Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame^] | 1 | From c7b375747cffb627d02543d946b28525455d7d46 Mon Sep 17 00:00:00 2001 |
| 2 | From: "Hongzhi.Song" <hongzhi.song@windriver.com> |
| 3 | Date: Fri, 13 Jul 2018 06:06:19 -0700 |
| 4 | Subject: [PATCH] vm: add some funtions to support musl libc |
| 5 | |
| 6 | Signed-off-by: Hongzhi.Song <hongzhi.song@windriver.com> |
| 7 | --- |
| 8 | tools/testing/selftests/vm/userfaultfd.c | 298 +++++++++++++++++++++++++++++++ |
| 9 | 1 file changed, 298 insertions(+) |
| 10 | |
| 11 | diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c |
| 12 | index de2f9ec..dc73021 100644 |
| 13 | --- a/tools/testing/selftests/vm/userfaultfd.c |
| 14 | +++ b/tools/testing/selftests/vm/userfaultfd.c |
| 15 | @@ -71,6 +71,304 @@ |
| 16 | |
| 17 | #ifdef __NR_userfaultfd |
| 18 | |
| 19 | +/* Linear congruential. */ |
| 20 | +#define TYPE_0 0 |
| 21 | +#define BREAK_0 8 |
| 22 | +#define DEG_0 0 |
| 23 | +#define SEP_0 0 |
| 24 | + |
| 25 | +/* x**7 + x**3 + 1. */ |
| 26 | +#define TYPE_1 1 |
| 27 | +#define BREAK_1 32 |
| 28 | +#define DEG_1 7 |
| 29 | +#define SEP_1 3 |
| 30 | + |
| 31 | +/* x**15 + x + 1. */ |
| 32 | +#define TYPE_2 2 |
| 33 | +#define BREAK_2 64 |
| 34 | +#define DEG_2 15 |
| 35 | +#define SEP_2 1 |
| 36 | + |
| 37 | +/* x**31 + x**3 + 1. */ |
| 38 | +#define TYPE_3 3 |
| 39 | +#define BREAK_3 128 |
| 40 | +#define DEG_3 31 |
| 41 | +#define SEP_3 3 |
| 42 | + |
| 43 | +/* x**63 + x + 1. */ |
| 44 | +#define TYPE_4 4 |
| 45 | +#define BREAK_4 256 |
| 46 | +#define DEG_4 63 |
| 47 | +#define SEP_4 1 |
| 48 | + |
| 49 | +/* Array versions of the above information to make code run faster. |
| 50 | + Relies on fact that TYPE_i == i. */ |
| 51 | + |
| 52 | +#define MAX_TYPES 5 /* Max number of types above. */ |
| 53 | + |
| 54 | +#define __set_errno(val) (errno = (val)) |
| 55 | + |
| 56 | +struct random_data |
| 57 | + { |
| 58 | + int32_t *fptr; /* Front pointer. */ |
| 59 | + int32_t *rptr; /* Rear pointer. */ |
| 60 | + int32_t *state; /* Array of state values. */ |
| 61 | + int rand_type; /* Type of random number generator. */ |
| 62 | + int rand_deg; /* Degree of random number generator. */ |
| 63 | + int rand_sep; /* Distance between front and rear. */ |
| 64 | + int32_t *end_ptr; /* Pointer behind state table. */ |
| 65 | + }; |
| 66 | + |
| 67 | +struct random_poly_info |
| 68 | +{ |
| 69 | + int seps[MAX_TYPES]; |
| 70 | + int degrees[MAX_TYPES]; |
| 71 | +}; |
| 72 | + |
| 73 | +static const struct random_poly_info random_poly_info = |
| 74 | +{ |
| 75 | + { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 }, |
| 76 | + { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 } |
| 77 | +}; |
| 78 | + |
| 79 | +/* If we are using the trivial TYPE_0 R.N.G., just do the old linear |
| 80 | + congruential bit. Otherwise, we do our fancy trinomial stuff, which is the |
| 81 | + same in all the other cases due to all the global variables that have been |
| 82 | + set up. The basic operation is to add the number at the rear pointer into |
| 83 | + the one at the front pointer. Then both pointers are advanced to the next |
| 84 | + location cyclically in the table. The value returned is the sum generated, |
| 85 | + reduced to 31 bits by throwing away the "least random" low bit. |
| 86 | + Note: The code takes advantage of the fact that both the front and |
| 87 | + rear pointers can't wrap on the same call by not testing the rear |
| 88 | + pointer if the front one has wrapped. Returns a 31-bit random number. */ |
| 89 | + |
| 90 | +int random_r (struct random_data *buf, int32_t *result) |
| 91 | +{ |
| 92 | + int32_t *state; |
| 93 | + |
| 94 | + if (buf == NULL || result == NULL) |
| 95 | + goto fail; |
| 96 | + |
| 97 | + state = buf->state; |
| 98 | + |
| 99 | + if (buf->rand_type == TYPE_0) |
| 100 | + { |
| 101 | + int32_t val = ((state[0] * 1103515245U) + 12345U) & 0x7fffffff; |
