tools/testing/selftests/rseq/rseq-arm.h

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This source file includes following definitions.
rseq_cmpeqv_storev
rseq_cmpnev_storeoffp_load
rseq_addv
rseq_cmpeqv_trystorev_storev
rseq_cmpeqv_trystorev_storev_release
rseq_cmpeqv_cmpeqv_storev
rseq_cmpeqv_trymemcpy_storev
rseq_cmpeqv_trymemcpy_storev_release
   1 /* SPDX-License-Identifier: LGPL-2.1 OR MIT */
   2 /*
   3  * rseq-arm.h
   4  *
   5  * (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  */
   7 
   8 /*
   9  * - ARM little endian
  10  *
  11  * RSEQ_SIG uses the udf A32 instruction with an uncommon immediate operand
  12  * value 0x5de3. This traps if user-space reaches this instruction by mistake,
  13  * and the uncommon operand ensures the kernel does not move the instruction
  14  * pointer to attacker-controlled code on rseq abort.
  15  *
  16  * The instruction pattern in the A32 instruction set is:
  17  *
  18  * e7f5def3    udf    #24035    ; 0x5de3
  19  *
  20  * This translates to the following instruction pattern in the T16 instruction
  21  * set:
  22  *
  23  * little endian:
  24  * def3        udf    #243      ; 0xf3
  25  * e7f5        b.n    <7f5>
  26  *
  27  * - ARMv6+ big endian (BE8):
  28  *
  29  * ARMv6+ -mbig-endian generates mixed endianness code vs data: little-endian
  30  * code and big-endian data. The data value of the signature needs to have its
  31  * byte order reversed to generate the trap instruction:
  32  *
  33  * Data: 0xf3def5e7
  34  *
  35  * Translates to this A32 instruction pattern:
  36  *
  37  * e7f5def3    udf    #24035    ; 0x5de3
  38  *
  39  * Translates to this T16 instruction pattern:
  40  *
  41  * def3        udf    #243      ; 0xf3
  42  * e7f5        b.n    <7f5>
  43  *
  44  * - Prior to ARMv6 big endian (BE32):
  45  *
  46  * Prior to ARMv6, -mbig-endian generates big-endian code and data
  47  * (which match), so the endianness of the data representation of the
  48  * signature should not be reversed. However, the choice between BE32
  49  * and BE8 is done by the linker, so we cannot know whether code and
  50  * data endianness will be mixed before the linker is invoked. So rather
  51  * than try to play tricks with the linker, the rseq signature is simply
  52  * data (not a trap instruction) prior to ARMv6 on big endian. This is
  53  * why the signature is expressed as data (.word) rather than as
  54  * instruction (.inst) in assembler.
  55  */
  56 
  57 #ifdef __ARMEB__
  58 #define RSEQ_SIG    0xf3def5e7      /* udf    #24035    ; 0x5de3 (ARMv6+) */
  59 #else
  60 #define RSEQ_SIG    0xe7f5def3      /* udf    #24035    ; 0x5de3 */
  61 #endif
  62 
  63 #define rseq_smp_mb()   __asm__ __volatile__ ("dmb" ::: "memory", "cc")
  64 #define rseq_smp_rmb()  __asm__ __volatile__ ("dmb" ::: "memory", "cc")
  65 #define rseq_smp_wmb()  __asm__ __volatile__ ("dmb" ::: "memory", "cc")
  66 
  67 #define rseq_smp_load_acquire(p)                                        \
  68 __extension__ ({                                                        \
  69         __typeof(*p) ____p1 = RSEQ_READ_ONCE(*p);                       \
  70         rseq_smp_mb();                                                  \
  71         ____p1;                                                         \
  72 })
  73 
  74 #define rseq_smp_acquire__after_ctrl_dep()      rseq_smp_rmb()
  75 
  76 #define rseq_smp_store_release(p, v)                                    \
  77 do {                                                                    \
  78         rseq_smp_mb();                                                  \
  79         RSEQ_WRITE_ONCE(*p, v);                                         \
  80 } while (0)
  81 
  82 #ifdef RSEQ_SKIP_FASTPATH
  83 #include "rseq-skip.h"
  84 #else /* !RSEQ_SKIP_FASTPATH */
  85 
  86 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip,        \
  87                                 post_commit_offset, abort_ip)           \
  88                 ".pushsection __rseq_cs, \"aw\"\n\t"                    \
  89                 ".balign 32\n\t"                                        \
  90                 __rseq_str(label) ":\n\t"                                       \
  91                 ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
  92                 ".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
  93                 ".popsection\n\t"                                       \
  94                 ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t"          \
  95                 ".word " __rseq_str(label) "b, 0x0\n\t"                 \
  96                 ".popsection\n\t"
  97 
  98 #define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
  99         __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip,              \
 100                                 (post_commit_ip - start_ip), abort_ip)
 101 
 102 /*
 103  * Exit points of a rseq critical section consist of all instructions outside
 104  * of the critical section where a critical section can either branch to or
 105  * reach through the normal course of its execution. The abort IP and the
 106  * post-commit IP are already part of the __rseq_cs section and should not be
 107  * explicitly defined as additional exit points. Knowing all exit points is
 108  * useful to assist debuggers stepping over the critical section.
