1 //===-- asan_asm_test.cc --------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of AddressSanitizer, an address sanity checker.
11 //
12 //===----------------------------------------------------------------------===//
13 #include "asan_test_utils.h"
14 
15 #if defined(__linux__)
16 
17 // Assembly instrumentation is broken on x86 Android (x86 + PIC + shared runtime
18 // library). See https://github.com/google/sanitizers/issues/353
19 #if defined(__x86_64__) ||                                                     \
20     (defined(__i386__) && defined(__SSE2__) && !defined(__ANDROID__))
21 
22 #include <emmintrin.h>
23 
24 namespace {
25 
26 template<typename T> void asm_write(T *ptr, T val);
27 template<typename T> T asm_read(T *ptr);
28 template<typename T> void asm_rep_movs(T *dst, T *src, size_t n);
29 
30 } // End of anonymous namespace
31 
32 #endif // defined(__x86_64__) || (defined(__i386__) && defined(__SSE2__))
33 
34 #if defined(__x86_64__)
35 
36 namespace {
37 
38 #define DECLARE_ASM_WRITE(Type, Size, Mov, Reg)        \
39 template<> void asm_write<Type>(Type *ptr, Type val) { \
40   __asm__(                                             \
41     Mov " %[val], (%[ptr])  \n\t"                      \
42     :                                                  \
43     : [ptr] "r" (ptr), [val] Reg (val)                 \
44     : "memory"                                         \
45   );                                                   \
46 }
47 
48 #define DECLARE_ASM_READ(Type, Size, Mov, Reg)     \
49 template<> Type asm_read<Type>(Type *ptr) {        \
50   Type res;                                        \
51   __asm__(                                         \
52     Mov " (%[ptr]), %[res]  \n\t"                  \
53     : [res] Reg (res)                              \
54     : [ptr] "r" (ptr)                              \
55     : "memory"                                     \
56   );                                               \
57   return res;                                      \
58 }
59 
60 #define DECLARE_ASM_REP_MOVS(Type, Movs)                                       \
61   template <> void asm_rep_movs<Type>(Type * dst, Type * src, size_t size) {   \
62     __asm__("rep " Movs " \n\t"                                                \
63             :                                                                  \
64             : "D"(dst), "S"(src), "c"(size)                                    \
65             : "rsi", "rdi", "rcx", "memory");                                  \
66   }
67 
68 DECLARE_ASM_WRITE(U8, "8", "movq", "r");
69 DECLARE_ASM_READ(U8, "8", "movq", "=r");
70 DECLARE_ASM_REP_MOVS(U8, "movsq");
71 
72 } // End of anonymous namespace
73 
74 #endif // defined(__x86_64__)
75 
76 #if defined(__i386__) && defined(__SSE2__) && !defined(__ANDROID__)
77 
78 namespace {
79 
80 #define DECLARE_ASM_WRITE(Type, Size, Mov, Reg)        \
81 template<> void asm_write<Type>(Type *ptr, Type val) { \
82   __asm__(                                             \
83     Mov " %[val], (%[ptr])  \n\t"                      \
84     :                                                  \
85     : [ptr] "r" (ptr), [val] Reg (val)                 \
86     : "memory"                                         \
87   );                                                   \
88 }
89 
90 #define DECLARE_ASM_READ(Type, Size, Mov, Reg)     \
