1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (C) 2019 ARM Limited */ 3 #include "testcases.h" 4 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 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 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 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 */ 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