 109  */
 110 #define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip)                   \
 111                 ".pushsection __rseq_exit_point_array, \"aw\"\n\t"      \
 112                 ".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(exit_ip) ", 0x0\n\t" \
 113                 ".popsection\n\t"
 114 
 115 #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs)                \
 116                 RSEQ_INJECT_ASM(1)                                      \
 117                 "adr r0, " __rseq_str(cs_label) "\n\t"                  \
 118                 "str r0, %[" __rseq_str(rseq_cs) "]\n\t"                \
 119                 __rseq_str(label) ":\n\t"
 120 
 121 #define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label)              \
 122                 RSEQ_INJECT_ASM(2)                                      \
 123                 "ldr r0, %[" __rseq_str(current_cpu_id) "]\n\t" \
 124                 "cmp %[" __rseq_str(cpu_id) "], r0\n\t"         \
 125                 "bne " __rseq_str(label) "\n\t"
 126 
 127 #define __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown,           \
 128                                 abort_label, version, flags,            \
 129                                 start_ip, post_commit_offset, abort_ip) \
 130                 ".balign 32\n\t"                                        \
 131                 __rseq_str(table_label) ":\n\t"                         \
 132                 ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
 133                 ".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
 134                 ".word " __rseq_str(RSEQ_SIG) "\n\t"                    \
 135                 __rseq_str(label) ":\n\t"                               \
 136                 teardown                                                \
 137                 "b %l[" __rseq_str(abort_label) "]\n\t"
 138 
 139 #define RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, abort_label, \
 140                               start_ip, post_commit_ip, abort_ip)       \
 141         __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown,           \
 142                                 abort_label, 0x0, 0x0, start_ip,        \
 143                                 (post_commit_ip - start_ip), abort_ip)
 144 
 145 #define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label)         \
 146                 __rseq_str(label) ":\n\t"                               \
 147                 teardown                                                \
 148                 "b %l[" __rseq_str(cmpfail_label) "]\n\t"
 149 
 150 #define rseq_workaround_gcc_asm_size_guess()    __asm__ __volatile__("")
 151 
 152 static inline __attribute__((always_inline))
 153 int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 154 {
 155         RSEQ_INJECT_C(9)
 156 
 157         rseq_workaround_gcc_asm_size_guess();
 158         __asm__ __volatile__ goto (
 159                 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 160                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
 161 #ifdef RSEQ_COMPARE_TWICE
 162                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 163                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 164 #endif
 165                 /* Start rseq by storing table entry pointer into rseq_cs. */
 166                 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
 167                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
 168                 RSEQ_INJECT_ASM(3)
 169                 "ldr r0, %[v]\n\t"
 170                 "cmp %[expect], r0\n\t"
 171                 "bne %l[cmpfail]\n\t"
 172                 RSEQ_INJECT_ASM(4)
 173 #ifdef RSEQ_COMPARE_TWICE
 174                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
 175                 "ldr r0, %[v]\n\t"
 176                 "cmp %[expect], r0\n\t"
 177                 "bne %l[error2]\n\t"
 178 #endif
 179                 /* final store */
 180                 "str %[newv], %[v]\n\t"
 181                 "2:\n\t"
 182                 RSEQ_INJECT_ASM(5)
 183                 "b 5f\n\t"
 184                 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
 185                 "5:\n\t"
 186                 : /* gcc asm goto does not allow outputs */
 187                 : [cpu_id]              "r" (cpu),
 188                   [current_cpu_id]      "m" (__rseq_abi.cpu_id),
 189                   [rseq_cs]             "m" (__rseq_abi.rseq_cs),
 190                   [v]                   "m" (*v),
 191                   [expect]              "r" (expect),
