/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ /* * RSEQ_SIG uses the trap4 instruction. As Linux does not make use of the * access-register mode nor the linkage stack this instruction will always * cause a special-operation exception (the trap-enabled bit in the DUCT * is and will stay 0). The instruction pattern is * b2 ff 0f ff trap4 4095(%r0) */ #define RSEQ_SIG 0xB2FF0FFF #define rseq_smp_mb() __asm__ __volatile__ ("bcr 15,0" ::: "memory") #define rseq_smp_rmb() rseq_smp_mb() #define rseq_smp_wmb() rseq_smp_mb() #define rseq_smp_load_acquire(p) \ __extension__ ({ \ __typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \ rseq_barrier(); \ ____p1; \ }) #define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb() #define rseq_smp_store_release(p, v) \ do { \ rseq_barrier(); \ RSEQ_WRITE_ONCE(*p, v); \ } while (0) #ifdef RSEQ_SKIP_FASTPATH #include "rseq-skip.h" #else /* !RSEQ_SKIP_FASTPATH */ #ifdef __s390x__ #define LONG_L "lg" #define LONG_S "stg" #define LONG_LT_R "ltgr" #define LONG_CMP "cg" #define LONG_CMP_R "cgr" #define LONG_ADDI "aghi" #define LONG_ADD_R "agr" #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ start_ip, post_commit_offset, abort_ip) \ ".pushsection __rseq_cs, \"aw\"\n\t" \ ".balign 32\n\t" \ __rseq_str(label) ":\n\t" \ ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ ".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \ ".popsection\n\t" \ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \ ".quad " __rseq_str(label) "b\n\t" \ ".popsection\n\t" /* * Exit points of a rseq critical section consist of all instructions outside * of the critical section where a critical section can either branch to or * reach through the normal course of its execution. The abort IP and the * post-commit IP are already part of the __rseq_cs section and should not be * explicitly defined as additional exit points. Knowing all exit points is * useful to assist debuggers stepping over the critical section. */ #define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \ ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ ".quad " __rseq_str(start_ip) ", " __rseq_str(exit_ip) "\n\t" \ ".popsection\n\t" #elif __s390__ #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ start_ip, post_commit_offset, abort_ip) \ ".pushsection __rseq_cs, \"aw\"\n\t" \ ".balign 32\n\t" \ __rseq_str(label) ":\n\t" \ ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ ".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \ ".popsection\n\t" \ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \ ".long 0x0, " __rseq_str(label) "b\n\t" \ ".popsection\n\t" /* * Exit points of a rseq critical section consist of all instructions outside * of the critical section where a critical section can either branch to or * reach through the normal course of its execution. The abort IP and the * post-commit IP are already part of the __rseq_cs section and should not be * explicitly defined as additional exit points. Knowing all exit points is * useful to assist debuggers stepping over the critical section. */ #define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \ ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ ".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(exit_ip) "\n\t" \ ".popsection\n\t" #define LONG_L "l" #define LONG_S "st" #define LONG_LT_R "ltr" #define LONG_CMP "c" #define LONG_CMP_R "cr" #define LONG_ADDI "ahi" #define LONG_ADD_R "ar" #endif #define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \ (post_commit_ip - start_ip), abort_ip) #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ RSEQ_INJECT_ASM(1) \ "larl %%r0, " __rseq_str(cs_label) "\n\t" \ LONG_S " %%r0, %[" __rseq_str(rseq_cs) "]\n\t" \ __rseq_str(label) ":\n\t" #define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \ RSEQ_INJECT_ASM(2) \ "c %[" __rseq_str(cpu_id) "], %[" __rseq_str(current_cpu_id) "]\n\t" \ "jnz " __rseq_str(label) "\n\t" #define RSEQ_ASM_DEFINE_ABORT(label, teardown, abort_label) \ ".pushsection __rseq_failure, \"ax\"\n\t" \ ".long " __rseq_str(RSEQ_SIG) "\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ "jg %l[" __rseq_str(abort_label) "]\n\t" \ ".popsection\n\t" #define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \ ".pushsection __rseq_failure, \"ax\"\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ "jg %l[" __rseq_str(cmpfail_label) "]\n\t" \ ".popsection\n\t" static inline __attribute__((always_inline)) int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) LONG_CMP " %[expect], %[v]\n\t" "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) LONG_CMP " %[expect], %[v]\n\t" "jnz %l[error2]\n\t" #endif /* final store */ LONG_S " %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(5) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), [current_cpu_id] "m" (__rseq_abi.cpu_id), [rseq_cs] "m" (__rseq_abi.rseq_cs), [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) RSEQ_INJECT_INPUT : "memory", "cc", "r0" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); return 0; abort: RSEQ_INJECT_FAILED return -1; cmpfail: return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("expected value comparison failed"); #endif } /* * Compare @v against @expectnot. When it does _not_ match, load @v * into @load, and store the content of *@v + voffp into @v. */ static inline __attribute__((always_inline)) int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, off_t voffp, intptr_t *load, int cpu) { RSEQ_INJECT_C(9) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) LONG_L " %%r1, %[v]\n\t" LONG_CMP_R " %%r1, %[expectnot]\n\t" "je %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) LONG_L " %%r1, %[v]\n\t" LONG_CMP_R " %%r1, %[expectnot]\n\t" "je %l[error2]\n\t" #endif LONG_S " %%r1, %[load]\n\t" LONG_ADD_R " %%r1, %[voffp]\n\t" LONG_L " %%r1, 0(%%r1)\n\t" /* final store */ LONG_S " %%r1, %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(5) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), [current_cpu_id] "m" (__rseq_abi.cpu_id), [rseq_cs] "m" (__rseq_abi.rseq_cs), /* final store input */ [v] "m" (*v), [expectnot] "r" (expectnot), [voffp] "r" (voffp), [load] "m" (*load) RSEQ_INJECT_INPUT : "memory", "cc", "r0", "r1" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); return 0; abort: RSEQ_INJECT_FAILED return -1; cmpfail: return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("expected value comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_addv(intptr_t *v, intptr_t count, int cpu) { RSEQ_INJECT_C(9) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) #endif LONG_L " %%r0, %[v]\n\t" LONG_ADD_R " %%r0, %[count]\n\t" /* final store */ LONG_S " %%r0, %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(4) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), [current_cpu_id] "m" (__rseq_abi.cpu_id), [rseq_cs] "m" (__rseq_abi.rseq_cs), /* final store input */ [v] "m" (*v), [count] "r" (count) RSEQ_INJECT_INPUT : "memory", "cc", "r0" RSEQ_INJECT_CLOBBER : abort #ifdef RSEQ_COMPARE_TWICE , error1 #endif ); return 0; abort: RSEQ_INJECT_FAILED return -1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, intptr_t *v2, intptr_t newv2, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) LONG_CMP " %[expect], %[v]\n\t" "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) LONG_CMP " %[expect], %[v]\n\t" "jnz %l[error2]\n\t" #endif /* try store */ LONG_S " %[newv2], %[v2]\n\t" RSEQ_INJECT_ASM(5) /* final store */ LONG_S " %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(6) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), [current_cpu_id] "m" (__rseq_abi.cpu_id), [rseq_cs] "m" (__rseq_abi.rseq_cs), /* try store input */ [v2] "m" (*v2), [newv2] "r" (newv2), /* final store input */ [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) RSEQ_INJECT_INPUT : "memory", "cc", "r0" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); return 0; abort: RSEQ_INJECT_FAILED return -1; cmpfail: return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("expected value comparison failed"); #endif } /* s390 is TSO. */ static inline __attribute__((always_inline)) int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, intptr_t *v2, intptr_t newv2, intptr_t newv, int cpu) { return rseq_cmpeqv_trystorev_storev(v, expect, v2, newv2, newv, cpu); } static inline __attribute__((always_inline)) int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t *v2, intptr_t expect2, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) LONG_CMP " %[expect], %[v]\n\t" "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) LONG_CMP " %[expect2], %[v2]\n\t" "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(5) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) LONG_CMP " %[expect], %[v]\n\t" "jnz %l[error2]\n\t" LONG_CMP " %[expect2], %[v2]\n\t" "jnz %l[error3]\n\t" #endif /* final store */ LONG_S " %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(6) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), [current_cpu_id] "m" (__rseq_abi.cpu_id), [rseq_cs] "m" (__rseq_abi.rseq_cs), /* cmp2 input */ [v2] "m" (*v2), [expect2] "r" (expect2), /* final store input */ [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) RSEQ_INJECT_INPUT : "memory", "cc", "r0" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2, error3 #endif ); return 0; abort: RSEQ_INJECT_FAILED return -1; cmpfail: return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("1st expected value comparison failed"); error3: rseq_bug("2nd expected value comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, void *dst, void *src, size_t len, intptr_t newv, int cpu) { uint64_t rseq_scratch[3]; RSEQ_INJECT_C(9) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) #endif LONG_S " %[src], %[rseq_scratch0]\n\t" LONG_S " %[dst], %[rseq_scratch1]\n\t" LONG_S " %[len], %[rseq_scratch2]\n\t" /* Start rseq by storing table entry pointer into rseq_cs. */ RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) LONG_CMP " %[expect], %[v]\n\t" "jnz 5f\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f) LONG_CMP " %[expect], %[v]\n\t" "jnz 7f\n\t" #endif /* try memcpy */ LONG_LT_R " %[len], %[len]\n\t" "jz 333f\n\t" "222:\n\t" "ic %%r0,0(%[src])\n\t" "stc %%r0,0(%[dst])\n\t" LONG_ADDI " %[src], 1\n\t" LONG_ADDI " %[dst], 1\n\t" LONG_ADDI " %[len], -1\n\t" "jnz 222b\n\t" "333:\n\t" RSEQ_INJECT_ASM(5) /* final store */ LONG_S " %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(6) /* teardown */ LONG_L " %[len], %[rseq_scratch2]\n\t" LONG_L " %[dst], %[rseq_scratch1]\n\t" LONG_L " %[src], %[rseq_scratch0]\n\t" RSEQ_ASM_DEFINE_ABORT(4, LONG_L " %[len], %[rseq_scratch2]\n\t" LONG_L " %[dst], %[rseq_scratch1]\n\t" LONG_L " %[src], %[rseq_scratch0]\n\t", abort) RSEQ_ASM_DEFINE_CMPFAIL(5, LONG_L " %[len], %[rseq_scratch2]\n\t" LONG_L " %[dst], %[rseq_scratch1]\n\t" LONG_L " %[src], %[rseq_scratch0]\n\t", cmpfail) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_CMPFAIL(6, LONG_L " %[len], %[rseq_scratch2]\n\t" LONG_L " %[dst], %[rseq_scratch1]\n\t" LONG_L " %[src], %[rseq_scratch0]\n\t", error1) RSEQ_ASM_DEFINE_CMPFAIL(7, LONG_L " %[len], %[rseq_scratch2]\n\t" LONG_L " %[dst], %[rseq_scratch1]\n\t" LONG_L " %[src], %[rseq_scratch0]\n\t", error2) #endif : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), [current_cpu_id] "m" (__rseq_abi.cpu_id), [rseq_cs] "m" (__rseq_abi.rseq_cs), /* final store input */ [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv), /* try memcpy input */ [dst] "r" (dst), [src] "r" (src), [len] "r" (len), [rseq_scratch0] "m" (rseq_scratch[0]), [rseq_scratch1] "m" (rseq_scratch[1]), [rseq_scratch2] "m" (rseq_scratch[2]) RSEQ_INJECT_INPUT : "memory", "cc", "r0" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); return 0; abort: RSEQ_INJECT_FAILED return -1; cmpfail: return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("expected value comparison failed"); #endif } /* s390 is TSO. */ static inline __attribute__((always_inline)) int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, void *dst, void *src, size_t len, intptr_t newv, int cpu) { return rseq_cmpeqv_trymemcpy_storev(v, expect, dst, src, len, newv, cpu); } #endif /* !RSEQ_SKIP_FASTPATH */