91 template<> Type asm_read<Type>(Type *ptr) {        \
92   Type res;                                        \
93   __asm__(                                         \
94     Mov " (%[ptr]), %[res]  \n\t"                  \
95     : [res] Reg (res)                              \
96     : [ptr] "r" (ptr)                              \
97     : "memory"                                     \
98   );                                               \
99   return res;                                      \
100 }
101 
102 #define DECLARE_ASM_REP_MOVS(Type, Movs)                                       \
103   template <> void asm_rep_movs<Type>(Type * dst, Type * src, size_t size) {   \
104     __asm__("rep " Movs " \n\t"                                                \
105             :                                                                  \
106             : "D"(dst), "S"(src), "c"(size)                                    \
107             : "esi", "edi", "ecx", "memory");                                  \
108   }
109 
110 } // End of anonymous namespace
111 
112 #endif  // defined(__i386__) && defined(__SSE2__)
113 
114 #if defined(__x86_64__) ||                                                     \
115     (defined(__i386__) && defined(__SSE2__) && !defined(__ANDROID__))
116 
117 namespace {
118 
119 DECLARE_ASM_WRITE(U1, "1", "movb", "r");
120 DECLARE_ASM_WRITE(U2, "2", "movw", "r");
121 DECLARE_ASM_WRITE(U4, "4", "movl", "r");
122 DECLARE_ASM_WRITE(__m128i, "16", "movaps", "x");
123 
124 DECLARE_ASM_READ(U1, "1", "movb", "=r");
125 DECLARE_ASM_READ(U2, "2", "movw", "=r");
126 DECLARE_ASM_READ(U4, "4", "movl", "=r");
127 DECLARE_ASM_READ(__m128i, "16", "movaps", "=x");
128 
129 DECLARE_ASM_REP_MOVS(U1, "movsb");
130 DECLARE_ASM_REP_MOVS(U2, "movsw");
131 DECLARE_ASM_REP_MOVS(U4, "movsl");
132 
TestAsmWrite(const char * DeathPattern)133 template<typename T> void TestAsmWrite(const char *DeathPattern) {
134   T *buf = new T;
135   EXPECT_DEATH(asm_write(&buf[1], static_cast<T>(0)), DeathPattern);
136   T var = 0x12;
137   asm_write(&var, static_cast<T>(0x21));
138   ASSERT_EQ(static_cast<T>(0x21), var);
139   delete buf;
140 }
141 
TestAsmWrite(const char * DeathPattern)142 template<> void TestAsmWrite<__m128i>(const char *DeathPattern) {
143   char *buf = new char[16];
144   char *p = buf + 16;
145   if (((uintptr_t) p % 16) != 0)
146     p = buf + 8;
147   assert(((uintptr_t) p % 16) == 0);
148   __m128i val = _mm_set1_epi16(0x1234);
149   EXPECT_DEATH(asm_write<__m128i>((__m128i*) p, val), DeathPattern);
150   __m128i var = _mm_set1_epi16(0x4321);
151   asm_write(&var, val);
152   ASSERT_EQ(0x1234, _mm_extract_epi16(var, 0));
153   delete [] buf;
154 }
155 
TestAsmRead(const char * DeathPattern)156 template<typename T> void TestAsmRead(const char *DeathPattern) {
157   T *buf = new T;
158   EXPECT_DEATH(asm_read(&buf[1]), DeathPattern);
159   T var = 0x12;
160   ASSERT_EQ(static_cast<T>(0x12), asm_read(&var));
161   delete buf;
162 }
163 
TestAsmRead(const char * DeathPattern)164 template<> void TestAsmRead<__m128i>(const char *DeathPattern) {
165   char *buf = new char[16];
166   char *p = buf + 16;
167   if (((uintptr_t) p % 16) != 0)
168     p = buf + 8;
169   assert(((uintptr_t) p % 16) == 0);
170   EXPECT_DEATH(asm_read<__m128i>((__m128i*) p), DeathPattern);
171   __m128i val = _mm_set1_epi16(0x1234);
172   ASSERT_EQ(0x1234, _mm_extract_epi16(asm_read(&val), 0));
173   delete [] buf;