 192                   [newv]                "r" (newv)
 193                   RSEQ_INJECT_INPUT
 194                 : "r0", "memory", "cc"
 195                   RSEQ_INJECT_CLOBBER
 196                 : abort, cmpfail
 197 #ifdef RSEQ_COMPARE_TWICE
 198                   , error1, error2
 199 #endif
 200         );
 201         rseq_workaround_gcc_asm_size_guess();
 202         return 0;
 203 abort:
 204         rseq_workaround_gcc_asm_size_guess();
 205         RSEQ_INJECT_FAILED
 206         return -1;
 207 cmpfail:
 208         rseq_workaround_gcc_asm_size_guess();
 209         return 1;
 210 #ifdef RSEQ_COMPARE_TWICE
 211 error1:
 212         rseq_bug("cpu_id comparison failed");
 213 error2:
 214         rseq_bug("expected value comparison failed");
 215 #endif
 216 }
 217 
 218 static inline __attribute__((always_inline))
 219 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 220                                off_t voffp, intptr_t *load, int cpu)
 221 {
 222         RSEQ_INJECT_C(9)
 223 
 224         rseq_workaround_gcc_asm_size_guess();
 225         __asm__ __volatile__ goto (
 226                 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 227                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
 228 #ifdef RSEQ_COMPARE_TWICE
 229                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 230                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 231 #endif
 232                 /* Start rseq by storing table entry pointer into rseq_cs. */
 233                 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
 234                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
 235                 RSEQ_INJECT_ASM(3)
 236                 "ldr r0, %[v]\n\t"
 237                 "cmp %[expectnot], r0\n\t"
 238                 "beq %l[cmpfail]\n\t"
 239                 RSEQ_INJECT_ASM(4)
 240 #ifdef RSEQ_COMPARE_TWICE
 241                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
 242                 "ldr r0, %[v]\n\t"
 243                 "cmp %[expectnot], r0\n\t"
 244                 "beq %l[error2]\n\t"
 245 #endif
 246                 "str r0, %[load]\n\t"
 247                 "add r0, %[voffp]\n\t"
 248                 "ldr r0, [r0]\n\t"
 249                 /* final store */
 250                 "str r0, %[v]\n\t"
 251                 "2:\n\t"
 252                 RSEQ_INJECT_ASM(5)
 253                 "b 5f\n\t"
 254                 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
 255                 "5:\n\t"
 256                 : /* gcc asm goto does not allow outputs */
 257                 : [cpu_id]              "r" (cpu),
 258                   [current_cpu_id]      "m" (__rseq_abi.cpu_id),
 259                   [rseq_cs]             "m" (__rseq_abi.rseq_cs),
 260                   /* final store input */
 261                   [v]                   "m" (*v),
 262                   [expectnot]           "r" (expectnot),
 263                   [voffp]               "Ir" (voffp),
 264                   [load]                "m" (*load)
 265                   RSEQ_INJECT_INPUT
 266                 : "r0", "memory", "cc"
 267                   RSEQ_INJECT_CLOBBER
 268                 : abort, cmpfail
 269 #ifdef RSEQ_COMPARE_TWICE
 270                   , error1, error2
 271 #endif
 272         );
 273         rseq_workaround_gcc_asm_size_guess();
 274         return 0;
 275 abort:
 276         rseq_workaround_gcc_asm_size_guess();
 277         RSEQ_INJECT_FAILED
 278         return -1;
 279 cmpfail:
 280         rseq_workaround_gcc_asm_size_guess();
 281         return 1;
 282 #ifdef RSEQ_COMPARE_TWICE
 283 error1:
 284         rseq_bug("cpu_id comparison failed");
 285 error2:
 286         rseq_bug("expected value comparison failed");
 287 #endif
 288 }
 289 
 290 static inline __attribute__((always_inline))
 291 int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 292 {
 293         RSEQ_INJECT_C(9)
 294 
 295         rseq_workaround_gcc_asm_size_guess();
 296         __asm__ __volatile__ goto (
 297                 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 298 #ifdef RSEQ_COMPARE_TWICE
 299                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 300 #endif
 301                 /* Start rseq by storing table entry pointer into rseq_cs. */
 302                 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
 303                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
 304                 RSEQ_INJECT_ASM(3)
 305 #ifdef RSEQ_COMPARE_TWICE
 306                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
 307 #endif
 308                 "ldr r0, %[v]\n\t"
