[Bug sanitizer/64435] [5 Regression] Bootstrap failure in libsanitizer on AArch64 with Linux kernel <= 3.15

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64435

--- Comment #19 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So, with:
--- libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h.jj   
2014-11-14 00:10:33.000000000 +0100
+++ libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h   
2015-01-19 19:22:43.777780408 +0100
@@ -167,7 +167,7 @@ namespace __sanitizer {
     unsigned __seq;
     u64 __unused1;
     u64 __unused2;
-#elif defined(__mips__)
+#elif defined(__mips__) || defined(__aarch64__)
     unsigned int mode;
     unsigned short __seq;
     unsigned short __pad1;
--- libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc.jj   
2015-01-19 09:39:09.000000000 +0100
+++ libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc   
2015-01-19 19:21:57.608564325 +0100
@@ -1059,7 +1059,13 @@ CHECK_SIZE_AND_OFFSET(ipc_perm, uid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, gid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, cuid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, cgid);
+#ifndef __GLIBC_PREREQ
+#define __GLIBC_PREREQ(x, y) 0
+#endif
+#if !defined(__aarch64__) || !SANITIZER_LINUX || __GLIBC_PREREQ (2, 21)
+/* On aarch64 glibc 2.20 and earlier provided incorrect mode field.  */
 CHECK_SIZE_AND_OFFSET(ipc_perm, mode);
+#endif

 CHECK_TYPE_SIZE(shmid_ds);
 CHECK_SIZE_AND_OFFSET(shmid_ds, shm_perm);
--- libsanitizer/sanitizer_common/sanitizer_posix.cc.jj    2014-11-14
00:10:33.000000000 +0100
+++ libsanitizer/sanitizer_common/sanitizer_posix.cc    2015-01-19
19:24:14.636237703 +0100
@@ -76,16 +76,15 @@ static uptr GetKernelAreaSize() {

 uptr GetMaxVirtualAddress() {
 #if SANITIZER_WORDSIZE == 64
-# if defined(__powerpc64__)
+# if defined(__powerpc64__) || defined(__aarch64__)
   // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
   // We somehow need to figure out which one we are using now and choose
   // 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 48-bit.
   return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
-# elif defined(__aarch64__)
-  return (1ULL << 39) - 1;
 # elif defined(__mips64)
   return (1ULL << 40) - 1;
 # else

the layout looks reasonable:
|| `[0x009000000000, 0x03ffffffffff]` || HighMem    ||
|| `[0x002200000000, 0x008fffffffff]` || HighShadow ||
|| `[0x001200000000, 0x0021ffffffff]` || ShadowGap  ||
|| `[0x001000000000, 0x0011ffffffff]` || LowShadow  ||
|| `[0x000000000000, 0x000fffffffff]` || LowMem     ||
MemToShadow(shadow): 0x001200000000 0x00123fffffff 0x001440000000
0x0021ffffffff
and should accomodate the different addresses I saw for 42-bit address space so
far: <4GB, 0x10000000000 (place where libraries are mapped with ulimit -s
unlimited), 0x2aaXXXXXXXX (PIEs), 0x3ffXXXXXXXX (stack, normal mmap area for
limited ulimit -s).
But it still doesn't work:
==4746==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000028 (pc
0x0000004008f8 bp 0x03fff8078fc0 sp 0x03fff8078fc0 T0)
==4746==AddressSanitizer CHECK failed:
../../../../libsanitizer/sanitizer_common/sanitizer_allocator.h:835 "((res)) <
((kNumPossibleRegions))" (0x3ffa33, 0x80000)

I've tried to change
#if SANITIZER_CAN_USE_ALLOCATOR64
# if defined(__powerpc64__)
const uptr kAllocatorSpace =  0xa0000000000ULL;
const uptr kAllocatorSize  =  0x20000000000ULL;  // 2T.
# else
const uptr kAllocatorSpace = 0x600000000000ULL;
const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
# endif
from the non-ppc64 values to the ppc64 values (i.e. added " ||
defined(__aarch64__)"), but strangely that didn't change anything.  So I'm out
of ideas on what else needs to be tweaked.  Kostya?