xref: /freebsd/contrib/llvm-project/compiler-rt/lib/ubsan_minimal/ubsan_minimal_handlers.cpp (revision 580744621f33383027108364dcadad718df46ffe)
1 #include "sanitizer_common/sanitizer_atomic.h"
2 
3 #include <stdlib.h>
4 #include <stdint.h>
5 #include <string.h>
6 #include <unistd.h>
7 
8 #ifdef KERNEL_USE
9 extern "C" void ubsan_message(const char *msg);
10 static void message(const char *msg) { ubsan_message(msg); }
11 #else
12 static void message(const char *msg) {
13   write(2, msg, strlen(msg));
14 }
15 #endif
16 
17 static const int kMaxCallerPcs = 20;
18 static __sanitizer::atomic_uintptr_t caller_pcs[kMaxCallerPcs];
19 // Number of elements in caller_pcs. A special value of kMaxCallerPcs + 1 means
20 // that "too many errors" has already been reported.
21 static __sanitizer::atomic_uint32_t caller_pcs_sz;
22 
23 __attribute__((noinline)) static bool report_this_error(void *caller_p) {
24   uintptr_t caller = reinterpret_cast<uintptr_t>(caller_p);
25   if (caller == 0) return false;
26   while (true) {
27     unsigned sz = __sanitizer::atomic_load_relaxed(&caller_pcs_sz);
28     if (sz > kMaxCallerPcs) return false;  // early exit
29     // when sz==kMaxCallerPcs print "too many errors", but only when cmpxchg
30     // succeeds in order to not print it multiple times.
31     if (sz > 0 && sz < kMaxCallerPcs) {
32       uintptr_t p;
33       for (unsigned i = 0; i < sz; ++i) {
34         p = __sanitizer::atomic_load_relaxed(&caller_pcs[i]);
35         if (p == 0) break;  // Concurrent update.
36         if (p == caller) return false;
37       }
38       if (p == 0) continue;  // FIXME: yield?
39     }
40 
41     if (!__sanitizer::atomic_compare_exchange_strong(
42             &caller_pcs_sz, &sz, sz + 1, __sanitizer::memory_order_seq_cst))
43       continue;  // Concurrent update! Try again from the start.
44 
45     if (sz == kMaxCallerPcs) {
46       message("ubsan: too many errors\n");
47       return false;
48     }
49     __sanitizer::atomic_store_relaxed(&caller_pcs[sz], caller);
50     return true;
51   }
52 }
53 
54 #if defined(__ANDROID__)
55 extern "C" __attribute__((weak)) void android_set_abort_message(const char *);
56 static void abort_with_message(const char *msg) {
57   if (&android_set_abort_message) android_set_abort_message(msg);
58   abort();
59 }
60 #else
61 static void abort_with_message(const char *) { abort(); }
62 #endif
63 
64 #if SANITIZER_DEBUG
65 namespace __sanitizer {
66 // The DCHECK macro needs this symbol to be defined.
67 void NORETURN CheckFailed(const char *file, int, const char *cond, u64, u64) {
68   message("Sanitizer CHECK failed: ");
69   message(file);
70   message(":?? : "); // FIXME: Show line number.
71   message(cond);
72   abort();
73 }
74 } // namespace __sanitizer
75 #endif
76 
77 #define INTERFACE extern "C" __attribute__((visibility("default")))
78 
79 // FIXME: add caller pc to the error message (possibly as "ubsan: error-type
80 // @1234ABCD").
81 #define HANDLER_RECOVER(name, msg)                               \
82   INTERFACE void __ubsan_handle_##name##_minimal() {             \
83     if (!report_this_error(__builtin_return_address(0))) return; \
84     message("ubsan: " msg "\n");                                 \
85   }
86 
87 #define HANDLER_NORECOVER(name, msg)                             \
88   INTERFACE void __ubsan_handle_##name##_minimal_abort() {       \
89     message("ubsan: " msg "\n");                                 \
90     abort_with_message("ubsan: " msg);                           \
91   }
92 
93 #define HANDLER(name, msg)                                       \
94   HANDLER_RECOVER(name, msg)                                     \
95   HANDLER_NORECOVER(name, msg)
96 
97 HANDLER(type_mismatch, "type-mismatch")
98 HANDLER(alignment_assumption, "alignment-assumption")
99 HANDLER(add_overflow, "add-overflow")
100 HANDLER(sub_overflow, "sub-overflow")
101 HANDLER(mul_overflow, "mul-overflow")
102 HANDLER(negate_overflow, "negate-overflow")
103 HANDLER(divrem_overflow, "divrem-overflow")
104 HANDLER(shift_out_of_bounds, "shift-out-of-bounds")
105 HANDLER(out_of_bounds, "out-of-bounds")
106 HANDLER_RECOVER(builtin_unreachable, "builtin-unreachable")
107 HANDLER_RECOVER(missing_return, "missing-return")
108 HANDLER(vla_bound_not_positive, "vla-bound-not-positive")
109 HANDLER(float_cast_overflow, "float-cast-overflow")
110 HANDLER(load_invalid_value, "load-invalid-value")
111 HANDLER(invalid_builtin, "invalid-builtin")
112 HANDLER(function_type_mismatch, "function-type-mismatch")
113 HANDLER(implicit_conversion, "implicit-conversion")
114 HANDLER(nonnull_arg, "nonnull-arg")
115 HANDLER(nonnull_return, "nonnull-return")
116 HANDLER(nullability_arg, "nullability-arg")
117 HANDLER(nullability_return, "nullability-return")
118 HANDLER(pointer_overflow, "pointer-overflow")
119 HANDLER(cfi_check_fail, "cfi-check-fail")
120