 309                 "add r0, %[count]\n\t"
 310                 /* final store */
 311                 "str r0, %[v]\n\t"
 312                 "2:\n\t"
 313                 RSEQ_INJECT_ASM(4)
 314                 "b 5f\n\t"
 315                 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
 316                 "5:\n\t"
 317                 : /* gcc asm goto does not allow outputs */
 318                 : [cpu_id]              "r" (cpu),
 319                   [current_cpu_id]      "m" (__rseq_abi.cpu_id),
 320                   [rseq_cs]             "m" (__rseq_abi.rseq_cs),
 321                   [v]                   "m" (*v),
 322                   [count]               "Ir" (count)
 323                   RSEQ_INJECT_INPUT
 324                 : "r0", "memory", "cc"
 325                   RSEQ_INJECT_CLOBBER
 326                 : abort
 327 #ifdef RSEQ_COMPARE_TWICE
 328                   , error1
 329 #endif
 330         );
 331         rseq_workaround_gcc_asm_size_guess();
 332         return 0;
 333 abort:
 334         rseq_workaround_gcc_asm_size_guess();
 335         RSEQ_INJECT_FAILED
 336         return -1;
 337 #ifdef RSEQ_COMPARE_TWICE
 338 error1:
 339         rseq_bug("cpu_id comparison failed");
 340 #endif
 341 }
 342 
 343 static inline __attribute__((always_inline))
 344 int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 345                                  intptr_t *v2, intptr_t newv2,
 346                                  intptr_t newv, int cpu)
 347 {
 348         RSEQ_INJECT_C(9)
 349 
 350         rseq_workaround_gcc_asm_size_guess();
 351         __asm__ __volatile__ goto (
 352                 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 353                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
 354 #ifdef RSEQ_COMPARE_TWICE
 355                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 356                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 357 #endif
 358                 /* Start rseq by storing table entry pointer into rseq_cs. */
 359                 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
 360                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
 361                 RSEQ_INJECT_ASM(3)
 362                 "ldr r0, %[v]\n\t"
 363                 "cmp %[expect], r0\n\t"
 364                 "bne %l[cmpfail]\n\t"
 365                 RSEQ_INJECT_ASM(4)
 366 #ifdef RSEQ_COMPARE_TWICE
 367                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
 368                 "ldr r0, %[v]\n\t"
 369                 "cmp %[expect], r0\n\t"
 370                 "bne %l[error2]\n\t"
 371 #endif
 372                 /* try store */
 373                 "str %[newv2], %[v2]\n\t"
 374                 RSEQ_INJECT_ASM(5)
 375                 /* final store */
 376                 "str %[newv], %[v]\n\t"
 377                 "2:\n\t"
 378                 RSEQ_INJECT_ASM(6)
 379                 "b 5f\n\t"
 380                 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
 381                 "5:\n\t"
 382                 : /* gcc asm goto does not allow outputs */
 383                 : [cpu_id]              "r" (cpu),
 384                   [current_cpu_id]      "m" (__rseq_abi.cpu_id),
 385                   [rseq_cs]             "m" (__rseq_abi.rseq_cs),
 386                   /* try store input */
 387                   [v2]                  "m" (*v2),
 388                   [newv2]               "r" (newv2),
 389                   /* final store input */
 390                   [v]                   "m" (*v),
 391                   [expect]              "r" (expect),
 392                   [newv]                "r" (newv)
 393                   RSEQ_INJECT_INPUT
 394                 : "r0", "memory", "cc"
 395                   RSEQ_INJECT_CLOBBER
 396                 : abort, cmpfail
 397 #ifdef RSEQ_COMPARE_TWICE
 398                   , error1, error2
 399 #endif
 400         );
 401         rseq_workaround_gcc_asm_size_guess();
 402         return 0;
 403 abort:
 404         rseq_workaround_gcc_asm_size_guess();
 405         RSEQ_INJECT_FAILED
 406         return -1;
 407 cmpfail:
 408         rseq_workaround_gcc_asm_size_guess();
 409         return 1;
 410 #ifdef RSEQ_COMPARE_TWICE
 411 error1:
 412         rseq_bug("cpu_id comparison failed");
 413 error2:
 414         rseq_bug("expected value comparison failed");
 415 #endif
 416 }
 417 
 418 static inline __attribute__((always_inline))
 419 int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 420                                          intptr_t *v2, intptr_t newv2,
