This rseq helper library provides a user-space API to the rseq() system call.

The rseq fast-path exposes the instruction pointer addresses where the rseq assembly blocks begin and end, as well as the associated abort instruction pointer, in the __rseq_table section. This section allows debuggers may know where to place breakpoints when single-stepping through assembly blocks which may be aborted at any point by the kernel.

Signed-off-by: Mathieu Desnoyers mathieu.desnoyers@efficios.com CC: Shuah Khan shuahkh@osg.samsung.com CC: Russell King linux@arm.linux.org.uk CC: Catalin Marinas catalin.marinas@arm.com CC: Will Deacon will.deacon@arm.com CC: Thomas Gleixner tglx@linutronix.de CC: Paul Turner pjt@google.com CC: Andrew Hunter ahh@google.com CC: Peter Zijlstra peterz@infradead.org CC: Andy Lutomirski luto@amacapital.net CC: Andi Kleen andi@firstfloor.org CC: Dave Watson davejwatson@fb.com CC: Chris Lameter cl@linux.com CC: Ingo Molnar mingo@redhat.com CC: "H. Peter Anvin" hpa@zytor.com CC: Ben Maurer bmaurer@fb.com CC: Steven Rostedt rostedt@goodmis.org CC: "Paul E. McKenney" paulmck@linux.vnet.ibm.com CC: Josh Triplett josh@joshtriplett.org CC: Linus Torvalds torvalds@linux-foundation.org CC: Andrew Morton akpm@linux-foundation.org CC: Boqun Feng boqun.feng@gmail.com CC: linux-kselftest@vger.kernel.org CC: linux-api@vger.kernel.org --- Changes since v1: - Provide abort-ip signature: The abort-ip signature is located just before the abort-ip target. It is currently hardcoded, but a user-space application could use the __rseq_table to iterate on all abort-ip targets and use a random value as signature if needed in the future. - Add rseq_prepare_unload(): Libraries and JIT code using rseq critical sections need to issue rseq_prepare_unload() on each thread at least once before reclaim of struct rseq_cs. - Use initial-exec TLS model, non-weak symbol: The initial-exec model is signal-safe, whereas the global-dynamic model is not. Remove the "weak" symbol attribute from the __rseq_abi in rseq.c. The rseq.so library will have ownership of that symbol, and there is not reason for an application or user library to try to define that symbol. The expected use is to link against libreq.so, which owns and provide that symbol. - Set cpu_id to -2 on register error - Add rseq_len syscall parameter, rseq_cs version - Ensure disassember-friendly signature: x86 32/64 disassembler have a hard time decoding the instruction stream after a bad instruction. Use a nopl instruction to encode the signature. Suggested by Andy Lutomirski. - Exercise parametrized tests variants in a shell scripts. - Restartable sequences selftests: Remove use of event counter. - Use cpu_id_start field: With the cpu_id_start field, the C preparation phase of the fast-path does not need to compare cpu_id < 0 anymore. - Signal-safe registration and refcounting: Allow libraries using librseq.so to register it from signal handlers. - Use OVERRIDE_TARGETS in makefile. - Use "m" constraints for rseq_cs field.

Changes since v2: - Update based on Thomas Gleixner's comments.

Changes since v3: - Generate param_test_skip_fastpath and param_test_benchmark with -DSKIP_FASTPATH and -DBENCHMARK (respectively). Add param_test_fastpath to run_param_test.sh.

Changes since v4: - Fold arm: workaround gcc asm size guess, - Namespace barrier() -> rseq_barrier() in library header, - Take into account coding style feedback from Peter Zijlstra, - Split rseq selftests into logical commits. --- tools/testing/selftests/rseq/rseq-arm.h | 732 +++++++++++++++++++ tools/testing/selftests/rseq/rseq-ppc.h | 688 ++++++++++++++++++ tools/testing/selftests/rseq/rseq-skip.h | 82 +++ tools/testing/selftests/rseq/rseq-x86.h | 1149 ++++++++++++++++++++++++++++++ tools/testing/selftests/rseq/rseq.c | 116 +++ tools/testing/selftests/rseq/rseq.h | 164 +++++ 6 files changed, 2931 insertions(+) create mode 100644 tools/testing/selftests/rseq/rseq-arm.h create mode 100644 tools/testing/selftests/rseq/rseq-ppc.h create mode 100644 tools/testing/selftests/rseq/rseq-skip.h create mode 100644 tools/testing/selftests/rseq/rseq-x86.h create mode 100644 tools/testing/selftests/rseq/rseq.c create mode 100644 tools/testing/selftests/rseq/rseq.h

diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h new file mode 100644 index 000000000000..adcaa6cbbd01 --- /dev/null +++ b/tools/testing/selftests/rseq/rseq-arm.h @@ -0,0 +1,732 @@ +/* + * rseq-arm.h + * + * (C) Copyright 2016 - Mathieu Desnoyers mathieu.desnoyers@efficios.com + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#define RSEQ_SIG 0x53053053 + +#define rseq_smp_mb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") +#define rseq_smp_rmb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") +#define rseq_smp_wmb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") + +#define rseq_smp_load_acquire(p) \ +__extension__ ({ \ + __typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \ + rseq_smp_mb(); \ + ____p1; \ +}) + +#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb() + +#define rseq_smp_store_release(p, v) \ +do { \ + rseq_smp_mb(); \ + RSEQ_WRITE_ONCE(*p, v); \ +} while (0) + +#ifdef RSEQ_SKIP_FASTPATH +#include "rseq-skip.h" +#else /* !RSEQ_SKIP_FASTPATH */ + +#define __RSEQ_ASM_DEFINE_TABLE(version, flags, start_ip, \ + post_commit_offset, abort_ip) \ + ".pushsection __rseq_table, "aw"\n\t" \ + ".balign 32\n\t" \ + ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ + ".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \ + ".popsection\n\t" + +#define RSEQ_ASM_DEFINE_TABLE(start_ip, post_commit_ip, abort_ip) \ + __RSEQ_ASM_DEFINE_TABLE(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) \ + "adr r0, " __rseq_str(cs_label) "\n\t" \ + "str 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) \ + "ldr r0, %[" __rseq_str(current_cpu_id) "]\n\t" \ + "cmp %[" __rseq_str(cpu_id) "], r0\n\t" \ + "bne " __rseq_str(label) "\n\t" + +#define __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \ + abort_label, version, flags, \ + start_ip, post_commit_offset, abort_ip) \ + __rseq_str(table_label) ":\n\t" \ + ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ + ".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \ + ".word " __rseq_str(RSEQ_SIG) "\n\t" \ + __rseq_str(label) ":\n\t" \ + teardown \ + "b %l[" __rseq_str(abort_label) "]\n\t" + +#define RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, abort_label, \ + start_ip, post_commit_ip, abort_ip) \ + __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \ + abort_label, 0x0, 0x0, start_ip, \ + (post_commit_ip - start_ip), abort_ip) + +#define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \ + __rseq_str(label) ":\n\t" \ + teardown \ + "b %l[" __rseq_str(cmpfail_label) "]\n\t" + +#define rseq_workaround_gcc_asm_size_guess() __asm__ __volatile__("") + +static inline __attribute__((always_inline)) +int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) +{ + RSEQ_INJECT_C(9) + + rseq_workaround_gcc_asm_size_guess(); + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs) + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne %l[cmpfail]\n\t" + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne %l[error2]\n\t" +#endif + /* final store */ + "str %[newv], %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(5) + "b 5f\n\t" + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) + "5:\n\t" + : /* 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 + : "r0", "memory", "cc" + RSEQ_INJECT_CLOBBER + : abort, cmpfail +#ifdef RSEQ_COMPARE_TWICE + , error1, error2 +#endif + ); + rseq_workaround_gcc_asm_size_guess(); + return 0; +abort: + rseq_workaround_gcc_asm_size_guess(); + RSEQ_INJECT_FAILED + return -1; +cmpfail: + rseq_workaround_gcc_asm_size_guess(); + 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_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, + off_t voffp, intptr_t *load, int cpu) +{ + RSEQ_INJECT_C(9) + + rseq_workaround_gcc_asm_size_guess(); + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs) + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + "ldr r0, %[v]\n\t" + "cmp %[expectnot], r0\n\t" + "beq %l[cmpfail]\n\t" + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + "ldr r0, %[v]\n\t" + "cmp %[expectnot], r0\n\t" + "beq %l[error2]\n\t" +#endif + "str r0, %[load]\n\t" + "add r0, %[voffp]\n\t" + "ldr r0, [r0]\n\t" + /* final store */ + "str r0, %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(5) + "b 5f\n\t" + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) + "5:\n\t" + : /* 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] "Ir" (voffp), + [load] "m" (*load) + RSEQ_INJECT_INPUT + : "r0", "memory", "cc" + RSEQ_INJECT_CLOBBER + : abort, cmpfail +#ifdef RSEQ_COMPARE_TWICE + , error1, error2 +#endif + ); + rseq_workaround_gcc_asm_size_guess(); + return 0; +abort: + rseq_workaround_gcc_asm_size_guess(); + RSEQ_INJECT_FAILED + return -1; +cmpfail: + rseq_workaround_gcc_asm_size_guess(); + 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) + + rseq_workaround_gcc_asm_size_guess(); + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, 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 + "ldr r0, %[v]\n\t" + "add r0, %[count]\n\t" + /* final store */ + "str r0, %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(4) + "b 5f\n\t" + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) + "5:\n\t" + : /* 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), + [count] "Ir" (count) + RSEQ_INJECT_INPUT + : "r0", "memory", "cc" + RSEQ_INJECT_CLOBBER + : abort +#ifdef RSEQ_COMPARE_TWICE + , error1 +#endif + ); + rseq_workaround_gcc_asm_size_guess(); + return 0; +abort: + rseq_workaround_gcc_asm_size_guess(); + 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) + + rseq_workaround_gcc_asm_size_guess(); + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs) + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne %l[cmpfail]\n\t" + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne %l[error2]\n\t" +#endif + /* try store */ + "str %[newv2], %[v2]\n\t" + RSEQ_INJECT_ASM(5) + /* final store */ + "str %[newv], %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(6) + "b 5f\n\t" + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) + "5:\n\t" + : /* 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 + : "r0", "memory", "cc" + RSEQ_INJECT_CLOBBER + : abort, cmpfail +#ifdef RSEQ_COMPARE_TWICE + , error1, error2 +#endif + ); + rseq_workaround_gcc_asm_size_guess(); + return 0; +abort: + rseq_workaround_gcc_asm_size_guess(); + RSEQ_INJECT_FAILED + return -1; +cmpfail: + rseq_workaround_gcc_asm_size_guess(); + 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_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, + intptr_t *v2, intptr_t newv2, + intptr_t newv, int cpu) +{ + RSEQ_INJECT_C(9) + + rseq_workaround_gcc_asm_size_guess(); + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs) + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne %l[cmpfail]\n\t" + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne %l[error2]\n\t" +#endif + /* try store */ + "str %[newv2], %[v2]\n\t" + RSEQ_INJECT_ASM(5) + "dmb\n\t" /* full mb provides store-release */ + /* final store */ + "str %[newv], %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(6) + "b 5f\n\t" + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) + "5:\n\t" + : /* 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 + : "r0", "memory", "cc" + RSEQ_INJECT_CLOBBER + : abort, cmpfail +#ifdef RSEQ_COMPARE_TWICE + , error1, error2 +#endif + ); + rseq_workaround_gcc_asm_size_guess(); + return 0; +abort: + rseq_workaround_gcc_asm_size_guess(); + RSEQ_INJECT_FAILED + return -1; +cmpfail: + rseq_workaround_gcc_asm_size_guess(); + 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_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, + intptr_t *v2, intptr_t expect2, + intptr_t newv, int cpu) +{ + RSEQ_INJECT_C(9) + + rseq_workaround_gcc_asm_size_guess(); + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs) + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne %l[cmpfail]\n\t" + RSEQ_INJECT_ASM(4) + "ldr r0, %[v2]\n\t" + "cmp %[expect2], r0\n\t" + "bne %l[cmpfail]\n\t" + RSEQ_INJECT_ASM(5) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne %l[error2]\n\t" + "ldr r0, %[v2]\n\t" + "cmp %[expect2], r0\n\t" + "bne %l[error3]\n\t" +#endif + /* final store */ + "str %[newv], %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(6) + "b 5f\n\t" + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) + "5:\n\t" + : /* 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 + : "r0", "memory", "cc" + RSEQ_INJECT_CLOBBER + : abort, cmpfail +#ifdef RSEQ_COMPARE_TWICE + , error1, error2, error3 +#endif + ); + rseq_workaround_gcc_asm_size_guess(); + return 0; +abort: + rseq_workaround_gcc_asm_size_guess(); + RSEQ_INJECT_FAILED + return -1; +cmpfail: + rseq_workaround_gcc_asm_size_guess(); + 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) +{ + uint32_t rseq_scratch[3]; + + RSEQ_INJECT_C(9) + + rseq_workaround_gcc_asm_size_guess(); + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + "str %[src], %[rseq_scratch0]\n\t" + "str %[dst], %[rseq_scratch1]\n\t" + "str %[len], %[rseq_scratch2]\n\t" + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs) + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne 5f\n\t" + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne 7f\n\t" +#endif + /* try memcpy */ + "cmp %[len], #0\n\t" \ + "beq 333f\n\t" \ + "222:\n\t" \ + "ldrb %%r0, [%[src]]\n\t" \ + "strb %%r0, [%[dst]]\n\t" \ + "adds %[src], #1\n\t" \ + "adds %[dst], #1\n\t" \ + "subs %[len], #1\n\t" \ + "bne 222b\n\t" \ + "333:\n\t" \ + RSEQ_INJECT_ASM(5) + /* final store */ + "str %[newv], %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(6) + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t" + "b 8f\n\t" + RSEQ_ASM_DEFINE_ABORT(3, 4, + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t", + abort, 1b, 2b, 4f) + RSEQ_ASM_DEFINE_CMPFAIL(5, + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t", + cmpfail) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_CMPFAIL(6, + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t", + error1) + RSEQ_ASM_DEFINE_CMPFAIL(7, + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t", + error2) +#endif + "8:\n\t" + : /* 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 + : "r0", "memory", "cc" + RSEQ_INJECT_CLOBBER + : abort, cmpfail +#ifdef RSEQ_COMPARE_TWICE + , error1, error2 +#endif + ); + rseq_workaround_gcc_asm_size_guess(); + return 0; +abort: + rseq_workaround_gcc_asm_size_guess(); + RSEQ_INJECT_FAILED + return -1; +cmpfail: + rseq_workaround_gcc_asm_size_guess(); + return 1; +#ifdef RSEQ_COMPARE_TWICE +error1: + rseq_workaround_gcc_asm_size_guess(); + rseq_bug("cpu_id comparison failed"); +error2: + rseq_workaround_gcc_asm_size_guess(); + rseq_bug("expected value comparison failed"); +#endif +} + +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) +{ + uint32_t rseq_scratch[3]; + + RSEQ_INJECT_C(9) + + rseq_workaround_gcc_asm_size_guess(); + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + "str %[src], %[rseq_scratch0]\n\t" + "str %[dst], %[rseq_scratch1]\n\t" + "str %[len], %[rseq_scratch2]\n\t" + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs) + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne 5f\n\t" + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f) + "ldr r0, %[v]\n\t" + "cmp %[expect], r0\n\t" + "bne 7f\n\t" +#endif + /* try memcpy */ + "cmp %[len], #0\n\t" \ + "beq 333f\n\t" \ + "222:\n\t" \ + "ldrb %%r0, [%[src]]\n\t" \ + "strb %%r0, [%[dst]]\n\t" \ + "adds %[src], #1\n\t" \ + "adds %[dst], #1\n\t" \ + "subs %[len], #1\n\t" \ + "bne 222b\n\t" \ + "333:\n\t" \ + RSEQ_INJECT_ASM(5) + "dmb\n\t" /* full mb provides store-release */ + /* final store */ + "str %[newv], %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(6) + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t" + "b 8f\n\t" + RSEQ_ASM_DEFINE_ABORT(3, 4, + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t", + abort, 1b, 2b, 4f) + RSEQ_ASM_DEFINE_CMPFAIL(5, + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t", + cmpfail) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_CMPFAIL(6, + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t", + error1) + RSEQ_ASM_DEFINE_CMPFAIL(7, + /* teardown */ + "ldr %[len], %[rseq_scratch2]\n\t" + "ldr %[dst], %[rseq_scratch1]\n\t" + "ldr %[src], %[rseq_scratch0]\n\t", + error2) +#endif + "8:\n\t" + : /* 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 + : "r0", "memory", "cc" + RSEQ_INJECT_CLOBBER + : abort, cmpfail +#ifdef RSEQ_COMPARE_TWICE + , error1, error2 +#endif + ); + rseq_workaround_gcc_asm_size_guess(); + return 0; +abort: + rseq_workaround_gcc_asm_size_guess(); + RSEQ_INJECT_FAILED + return -1; +cmpfail: + rseq_workaround_gcc_asm_size_guess(); + return 1; +#ifdef RSEQ_COMPARE_TWICE +error1: + rseq_workaround_gcc_asm_size_guess(); + rseq_bug("cpu_id comparison failed"); +error2: + rseq_workaround_gcc_asm_size_guess(); + rseq_bug("expected value comparison failed"); +#endif +} + +#endif /* !RSEQ_SKIP_FASTPATH */ diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h new file mode 100644 index 000000000000..2d6d2dfa1235 --- /dev/null +++ b/tools/testing/selftests/rseq/rseq-ppc.h @@ -0,0 +1,688 @@ +/* + * rseq-ppc.h + * + * (C) Copyright 2016 - Mathieu Desnoyers mathieu.desnoyers@efficios.com + * (C) Copyright 2016 - Boqun Feng boqun.feng@gmail.com + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#define RSEQ_SIG 0x53053053 + +#define rseq_smp_mb() __asm__ __volatile__ ("sync" ::: "memory", "cc") +#define rseq_smp_lwsync() __asm__ __volatile__ ("lwsync" ::: "memory", "cc") +#define rseq_smp_rmb() rseq_smp_lwsync() +#define rseq_smp_wmb() rseq_smp_lwsync() + +#define rseq_smp_load_acquire(p) \ +__extension__ ({ \ + __typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \ + rseq_smp_lwsync(); \ + ____p1; \ +}) + +#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_lwsync() + +#define rseq_smp_store_release(p, v) \ +do { \ + rseq_smp_lwsync(); \ + RSEQ_WRITE_ONCE(*p, v); \ +} while (0) + +#ifdef