1 /* Test that lazy binding does not clobber r0.
2 Copyright (C) 2018-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <assert.h>
20 #include <dlfcn.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <unistd.h>
24
25 #if defined (__s390x__)
26 static const unsigned long magic_value = 0x0011223344556677UL;
27 #else
28 static const unsigned long magic_value = 0x00112233;
29 #endif
30
31 unsigned long r0x2_trampoline (unsigned long);
32
33 /* Invoke r0x2, which doubles the value in r0. If we get
34 value * 2 back, this means nothing clobbers r0, particularly,
35 _dl_runtime_resolve and _dl_runtime_profile. */
36 asm (" .type r0x2_trampoline, @function\n"
37 "r0x2_trampoline:\n"
38 #if defined (__s390x__)
39 " lgr %r0,%r2\n"
40 " stg %r14,112(%r15)\n"
41 " aghi %r15,-160\n"
42 " brasl %r14,r0x2@plt\n"
43 " aghi %r15,160\n"
44 " lg %r14,112(%r15)\n"
45 " lgr %r2,%r0\n"
46 " br %r14\n"
47 #elif defined (__zarch__)
48 " lr %r0,%r2\n"
49 " st %r14,56(%r15)\n"
50 " ahi %r15,-96\n"
51 " brasl %r14,r0x2@plt\n"
52 " ahi %r15,96\n"
53 " l %r14,56(%r15)\n"
54 " lr %r2,%r0\n"
55 " br %r14\n"
56 #else
57 " lr %r0,%r2\n"
58 " st %r14,56(%r15)\n"
59 " ahi %r15,-96\n"
60 " balr %r14,0\n"
61 " l %r14,1f-.(%r14)\n"
62 " basr %r14,%r14\n"
63 " ahi %r15,96\n"
64 " l %r14,56(%r15)\n"
65 " lr %r2,%r0\n"
66 " br %r14\n"
67 "1: .long r0x2\n"
68 #endif
69 );
70
71 static int
do_test(void)72 do_test (void)
73 {
74 int i;
75 unsigned long r0;
76 const char *run;
77
78 for (i = 0; i < 2; i++)
79 {
80 run = (i == 0) ? "lazy" : "non-lazy";
81 r0 = magic_value;
82 printf ("-> %s r0 = 0x%lx\n", run, r0);
83 r0 = r0x2_trampoline (r0);
84 printf ("<- %s r0 * 2 = 0x%lx\n", run, r0);
85 if (r0 != magic_value * 2)
86 return EXIT_FAILURE;
87 }
88 return EXIT_SUCCESS;
89 }
90
91 #include <support/test-driver.c>
92