 421                                          intptr_t newv, int cpu)
 422 {
 423         RSEQ_INJECT_C(9)
 424 
 425         rseq_workaround_gcc_asm_size_guess();
 426         __asm__ __volatile__ goto (
 427                 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 428                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
 429 #ifdef RSEQ_COMPARE_TWICE
 430                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 431                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 432 #endif
 433                 /* Start rseq by storing table entry pointer into rseq_cs. */
 434                 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
 435                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
 436                 RSEQ_INJECT_ASM(3)
 437                 "ldr r0, %[v]\n\t"
 438                 "cmp %[expect], r0\n\t"
 439                 "bne %l[cmpfail]\n\t"
 440                 RSEQ_INJECT_ASM(4)
 441 #ifdef RSEQ_COMPARE_TWICE
 442                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
 443                 "ldr r0, %[v]\n\t"
 444                 "cmp %[expect], r0\n\t"
 445                 "bne %l[error2]\n\t"
 446 #endif
 447                 /* try store */
 448                 "str %[newv2], %[v2]\n\t"
 449                 RSEQ_INJECT_ASM(5)
 450                 "dmb\n\t"       /* full mb provides store-release */
 451                 /* final store */
 452                 "str %[newv], %[v]\n\t"
 453                 "2:\n\t"
 454                 RSEQ_INJECT_ASM(6)
 455                 "b 5f\n\t"
 456                 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
 457                 "5:\n\t"
 458                 : /* gcc asm goto does not allow outputs */
 459                 : [cpu_id]              "r" (cpu),
 460                   [current_cpu_id]      "m" (__rseq_abi.cpu_id),
 461                   [rseq_cs]             "m" (__rseq_abi.rseq_cs),
 462                   /* try store input */
 463                   [v2]                  "m" (*v2),
 464                   [newv2]               "r" (newv2),
 465                   /* final store input */
 466                   [v]                   "m" (*v),
 467                   [expect]              "r" (expect),
 468                   [newv]                "r" (newv)
 469                   RSEQ_INJECT_INPUT
 470                 : "r0", "memory", "cc"
 471                   RSEQ_INJECT_CLOBBER
 472                 : abort, cmpfail
 473 #ifdef RSEQ_COMPARE_TWICE
 474                   , error1, error2
 475 #endif
 476         );
 477         rseq_workaround_gcc_asm_size_guess();
 478         return 0;
 479 abort:
 480         rseq_workaround_gcc_asm_size_guess();
 481         RSEQ_INJECT_FAILED
 482         return -1;
 483 cmpfail:
 484         rseq_workaround_gcc_asm_size_guess();
 485         return 1;
 486 #ifdef RSEQ_COMPARE_TWICE
 487 error1:
 488         rseq_bug("cpu_id comparison failed");
 489 error2:
 490         rseq_bug("expected value comparison failed");
 491 #endif
 492 }
 493 
 494 static inline __attribute__((always_inline))
 495 int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 496                               intptr_t *v2, intptr_t expect2,
 497                               intptr_t newv, int cpu)
 498 {
 499         RSEQ_INJECT_C(9)
 500 
 501         rseq_workaround_gcc_asm_size_guess();
 502         __asm__ __volatile__ goto (
 503                 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 504                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
 505 #ifdef RSEQ_COMPARE_TWICE
 506                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 507                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 508                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
 509 #endif
 510                 /* Start rseq by storing table entry pointer into rseq_cs. */
 511                 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
 512                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
 513                 RSEQ_INJECT_ASM(3)
 514                 "ldr r0, %[v]\n\t"
 515                 "cmp %[expect], r0\n\t"
 516                 "bne %l[cmpfail]\n\t"
 517                 RSEQ_INJECT_ASM(4)
 518                 "ldr r0, %[v2]\n\t"
 519                 "cmp %[expect2], r0\n\t"
 520                 "bne %l[cmpfail]\n\t"
 521                 RSEQ_INJECT_ASM(5)
 522 #ifdef RSEQ_COMPARE_TWICE
 523                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
 524                 "ldr r0, %[v]\n\t"
 525                 "cmp %[expect], r0\n\t"
