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Commit 2501cf768e4009a06287a5ee842fd93dd4fd690e

Authored by David Howells
1 parent c9034c3a1d
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

m68k: Fix xchg/cmpxchg to fail to link if given an inappropriate pointer 

Fix the m68k versions of xchg() and cmpxchg() to fail to link if given an
inappropriately sized pointer rather than BUG()'ing at runtime.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
cc: linux-m68k@lists.linux-m68k.org

Showing 1 changed file with 16 additions and 4 deletions Side-by-side Diff

arch/m68k/include/asm/system.h
Diff comments   View file @ 2501cf7
... ... @@ -68,6 +68,8 @@
68 68 struct __xchg_dummy { unsigned long a[100]; };
69 69 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
70 70  
  71 +extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
  72 +
71 73 #ifndef CONFIG_RMW_INSNS
72 74 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
73 75 {
... ... @@ -92,7 +94,8 @@
92 94 x = tmp;
93 95 break;
94 96 default:
95   - BUG();
  97 + tmp = __invalid_xchg_size(x, ptr, size);
  98 + break;
96 99 }
97 100  
98 101 local_irq_restore(flags);
... ... @@ -102,7 +105,7 @@
102 105 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
103 106 {
104 107 switch (size) {
105   - case 1:
  108 + case 1:
106 109 __asm__ __volatile__
107 110 ("moveb %2,%0\n\t"
108 111 "1:\n\t"
... ... @@ -110,7 +113,7 @@
110 113 "jne 1b"
111 114 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
112 115 break;
113   - case 2:
  116 + case 2:
114 117 __asm__ __volatile__
115 118 ("movew %2,%0\n\t"
116 119 "1:\n\t"
... ... @@ -118,7 +121,7 @@
118 121 "jne 1b"
119 122 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
120 123 break;
121   - case 4:
  124 + case 4:
122 125 __asm__ __volatile__
123 126 ("movel %2,%0\n\t"
124 127 "1:\n\t"
... ... @@ -126,6 +129,9 @@
126 129 "jne 1b"
127 130 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
128 131 break;
  132 + default:
  133 + x = __invalid_xchg_size(x, ptr, size);
  134 + break;
129 135 }
130 136 return x;
131 137 }
... ... @@ -135,6 +141,9 @@
135 141  
136 142 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
137 143  
  144 +extern unsigned long __invalid_cmpxchg_size(volatile void *,
  145 + unsigned long, unsigned long, int);
  146 +
138 147 /*
139 148 * Atomic compare and exchange. Compare OLD with MEM, if identical,
140 149 * store NEW in MEM. Return the initial value in MEM. Success is
... ... @@ -161,6 +170,9 @@
161 170 __asm__ __volatile__ ("casl %0,%2,%1"
162 171 : "=d" (old), "=m" (*(int *)p)
163 172 : "d" (new), "0" (old), "m" (*(int *)p));
  173 + break;
  174 + default:
  175 + old = __invalid_cmpxchg_size(p, old, new, size);
164 176 break;
165 177 }
166 178 return old;