RSEQ_SKIP_FASTPATH +#include "rseq-skip.h" +#else /* !RSEQ_SKIP_FASTPATH */ + +/* + * The __rseq_table section can be used by debuggers to better handle + * single-stepping through the restartable critical sections. + */ + +#ifdef __PPC64__ + +#define STORE_WORD "std " +#define LOAD_WORD "ld " +#define LOADX_WORD "ldx " +#define CMP_WORD "cmpd " + +#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ + start_ip, post_commit_offset, abort_ip) \ + ".pushsection __rseq_table, "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" + +#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ + RSEQ_INJECT_ASM(1) \ + "lis %%r17, (" __rseq_str(cs_label) ")@highest\n\t" \ + "ori %%r17, %%r17, (" __rseq_str(cs_label) ")@higher\n\t" \ + "rldicr %%r17, %%r17, 32, 31\n\t" \ + "oris %%r17, %%r17, (" __rseq_str(cs_label) ")@high\n\t" \ + "ori %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t" \ + "std %%r17, %[" __rseq_str(rseq_cs) "]\n\t" \ + __rseq_str(label) ":\n\t" + +#else /* #ifdef __PPC64__ */ + +#define STORE_WORD "stw " +#define LOAD_WORD "lwz " +#define LOADX_WORD "lwzx " +#define CMP_WORD "cmpw " + +#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ + start_ip, post_commit_offset, abort_ip) \ + ".pushsection __rseq_table, "aw"\n\t" \ + ".balign 32\n\t" \ + __rseq_str(label) ":\n\t" \ + ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ + /* 32-bit only supported on BE */ \ + ".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \ + ".popsection\n\t" + +#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ + RSEQ_INJECT_ASM(1) \ + "lis %%r17, (" __rseq_str(cs_label) ")@ha\n\t" \ + "addi %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t" \ + "stw %%r17, %[" __rseq_str(rseq_cs) "]\n\t" \ + __rseq_str(label) ":\n\t" + +#endif /* #ifdef __PPC64__ */ + +#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_CMP_CPU_ID(cpu_id, current_cpu_id, label) \ + RSEQ_INJECT_ASM(2) \ + "lwz %%r17, %[" __rseq_str(current_cpu_id) "]\n\t" \ + "cmpw cr7, %[" __rseq_str(cpu_id) "], %%r17\n\t" \ + "bne- cr7, " __rseq_str(label) "\n\t" + +#define RSEQ_ASM_DEFINE_ABORT(label, abort_label) \ + ".pushsection __rseq_failure, "ax"\n\t" \ + ".long " __rseq_str(RSEQ_SIG) "\n\t" \ + __rseq_str(label) ":\n\t" \ + "b %l[" __rseq_str(abort_label) "]\n\t" \ + ".popsection\n\t" + +/* + * RSEQ_ASM_OPs: asm operations for rseq + * RSEQ_ASM_OP_R_*: has hard-code registers in it + * RSEQ_ASM_OP_* (else): doesn't have hard-code registers(unless cr7) + */ +#define RSEQ_ASM_OP_CMPEQ(var, expect, label) \ + LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \ + CMP_WORD "cr7, %%r17, %[" __rseq_str(expect) "]\n\t" \ + "bne- cr7, " __rseq_str(label) "\n\t" + +#define RSEQ_ASM_OP_CMPNE(var, expectnot, label) \ + LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \ + CMP_WORD "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t" \ + "beq- cr7, " __rseq_str(label) "\n\t" + +#define RSEQ_ASM_OP_STORE(value, var) \ + STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" + +/* Load @var to r17 */ +#define RSEQ_ASM_OP_R_LOAD(var) \ + LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t" + +/* Store r17 to @var */ +#define RSEQ_ASM_OP_R_STORE(var) \ + STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t" + +/* Add @count to r17 */ +#define RSEQ_ASM_OP_R_ADD(count) \ + "add %%r17, %[" __rseq_str(count) "], %%r17\n\t" + +/* Load (r17 + voffp) to r17 */ +#define RSEQ_ASM_OP_R_LOADX(voffp) \ + LOADX_WORD "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t" + +/* TODO: implement a faster memcpy. */ +#define RSEQ_ASM_OP_R_MEMCPY() \ + "cmpdi %%r19, 0\n\t" \ + "beq 333f\n\t" \ + "addi %%r20, %%r20, -1\n\t" \ + "addi %%r21, %%r21, -1\n\t" \ + "222:\n\t" \ + "lbzu %%r18, 1(%%r20)\n\t" \ + "stbu %%r18, 1(%%r21)\n\t" \ + "addi %%r19, %%r19, -1\n\t" \ + "cmpdi %%r19, 0\n\t" \ + "bne 222b\n\t" \ + "333:\n\t" \ + +#define RSEQ_ASM_OP_R_FINAL_STORE(var, post_commit_label) \ + STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \ + __rseq_str(post_commit_label) ":\n\t" + +#define RSEQ_ASM_OP_FINAL_STORE(value, var, post_commit_label) \ + STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \ + __rseq_str(post_commit_label) ":\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 */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail]) + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2]) +#endif + /* final store */ + RSEQ_ASM_OP_FINAL_STORE(newv, v, 2) + 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", "r17" + 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_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 */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + /* cmp @v not equal to @expectnot */ + RSEQ_ASM_OP_CMPNE(v, expectnot, %l[cmpfail]) + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + /* cmp @v not equal to @expectnot */ + RSEQ_ASM_OP_CMPNE(v, expectnot, %l[error2]) +#endif + /* load the value of @v */ + RSEQ_ASM_OP_R_LOAD(v) + /* store it in @load */ + RSEQ_ASM_OP_R_STORE(load) + /* dereference voffp(v) */ + RSEQ_ASM_OP_R_LOADX(voffp) + /* final store the value at voffp(v) */ + RSEQ_ASM_OP_R_FINAL_STORE(v, 2) + 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] "b" (voffp), + [load] "m" (*load) + RSEQ_INJECT_INPUT + : "memory", "cc", "r17" + 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 */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) +#ifdef RSEQ_COMPARE_TWICE + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) +#endif + /* load the value of @v */ + RSEQ_ASM_OP_R_LOAD(v) + /* add @count to it */ + RSEQ_ASM_OP_R_ADD(count) + /* final store */ + RSEQ_ASM_OP_R_FINAL_STORE(v, 2) + 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", "r17" + 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 */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail]) + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2]) +#endif + /* try store */ + RSEQ_ASM_OP_STORE(newv2, v2) + RSEQ_INJECT_ASM(5) + /* final store */ + RSEQ_ASM_OP_FINAL_STORE(newv, v, 2) + 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", "r17" + 