1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (C) 2019 ARM Limited */ 3 4 #include <ctype.h> 5 #include <string.h> 6 7 #include "testcases.h" 8 9 struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic, 10 size_t resv_sz, size_t *offset) 11 { 12 size_t offs = 0; 13 struct _aarch64_ctx *found = NULL; 14 15 if (!head || resv_sz < HDR_SZ) 16 return found; 17 18 while (offs <= resv_sz - HDR_SZ && 19 head->magic != magic && head->magic) { 20 offs += head->size; 21 head = GET_RESV_NEXT_HEAD(head); 22 } 23 if (head->magic == magic) { 24 found = head; 25 if (offset) 26 *offset = offs; 27 } 28 29 return found; 30 } 31 32 bool validate_extra_context(struct extra_context *extra, char **err, 33 void **extra_data, size_t *extra_size) 34 { 35 struct _aarch64_ctx *term; 36 37 if (!extra || !err) 38 return false; 39 40 fprintf(stderr, "Validating EXTRA...\n"); 41 term = GET_RESV_NEXT_HEAD(&extra->head); 42 if (!term || term->magic || term->size) { 43 *err = "Missing terminator after EXTRA context"; 44 return false; 45 } 46 if (extra->datap & 0x0fUL) 47 *err = "Extra DATAP misaligned"; 48 else if (extra->size & 0x0fUL) 49 *err = "Extra SIZE misaligned"; 50 else if (extra->datap != (uint64_t)term + 0x10UL) 51 *err = "Extra DATAP misplaced (not contiguous)"; 52 if (*err) 53 return false; 54 55 *extra_data = (void *)extra->datap; 56 *extra_size = extra->size; 57 58 return true; 59 } 60 61 bool validate_sve_context(struct sve_context *sve, char **err) 62 { 63 /* Size will be rounded up to a multiple of 16 bytes */ 64 size_t regs_size 65 = ((SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve->vl)) + 15) / 16) * 16; 66 67 if (!sve || !err) 68 return false; 69 70 /* Either a bare sve_context or a sve_context followed by regs data */ 71 if ((sve->head.size != sizeof(struct sve_context)) && 72 (sve->head.size != regs_size)) { 73 *err = "bad size for SVE context"; 74 return false; 75 } 76 77 if (!sve_vl_valid(sve->vl)) { 78 *err = "SVE VL invalid"; 79 80 return false; 81 } 82 83 return true; 84 } 85 86 bool validate_za_context(struct za_context *za, char **err) 87 { 88 /* Size will be rounded up to a multiple of 16 bytes */ 89 size_t regs_size 90 = ((ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za->vl)) + 15) / 16) * 16; 91 92 if (!za || !err) 93 return false; 94 95 /* Either a bare za_context or a za_context followed by regs data */ 96 if ((za->head.size != sizeof(struct za_context)) && 97 (za->head.size != regs_size)) { 98 *err = "bad size for ZA context"; 99 return false; 100 } 101 102 if (!sve_vl_valid(za->vl)) { 103 *err = "SME VL in ZA context invalid"; 104 105 return false; 106 } 107 108 return true; 109 } 110 111 bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err) 112 { 113 bool terminated = false; 114 size_t offs = 0; 115 int flags = 0; 116 int new_flags, i; 117 struct extra_context *extra = NULL; 118 struct sve_context *sve = NULL; 119 struct za_context *za = NULL; 120 struct _aarch64_ctx *head = 121 (struct _aarch64_ctx *)uc->uc_mcontext.__reserved; 122 void *extra_data = NULL; 123 size_t extra_sz = 0; 124 char magic[4]; 125 126 if (!err) 127 return false; 128 /* Walk till the end terminator verifying __reserved contents */ 129 while (head && !terminated && offs < resv_sz) { 130 if ((uint64_t)head & 0x0fUL) { 131 *err = "Misaligned HEAD"; 132 return false; 133 } 134 135 new_flags = 0; 136 137 switch (head->magic) { 138 case 0: 139 if (head->size) { 140 *err = "Bad size for terminator"; 141 } else if (extra_data) { 142 /* End of main data, walking the extra data */ 143 head = extra_data; 144 resv_sz = extra_sz; 145 offs = 0; 146 147 extra_data = NULL; 148 extra_sz = 0; 149 continue; 150 } else { 151 terminated = true; 152 } 153 break; 154 case FPSIMD_MAGIC: 155 if (flags & FPSIMD_CTX) 156 *err = "Multiple FPSIMD_MAGIC"; 157 else if (head->size != 158 sizeof(struct fpsimd_context)) 159 *err = "Bad size for fpsimd_context"; 