 526                 "bne %l[error2]\n\t"
 527                 "ldr r0, %[v2]\n\t"
 528                 "cmp %[expect2], r0\n\t"
 529                 "bne %l[error3]\n\t"
 530 #endif
 531                 /* final store */
 532                 "str %[newv], %[v]\n\t"
 533                 "2:\n\t"
 534                 RSEQ_INJECT_ASM(6)
 535                 "b 5f\n\t"
 536                 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
 537                 "5:\n\t"
 538                 : /* gcc asm goto does not allow outputs */
 539                 : [cpu_id]              "r" (cpu),
 540                   [current_cpu_id]      "m" (__rseq_abi.cpu_id),
 541                   [rseq_cs]             "m" (__rseq_abi.rseq_cs),
 542                   /* cmp2 input */
 543                   [v2]                  "m" (*v2),
 544                   [expect2]             "r" (expect2),
 545                   /* final store input */
 546                   [v]                   "m" (*v),
 547                   [expect]              "r" (expect),
 548                   [newv]                "r" (newv)
 549                   RSEQ_INJECT_INPUT
 550                 : "r0", "memory", "cc"
 551                   RSEQ_INJECT_CLOBBER
 552                 : abort, cmpfail
 553 #ifdef RSEQ_COMPARE_TWICE
 554                   , error1, error2, error3
 555 #endif
 556         );
 557         rseq_workaround_gcc_asm_size_guess();
 558         return 0;
 559 abort:
 560         rseq_workaround_gcc_asm_size_guess();
 561         RSEQ_INJECT_FAILED
 562         return -1;
 563 cmpfail:
 564         rseq_workaround_gcc_asm_size_guess();
 565         return 1;
 566 #ifdef RSEQ_COMPARE_TWICE
 567 error1:
 568         rseq_bug("cpu_id comparison failed");
 569 error2:
 570         rseq_bug("1st expected value comparison failed");
 571 error3:
 572         rseq_bug("2nd expected value comparison failed");
 573 #endif
 574 }
 575 
 576 static inline __attribute__((always_inline))
 577 int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 578                                  void *dst, void *src, size_t len,
 579                                  intptr_t newv, int cpu)
 580 {
 581         uint32_t rseq_scratch[3];
 582 
 583         RSEQ_INJECT_C(9)
 584 
 585         rseq_workaround_gcc_asm_size_guess();
 586         __asm__ __volatile__ goto (
 587                 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 588                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
 589 #ifdef RSEQ_COMPARE_TWICE
 590                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 591                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 592 #endif
 593                 "str %[src], %[rseq_scratch0]\n\t"
 594                 "str %[dst], %[rseq_scratch1]\n\t"
 595                 "str %[len], %[rseq_scratch2]\n\t"
 596                 /* Start rseq by storing table entry pointer into rseq_cs. */
 597                 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
 598                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
 599                 RSEQ_INJECT_ASM(3)
 600                 "ldr r0, %[v]\n\t"
 601                 "cmp %[expect], r0\n\t"
 602                 "bne 5f\n\t"
 603                 RSEQ_INJECT_ASM(4)
 604 #ifdef RSEQ_COMPARE_TWICE
 605                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
 606                 "ldr r0, %[v]\n\t"
 607                 "cmp %[expect], r0\n\t"
 608                 "bne 7f\n\t"
 609 #endif
 610                 /* try memcpy */
 611                 "cmp %[len], #0\n\t" \
 612                 "beq 333f\n\t" \
 613                 "222:\n\t" \
 614                 "ldrb %%r0, [%[src]]\n\t" \
 615                 "strb %%r0, [%[dst]]\n\t" \
 616                 "adds %[src], #1\n\t" \
 617                 "adds %[dst], #1\n\t" \
 618                 "subs %[len], #1\n\t" \
 619                 "bne 222b\n\t" \
 620                 "333:\n\t" \
 621                 RSEQ_INJECT_ASM(5)
 622                 /* final store */
 623                 "str %[newv], %[v]\n\t"
 624                 "2:\n\t"
 625                 RSEQ_INJECT_ASM(6)
 626                 /* teardown */
 627                 "ldr %[len], %[rseq_scratch2]\n\t"
 628                 "ldr %[dst], %[rseq_scratch1]\n\t"
 629                 "ldr %[src], %[rseq_scratch0]\n\t"
 630                 "b 8f\n\t"
 631                 RSEQ_ASM_DEFINE_ABORT(3, 4,
 632                                       /* teardown */
 633                                       "ldr %[len], %[rseq_scratch2]\n\t"
 634                                       "ldr %[dst], %[rseq_scratch1]\n\t"
