• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2024 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 // LLD tries not to generate a PT_TLS segment where (p_vaddr % p_align) is
30 // non-zero. It can still do so if the p_align values are greater than a page.
31 
32 #include <stdint.h>
33 #include <unistd.h>
34 
35 #include "CHECK.h"
36 
37 struct SmallVar {
38   int field;
39   char buffer[0x100 - sizeof(int)];
40 };
41 
42 struct AlignedVar {
43   int field;
44   char buffer[0x20000 - sizeof(int)];
45 } __attribute__((aligned(0x20000)));
46 
47 __thread struct SmallVar var1 = {13};
48 __thread struct SmallVar var2 = {17};
49 __thread struct AlignedVar var3;
50 __thread struct AlignedVar var4;
51 
var_addr(void * value)52 static uintptr_t var_addr(void* value) {
53   // Maybe the optimizer would assume that the variable has the alignment it is
54   // declared with.
55   asm volatile("" : "+r,m"(value) : : "memory");
56   return reinterpret_cast<uintptr_t>(value);
57 }
58 
main()59 int main() {
60   // Bionic only allocates ELF TLS blocks with up to page alignment.
61   CHECK((var_addr(&var3) & (getpagesize() - 1)) == 0);
62   CHECK((var_addr(&var4) & (getpagesize() - 1)) == 0);
63 
64   // TODO: These TLS accesses are broken with the current version of LLD. See
65   // https://github.com/llvm/llvm-project/issues/84743.
66 #if !defined(__riscv)
67   CHECK(var1.field == 13);
68   CHECK(var2.field == 17);
69 #endif
70 
71   CHECK(var3.field == 0);
72   CHECK(var4.field == 0);
73   return 0;
74 }
75