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_cmpeqv_trystorev_storev_release(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 */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail]) + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2]) +#endif + /* try store */ + RSEQ_ASM_OP_STORE(newv2, v2) + RSEQ_INJECT_ASM(5) + /* for 'release' */ + "lwsync\n\t" + /* final store */ + RSEQ_ASM_OP_FINAL_STORE(newv, v, 2) + 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", "r17" + 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_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 */ + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail]) + RSEQ_INJECT_ASM(4) + /* cmp @v2 equal to @expct2 */ + RSEQ_ASM_OP_CMPEQ(v2, expect2, %l[cmpfail]) + RSEQ_INJECT_ASM(5) +#ifdef RSEQ_COMPARE_TWICE + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2]) + /* cmp @v2 equal to @expct2 */ + RSEQ_ASM_OP_CMPEQ(v2, expect2, %l[error3]) +#endif + /* final store */ + RSEQ_ASM_OP_FINAL_STORE(newv, v, 2) + 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", "r17" + 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) +{ + RSEQ_INJECT_C(9) + + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + /* setup for mempcy */ + "mr %%r19, %[len]\n\t" + "mr %%r20, %[src]\n\t" + "mr %%r21, %[dst]\n\t" + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail]) + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2]) +#endif + /* try memcpy */ + RSEQ_ASM_OP_R_MEMCPY() + RSEQ_INJECT_ASM(5) + /* final store */ + RSEQ_ASM_OP_FINAL_STORE(newv, v, 2) + RSEQ_INJECT_ASM(6) + /* teardown */ + 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), + [expect] "r" (expect), + [newv] "r" (newv), + /* try memcpy input */ + [dst] "r" (dst), + [src] "r" (src), + [len] "r" (len) + RSEQ_INJECT_INPUT + : "memory", "cc", "r17", "r18", "r19", "r20", "r21" + 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_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, + void *dst, void *src, size_t len, + intptr_t newv, int cpu) +{ + RSEQ_INJECT_C(9) + + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + /* setup for mempcy */ + "mr %%r19, %[len]\n\t" + "mr %%r20, %[src]\n\t" + "mr %%r21, %[dst]\n\t" + /* Start rseq by storing table entry pointer into rseq_cs. */ + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + RSEQ_INJECT_ASM(3) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail]) + RSEQ_INJECT_ASM(4) +#ifdef RSEQ_COMPARE_TWICE + /* cmp cpuid */ + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + /* cmp @v equal to @expect */ + RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2]) +#endif + /* try memcpy */ + RSEQ_ASM_OP_R_MEMCPY() + RSEQ_INJECT_ASM(5) + /* for 'release' */ + "lwsync\n\t" + /* final store */ + RSEQ_ASM_OP_FINAL_STORE(newv, v, 2) + RSEQ_INJECT_ASM(6) + /* teardown */ + 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), + [expect] "r" (expect), + [newv] "r" (newv), + /* try memcpy input */ + [dst] "r" (dst), + [src] "r" (src), + [len] "r" (len) + RSEQ_INJECT_INPUT + : "memory", "cc", "r17", "r18", "r19", "r20", "r21" + 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 +} + +#undef STORE_WORD +#undef LOAD_WORD +#undef LOADX_WORD +#undef CMP_WORD + +#endif /* !RSEQ_SKIP_FASTPATH */ diff --git a/tools/testing/selftests/rseq/rseq-skip.h b/tools/testing/selftests/rseq/rseq-skip.h new file mode 100644 index 000000000000..dc8f8e74b737 --- /dev/null +++ b/tools/testing/selftests/rseq/rseq-skip.h @@ -0,0 +1,82 @@ +/* + * rseq-skip.h + * + * (C) Copyright 2017 - Mathieu Desnoyers mathieu.desnoyers@efficios.com + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +static inline __attribute__((always_inline)) +int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) +{ + return -1; +} + +static inline __attribute__((always_inline)) +int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, + off_t voffp, intptr_t *load, int cpu) +{ + return -1; +} + +static inline __attribute__((always_inline)) +int rseq_addv(intptr_t *v, intptr_t count, int cpu) +{ + return -1; +} + +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) +{ + return -1; +} + +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 -1; +} + +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) +{ + return -1; +} + +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) +{ + return -1; +} + +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 -1; +} diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h new file mode 100644 index 000000000000..02d853ae2ce1 --- /dev/null +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -0,0 +1,1149 @@ +/* + * rseq-x86.h + * + * (C) Copyright 2016 - Mathieu Desnoyers mathieu.desnoyers@efficios.com + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include <stdint.h> + +#define RSEQ_SIG 0x53053053 + +#ifdef __x86_64__ + +#define rseq_smp_mb() \ + __asm__ __volatile__ ("lock; addl $0,-128(%%rsp)" ::: "memory", "cc") +#define rseq_smp_rmb() rseq_barrier() +#define rseq_smp_wmb() rseq_barrier() + +#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 */ + +#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ + start_ip, post_commit_offset, abort_ip) \ + ".pushsection __rseq_table, "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" + +#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) \ + "leaq " __rseq_str(cs_label) "(%%rip), %%rax\n\t" \ + "movq %%rax, %[" __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) \ + "cmpl %[" __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" \ + /* Disassembler-friendly signature: nopl <sig>(%rip). */\ + ".byte 0x0f, 0x1f, 0x05\n\t" \ + ".long " __rseq_str(RSEQ_SIG) "\n\t" \ + __rseq_str(label) ":\n\t" \ + teardown \ + "jmp %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 \ + "jmp %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 */ + /* 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) + "cmpq %[v], %[expect]\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]) + "cmpq %[v], %[expect]\n\t" + "jnz %l[error2]\n\t" +#endif + /* final store */ + "movq %[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) + : "memory", "cc", "rax" + 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 */ + /* 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) + "movq %[v], %%rbx\n\t" + "cmpq %%rbx, %[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]) + "movq %[v], %%rbx\n\t" + "cmpq %%rbx, %[expectnot]\n\t" + "je %l[error2]\n\t" +#endif + "movq %%rbx, %[load]\n\t" + "addq %[voffp], %%rbx\n\t" + "movq (%%rbx), %%rbx\n\t" + /* final store */ + "movq %%rbx, %[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] "er" (voffp), + [load] "m" (*load) + : "memory", "cc", "rax", "rbx" + 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 */ + /* 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 + /* final store */ + "addq %[count], %[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] "er" (count) + : "memory", "cc", "rax" + 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 */ + /* 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) + "cmpq %[v], %[expect]\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]) + "cmpq %[v], %[expect]\n\t" + "jnz %l[error2]\n\t" +#endif + /* try store */ + "movq %[newv2], %[v2]\n\t" + RSEQ_INJECT_ASM(5) + /* final store */ + "movq %[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) + : "memory", "cc", "rax" + 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 +} + +/* x86-64 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 */ + /* 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) + "cmpq %[v], %[expect]\n\t" + "jnz %l[cmpfail]\n\t" + RSEQ_INJECT_ASM(4) + "cmpq %[v2], %[expect2]\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]) + "cmpq %[v], %[expect]\n\t" + "jnz %l[error2]\n\t" + "cmpq %[v2], %[expect2]\n\t" + "jnz %l[error3]\n\t" +#endif + /* final store */ + "movq %[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) + : "memory", "cc", "rax" + 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 */ + "movq %[src], %[rseq_scratch0]\n\t" + "movq %[dst], %[rseq_scratch1]\n\t" + "movq %[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) + "cmpq %[v], %[expect]\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) + "cmpq %[v], %[expect]\n\t" + "jnz 7f\n\t" +#endif + /* try memcpy */ + "test %[len], %[len]\n\t" \ + "jz 333f\n\t" \ + "222:\n\t" \ + "movb (%[src]), %%al\n\t" \ + "movb %%al, (%[dst])\n\t" \ + "inc %[src]\n\t" \ + "inc %[dst]\n\t" \ + "dec %[len]\n\t" \ + "jnz 222b\n\t" \ + "333:\n\t" \ + RSEQ_INJECT_ASM(5) + /* final store */ + "movq %[newv], %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(6) + /* teardown */ + "movq %[rseq_scratch2], %[len]\n\t" + "movq %[rseq_scratch1], %[dst]\n\t" + "movq %[rseq_scratch0], %[src]\n\t" + RSEQ_ASM_DEFINE_ABORT(4, + "movq %[rseq_scratch2], %[len]\n\t" + "movq %[rseq_scratch1], %[dst]\n\t" + "movq %[rseq_scratch0], %[src]\n\t", + abort) + RSEQ_ASM_DEFINE_CMPFAIL(5, + "movq %[rseq_scratch2], %[len]\n\t" + "movq %[rseq_scratch1], %[dst]\n\t" + "movq %[rseq_scratch0], %[src]\n\t", + cmpfail) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_CMPFAIL(6, + "movq %[rseq_scratch2], %[len]\n\t" + "movq %[rseq_scratch1], %[dst]\n\t" + "movq %[rseq_scratch0], %[src]\n\t", + error1) + RSEQ_ASM_DEFINE_CMPFAIL(7, + "movq %[rseq_scratch2], %[len]\n\t" + "movq %[rseq_scratch1], %[dst]\n\t" + "movq %[rseq_scratch0], %[src]\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]) + : "memory", "cc", "rax" + 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 +} + +/* x86-64 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 */ + +#elif __i386__ + +#define rseq_smp_mb() \ + __asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc") +#define rseq_smp_rmb() \ + __asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc") +#define rseq_smp_wmb() \ + __asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc") + +#define rseq_smp_load_acquire(p) \ +__extension__ ({ \ + __typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \ + rseq_smp_mb(); \ + ____p1; \ +}) + +#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb() + +#define rseq_smp_store_release(p, v) \ +do { \ + rseq_smp_mb(); \ + RSEQ_WRITE_ONCE(*p, v); \ +} while (0) + +#ifdef RSEQ_SKIP_FASTPATH +#include "rseq-skip.h" +#else /* !RSEQ_SKIP_FASTPATH */ + +/* + * Use eax as scratch register and take memory operands as input to + * lessen register pressure. Especially needed when compiling in O0. + */ +#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ + start_ip, post_commit_offset, abort_ip) \ + ".pushsection __rseq_table, "aw"\n\t" \ + ".balign 32\n\t" \ + __rseq_str(label) ":\n\t" \ + ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ + ".long " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \ + ".popsection\n\t" + +#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) \ + "movl $" __rseq_str(cs_label) ", %[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) \ + "cmpl %[" __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" \ + /* Disassembler-friendly signature: nopl <sig>. */ \ + ".byte 0x0f, 0x1f, 0x05\n\t" \ + ".long " __rseq_str(RSEQ_SIG) "\n\t" \ + __rseq_str(label) ":\n\t" \ + teardown \ + "jmp %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 \ + "jmp %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 */ + /* 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) + "cmpl %[v], %[expect]\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]) + "cmpl %[v], %[expect]\n\t" + "jnz %l[error2]\n\t" +#endif + /* final store */ + "movl %[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) + : "memory", "cc", "eax" + 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 */ + /* 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) + "movl %[v], %%ebx\n\t" + "cmpl %%ebx, %[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]) + "movl %[v], %%ebx\n\t" + "cmpl %%ebx, %[expectnot]\n\t" + "je %l[error2]\n\t" +#endif + "movl %%ebx, %[load]\n\t" + "addl %[voffp], %%ebx\n\t" + "movl (%%ebx), %%ebx\n\t" + /* final store */ + "movl %%ebx, %[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] "ir" (voffp), + [load] "m" (*load) + : "memory", "cc", "eax", "ebx" + 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 */ + /* 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 + /* final store */ + "addl %[count], %[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] "ir" (count) + : "memory", "cc", "eax" + 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 */ + /* 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) + "cmpl %[v], %[expect]\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]) + "cmpl %[v], %[expect]\n\t" + "jnz %l[error2]\n\t" +#endif + /* try store */ + "movl %[newv2], %%eax\n\t" + "movl %%eax, %[v2]\n\t" + RSEQ_INJECT_ASM(5) + /* final store */ + "movl %[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] "m" (newv2), + /* final store input */ + [v] "m" (*v), + [expect] "r" (expect), + [newv] "r" (newv) + : "memory", "cc", "eax" + 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_cmpeqv_trystorev_storev_release(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 */ + /* 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) + "movl %[expect], %%eax\n\t" + "cmpl %[v], %%eax\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]) + "movl %[expect], %%eax\n\t" + "cmpl %[v], %%eax\n\t" + "jnz %l[error2]\n\t" +#endif + /* try store */ + "movl %[newv2], %[v2]\n\t" + RSEQ_INJECT_ASM(5) + "lock; addl $0,-128(%%esp)\n\t" + /* final store */ + "movl %[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] "m" (expect), + [newv] "r" (newv) + : "memory", "cc", "eax" + 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_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 */ + /* 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) + "cmpl %[v], %[expect]\n\t" + "jnz %l[cmpfail]\n\t" + RSEQ_INJECT_ASM(4) + "cmpl %[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]) + "cmpl %[v], %[expect]\n\t" + "jnz %l[error2]\n\t" + "cmpl %[expect2], %[v2]\n\t" + "jnz %l[error3]\n\t" +#endif + "movl %[newv], %%eax\n\t" + /* final store */ + "movl %%eax, %[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] "m" (newv) + : "memory", "cc", "eax" + 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 +} + +/* TODO: implement a faster memcpy. */ +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) +{ + uint32_t rseq_scratch[3]; + + RSEQ_INJECT_C(9) + + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + "movl %[src], %[rseq_scratch0]\n\t" + "movl %[dst], %[rseq_scratch1]\n\t" + "movl %[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) + "movl %[expect], %%eax\n\t" + "cmpl %%eax, %[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) + "movl %[expect], %%eax\n\t" + "cmpl %%eax, %[v]\n\t" + "jnz 7f\n\t" +#endif + /* try memcpy */ + "test %[len], %[len]\n\t" \ + "jz 333f\n\t" \ + "222:\n\t" \ + "movb (%[src]), %%al\n\t" \ + "movb %%al, (%[dst])\n\t" \ + "inc %[src]\n\t" \ + "inc %[dst]\n\t" \ + "dec %[len]\n\t" \ + "jnz 222b\n\t" \ + "333:\n\t" \ + RSEQ_INJECT_ASM(5) + "movl %[newv], %%eax\n\t" + /* final store */ + "movl %%eax, %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(6) + /* teardown */ + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\n\t" + RSEQ_ASM_DEFINE_ABORT(4, + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\n\t", + abort) + RSEQ_ASM_DEFINE_CMPFAIL(5, + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\n\t", + cmpfail) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_CMPFAIL(6, + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\n\t", + error1) + RSEQ_ASM_DEFINE_CMPFAIL(7, + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\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] "m" (expect), + [newv] "m" (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]) + : "memory", "cc", "eax" + 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 +} + +/* TODO: implement a faster memcpy. */ +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) +{ + uint32_t rseq_scratch[3]; + + RSEQ_INJECT_C(9) + + __asm__ __volatile__ goto ( + RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + "movl %[src], %[rseq_scratch0]\n\t" + "movl %[dst], %[rseq_scratch1]\n\t" + "movl %[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) + "movl %[expect], %%eax\n\t" + "cmpl %%eax, %[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) + "movl %[expect], %%eax\n\t" + "cmpl %%eax, %[v]\n\t" + "jnz 7f\n\t" +#endif + /* try memcpy */ + "test %[len], %[len]\n\t" \ + "jz 333f\n\t" \ + "222:\n\t" \ + "movb (%[src]), %%al\n\t" \ + "movb %%al, (%[dst])\n\t" \ + "inc %[src]\n\t" \ + "inc %[dst]\n\t" \ + "dec %[len]\n\t" \ + "jnz 222b\n\t" \ + "333:\n\t" \ + RSEQ_INJECT_ASM(5) + "lock; addl $0,-128(%%esp)\n\t" + "movl %[newv], %%eax\n\t" + /* final store */ + "movl %%eax, %[v]\n\t" + "2:\n\t" + RSEQ_INJECT_ASM(6) + /* teardown */ + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\n\t" + RSEQ_ASM_DEFINE_ABORT(4, + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\n\t", + abort) + RSEQ_ASM_DEFINE_CMPFAIL(5, + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\n\t", + cmpfail) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_CMPFAIL(6, + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\n\t", + error1) + RSEQ_ASM_DEFINE_CMPFAIL(7, + "movl %[rseq_scratch2], %[len]\n\t" + "movl %[rseq_scratch1], %[dst]\n\t" + "movl %[rseq_scratch0], %[src]\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] "m" (expect), + [newv] "m" (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]) + : "memory", "cc", "eax" + 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 +} + +#endif /* !RSEQ_SKIP_FASTPATH */ + +#endif diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c new file mode 100644 index 000000000000..ba65c14ef3ae --- /dev/null +++ b/tools/testing/selftests/rseq/rseq.c @@ -0,0 +1,116 @@ +/* + * rseq.c + * + * Copyright (C) 2016 Mathieu Desnoyers mathieu.desnoyers@efficios.com + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; only + * version 2.1 of the License. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + */ + +#define _GNU_SOURCE +#include <errno.h> +#include <sched.