[gcc r13-1797] libsanitizer: Fix Solaris 11.3 compilation [PR105531]

[Rainer Orth <ro@gcc.gnu.org>]

https://gcc.gnu.org/g:786e51648bd9a6880339329380751809fb97cd6d

commit r13-1797-g786e51648bd9a6880339329380751809fb97cd6d
Author: Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
Date:   Fri Jul 22 13:18:14 2022 +0200

    libsanitizer: Fix Solaris 11.3 compilation [PR105531]
    
    The libsanitizer build has been broken on Solaris 11.3 by the latest
    import.  An upstream patch to fix this has now been committed:
    
            [sanitizer_common] Support Solaris < 11.4 in GetStaticTlsBoundary
            https://reviews.llvm.org/D120059
    
    I'd like to cherry-pick it into libsanitizer, too.
    
    Bootstrapped without regressions on sparc-sun-solaris2.11,
    i386-pc-solaris2.11 (both Solaris 11.3 and 11.4), and
    x86_64-pc-linux-gnu.
    
    2022-07-21  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
    
            libsanitizer:
            PR sanitizer/105531
            * sanitizer_common/sanitizer_linux_libcdep.cpp,
            sanitizer_common/sanitizer_solaris.h:: Cherry-pick
            llvm-project revision 3776db9a4fd2080d23d6a5f52e405eea44558761.

Diff:
---
 .../sanitizer_common/sanitizer_linux_libcdep.cpp   | 44 +++++++++++++----
 libsanitizer/sanitizer_common/sanitizer_solaris.h  | 56 ++++++++++++++++++++++
 2 files changed, 91 insertions(+), 9 deletions(-)

diff --git a/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp b/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp
index 620267cdd02..6dd27402ac9 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp
+++ b/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp
@@ -27,6 +27,7 @@
 #include "sanitizer_linux.h"
 #include "sanitizer_placement_new.h"
 #include "sanitizer_procmaps.h"
+#include "sanitizer_solaris.h"
 
 #if SANITIZER_NETBSD
 #define _RTLD_SOURCE  // for __lwp_gettcb_fast() / __lwp_getprivate_fast()
@@ -62,6 +63,7 @@
 #endif
 
 #if SANITIZER_SOLARIS
+#include <stddef.h>
 #include <stdlib.h>
 #include <thread.h>
 #endif
@@ -350,19 +352,43 @@ static uptr TlsGetOffset(uptr ti_module, uptr ti_offset) {
 extern "C" void *__tls_get_addr(size_t *);
 #endif
 
+static size_t main_tls_modid;
+
 static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size,
                                   void *data) {
-  if (!info->dlpi_tls_modid)
+  size_t tls_modid;
+#if SANITIZER_SOLARIS
+  // dlpi_tls_modid is only available since Solaris 11.4 SRU 10.  Use
+  // dlinfo(RTLD_DI_LINKMAP) instead which works on all of Solaris 11.3,
+  // 11.4, and Illumos.  The tlsmodid of the executable was changed to 1 in
+  // 11.4 to match other implementations.
+  if (size >= offsetof(dl_phdr_info_test, dlpi_tls_modid))
+    main_tls_modid = 1;
+  else
+    main_tls_modid = 0;
+  g_use_dlpi_tls_data = 0;
+  Rt_map *map;
+  dlinfo(RTLD_SELF, RTLD_DI_LINKMAP, &map);
+  tls_modid = map->rt_tlsmodid;
+#else
+  main_tls_modid = 1;
+  tls_modid = info->dlpi_tls_modid;
+#endif
+
+  if (tls_modid < main_tls_modid)
     return 0;
-  uptr begin = (uptr)info->dlpi_tls_data;
+  uptr begin;
+#if !SANITIZER_SOLARIS
+  begin = (uptr)info->dlpi_tls_data;
+#endif
   if (!g_use_dlpi_tls_data) {
     // Call __tls_get_addr as a fallback. This forces TLS allocation on glibc
     // and FreeBSD.
 #ifdef __s390__
     begin = (uptr)__builtin_thread_pointer() +
-            TlsGetOffset(info->dlpi_tls_modid, 0);
+            TlsGetOffset(tls_modid, 0);
 #else
-    size_t mod_and_off[2] = {info->dlpi_tls_modid, 0};
+    size_t mod_and_off[2] = {tls_modid, 0};
     begin = (uptr)__tls_get_addr(mod_and_off);
 #endif
   }
@@ -370,7 +396,7 @@ static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size,
     if (info->dlpi_phdr[i].p_type == PT_TLS) {
       static_cast<InternalMmapVector<TlsBlock> *>(data)->push_back(
           TlsBlock{begin, begin + info->dlpi_phdr[i].p_memsz,
-                   info->dlpi_phdr[i].p_align, info->dlpi_tls_modid});
+                   info->dlpi_phdr[i].p_align, tls_modid});
       break;
     }
   return 0;
@@ -382,11 +408,11 @@ __attribute__((unused)) static void GetStaticTlsBoundary(uptr *addr, uptr *size,
   dl_iterate_phdr(CollectStaticTlsBlocks, &ranges);
   uptr len = ranges.size();
   Sort(ranges.begin(), len);
-  // Find the range with tls_modid=1. For glibc, because libc.so uses PT_TLS,
-  // this module is guaranteed to exist and is one of the initially loaded
-  // modules.
+  // Find the range with tls_modid == main_tls_modid. For glibc, because
+  // libc.so uses PT_TLS, this module is guaranteed to exist and is one of
+  // the initially loaded modules.
   uptr one = 0;
-  while (one != len && ranges[one].tls_modid != 1) ++one;
+  while (one != len && ranges[one].tls_modid != main_tls_modid) ++one;
   if (one == len) {
     // This may happen with musl if no module uses PT_TLS.
     *addr = 0;
diff --git a/libsanitizer/sanitizer_common/sanitizer_solaris.h b/libsanitizer/sanitizer_common/sanitizer_solaris.h
new file mode 100644
index 00000000000..2a21693efbf
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_solaris.h
@@ -0,0 +1,56 @@
+//===-- sanitizer_solaris.h -------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of Sanitizer runtime. It contains Solaris-specific
+// definitions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_SOLARIS_H
+#define SANITIZER_SOLARIS_H
+
+#include "sanitizer_internal_defs.h"
+
+#if SANITIZER_SOLARIS
+
+#include <link.h>
+
+namespace __sanitizer {
+
+// Beginning of declaration from OpenSolaris/Illumos
+// $SRC/cmd/sgs/include/rtld.h.
+struct Rt_map {
+  Link_map rt_public;
+  const char *rt_pathname;
+  ulong_t rt_padstart;
+  ulong_t rt_padimlen;
+  ulong_t rt_msize;
+  uint_t rt_flags;
+  uint_t rt_flags1;
+  ulong_t rt_tlsmodid;
+};
+
+// Structure matching the Solaris 11.4 struct dl_phdr_info used to determine
+// presence of dlpi_tls_modid field at runtime.  Cf. Solaris 11.4
+// dl_iterate_phdr(3C), Example 2.
+struct dl_phdr_info_test {
+  ElfW(Addr) dlpi_addr;
+  const char *dlpi_name;
+  const ElfW(Phdr) * dlpi_phdr;
+  ElfW(Half) dlpi_phnum;
+  u_longlong_t dlpi_adds;
+  u_longlong_t dlpi_subs;
+  size_t dlpi_tls_modid;
+  void *dlpi_tls_data;
+};
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_SOLARIS
+
+#endif  // SANITIZER_SOLARIS_H