1 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 // REQUIRES: x86_64-target-arch
3 // UNSUPPORTED: tvos, watchos
4 #include "test.h"
5
6 struct ucontext {
7 void *sp;
8 void *fiber;
9 };
10
11 extern "C" {
12 void ucontext_do_switch(void **save, void **load);
13 void ucontext_trampoline();
14 }
15
16 __asm__(".global " ASM_SYMBOL(ucontext_do_switch) "\n"
17 ASM_SYMBOL(ucontext_do_switch) ":\n\t"
18 "pushq %rbp\n\t"
19 "pushq %r15\n\t"
20 "pushq %r14\n\t"
21 "pushq %r13\n\t"
22 "pushq %r12\n\t"
23 "pushq %rbx\n\t"
24 "movq %rsp, (%rdi)\n\t"
25 "movq (%rsi), %rsp\n\t"
26 "popq %rbx\n\t"
27 "popq %r12\n\t"
28 "popq %r13\n\t"
29 "popq %r14\n\t"
30 "popq %r15\n\t"
31 "popq %rbp\n\t"
32 "retq");
33
34 __asm__(".global " ASM_SYMBOL(ucontext_trampoline) "\n"
35 ASM_SYMBOL(ucontext_trampoline) ":\n\t"
36 ".cfi_startproc\n\t"
37 ".cfi_undefined rip\n\t"
38 "movq %r12, %rdi\n\t"
39 "jmpq *%rbx\n\t"
40 ".cfi_endproc");
41
ucontext_init(ucontext * context,void * stack,unsigned stack_sz,void (* func)(void *),void * arg)42 void ucontext_init(ucontext *context, void *stack, unsigned stack_sz,
43 void (*func)(void*), void *arg) {
44 void **sp = reinterpret_cast<void **>(static_cast<char *>(stack) + stack_sz);
45 *(--sp) = 0;
46 *(--sp) = reinterpret_cast<void *>(ucontext_trampoline);
47 *(--sp) = 0; // rbp
48 *(--sp) = 0; // r15
49 *(--sp) = 0; // r14
50 *(--sp) = 0; // r13
51 *(--sp) = arg; // r12
52 *(--sp) = reinterpret_cast<void *>(func); // rbx
53 context->sp = sp;
54 context->fiber = __tsan_create_fiber(0);
55 }
56
ucontext_free(ucontext * context)57 void ucontext_free(ucontext *context) {
58 __tsan_destroy_fiber(context->fiber);
59 }
60
61 __attribute__((no_sanitize_thread))
ucontext_switch(ucontext * save,ucontext * load)62 void ucontext_switch(ucontext *save, ucontext *load) {
63 save->fiber = __tsan_get_current_fiber();
64 __tsan_switch_to_fiber(load->fiber, 0);
65 ucontext_do_switch(&save->sp, &load->sp);
66 }
67
68 char stack[64 * 1024] __attribute__((aligned(16)));
69
70 ucontext uc, orig_uc;
71
func(void * arg)72 void func(void *arg) {
73 __asm__ __volatile__(".cfi_undefined rip");
74 ucontext_switch(&uc, &orig_uc);
75 }
76
main()77 int main() {
78 ucontext_init(&uc, stack, sizeof(stack), func, 0);
79 ucontext_switch(&orig_uc, &uc);
80 ucontext_free(&uc);
81 fprintf(stderr, "PASS\n");
82 return 0;
83 }
84
85 // CHECK-NOT: WARNING: ThreadSanitizer:
86 // CHECK: PASS
87