 635                                       "ldr %[src], %[rseq_scratch0]\n\t",
 636                                       abort, 1b, 2b, 4f)
 637                 RSEQ_ASM_DEFINE_CMPFAIL(5,
 638                                         /* teardown */
 639                                         "ldr %[len], %[rseq_scratch2]\n\t"
 640                                         "ldr %[dst], %[rseq_scratch1]\n\t"
 641                                         "ldr %[src], %[rseq_scratch0]\n\t",
 642                                         cmpfail)
 643 #ifdef RSEQ_COMPARE_TWICE
 644                 RSEQ_ASM_DEFINE_CMPFAIL(6,
 645                                         /* teardown */
 646                                         "ldr %[len], %[rseq_scratch2]\n\t"
 647                                         "ldr %[dst], %[rseq_scratch1]\n\t"
 648                                         "ldr %[src], %[rseq_scratch0]\n\t",
 649                                         error1)
 650                 RSEQ_ASM_DEFINE_CMPFAIL(7,
 651                                         /* teardown */
 652                                         "ldr %[len], %[rseq_scratch2]\n\t"
 653                                         "ldr %[dst], %[rseq_scratch1]\n\t"
 654                                         "ldr %[src], %[rseq_scratch0]\n\t",
 655                                         error2)
 656 #endif
 657                 "8:\n\t"
 658                 : /* gcc asm goto does not allow outputs */
 659                 : [cpu_id]              "r" (cpu),
 660                   [current_cpu_id]      "m" (__rseq_abi.cpu_id),
 661                   [rseq_cs]             "m" (__rseq_abi.rseq_cs),
 662                   /* final store input */
 663                   [v]                   "m" (*v),
 664                   [expect]              "r" (expect),
 665                   [newv]                "r" (newv),
 666                   /* try memcpy input */
 667                   [dst]                 "r" (dst),
 668                   [src]                 "r" (src),
 669                   [len]                 "r" (len),
 670                   [rseq_scratch0]       "m" (rseq_scratch[0]),
 671                   [rseq_scratch1]       "m" (rseq_scratch[1]),
 672                   [rseq_scratch2]       "m" (rseq_scratch[2])
 673                   RSEQ_INJECT_INPUT
 674                 : "r0", "memory", "cc"
 675                   RSEQ_INJECT_CLOBBER
 676                 : abort, cmpfail
 677 #ifdef RSEQ_COMPARE_TWICE
 678                   , error1, error2
 679 #endif
 680         );
 681         rseq_workaround_gcc_asm_size_guess();
 682         return 0;
 683 abort:
 684         rseq_workaround_gcc_asm_size_guess();
 685         RSEQ_INJECT_FAILED
 686         return -1;
 687 cmpfail:
 688         rseq_workaround_gcc_asm_size_guess();
 689         return 1;
 690 #ifdef RSEQ_COMPARE_TWICE
 691 error1:
 692         rseq_workaround_gcc_asm_size_guess();
 693         rseq_bug("cpu_id comparison failed");
 694 error2:
 695         rseq_workaround_gcc_asm_size_guess();
 696         rseq_bug("expected value comparison failed");
 697 #endif
 698 }
 699 
 700 static inline __attribute__((always_inline))
 701 int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 702                                          void *dst, void *src, size_t len,
 703                                          intptr_t newv, int cpu)
 704 {
 705         uint32_t rseq_scratch[3];
 706 
 707         RSEQ_INJECT_C(9)
 708 
 709         rseq_workaround_gcc_asm_size_guess();
 710         __asm__ __volatile__ goto (
 711                 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 712                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
 713 #ifdef RSEQ_COMPARE_TWICE
 714                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 715                 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 716 #endif
 717                 "str %[src], %[rseq_scratch0]\n\t"
 718                 "str %[dst], %[rseq_scratch1]\n\t"
 719                 "str %[len], %[rseq_scratch2]\n\t"
 720                 /* Start rseq by storing table entry pointer into rseq_cs. */
 721                 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
 722                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
 723                 RSEQ_INJECT_ASM(3)
 724                 "ldr r0, %[v]\n\t"
 725                 "cmp %[expect], r0\n\t"
 726                 "bne 5f\n\t"
 727                 RSEQ_INJECT_ASM(4)
 728 #ifdef RSEQ_COMPARE_TWICE
 729                 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
