202 lines · cpp
1#include "sanitizer_common/sanitizer_atomic.h"2 3#include <stdint.h>4#include <stdlib.h>5#include <string.h>6#include <unistd.h>7 8#ifdef KERNEL_USE9extern "C" void ubsan_message(const char *msg);10static void message(const char *msg) { ubsan_message(msg); }11#else12static void message(const char *msg) { (void)write(2, msg, strlen(msg)); }13#endif14 15// If for some reason we cannot build the runtime with preserve_all, don't16// emit any symbol. Programs that need them will fail to link, but that is17// better than randomly corrupted registers.18// Some architectures don't support preserve_all (but clang still has the)19// attribute. For now, only support x86-64 and aarch64.20#if defined(__clang__) && defined(__has_cpp_attribute) && \21 (defined(__x86_64__) || defined(__aarch64__))22#if __has_cpp_attribute(clang::preserve_all)23#define PRESERVE_HANDLERS true24#else25#define PRESERVE_HANDLERS false26#endif27#else28#define PRESERVE_HANDLERS false29#endif30 31static const int kMaxCallerPcs = 20;32static __sanitizer::atomic_uintptr_t caller_pcs[kMaxCallerPcs];33// Number of elements in caller_pcs. A special value of kMaxCallerPcs + 1 means34// that "too many errors" has already been reported.35static __sanitizer::atomic_uint32_t caller_pcs_sz;36 37static char *append_str(const char *s, char *buf, const char *end) {38 for (const char *p = s; (buf < end) && (*p != '\0'); ++p, ++buf)39 *buf = *p;40 return buf;41}42 43static char *append_hex(uintptr_t d, char *buf, const char *end) {44 // Print the address by nibbles.45 for (unsigned shift = sizeof(uintptr_t) * 8; shift && buf < end;) {46 shift -= 4;47 unsigned nibble = (d >> shift) & 0xf;48 *(buf++) = nibble < 10 ? nibble + '0' : nibble - 10 + 'a';49 }50 return buf;51}52 53static void format_msg(const char *kind, uintptr_t caller, char *buf,54 const char *end) {55 buf = append_str("ubsan: ", buf, end);56 buf = append_str(kind, buf, end);57 buf = append_str(" by 0x", buf, end);58 buf = append_hex(caller, buf, end);59 buf = append_str("\n", buf, end);60 if (buf == end)61 --buf; // Make sure we don't cause a buffer overflow.62 *buf = '\0';63}64 65SANITIZER_INTERFACE_WEAK_DEF(void, __ubsan_report_error, const char *kind,66 uintptr_t caller) {67 if (caller == 0)68 return;69 while (true) {70 unsigned sz = __sanitizer::atomic_load_relaxed(&caller_pcs_sz);71 if (sz > kMaxCallerPcs)72 return; // early exit73 // when sz==kMaxCallerPcs print "too many errors", but only when cmpxchg74 // succeeds in order to not print it multiple times.75 if (sz > 0 && sz < kMaxCallerPcs) {76 uintptr_t p;77 for (unsigned i = 0; i < sz; ++i) {78 p = __sanitizer::atomic_load_relaxed(&caller_pcs[i]);79 if (p == 0)80 break; // Concurrent update.81 if (p == caller)82 return;83 }84 if (p == 0)85 continue; // FIXME: yield?86 }87 88 if (!__sanitizer::atomic_compare_exchange_strong(89 &caller_pcs_sz, &sz, sz + 1, __sanitizer::memory_order_seq_cst))90 continue; // Concurrent update! Try again from the start.91 92 if (sz == kMaxCallerPcs) {93 message("ubsan: too many errors\n");94 return;95 }96 __sanitizer::atomic_store_relaxed(&caller_pcs[sz], caller);97 98 char msg_buf[128];99 format_msg(kind, caller, msg_buf, msg_buf + sizeof(msg_buf));100 message(msg_buf);101 }102}103 104#if PRESERVE_HANDLERS105SANITIZER_INTERFACE_WEAK_DEF(void, __ubsan_report_error_preserve,106 const char *kind, uintptr_t caller)107[[clang::preserve_all]] {108 // Additional indirecton