[MIPS][AddressSanitizer] Resolve build issues for the n32 ABI

[dmilosevic141]

Summary

Building the compiler-rt's AddressSanitizer for the n32 MIPS ABI currently fails, due to a few reasons:

• defined(__mips64), which is set solely based on the architecture type (32-bit/64-bit), was still used in some places. Therefore, defined(__mips64) is swapped with SANITIZER_MIPS64, which takes the ABI into account as well - defined(__mips64) && _MIPS_SIM == ABI64.
• The n32 ABI still uses 64-bit *Linux* system calls, even though the word size is 32 bits.
• After the transition to canonical system calls (D124212), the n32 ABI still didn't use them, even though they are supported, as per https://github.com/torvalds/linux/blob/master/arch/mips/kernel/syscalls/syscall_n32.tbl.

[dmilosevic141]

I've changed the following:

• Rebased.
• Made sure MIPS is targeted before checking its ABI.

[djtodoro]

lgtm

compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp

 #if SANITIZER_LINUX && !SANITIZER_GO
 #include <asm/param.h>
 #endif
 
 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
 // access stat from asm/stat.h, without conflicting with definition in
 // sys/stat.h, we use this trick.
-#if defined(__mips64)
+#if SANITIZER_MIPS64
 #include <asm/unistd.h>
 #include <sys/types.h>
 #define stat kernel_stat
 #if SANITIZER_GO
 #undef st_atime
 #undef st_mtime
 #undef st_ctime
 #define st_atime st_atim

 const int FUTEX_PRIVATE_FLAG = 128;
 const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
 const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
 #endif  // SANITIZER_LINUX
 
 // Are we using 32-bit or 64-bit Linux syscalls?
 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
 // but it still needs to use 64-bit syscalls.
-#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) ||       \
-                        SANITIZER_WORDSIZE == 64)
+#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
+                        SANITIZER_WORDSIZE == 64 ||                      \
+                        (defined(__mips__) && _MIPS_SIM == _ABIN32))
 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
 #else
 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
 #endif
 
 // Note : FreeBSD had implemented both
 // Linux apis, available from
 // future 12.x version most likely
static void stat64_to_stat(struct stat64 *in, struct stat *out) {
   out->st_blksize = in->st_blksize;
   out->st_blocks = in->st_blocks;
   out->st_atime = in->st_atime;
   out->st_mtime = in->st_mtime;
   out->st_ctime = in->st_ctime;
 }
 #endif
 
-#if defined(__mips64)
+#if SANITIZER_MIPS64
 // Undefine compatibility macros from <sys/stat.h>
 // so that they would not clash with the kernel_stat
 // st_[a|m|c]time fields
 #if !SANITIZER_GO
 #undef st_atime
 #undef st_mtime
 #undef st_ctime
 #endif

 #endif
 }
 #endif
 
 uptr internal_stat(const char *path, void *buf) {
 #if SANITIZER_FREEBSD
   return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
 #    elif SANITIZER_LINUX
-#      if (SANITIZER_WORDSIZE == 64 || SANITIZER_X32) && !SANITIZER_SPARC
+#      if (SANITIZER_WORDSIZE == 64 || SANITIZER_X32 ||    \
+           (defined(__mips__) && _MIPS_SIM == _ABIN32)) && \
+          !SANITIZER_SPARC
   return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
                           0);
 #      else
   struct stat64 buf64;
   int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
                              (uptr)&buf64, 0);
   stat64_to_stat(&buf64, (struct stat *)buf);
   return res;
 #      endif
 #    else
   struct stat64 buf64;
   int res = internal_syscall(SYSCALL(stat64), path, &buf64);
   stat64_to_stat(&buf64, (struct stat *)buf);
   return res;
 #    endif
 }
 
 uptr internal_lstat(const char *path, void *buf) {
 #if SANITIZER_FREEBSD
   return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
                           AT_SYMLINK_NOFOLLOW);
 #    elif SANITIZER_LINUX
-#      if (defined(_LP64) || SANITIZER_X32) && !SANITIZER_SPARC
+#      if (defined(_LP64) || SANITIZER_X32 ||              \
+           (defined(__mips__) && _MIPS_SIM == _ABIN32)) && \
+          !SANITIZER_SPARC
   return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
                           AT_SYMLINK_NOFOLLOW);
 #      else
   struct stat64 buf64;
   int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
                              (uptr)&buf64, AT_SYMLINK_NOFOLLOW);
   stat64_to_stat(&buf64, (struct stat *)buf);
   return res;
# if defined(__powerpc64__) || defined(__aarch64__)
   // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
   // Note that with 'ulimit -s unlimited' the stack is moved away from the top
   // of the address space, so simply checking the stack address is not enough.
   // This should (does) work for both PowerPC64 Endian modes.
   // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
   return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
 #elif SANITIZER_RISCV64
   return (1ULL << 38) - 1;
-# elif defined(__mips64)
+# elif SANITIZER_MIPS64
   return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
 # elif defined(__s390x__)
   return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
 #elif defined(__sparc__)
   return ~(uptr)0;
 # else
   return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
 # endif

compiler-rt/lib/sanitizer_common/sanitizer_platform.h

 #if defined(__i386__) || defined(_M_IX86)
 #  define SANITIZER_I386 1
 #else
 #  define SANITIZER_I386 0
 #endif
 
 #if defined(__mips__)
 #  define SANITIZER_MIPS 1
-#  if defined(__mips64)
+#  if defined(__mips64) && _MIPS_SIM == _ABI64
 #    define SANITIZER_MIPS32 0
 #    define SANITIZER_MIPS64 1
 #  else
 #    define SANITIZER_MIPS32 1
 #    define SANITIZER_MIPS64 0
 #  endif
 #else
 #  define SANITIZER_MIPS 0