 730                 "ldr r0, %[v]\n\t"
 731                 "cmp %[expect], r0\n\t"
 732                 "bne 7f\n\t"
 733 #endif
 734                 /* try memcpy */
 735                 "cmp %[len], #0\n\t" \
 736                 "beq 333f\n\t" \
 737                 "222:\n\t" \
 738                 "ldrb %%r0, [%[src]]\n\t" \
 739                 "strb %%r0, [%[dst]]\n\t" \
 740                 "adds %[src], #1\n\t" \
 741                 "adds %[dst], #1\n\t" \
 742                 "subs %[len], #1\n\t" \
 743                 "bne 222b\n\t" \
 744                 "333:\n\t" \
 745                 RSEQ_INJECT_ASM(5)
 746                 "dmb\n\t"       /* full mb provides store-release */
 747                 /* final store */
 748                 "str %[newv], %[v]\n\t"
 749                 "2:\n\t"
 750                 RSEQ_INJECT_ASM(6)
 751                 /* teardown */
 752                 "ldr %[len], %[rseq_scratch2]\n\t"
 753                 "ldr %[dst], %[rseq_scratch1]\n\t"
 754                 "ldr %[src], %[rseq_scratch0]\n\t"
 755                 "b 8f\n\t"
 756                 RSEQ_ASM_DEFINE_ABORT(3, 4,
 757                                       /* teardown */
 758                                       "ldr %[len], %[rseq_scratch2]\n\t"
 759                                       "ldr %[dst], %[rseq_scratch1]\n\t"
 760                                       "ldr %[src], %[rseq_scratch0]\n\t",
 761                                       abort, 1b, 2b, 4f)
 762                 RSEQ_ASM_DEFINE_CMPFAIL(5,
 763                                         /* teardown */
 764                                         "ldr %[len], %[rseq_scratch2]\n\t"
 765                                         "ldr %[dst], %[rseq_scratch1]\n\t"
 766                                         "ldr %[src], %[rseq_scratch0]\n\t",
 767                                         cmpfail)
 768 #ifdef RSEQ_COMPARE_TWICE
 769                 RSEQ_ASM_DEFINE_CMPFAIL(6,
 770                                         /* teardown */
 771                                         "ldr %[len], %[rseq_scratch2]\n\t"
 772                                         "ldr %[dst], %[rseq_scratch1]\n\t"
 773                                         "ldr %[src], %[rseq_scratch0]\n\t",
 774                                         error1)
 775                 RSEQ_ASM_DEFINE_CMPFAIL(7,
 776                                         /* teardown */
 777                                         "ldr %[len], %[rseq_scratch2]\n\t"
 778                                         "ldr %[dst], %[rseq_scratch1]\n\t"
 779                                         "ldr %[src], %[rseq_scratch0]\n\t",
 780                                         error2)
 781 #endif
 782                 "8:\n\t"
 783                 : /* gcc asm goto does not allow outputs */
 784                 : [cpu_id]              "r" (cpu),
 785                   [current_cpu_id]      "m" (__rseq_abi.cpu_id),
 786                   [rseq_cs]             "m" (__rseq_abi.rseq_cs),
 787                   /* final store input */
 788                   [v]                   "m" (*v),
 789                   [expect]              "r" (expect),
 790                   [newv]                "r" (newv),
 791                   /* try memcpy input */
 792                   [dst]                 "r" (dst),
 793                   [src]                 "r" (src),
 794                   [len]                 "r" (len),
 795                   [rseq_scratch0]       "m" (rseq_scratch[0]),
 796                   [rseq_scratch1]       "m" (rseq_scratch[1]),
 797                   [rseq_scratch2]       "m" (rseq_scratch[2])
 798                   RSEQ_INJECT_INPUT
 799                 : "r0", "memory", "cc"
 800                   RSEQ_INJECT_CLOBBER
 801                 : abort, cmpfail
 802 #ifdef RSEQ_COMPARE_TWICE
 803                   , error1, error2
 804 #endif
 805         );
 806         rseq_workaround_gcc_asm_size_guess();
 807         return 0;
 808 abort:
 809         rseq_workaround_gcc_asm_size_guess();
 810         RSEQ_INJECT_FAILED
 811         return -1;
 812 cmpfail:
 813         rseq_workaround_gcc_asm_size_guess();
 814         return 1;
 815 #ifdef RSEQ_COMPARE_TWICE
 816 error1:
 817         rseq_workaround_gcc_asm_size_guess();
 818         rseq_bug("cpu_id comparison failed");
 819 error2:
 820         rseq_workaround_gcc_asm_size_guess();
 821         rseq_bug("expected value comparison failed");
 822 #endif
 823 }
 824 
 825 #endif /* !RSEQ_SKIP_FASTPATH */
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root/tools/testing/selftests/rseq/rseq-arm.h

INCLUDED FROM

DEFINITIONS