| 102 | + state[0] = val; |
| 103 | + *result = val; |
| 104 | + } |
| 105 | + else |
| 106 | + { |
| 107 | + int32_t *fptr = buf->fptr; |
| 108 | + int32_t *rptr = buf->rptr; |
| 109 | + int32_t *end_ptr = buf->end_ptr; |
| 110 | + uint32_t val; |
| 111 | + |
| 112 | + val = *fptr += (uint32_t) *rptr; |
| 113 | + /* Chucking least random bit. */ |
| 114 | + *result = val >> 1; |
| 115 | + ++fptr; |
| 116 | + if (fptr >= end_ptr) |
| 117 | + { |
| 118 | + fptr = state; |
| 119 | + ++rptr; |
| 120 | + } |
| 121 | + else |
| 122 | + { |
| 123 | + ++rptr; |
| 124 | + if (rptr >= end_ptr) |
| 125 | + rptr = state; |
| 126 | + } |
| 127 | + buf->fptr = fptr; |
| 128 | + buf->rptr = rptr; |
| 129 | + } |
| 130 | + return 0; |
| 131 | + |
| 132 | + fail: |
| 133 | + __set_errno (EINVAL); |
| 134 | + return -1; |
| 135 | +} |
| 136 | + |
| 137 | +/* Initialize the random number generator based on the given seed. If the |
| 138 | + type is the trivial no-state-information type, just remember the seed. |
| 139 | + Otherwise, initializes state[] based on the given "seed" via a linear |
| 140 | + congruential generator. Then, the pointers are set to known locations |
| 141 | + that are exactly rand_sep places apart. Lastly, it cycles the state |
| 142 | + information a given number of times to get rid of any initial dependencies |
| 143 | + introduced by the L.C.R.N.G. Note that the initialization of randtbl[] |
| 144 | + for default usage relies on values produced by this routine. */ |
| 145 | +int srandom_r (unsigned int seed, struct random_data *buf) |
| 146 | +{ |
| 147 | + int type; |
| 148 | + int32_t *state; |
| 149 | + long int i; |
| 150 | + int32_t word; |
| 151 | + int32_t *dst; |
| 152 | + int kc; |
| 153 | + |
| 154 | + if (buf == NULL) |
| 155 | + goto fail; |
| 156 | + type = buf->rand_type; |
| 157 | + if ((unsigned int) type >= MAX_TYPES) |
| 158 | + goto fail; |
| 159 | + |
| 160 | + state = buf->state; |
| 161 | + /* We must make sure the seed is not 0. Take arbitrarily 1 in this case. */ |
| 162 | + if (seed == 0) |
| 163 | + seed = 1; |
| 164 | + state[0] = seed; |
| 165 | + if (type == TYPE_0) |
| 166 | + goto done; |
| 167 | + |
| 168 | + dst = state; |
| 169 | + word = seed; |
| 170 | + kc = buf->rand_deg; |
| 171 | + for (i = 1; i < kc; ++i) |
| 172 | + { |
| 173 | + /* This does: |
| 174 | + state[i] = (16807 * state[i - 1]) % 2147483647; |
| 175 | + but avoids overflowing 31 bits. */ |
| 176 | + long int hi = word / 127773; |
| 177 | + long int lo = word % 127773; |
| 178 | + word = 16807 * lo - 2836 * hi; |
| 179 | + if (word < 0) |
| 180 | + word += 2147483647; |
| 181 | + *++dst = word; |
| 182 | + } |
| 183 | + |
| 184 | + buf->fptr = &state[buf->rand_sep]; |
| 185 | + buf->rptr = &state[0]; |
| 186 | + kc *= 10; |
| 187 | + while (--kc >= 0) |
| 188 | + { |
| 189 | + int32_t discard; |
| 190 | + (void) random_r (buf, &discard); |
| 191 | + } |
| 192 | + |
| 193 | + done: |
| 194 | + return 0; |
| 195 | + |
| 196 | + fail: |
| 197 | + return -1; |
| 198 | +} |
| 199 | + |
| 200 | +/* Initialize the state information in the given array of N bytes for |
| 201 | + future random number generation. Based on the number of bytes we |
| 202 | + are given, and the break values for the different R.N.G.'s, we choose |
| 203 | + the best (largest) one we can and set things up for it. srandom is |
| 204 | + then called to initialize the state information. Note that on return |
| 205 | + from srandom, we set state[-1] to be the type multiplexed with the current |
| 206 | + value of the rear pointer; this is so successive calls to initstate won't |
| 207 | + lose this information and will be able to restart with setstate. |
| 208 | + Note: The first thing we do is save the current state, if any, just like |
| 209 | + setstate so that it doesn't matter when initstate is called. |
