[compiler-rt] r348984 - Switch Android from TLS_SLOT_TSAN(8) to TLS_SLOT_SANITIZER(6)

[Ryan Prichard via llvm-commits]

Author: rprichard
Date: Wed Dec 12 14:45:12 2018
New Revision: 348984

URL: http://llvm.org/viewvc/llvm-project?rev=348984&view=rev
Log:
Switch Android from TLS_SLOT_TSAN(8) to TLS_SLOT_SANITIZER(6)

Summary:
The TLS_SLOT_TSAN slot is available starting in N, but its location (8)
is incompatible with the proposed solution for implementing ELF TLS on
Android (i.e. bump ARM/AArch64 alignment to reserve an 8-word TCB).

Instead, starting in Q, Bionic replaced TLS_SLOT_DLERROR(6) with
TLS_SLOT_SANITIZER(6). Switch compiler-rt to the new slot.

Reviewers: eugenis, srhines, enh

Reviewed By: eugenis

Subscribers: ruiu, srhines, kubamracek, javed.absar, kristof.beyls, delcypher, llvm-commits, #sanitizers

Differential Revision: https://reviews.llvm.org/D55581

Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h?rev=348984&r1=348983&r2=348984&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h Wed Dec 12 14:45:12 2018
@@ -134,13 +134,13 @@ void ForEachMappedRegion(link_map *map,
 #error "Unsupported architecture."
 #endif
 
-// The Android Bionic team has allocated a TLS slot for TSan starting with N,
-// given that Android currently doesn't support ELF TLS. It is used to store
-// Sanitizers thread specific data.
-static const int TLS_SLOT_TSAN = 8;
+// The Android Bionic team has allocated a TLS slot for sanitizers starting
+// with Q, given that Android currently doesn't support ELF TLS. It is used to
+// store sanitizer thread specific data.
+static const int TLS_SLOT_SANITIZER = 6;
 
 ALWAYS_INLINE uptr *get_android_tls_ptr() {
-  return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_TSAN]);
+  return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]);
 }
 
 #endif  // SANITIZER_ANDROID