[TSan] Improve handling of stack pointer mangling in {set,long}jmp, pt.7

[yln]

Summary

Factor out ExtractLongJmpSp helper function and move platform-specific
code to tsan_platform_{linux,mac}.cc.

[dvyukov]

Is there anything else to review at the moment? Want to make sure I did not lost track of things.

[yln]

In D64050#1565996, @dvyukov wrote:

Is there anything else to review at the moment? Want to make sure I did not lost track of things.

There is part 4, and 5:
https://reviews.llvm.org/D63946
https://reviews.llvm.org/D64022

compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc

static void SetJmp(ThreadState *thr, uptr 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) {
-#ifdef __powerpc__
-  uptr mangled_sp = env[0];
-#elif SANITIZER_FREEBSD
-  uptr mangled_sp = env[2];
-#elif SANITIZER_NETBSD
-  uptr mangled_sp = env[6];
-#elif SANITIZER_MAC
-# ifdef __aarch64__
-  uptr mangled_sp =
-      (GetMacosVersion() >= MACOS_VERSION_MOJAVE) ? env[12] : env[13];
-# else
-    uptr mangled_sp = env[2];
-# endif
-#elif SANITIZER_LINUX
-# ifdef __aarch64__
-  uptr mangled_sp = env[13];
-# elif defined(__mips64)
-  uptr mangled_sp = env[1];
-# else
-  uptr mangled_sp = env[6];
-# endif
-#endif
-  uptr sp = UnmangleLongJmpSp(mangled_sp);
+  uptr sp = ExtractLongJmpSp(env);
   // Find the saved buf with matching sp.
   for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) {
     JmpBuf *buf = &thr->jmp_bufs[i];
     if (buf->sp == 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);

compiler-rt/trunk/lib/tsan/rtl/tsan_platform.h

 void InitializePlatform();
 void InitializePlatformEarly();
 void CheckAndProtect();
 void InitializeShadowMemoryPlatform();
 void FlushShadowMemory();
 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive);
 int ExtractResolvFDs(void *state, int *fds, int nfd);
 int ExtractRecvmsgFDs(void *msg, int *fds, int nfd);
-uptr UnmangleLongJmpSp(uptr mangled_sp);
+uptr ExtractLongJmpSp(uptr *env);
 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size);
 
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
     void *abstime), void *c, void *m, void *abstime,
     void(*cleanup)(void *arg), void *arg);
 
 void DestroyThreadState();
 
 }  // namespace __tsan
 
 #endif  // TSAN_PLATFORM_H

compiler-rt/trunk/lib/tsan/rtl/tsan_platform_linux.cc

for (int i = 0; i < n; i++) {
       if (res == nfd)
         return res;
     }
   }
   return res;
 }
 
 // Reverse operation of libc stack pointer mangling
-uptr UnmangleLongJmpSp(uptr mangled_sp) {
+static uptr UnmangleLongJmpSp(uptr mangled_sp) {
 #if defined(__x86_64__)
-#if SANITIZER_FREEBSD || SANITIZER_NETBSD
+# if SANITIZER_FREEBSD || SANITIZER_NETBSD
   return mangled_sp;
-#else  // Linux
+# else  // Linux
   // Reverse of:
   //   xor  %fs:0x30, %rsi
   //   rol  $0x11, %rsi
   uptr sp;
   asm("ror  $0x11,     %0 \n"
       "xor  %%fs:0x30, %0 \n"
       : "=r" (sp)
       : "0" (mangled_sp));
   return sp;
-#endif
+# endif
 #elif defined(__aarch64__)
 # if SANITIZER_LINUX
   return mangled_sp ^ _tsan_pointer_chk_guard;
 # else
   return mangled_sp;
 # endif
 #elif defined(__powerpc64__)
   // Reverse of:
   //  ld   r4, -28696(r13)
   //  xor  r4, r3, r4
   uptr xor_guard;
   asm("ld  %0, -28696(%%r13) \n" : "=r" (xor_guard));
   return mangled_sp ^ xor_guard;
 #elif defined(__mips__)
   return mangled_sp;
 #else
   #error "Unknown platform"
 #endif
 }
 
+#ifdef __powerpc__
+# define LONG_JMP_SP_ENV_SLOT 0
+#elif SANITIZER_FREEBSD
+# define LONG_JMP_SP_ENV_SLOT 2
+#elif SANITIZER_NETBSD
+# define LONG_JMP_SP_ENV_SLOT 6
+#elif SANITIZER_LINUX
+# ifdef __aarch64__
+#  define LONG_JMP_SP_ENV_SLOT 13
+# elif defined(__mips64)
+#  define LONG_JMP_SP_ENV_SLOT 1
+# else
+#  define LONG_JMP_SP_ENV_SLOT 6
+# endif
+#endif
+
+uptr ExtractLongJmpSp(uptr *env) {
+  uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
+  return UnmangleLongJmpSp(mangled_sp);
+}
+
 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
   // Check that the thr object is in tls;
   const uptr thr_beg = (uptr)thr;
   const uptr thr_end = (uptr)thr + sizeof(*thr);
   CHECK_GE(thr_beg, tls_addr);
   CHECK_LE(thr_beg, tls_addr + tls_size);
   CHECK_GE(thr_end, tls_addr);
   CHECK_LE(thr_end, tls_addr + tls_size);

compiler-rt/trunk/lib/tsan/rtl/tsan_platform_mac.cc

 #endif
 
   if (GetMacosVersion() >= MACOS_VERSION_MOJAVE) {
     __tsan_darwin_setjmp_xor_key =
         (uptr)pthread_getspecific(kPthreadSetjmpXorKeySlot);
   }
 }
 
-uptr UnmangleLongJmpSp(uptr mangled_sp) {
+#ifdef __aarch64__
+# define LONG_JMP_SP_ENV_SLOT \
+    ((GetMacosVersion() >= MACOS_VERSION_MOJAVE) ? 12 : 13)
+#else
+# define LONG_JMP_SP_ENV_SLOT 2
+#endif
+
+uptr ExtractLongJmpSp(uptr *env) {
+  uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
   return mangled_sp ^ __tsan_darwin_setjmp_xor_key;
 }
 
 #if !SANITIZER_GO
 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
   // The pointer to the ThreadState object is stored in the shadow memory
   // of the tls.
   uptr tls_end = tls_addr + tls_size;