502 lines
16 KiB
C++
502 lines
16 KiB
C++
//===-- asan_descriptions.cpp -----------------------------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file is a part of AddressSanitizer, an address sanity checker.
|
|
//
|
|
// ASan functions for getting information about an address and/or printing it.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "asan_descriptions.h"
|
|
#include "asan_mapping.h"
|
|
#include "asan_report.h"
|
|
#include "asan_stack.h"
|
|
#include "sanitizer_common/sanitizer_stackdepot.h"
|
|
|
|
namespace __asan {
|
|
|
|
AsanThreadIdAndName::AsanThreadIdAndName(AsanThreadContext *t) {
|
|
Init(t->tid, t->name);
|
|
}
|
|
|
|
AsanThreadIdAndName::AsanThreadIdAndName(u32 tid) {
|
|
if (tid == kInvalidTid) {
|
|
Init(tid, "");
|
|
} else {
|
|
asanThreadRegistry().CheckLocked();
|
|
AsanThreadContext *t = GetThreadContextByTidLocked(tid);
|
|
Init(tid, t->name);
|
|
}
|
|
}
|
|
|
|
void AsanThreadIdAndName::Init(u32 tid, const char *tname) {
|
|
int len = internal_snprintf(name, sizeof(name), "T%d", tid);
|
|
CHECK(((unsigned int)len) < sizeof(name));
|
|
if (tname[0] != '\0')
|
|
internal_snprintf(&name[len], sizeof(name) - len, " (%s)", tname);
|
|
}
|
|
|
|
void DescribeThread(AsanThreadContext *context) {
|
|
CHECK(context);
|
|
asanThreadRegistry().CheckLocked();
|
|
// No need to announce the main thread.
|
|
if (context->tid == 0 || context->announced) {
|
|
return;
|
|
}
|
|
context->announced = true;
|
|
InternalScopedString str(1024);
|
|
str.append("Thread %s", AsanThreadIdAndName(context).c_str());
|
|
if (context->parent_tid == kInvalidTid) {
|
|
str.append(" created by unknown thread\n");
|
|
Printf("%s", str.data());
|
|
return;
|
|
}
|
|
str.append(" created by %s here:\n",
|
|
AsanThreadIdAndName(context->parent_tid).c_str());
|
|
Printf("%s", str.data());
|
|
StackDepotGet(context->stack_id).Print();
|
|
// Recursively described parent thread if needed.
|
|
if (flags()->print_full_thread_history) {
|
|
AsanThreadContext *parent_context =
|
|
GetThreadContextByTidLocked(context->parent_tid);
|
|
DescribeThread(parent_context);
|
|
}
|
|
}
|
|
|
|
// Shadow descriptions
|
|
static bool GetShadowKind(uptr addr, ShadowKind *shadow_kind) {
|
|
CHECK(!AddrIsInMem(addr));
|
|
if (AddrIsInShadowGap(addr)) {
|
|
*shadow_kind = kShadowKindGap;
|
|
} else if (AddrIsInHighShadow(addr)) {
|
|
*shadow_kind = kShadowKindHigh;
|
|
} else if (AddrIsInLowShadow(addr)) {
|
|
*shadow_kind = kShadowKindLow;
|
|
} else {
|
|
CHECK(0 && "Address is not in memory and not in shadow?");
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool DescribeAddressIfShadow(uptr addr) {
|
|
ShadowAddressDescription descr;
|
|
if (!GetShadowAddressInformation(addr, &descr)) return false;
|
|
descr.Print();
|
|
return true;
|
|
}
|
|
|
|
bool GetShadowAddressInformation(uptr addr, ShadowAddressDescription *descr) {
|
|
if (AddrIsInMem(addr)) return false;
|
|
ShadowKind shadow_kind;
|
|
if (!GetShadowKind(addr, &shadow_kind)) return false;
|
|
if (shadow_kind != kShadowKindGap) descr->shadow_byte = *(u8 *)addr;
|
|
descr->addr = addr;
|
|
descr->kind = shadow_kind;
|
|
return true;
|
|
}
|
|
|
|
// Heap descriptions
|
|
