followed by regs data */
63 if ((sve->head.size != sizeof(struct sve_context)) &&
64 (sve->head.size != regs_size)) {
65 *err = "bad size for SVE context";
66 return false;
67 }
68
69 if (!sve_vl_valid(sve->vl)) {
70 *err = "SVE VL invalid";
71
72 return false;
73 }
74
75 return true;
76 }
77
validate_reserved(ucontext_t * uc,size_t resv_sz,char ** err)78 bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
79 {
80 bool terminated = false;
81 size_t offs = 0;
82 int flags = 0;
83 struct extra_context *extra = NULL;
84 struct sve_context *sve = NULL;
85 struct _aarch64_ctx *head =
86 (struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
87
88 if (!err)
89 return false;
90 /* Walk till the end terminator verifying __reserved contents */
91 while (head && !terminated && offs < resv_sz) {
92 if ((uint64_t)head & 0x0fUL) {
93 *err = "Misaligned HEAD";
94 return false;
95 }
96
97 switch (head->magic) {
98 case 0:
99 if (head->size)
100 *err = "Bad size for terminator";
101 else
102 terminated = true;
103 break;
104 case FPSIMD_MAGIC:
105 if (flags & FPSIMD_CTX)
106 *err = "Multiple FPSIMD_MAGIC";
107 else if (head->size !=
108 sizeof(struct fpsimd_context))
109 *err = "Bad size for fpsimd_context";
110 flags |= FPSIMD_CTX;
111 break;
112 case ESR_MAGIC:
113 if (head->size != sizeof(struct esr_context))
114 *err = "Bad size for esr_context";
115 break;
116 case SVE_MAGIC:
117 if (flags & SVE_CTX)
118 *err = "Multiple SVE_MAGIC";
119 /* Size is validated in validate_sve_context() */
120 sve = (struct sve_context *)head;
121 flags |= SVE_CTX;
122 break;
123 case EXTRA_MAGIC:
124 if (flags & EXTRA_CTX)
125 *err = "Multiple EXTRA_MAGIC";
126 else if (head->size !=
127 sizeof(struct extra_context))
128 *err = "Bad size for extra_context";
129 flags |= EXTRA_CTX;
130 extra = (struct extra_context *)head;
131 break;
132 case KSFT_BAD_MAGIC:
133 /*
134 * This is a BAD magic header defined
135 * artificially by a testcase and surely
136 * unknown to the Kernel parse_user_sigframe().
137 * It MUST cause a Kernel induced SEGV
138 */
139 *err = "BAD MAGIC !";
140 break;
141 default:
142 /*
143 * A still unknown Magic: potentially freshly added
144 * to the Kernel code and still unknown to the
145 * tests.
146 */
147 fprintf(stdout,
148 "SKIP Unknown MAGIC: 0x%X - Is KSFT arm64/signal up to date ?\n",
149 head->magic);
150 break;
151 }
152
153 if (*err)
154 return false;
155
156 offs += head->size;
157 if (resv_sz < offs + sizeof(*head)) {
158 *err = "HEAD Overrun";
159 return false;
160 }
161
162 if (flags & EXTRA_CTX)
163 if (!validate_extra_context(extra, err))
164 return false;
165 if (flags & SVE_CTX)
166 if (!validate_sve_context(sve, err))
167 return false;
168
169 head = GET_RESV_NEXT_HEAD(head);
170 }
171
172 if (terminated && !(flags & FPSIMD_CTX)) {
173 *err = "Missing FPSIMD";
174 return false;
175 }
176
177 return true;
178 }
179
180 /*
181 * This function walks through the records inside the provided reserved area
182 * trying to find enough space to fit @need_sz bytes: if not enough space is
183 * available and an extra_context record is present, it throws away the
184 * extra_context record.
185 *
186 * It returns a pointer to a new header where it is possible to start storing
187 * our need_sz bytes.
188 *
189 * @shead: points to the start of reserved area
190 * @need_sz: needed bytes
191 * @resv_sz: reserved area size in bytes
192 * @offset: if not null, this will be filled with the offset of the return
193 * head pointer from @shead
194 *
195 * @return: pointer to a new head where to start storing need_sz bytes, or
196 * NULL if space could not be made available.
197 */
get_starting_head(struct _aarch64_ctx * shead,size_t need_sz,size_t resv_sz,size_t * offset)198 struct _aarch64_ctx *get_starting_head(struct _aarch64_ctx *shead,
199 size_t need_sz, size_t resv_sz,
200 size_t *offset)
201 {
202 size_t offs = 0;
203 struct _aarch64_ctx *head;
204
205 head = get_terminator(shead, resv_sz, &offs);
206 /* not found a terminator...no need to update offset if any */
207 if (!head)
208 return head;
209 if (resv_sz - offs < need_sz) {
210 fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
211 resv_sz - offs);
212 head = get_header(shead, EXTRA_MAGIC, resv_sz, &offs);
213 if (!head || resv_sz - offs < need_sz) {
214 fprintf(stderr,
215 "Failed to reclaim space on sigframe.\n");
216 return NULL;
217 }
218 }
219
220 fprintf(stderr, "Available space:%zd\n", resv_sz - offs);
221 if (offset)
222 *offset = offs;
223 return head;
224 }
225