[tsan] Derive the unmangled SP in longjmp with xor key on loongarch64

[Ami-zhang]

Summary

Introducing xor key to derive unmangled sp is here to follow the way
that the glibc adds support for pointer mangling on loongarch in commit
1c9bc1b6e50293a1b7037a7bfbf835868a55baed.

[Ami-zhang]

Without this change, there are eight failed tests:

$ make check-tsan
Failed Tests (8):
  ThreadSanitizer-loongarch64 :: exceptions.cpp
  ThreadSanitizer-loongarch64 :: fiber_longjmp.cpp
  ThreadSanitizer-loongarch64 :: ignore_lib4.cpp
  ThreadSanitizer-loongarch64 :: longjmp.cpp
  ThreadSanitizer-loongarch64 :: longjmp2.cpp
  ThreadSanitizer-loongarch64 :: longjmp3.cpp
  ThreadSanitizer-loongarch64 :: longjmp4.cpp
  ThreadSanitizer-loongarch64 :: signal_longjmp.cpp

Testing Time: 151.22s
  Unsupported      :  91
  Passed           : 338
  Expectedly Failed:   2
  Failed           :   8

With this change, tests all pass:

$ make check-tsan
Testing Time: 238.30s
  Unsupported      :  91
  Passed           : 346
  Expectedly Failed:   2

[SixWeining]

compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp

69–70

Should be __loongarch_lp64 since we don't know whether loongarch32 needs it?

318

Ditto.

[Ami-zhang]

use xor key on __loongarch_lp64 instead of __loongarch__ at present

[Ami-zhang]

compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp

69–70

Yes.
Updated it. Thank you.

[wangleiat]

LGTM

[xen0n]

compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp

391

Does this condition need to be changed to __loongarch_lp64?

[Ami-zhang]

compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp

391

Yes.
Thanks.

[Ami-zhang]

__loongarch__ -> __loongarch_lp64

compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp

 # undef sa_sigaction
 #endif
 
 #if SANITIZER_FREEBSD
 extern "C" void *__libc_stack_end;
 void *__libc_stack_end = 0;
 #endif
 
-#if SANITIZER_LINUX && defined(__aarch64__) && !SANITIZER_GO
+#if SANITIZER_LINUX && (defined(__aarch64__) || defined(__loongarch_lp64)) && \
+    !SANITIZER_GO
 # define INIT_LONGJMP_XOR_KEY 1
 #else
 # define INIT_LONGJMP_XOR_KEY 0
 #endif
 
 #if INIT_LONGJMP_XOR_KEY
 #include "interception/interception.h"
 // Must be declared outside of other namespaces.
if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
       VReport(1, "WARNING: Program is run with randomized virtual address "
               "space, which wouldn't work with ThreadSanitizer.\n"
               "Re-execing with fixed virtual address space.\n");
       CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
       reexec = true;
     }
 
 #endif
-#if SANITIZER_LINUX && defined(__aarch64__)
+#if SANITIZER_LINUX && (defined(__aarch64__) || defined(__loongarch_lp64))
     // Initialize the xor key used in {sig}{set,long}jump.
     InitializeLongjmpXorKey();
 #endif
     if (reexec)
       ReExec();
   }
 
   CheckAndProtect();
# else
   return mangled_sp;
 # endif
 #elif defined(__aarch64__)
 # if SANITIZER_LINUX
   return mangled_sp ^ longjmp_xor_key;
 # else
   return mangled_sp;
 # endif
 #elif defined(__loongarch__)
-  return mangled_sp;
+  return mangled_sp ^ longjmp_xor_key;
 #elif defined(__powerpc64__)
   // Reverse of:
   //   ld   r4, -28696(r13)
   //   xor  r4, r3, r4
   uptr xor_key;
   asm("ld  %0, -28696(%%r13)" : "=r" (xor_key));
   return mangled_sp ^ xor_key;
 #elif defined(__mips__)

 // issuing a setjmp and XORing the SP pointer values to derive the key.
 static void InitializeLongjmpXorKey() {
   // 1. Call REAL(setjmp), which stores the mangled SP in env.
   jmp_buf env;
   REAL(_setjmp)(env);
 
   // 2. Retrieve vanilla/mangled SP.
   uptr sp;
+#ifdef __loongarch__
+  asm("move  %0, $sp" : "=r" (sp));
+#else
   asm("mov  %0, sp" : "=r" (sp));
+#endif
   uptr mangled_sp = ((uptr *)&env)[LONG_JMP_SP_ENV_SLOT];
 
   // 3. xor SPs to obtain key.
   longjmp_xor_key = mangled_sp ^ sp;
 }
 #endif
 
 extern "C" void __tsan_tls_initialization() {}