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <syscall.h> +#include <assert.h> +#include <signal.h> + +#include "rseq.h" + +#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) + +__attribute__((tls_model("initial-exec"))) __thread +volatile struct rseq __rseq_abi = { + .cpu_id = RSEQ_CPU_ID_UNINITIALIZED, +}; + +static __attribute__((tls_model("initial-exec"))) __thread +volatile int refcount; + +static void signal_off_save(sigset_t *oldset) +{ + sigset_t set; + int ret; + + sigfillset(&set); + ret = pthread_sigmask(SIG_BLOCK, &set, oldset); + if (ret) + abort(); +} + +static void signal_restore(sigset_t oldset) +{ + int ret; + + ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL); + if (ret) + abort(); +} + +static int sys_rseq(volatile struct rseq *rseq_abi, uint32_t rseq_len, + int flags, uint32_t sig) +{ + return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig); +} + +int rseq_register_current_thread(void) +{ + int rc, ret = 0; + sigset_t oldset; + + signal_off_save(&oldset); + if (refcount++) + goto end; + rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), 0, RSEQ_SIG); + if (!rc) { + assert(rseq_current_cpu_raw() >= 0); + goto end; + } + if (errno != EBUSY) + __rseq_abi.cpu_id = -2; + ret = -1; + refcount--; +end: + signal_restore(oldset); + return ret; +} + +int rseq_unregister_current_thread(void) +{ + int rc, ret = 0; + sigset_t oldset; + + signal_off_save(&oldset); + if (--refcount) + goto end; + rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), + RSEQ_FLAG_UNREGISTER, RSEQ_SIG); + if (!rc) + goto end; + ret = -1; +end: + signal_restore(oldset); + return ret; +} + +int32_t rseq_fallback_current_cpu(void) +{ + int32_t cpu; + + cpu = sched_getcpu(); + if (cpu < 0) { + perror("sched_getcpu()"); + abort(); + } + return cpu; +} diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h new file mode 100644 index 000000000000..d199f0beee1b --- /dev/null +++ b/tools/testing/selftests/rseq/rseq.h @@ -0,0 +1,164 @@ +/* + * rseq.h + * + * (C) Copyright 2016 - Mathieu Desnoyers mathieu.desnoyers@efficios.com + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef RSEQ_H +#define RSEQ_H + +#include <stdint.h> +#include <stdbool.h> +#include <pthread.h> +#include <signal.h> +#include <sched.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <sched.h> +#include <linux/rseq.h> + +/* + * Empty code injection macros, override when testing. + * It is important to consider that the ASM injection macros need to be + * fully reentrant (e.g. do not modify the stack). + */ +#ifndef RSEQ_INJECT_ASM +#define RSEQ_INJECT_ASM(n) +#endif + +#ifndef RSEQ_INJECT_C +#define RSEQ_INJECT_C(n) +#endif + +#ifndef RSEQ_INJECT_INPUT +#define RSEQ_INJECT_INPUT +#endif + +#ifndef RSEQ_INJECT_CLOBBER +#define RSEQ_INJECT_CLOBBER +#endif + +#ifndef RSEQ_INJECT_FAILED +#define RSEQ_INJECT_FAILED +#endif + +extern __thread volatile struct rseq __rseq_abi; + +#define rseq_likely(x) __builtin_expect(!!(x), 1) +#define rseq_unlikely(x) __builtin_expect(!!(x), 0) +#define rseq_barrier() __asm__ __volatile__("" : : : "memory") + +#define RSEQ_ACCESS_ONCE(x) (*(__volatile__ __typeof__(x) *)&(x)) +#define RSEQ_WRITE_ONCE(x, v) __extension__ ({ RSEQ_ACCESS_ONCE(x) = (v); }) +#define RSEQ_READ_ONCE(x) RSEQ_ACCESS_ONCE(x) + +#define __rseq_str_1(x) #x +#define __rseq_str(x) __rseq_str_1(x) + +#define rseq_log(fmt, args...) \ + fprintf(stderr, fmt "(in %s() at " __FILE__ ":" __rseq_str(__LINE__)"\n", \ + ## args, __func__) + +#define rseq_bug(fmt, args...) \ + do { \ + rseq_log(fmt, ##args); \ + abort(); \ + } while (0) + +#if defined(__x86_64__) || defined(__i386__) +#include <rseq-x86.h> +#elif defined(__ARMEL__) +#include <rseq-arm.h> +#elif defined(__PPC__) +#include <rseq-ppc.h> +#else +#error unsupported target +#endif + +/* + * Register rseq for the current thread. This needs to be called once + * by any thread which uses restartable sequences, before they start + * using restartable sequences, to ensure restartable sequences + * succeed. A restartable sequence executed from a non-registered + * thread will always fail. + */ +int rseq_register_current_thread(void); + +/* + * Unregister rseq for current thread. + */ +int rseq_unregister_current_thread(void); + +/* + * Restartable sequence fallback for reading the current CPU number. + */ +int32_t rseq_fallback_current_cpu(void); + +/* + * Values returned can be either the current CPU number, -1 (rseq is + * uninitialized), or -2 (rseq initialization has failed). + */ +static inline int32_t rseq_current_cpu_raw(void) +{ + return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id); +} + +/* + * Returns a possible CPU number, which is typically the current CPU. + * The returned CPU number can be used to prepare for an rseq critical + * section, which will confirm whether the cpu number is indeed the + * current one, and whether rseq is initialized. + * + * The CPU number returned by rseq_cpu_start should always be validated + * by passing it to a rseq asm sequence, or by comparing it to the + * return value of rseq_current_cpu_raw() if the rseq asm sequence + * does not need to be invoked. + */ +static inline uint32_t rseq_cpu_start(void) +{ + return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id_start); +} + +static inline uint32_t rseq_current_cpu(void) +{ + int32_t cpu; + + cpu = rseq_current_cpu_raw(); + if (rseq_unlikely(cpu < 0)) + cpu = rseq_fallback_current_cpu(); + return cpu; +} + +/* + * rseq_prepare_unload() should be invoked by each thread using rseq_finish*() + * at least once between their last rseq_finish*() and library unload of the + * library defining the rseq critical section (struct rseq_cs). This also + * applies to use of rseq in code generated by JIT: rseq_prepare_unload() + * should be invoked at least once by each thread using rseq_finish*() before + * reclaim of the memory holding the struct rseq_cs. + */ +static inline void rseq_prepare_unload(void) +{ + __rseq_abi.rseq_cs = 0; +} + +#endif /* RSEQ_H_ */