so the user can override this with their own109 // preserve_all function. This would allow, e.g., a function that reports the110 // first error only, so for all subsequent calls we can skip the register save111 // / restore.112 __ubsan_report_error(kind, caller);113}114#endif115 116SANITIZER_INTERFACE_WEAK_DEF(void, __ubsan_report_error_fatal, const char *kind,117 uintptr_t caller) {118 // Use another handlers, in case it's already overriden.119 __ubsan_report_error(kind, caller);120}121 122#if defined(__ANDROID__)123extern "C" __attribute__((weak)) void android_set_abort_message(const char *);124static void abort_with_message(const char *kind, uintptr_t caller) {125 char msg_buf[128];126 format_msg(kind, caller, msg_buf, msg_buf + sizeof(msg_buf));127 if (&android_set_abort_message)128 android_set_abort_message(msg_buf);129 abort();130}131#else132static void abort_with_message(const char *kind, uintptr_t caller) { abort(); }133#endif134 135#if SANITIZER_DEBUG136namespace __sanitizer {137// The DCHECK macro needs this symbol to be defined.138void NORETURN CheckFailed(const char *file, int, const char *cond, u64, u64) {139 message("Sanitizer CHECK failed: ");140 message(file);141 message(":?? : "); // FIXME: Show line number.142 message(cond);143 abort();144}145} // namespace __sanitizer146#endif147 148#define INTERFACE extern "C" __attribute__((visibility("default")))149 150#if PRESERVE_HANDLERS151#define HANDLER_PRESERVE(name, kind) \152 INTERFACE void __ubsan_handle_##name##_minimal_preserve() \153 [[clang::preserve_all]] { \154 __ubsan_report_error_preserve(kind, GET_CALLER_PC()); \155 }156#else157#define HANDLER_PRESERVE(name, kind)158#endif159 160#define HANDLER_RECOVER(name, kind) \161 INTERFACE void __ubsan_handle_##name##_minimal() { \162 __ubsan_report_error(kind, GET_CALLER_PC()); \163 }164 165#define HANDLER_NORECOVER(name, kind) \166 INTERFACE void __ubsan_handle_##name##_minimal_abort() { \167 uintptr_t caller = GET_CALLER_PC(); \168 __ubsan_report_error_fatal(kind, caller); \169 abort_with_message(kind, caller); \170 }171 172#define HANDLER(name, kind) \173 HANDLER_RECOVER(name, kind) \174 HANDLER_NORECOVER(name, kind) \175 HANDLER_PRESERVE(name, kind)176 177HANDLER(type_mismatch, "type-mismatch")178HANDLER(alignment_assumption, "alignment-assumption")179HANDLER(add_overflow, "add-overflow")180HANDLER(sub_overflow, "sub-overflow")181HANDLER(mul_overflow, "mul-overflow")182HANDLER(negate_overflow, "negate-overflow")183HANDLER(divrem_overflow, "divrem-overflow")184HANDLER(shift_out_of_bounds, "shift-out-of-bounds")185HANDLER(out_of_bounds, "out-of-bounds")186HANDLER(local_out_of_bounds, "local-out-of-bounds")187HANDLER_RECOVER(builtin_unreachable, "builtin-unreachable")188HANDLER_RECOVER(missing_return, "missing-return")189HANDLER(vla_bound_not_positive, "vla-bound-not-positive")190HANDLER(float_cast_overflow, "float-cast-overflow")191HANDLER(load_invalid_value, "load-invalid-value")192HANDLER(invalid_builtin, "invalid-builtin")193HANDLER(invalid_objc_cast, "invalid-objc-cast")194HANDLER(function_type_mismatch, "function-type-mismatch")195HANDLER(implicit_conversion, "implicit-conversion")196HANDLER(nonnull_arg, "nonnull-arg")197HANDLER(nonnull_return, "nonnull-return")198HANDLER(nullability_arg, "nullability-arg")199HANDLER(nullability_return, "nullability-return")200HANDLER(pointer_overflow, "pointer-overflow")201HANDLER(cfi_check_fail, "cfi-check-fail")202