| 210 | + Returns 0 on success, non-zero on failure. */ |
| 211 | +int initstate_r (unsigned int seed, char *arg_state, size_t n, |
| 212 | + struct random_data *buf) |
| 213 | +{ |
| 214 | + if (buf == NULL) |
| 215 | + goto fail; |
| 216 | + |
| 217 | + int32_t *old_state = buf->state; |
| 218 | + if (old_state != NULL) |
| 219 | + { |
| 220 | + int old_type = buf->rand_type; |
| 221 | + if (old_type == TYPE_0) |
| 222 | + old_state[-1] = TYPE_0; |
| 223 | + else |
| 224 | + old_state[-1] = (MAX_TYPES * (buf->rptr - old_state)) + old_type; |
| 225 | + } |
| 226 | + |
| 227 | + int type; |
| 228 | + if (n >= BREAK_3) |
| 229 | + type = n < BREAK_4 ? TYPE_3 : TYPE_4; |
| 230 | + else if (n < BREAK_1) |
| 231 | + { |
| 232 | + if (n < BREAK_0) |
| 233 | + goto fail; |
| 234 | + |
| 235 | + type = TYPE_0; |
| 236 | + } |
| 237 | + else |
| 238 | + type = n < BREAK_2 ? TYPE_1 : TYPE_2; |
| 239 | + |
| 240 | + int degree = random_poly_info.degrees[type]; |
| 241 | + int separation = random_poly_info.seps[type]; |
| 242 | + |
| 243 | + buf->rand_type = type; |
| 244 | + buf->rand_sep = separation; |
| 245 | + buf->rand_deg = degree; |
| 246 | + int32_t *state = &((int32_t *) arg_state)[1]; /* First location. */ |
| 247 | + /* Must set END_PTR before srandom. */ |
| 248 | + buf->end_ptr = &state[degree]; |
| 249 | + |
| 250 | + buf->state = state; |
| 251 | + |
| 252 | + srandom_r (seed, buf); |
| 253 | + |
| 254 | + state[-1] = TYPE_0; |
| 255 | + if (type != TYPE_0) |
| 256 | + state[-1] = (buf->rptr - state) * MAX_TYPES + type; |
| 257 | + |
| 258 | + return 0; |
| 259 | + |
| 260 | + fail: |
| 261 | + __set_errno (EINVAL); |
| 262 | + return -1; |
| 263 | +} |
| 264 | + |
| 265 | +/* Restore the state from the given state array. |
| 266 | + Note: It is important that we also remember the locations of the pointers |
| 267 | + in the current state information, and restore the locations of the pointers |
| 268 | + from the old state information. This is done by multiplexing the pointer |
| 269 | + location into the zeroth word of the state information. Note that due |
| 270 | + to the order in which things are done, it is OK to call setstate with the |
| 271 | + same state as the current state |
| 272 | + Returns 0 on success, non-zero on failure. */ |
| 273 | +int setstate_r (char *arg_state, struct random_data *buf) |
| 274 | +{ |
| 275 | + int32_t *new_state = 1 + (int32_t *) arg_state; |
| 276 | + int type; |
| 277 | + int old_type; |
| 278 | + int32_t *old_state; |
| 279 | + int degree; |
| 280 | + int separation; |
| 281 | + |
| 282 | + if (arg_state == NULL || buf == NULL) |
| 283 | + goto fail; |
| 284 | + |
| 285 | + old_type = buf->rand_type; |
| 286 | + old_state = buf->state; |
| 287 | + if (old_type == TYPE_0) |
| 288 | + old_state[-1] = TYPE_0; |
| 289 | + else |
| 290 | + old_state[-1] = (MAX_TYPES * (buf->rptr - old_state)) + old_type; |
| 291 | + |
| 292 | + type = new_state[-1] % MAX_TYPES; |
| 293 | + if (type < TYPE_0 || type > TYPE_4) |
| 294 | + goto fail; |
| 295 | + |
| 296 | + buf->rand_deg = degree = random_poly_info.degrees[type]; |
| 297 | + buf->rand_sep = separation = random_poly_info.seps[type]; |
| 298 | + buf->rand_type = type; |
| 299 | + |
| 300 | + if (type != TYPE_0) |
| 301 | + { |
| 302 | + int rear = new_state[-1] / MAX_TYPES; |
| 303 | + buf->rptr = &new_state[rear]; |
| 304 | + buf->fptr = &new_state[(rear + separation) % degree]; |
| 305 | + } |
| 306 | + buf->state = new_state; |
| 307 | + /* Set end_ptr too. */ |
| 308 | + buf->end_ptr = &new_state[degree]; |
| 309 | + |
| 310 | + return 0; |
| 311 | + |
| 312 | + fail: |
| 313 | + __set_errno (EINVAL); |
| 314 | + return -1; |
| 315 | +} |
| 316 | + |
| 317 | static unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; |
| 318 | |
| 319 | #define BOUNCE_RANDOM (1<<0) |
| 320 | -- |
| 321 | 2.11.0 |
| 322 | |