174 }
175 
AsmLoad(U4 * a)176 U4 AsmLoad(U4 *a) {
177   U4 r;
178   __asm__("movl (%[a]), %[r]  \n\t" : [r] "=r" (r) : [a] "r" (a) : "memory");
179   return r;
180 }
181 
AsmStore(U4 r,U4 * a)182 void AsmStore(U4 r, U4 *a) {
183   __asm__("movl %[r], (%[a])  \n\t" : : [a] "r" (a), [r] "r" (r) : "memory");
184 }
185 
186 template <typename T>
TestAsmRepMovs(const char * DeathPatternRead,const char * DeathPatternWrite)187 void TestAsmRepMovs(const char *DeathPatternRead,
188                     const char *DeathPatternWrite) {
189   T src_good[4] = { 0x0, 0x1, 0x2, 0x3 };
190   T dst_good[4] = {};
191   asm_rep_movs(dst_good, src_good, 4);
192   ASSERT_EQ(static_cast<T>(0x0), dst_good[0]);
193   ASSERT_EQ(static_cast<T>(0x1), dst_good[1]);
194   ASSERT_EQ(static_cast<T>(0x2), dst_good[2]);
195   ASSERT_EQ(static_cast<T>(0x3), dst_good[3]);
196 
197   T dst_bad[3];
198   EXPECT_DEATH(asm_rep_movs(dst_bad, src_good, 4), DeathPatternWrite);
199 
200   T src_bad[3] = { 0x0, 0x1, 0x2 };
201   EXPECT_DEATH(asm_rep_movs(dst_good, src_bad, 4), DeathPatternRead);
202 
203   T* dp = dst_bad + 4;
204   T* sp = src_bad + 4;
205   asm_rep_movs(dp, sp, 0);
206 }
207 
208 } // End of anonymous namespace
209 
TEST(AddressSanitizer,asm_load_store)210 TEST(AddressSanitizer, asm_load_store) {
211   U4* buf = new U4[2];
212   EXPECT_DEATH(AsmLoad(&buf[3]), "READ of size 4");
213   EXPECT_DEATH(AsmStore(0x1234, &buf[3]), "WRITE of size 4");
214   delete [] buf;
215 }
216 
TEST(AddressSanitizer,asm_rw)217 TEST(AddressSanitizer, asm_rw) {
218   TestAsmWrite<U1>("WRITE of size 1");
219   TestAsmWrite<U2>("WRITE of size 2");
220   TestAsmWrite<U4>("WRITE of size 4");
221 #if defined(__x86_64__)
222   TestAsmWrite<U8>("WRITE of size 8");
223 #endif // defined(__x86_64__)
224   TestAsmWrite<__m128i>("WRITE of size 16");
225 
226   TestAsmRead<U1>("READ of size 1");
227   TestAsmRead<U2>("READ of size 2");
228   TestAsmRead<U4>("READ of size 4");
229 #if defined(__x86_64__)
230   TestAsmRead<U8>("READ of size 8");
231 #endif // defined(__x86_64__)
232   TestAsmRead<__m128i>("READ of size 16");
233 }
234 
TEST(AddressSanitizer,asm_flags)235 TEST(AddressSanitizer, asm_flags) {
236   long magic = 0x1234;
237   long r = 0x0;
238 
239 #if defined(__x86_64__) && !defined(__ILP32__)
240   __asm__("xorq %%rax, %%rax  \n\t"
241           "movq (%[p]), %%rax \n\t"
242           "sete %%al          \n\t"
243           "movzbq %%al, %[r]  \n\t"
244           : [r] "=r"(r)
245           : [p] "r"(&magic)
246           : "rax", "memory");
247 #else
248   __asm__("xorl %%eax, %%eax  \n\t"
249           "movl (%[p]), %%eax \n\t"
250           "sete %%al          \n\t"
251           "movzbl %%al, %[r]  \n\t"
252           : [r] "=r"(r)
253           : [p] "r"(&magic)
254           : "eax", "memory");
255 #endif // defined(__x86_64__) && !defined(__ILP32__)
256 
257   ASSERT_EQ(0x1, r);
258 }
259 
TEST(AddressSanitizer,asm_rep_movs)260 TEST(AddressSanitizer, asm_rep_movs) {
261   TestAsmRepMovs<U1>("READ of size 1", "WRITE of size 1");
262   TestAsmRepMovs<U2>("READ of size 2", "WRITE of size 2");
263   TestAsmRepMovs<U4>("READ of size 4", "WRITE of size 4");
264 #if defined(__x86_64__)
265   TestAsmRepMovs<U8>("READ of size 8", "WRITE of size 8");
266 #endif  // defined(__x86_64__)
267 }
268 
269 #endif // defined(__x86_64__) || (defined(__i386__) && defined(__SSE2__))
270 
271 #endif // defined(__linux__)
272