160 new_flags |= FPSIMD_CTX; 161 break; 162 case ESR_MAGIC: 163 if (head->size != sizeof(struct esr_context)) 164 *err = "Bad size for esr_context"; 165 break; 166 case SVE_MAGIC: 167 if (flags & SVE_CTX) 168 *err = "Multiple SVE_MAGIC"; 169 /* Size is validated in validate_sve_context() */ 170 sve = (struct sve_context *)head; 171 new_flags |= SVE_CTX; 172 break; 173 case ZA_MAGIC: 174 if (flags & ZA_CTX) 175 *err = "Multiple ZA_MAGIC"; 176 /* Size is validated in validate_za_context() */ 177 za = (struct za_context *)head; 178 new_flags |= ZA_CTX; 179 break; 180 case EXTRA_MAGIC: 181 if (flags & EXTRA_CTX) 182 *err = "Multiple EXTRA_MAGIC"; 183 else if (head->size != 184 sizeof(struct extra_context)) 185 *err = "Bad size for extra_context"; 186 new_flags |= EXTRA_CTX; 187 extra = (struct extra_context *)head; 188 break; 189 case KSFT_BAD_MAGIC: 190 /* 191 * This is a BAD magic header defined 192 * artificially by a testcase and surely 193 * unknown to the Kernel parse_user_sigframe(). 194 * It MUST cause a Kernel induced SEGV 195 */ 196 *err = "BAD MAGIC !"; 197 break; 198 default: 199 /* 200 * A still unknown Magic: potentially freshly added 201 * to the Kernel code and still unknown to the 202 * tests. Magic numbers are supposed to be allocated 203 * as somewhat meaningful ASCII strings so try to 204 * print as such as well as the raw number. 205 */ 206 memcpy(magic, &head->magic, sizeof(magic)); 207 for (i = 0; i < sizeof(magic); i++) 208 if (!isalnum(magic[i])) 209 magic[i] = '?'; 210 211 fprintf(stdout, 212 "SKIP Unknown MAGIC: 0x%X (%c%c%c%c) - Is KSFT arm64/signal up to date ?\n", 213 head->magic, 214 magic[3], magic[2], magic[1], magic[0]); 215 break; 216 } 217 218 if (*err) 219 return false; 220 221 offs += head->size; 222 if (resv_sz < offs + sizeof(*head)) { 223 *err = "HEAD Overrun"; 224 return false; 225 } 226 227 if (new_flags & EXTRA_CTX) 228 if (!validate_extra_context(extra, err, 229 &extra_data, &extra_sz)) 230 return false; 231 if (new_flags & SVE_CTX) 232 if (!validate_sve_context(sve, err)) 233 return false; 234 if (new_flags & ZA_CTX) 235 if (!validate_za_context(za, err)) 236 return false; 237 238 flags |= new_flags; 239 240 head = GET_RESV_NEXT_HEAD(head); 241 } 242 243 if (terminated && !(flags & FPSIMD_CTX)) { 244 *err = "Missing FPSIMD"; 245 return false; 246 } 247 248 return true; 249 } 250 251 /* 252 * This function walks through the records inside the provided reserved area 253 * trying to find enough space to fit @need_sz bytes: if not enough space is 254 * available and an extra_context record is present, it throws away the 255 * extra_context record. 256 * 257 * It returns a pointer to a new header where it is possible to start storing 258 * our need_sz bytes. 259 * 260 * @shead: points to the start of reserved area 261 * @need_sz: needed bytes 262 * @resv_sz: reserved area size in bytes 263 * @offset: if not null, this will be filled with the offset of the return 264 * head pointer from @shead 265 * 266 * @return: pointer to a new head where to start storing need_sz bytes, or 267 * NULL if space could not be made available. 268 */ 269 struct _aarch64_ctx *get_starting_head(struct _aarch64_ctx *shead, 270 size_t need_sz, size_t resv_sz, 271 size_t *offset) 272 { 273 size_t offs = 0; 274 struct _aarch64_ctx *head; 275 276 head = get_terminator(shead, resv_sz, &offs); 277 /* not found a terminator...no need to update offset if any */ 278 if (!head) 279 return head; 280 if (resv_sz - offs < need_sz) { 281 fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n", 282 resv_sz - offs); 283 head = get_header(shead, EXTRA_MAGIC, resv_sz, &offs); 284 if (!head || resv_sz - offs < need_sz) { 285 fprintf(stderr, 286 "Failed to reclaim space on sigframe.\n"); 287 return NULL; 288 } 289 } 290 291 fprintf(stderr, "Available space:%zd\n", resv_sz - offs); 292 if (offset) 293 *offset = offs; 294 return head; 295 } 296