1
2 #include "config.h"
3 #include <pthread.h>
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <assert.h>
7
8 /* Simple test program, no race. Parent and child both modify x and
9 use the hardware bus lock (implicitly, since XCHG r,m on x86/amd64
10 does not require an explicit LOCK prefix.). */
11
12 #undef PLAT_x86_darwin
13 #undef PLAT_amd64_darwin
14 #undef PLAT_x86_linux
15 #undef PLAT_amd64_linux
16 #undef PLAT_ppc32_linux
17 #undef PLAT_ppc64be_linux
18 #undef PLAT_arm_linux
19 #undef PLAT_s390x_linux
20 #undef PLAT_mips32_linux
21 #undef PLAT_tilegx_linux
22 #undef PLAT_x86_solaris
23 #undef PLAT_amd64_solaris
24
25 #if defined(__APPLE__) && defined(__i386__)
26 # define PLAT_x86_darwin 1
27 #elif defined(__APPLE__) && defined(__x86_64__)
28 # define PLAT_amd64_darwin 1
29 #elif defined(__linux__) && defined(__i386__)
30 # define PLAT_x86_linux 1
31 #elif defined(__linux__) && defined(__x86_64__)
32 # define PLAT_amd64_linux 1
33 #elif defined(__linux__) && defined(__powerpc__) && !defined(__powerpc64__)
34 # define PLAT_ppc32_linux 1
35 #elif defined(__linux__) && defined(__powerpc__) && defined(__powerpc64__)
36 # define PLAT_ppc64_linux 1
37 #elif defined(__linux__) && defined(__arm__) && !defined(__aarch64__)
38 # define PLAT_arm_linux 1
39 #elif defined(__linux__) && defined(__aarch64__) && !defined(__arm__)
40 # define PLAT_arm64_linux 1
41 #elif defined(__linux__) && defined(__s390x__)
42 # define PLAT_s390x_linux 1
43 #elif defined(__linux__) && defined(__mips__)
44 # define PLAT_mips32_linux 1
45 #elif defined(__linux__) && defined(__tilegx__)
46 # define PLAT_tilegx_linux 1
47 #elif defined(__sun__) && defined(__i386__)
48 # define PLAT_x86_solaris 1
49 #elif defined(__sun__) && defined(__x86_64__)
50 # define PLAT_amd64_solaris 1
51 #endif
52
53
54 #if defined(PLAT_amd64_linux) || defined(PLAT_x86_linux) \
55 || defined(PLAT_amd64_darwin) || defined(PLAT_x86_darwin) \
56 || defined(PLAT_amd64_solaris) || defined(PLAT_x86_solaris)
57 # define XCHG_M_R(_addr,_lval) \
58 __asm__ __volatile__( \
59 "xchgl %0, %1" \
60 : /*out*/ "+r"(_lval) \
61 : /*in*/ "m"(_addr) \
62 : "memory", "cc" \
63 )
64 # define XCHG_M_R_with_redundant_LOCK(_addr,_lval) \
65 __asm__ __volatile__( \
66 "lock xchgl %0, %1" \
67 : /*out*/ "+r"(_lval) \
68 : /*in*/ "m"(_addr) \
69 : "memory", "cc" \
70 )
71
72 #elif defined(PLAT_s390x_linux)
73 # define XCHG_M_R(_addr,_lval) \
74 do { \
75 __asm__ __volatile__( \
76 "0: l 0,%[global]\n\t" \
77 " cs 0,%[local],%[global]\n\t" \
78 " bne 0b\n\t" \
79 " lr %[local],0\n\t" \
80 : /*out*/ [global]"+m"(_addr), [local]"+d"(_lval) \
81 : /*in*/ \
82 : "0", "memory", "cc" \
83 ); \
84 } while (0)
85
86 # define XCHG_M_R_with_redundant_LOCK(_addr,_lval) \
87 XCHG_M_R(_addr,_lval)
88
89 #elif defined(PLAT_mips32_linux) || defined(PLAT_mips64_linux)
90 # define XCHG_M_R(_addr,_lval) \
91 __asm__ __volatile__( \
92 "move $12, %2\n" \
93 "move $13, %1\n" \
94 "ll $14, 0($13)\n" \
95 "sc $12, 0($13)\n" \
96 "move %0, $14\n" \
97 : /*out*/ "=r"(_lval) \
98 : /*in*/ "r"(&_addr), "r"(_lval) \
99 : "$12", "$13", "$14", "memory", "cc" \
100 )
101
102 # define XCHG_M_R_with_redundant_LOCK(_addr,_lval) \
103 XCHG_M_R(_addr,_lval)
104
105 #elif defined(PLAT_ppc32_linux) || defined(PLAT_ppc64_linux) \
106 || defined(PLAT_arm_linux) || defined(PLAT_arm64_linux)
107 # if defined(HAVE_BUILTIN_ATOMIC)
108 # define XCHG_M_R(_addr,_lval) \
109 do { \
110 int tmp; \
111 while ((tmp = *(int*)(& _addr)), \
112 ! __sync_bool_compare_and_swap((int*)&_addr, tmp, _lval)) \
113 ; \
114 _lval = tmp; \
115 } while (0)
116 # else
117 # warning "XCHG_M_R() implementation is missing. Either" \
118 "provide one or use a newer gcc version."
119 # define XCHG_M_R(_addr,_lval) \
120 do { int tmp = *(int*)(& _addr); \
121 *(int*)(& _addr) = (_lval); \
122 _lval = tmp; \
123 } while (0)
124 # endif
125 # define XCHG_M_R_with_redundant_LOCK(_addr,_lval) \
126 XCHG_M_R(_addr,_lval)
127
128 #elif defined(PLAT_tilegx_linux)
129 # define XCHG_M_R(_addr,_lval) \
130 _lval = __insn_exch4(&_addr, _lval)
131
132 # define XCHG_M_R_with_redundant_LOCK(_addr,_lval) \
133 XCHG_M_R(_addr, _lval)
134 #else
135 # error "Unsupported architecture"
136
137 #endif
138
139 int x = 0;
140
child_fn(void * arg)141 void* child_fn ( void* arg )
142 {
143 int v = 12345;
144 XCHG_M_R_with_redundant_LOCK(x, v);
145 assert(v == 0 || v == 6789);
146 return NULL;
147 }
148
main(void)149 int main ( void )
150 {
151 int v = 6789;
152 pthread_t child;
153
154 if (pthread_create(&child, NULL, child_fn, NULL)) {
155 perror("pthread_create");
156 exit(1);
157 }
158
159 XCHG_M_R(x, v);
160 assert(v == 0 || v == 12345);
161
162 if (pthread_join(child, NULL)) {
163 perror("pthread join");
164 exit(1);
165 }
166
167 if (v == 0 || v == 12345)
168 printf("success\n");
169 else
170 printf("failure\n");
171
172 return v;
173 }
174