[Tsan] Add FreeBSD support to longjmp-related definitions

[samsonov]

Looks reasonable to me, but I'll let Dmitry sign this off.

[dvyukov]

LGTM with a nit

lib/tsan/rtl/tsan_interceptors.cc

426

You already pass the same value in both RSI and RDI, so revert changes to this function.

Closed by commit rL220292 (authored by vkutuzov).

lib/tsan/rtl/tsan_interceptors.cc

static void SetJmp(ThreadState *thr, uptr sp, uptr mangled_sp) {
   buf->in_blocking_func = sctx ?
       atomic_load(&sctx->in_blocking_func, memory_order_relaxed) :
       false;
   buf->in_signal_handler = atomic_load(&thr->in_signal_handler,
       memory_order_relaxed);
 }
 
 static void LongJmp(ThreadState *thr, uptr *env) {
+#if SANITIZER_FREEBSD
+  uptr mangled_sp = env[2];
+#else
   uptr mangled_sp = env[6];
+#endif  // SANITIZER_FREEBSD
   // Find the saved buf by mangled_sp.
   for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) {
     JmpBuf *buf = &thr->jmp_bufs[i];
     if (buf->mangled_sp == mangled_sp) {
       CHECK_GE(thr->shadow_stack_pos, buf->shadow_stack_pos);
       // Unwind the stack.
       while (thr->shadow_stack_pos > buf->shadow_stack_pos)
         FuncExit(thr);
for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) {
     }
   }
   Printf("ThreadSanitizer: can't find longjmp buf\n");
   CHECK(0);
 }
 
 // FIXME: put everything below into a common extern "C" block?
 extern "C" void __tsan_setjmp(uptr sp, uptr mangled_sp) {
+#if SANITIZER_FREEBSD
+  SetJmp(cur_thread(), sp, sp);
+#else
   SetJmp(cur_thread(), sp, mangled_sp);
+#endif  // SANITIZER_FREEBSD
 }
 
 // Not called.  Merely to satisfy TSAN_INTERCEPT().
 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
 int __interceptor_setjmp(void *env);
 extern "C" int __interceptor_setjmp(void *env) {
   CHECK(0);
   return 0;

lib/tsan/rtl/tsan_rtl_amd64.S

 .type setjmp, @function
 setjmp:
   CFI_STARTPROC
   // save env parameter
   push %rdi
   CFI_ADJUST_CFA_OFFSET(8)
   CFI_REL_OFFSET(%rdi, 0)
   // obtain %rsp
+#if defined(__FreeBSD__)
+  lea 8(%rsp), %rdi
+  mov %rdi, %rsi
+#else
   lea 16(%rsp), %rdi
   mov %rdi, %rsi
   xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
   rol $0x11, %rsi
+#endif
   // call tsan interceptor
   call __tsan_setjmp
   // restore env parameter
   pop %rdi
   CFI_ADJUST_CFA_OFFSET(-8)
   CFI_RESTORE(%rdi)
   // tail jump to libc setjmp
   movl $0, %eax
   movq _ZN14__interception11real_setjmpE@GOTPCREL(%rip), %rdx
   jmp *(%rdx)
   CFI_ENDPROC
 .size setjmp, .-setjmp
 
 .comm _ZN14__interception12real__setjmpE,8,8
 .globl _setjmp
 .type _setjmp, @function
 _setjmp:
   CFI_STARTPROC
   // save env parameter
   push %rdi
   CFI_ADJUST_CFA_OFFSET(8)
   CFI_REL_OFFSET(%rdi, 0)
   // obtain %rsp
+#if defined(__FreeBSD__)
+  lea 8(%rsp), %rdi
+  mov %rdi, %rsi
+#else
   lea 16(%rsp), %rdi
   mov %rdi, %rsi
   xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
   rol $0x11, %rsi
+#endif
   // call tsan interceptor
   call __tsan_setjmp
   // restore env parameter
   pop %rdi
   CFI_ADJUST_CFA_OFFSET(-8)
   CFI_RESTORE(%rdi)
   // tail jump to libc setjmp
   movl $0, %eax
sigsetjmp:
   // save savesigs parameter
   push %rsi
   CFI_ADJUST_CFA_OFFSET(8)
   CFI_REL_OFFSET(%rsi, 0)
   // align stack frame
   sub $8, %rsp
   CFI_ADJUST_CFA_OFFSET(8)
   // obtain %rsp
+#if defined(__FreeBSD__)
+  lea 24(%rsp), %rdi
+  mov %rdi, %rsi
+#else
   lea 32(%rsp), %rdi
   mov %rdi, %rsi
   xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
   rol $0x11, %rsi
+#endif
   // call tsan interceptor
   call __tsan_setjmp
   // unalign stack frame
   add $8, %rsp
   CFI_ADJUST_CFA_OFFSET(-8)
   // restore savesigs parameter
   pop %rsi
   CFI_ADJUST_CFA_OFFSET(-8)
__sigsetjmp:
   // save savesigs parameter
   push %rsi
   CFI_ADJUST_CFA_OFFSET(8)
   CFI_REL_OFFSET(%rsi, 0)
   // align stack frame
   sub $8, %rsp
   CFI_ADJUST_CFA_OFFSET(8)
   // obtain %rsp
+#if defined(__FreeBSD__)
+  lea 24(%rsp), %rdi
+  mov %rdi, %rsi
+#else
   lea 32(%rsp), %rdi
   mov %rdi, %rsi
   xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
   rol $0x11, %rsi
+#endif
   // call tsan interceptor
   call __tsan_setjmp
   // unalign stack frame
   add $8, %rsp
   CFI_ADJUST_CFA_OFFSET(-8)
   // restore savesigs parameter
   pop %rsi
   CFI_ADJUST_CFA_OFFSET(-8)
   CFI_RESTORE(%rsi)
   // restore env parameter
   pop %rdi
   CFI_ADJUST_CFA_OFFSET(-8)
   CFI_RESTORE(%rdi)
   // tail jump to libc sigsetjmp
   movl $0, %eax
   movq _ZN14__interception16real___sigsetjmpE@GOTPCREL(%rip), %rdx
   jmp *(%rdx)
   CFI_ENDPROC
 .size __sigsetjmp, .-__sigsetjmp
 
-#ifdef __linux__
+#if defined(__FreeBSD__) || defined(__linux__)
 /* We do not need executable stack.  */
 .section        .note.GNU-stack,"",@progbits
 #endif