static void GetAccessToHeapChunkInformation(ChunkAccess *descr,
|
|
AsanChunkView chunk, uptr addr,
|
|
uptr access_size) {
|
|
descr->bad_addr = addr;
|
|
if (chunk.AddrIsAtLeft(addr, access_size, &descr->offset)) {
|
|
descr->access_type = kAccessTypeLeft;
|
|
} else if (chunk.AddrIsAtRight(addr, access_size, &descr->offset)) {
|
|
descr->access_type = kAccessTypeRight;
|
|
if (descr->offset < 0) {
|
|
descr->bad_addr -= descr->offset;
|
|
descr->offset = 0;
|
|
}
|
|
} else if (chunk.AddrIsInside(addr, access_size, &descr->offset)) {
|
|
descr->access_type = kAccessTypeInside;
|
|
} else {
|
|
descr->access_type = kAccessTypeUnknown;
|
|
}
|
|
descr->chunk_begin = chunk.Beg();
|
|
descr->chunk_size = chunk.UsedSize();
|
|
descr->user_requested_alignment = chunk.UserRequestedAlignment();
|
|
descr->alloc_type = chunk.GetAllocType();
|
|
}
|
|
|
|
static void PrintHeapChunkAccess(uptr addr, const ChunkAccess &descr) {
|
|
Decorator d;
|
|
InternalScopedString str(4096);
|
|
str.append("%s", d.Location());
|
|
switch (descr.access_type) {
|
|
case kAccessTypeLeft:
|
|
str.append("%p is located %zd bytes to the left of",
|
|
(void *)descr.bad_addr, descr.offset);
|
|
break;
|
|
case kAccessTypeRight:
|
|
str.append("%p is located %zd bytes to the right of",
|
|
(void *)descr.bad_addr, descr.offset);
|
|
break;
|
|
case kAccessTypeInside:
|
|
str.append("%p is located %zd bytes inside of", (void *)descr.bad_addr,
|
|
descr.offset);
|
|
break;
|
|
case kAccessTypeUnknown:
|
|
str.append(
|
|
"%p is located somewhere around (this is AddressSanitizer bug!)",
|
|
(void *)descr.bad_addr);
|
|
}
|
|
str.append(" %zu-byte region [%p,%p)\n", descr.chunk_size,
|
|
(void *)descr.chunk_begin,
|
|
(void *)(descr.chunk_begin + descr.chunk_size));
|
|
str.append("%s", d.Default());
|
|
Printf("%s", str.data());
|
|
}
|
|
|
|
bool GetHeapAddressInformation(uptr addr, uptr access_size,
|
|
HeapAddressDescription *descr) {
|
|
AsanChunkView chunk = FindHeapChunkByAddress(addr);
|
|
if (!chunk.IsValid()) {
|
|
return false;
|
|
}
|
|
descr->addr = addr;
|
|
GetAccessToHeapChunkInformation(&descr->chunk_access, chunk, addr,
|
|
access_size);
|
|
CHECK_NE(chunk.AllocTid(), kInvalidTid);
|
|
descr->alloc_tid = chunk.AllocTid();
|
|
descr->alloc_stack_id = chunk.GetAllocStackId();
|
|
descr->free_tid = chunk.FreeTid();
|
|
if (descr->free_tid != kInvalidTid)
|
|
descr->free_stack_id = chunk.GetFreeStackId();
|
|
return true;
|
|
}
|
|
|
|
static StackTrace GetStackTraceFromId(u32 id) {
|
|
CHECK(id);
|
|
StackTrace res = StackDepotGet(id);
|
|
CHECK(res.trace);
|
|
return res;
|
|
}
|
|
|
|
bool DescribeAddressIfHeap(uptr addr, uptr access_size) {
|
|
HeapAddressDescription descr;
|
|
if (!GetHeapAddressInformation(addr, access_size, &descr)) {
|
|
Printf(
|
|
"AddressSanitizer can not describe address in more detail "
|
|
"(wild memory access suspected).\n");
|
|
return false;
|
|
}
|
|
descr.Print();
|
|
return true;
|
|
}
|
|
|
|
// Stack descriptions
|
|
bool GetStackAddressInformation(uptr addr, uptr access_size,
|
|
StackAddressDescription *descr) {
|
|
AsanThread *t = FindThreadByStackAddress(addr);
|
|
if (!t) return false;
|
|
|
|
descr->addr = addr;
|
|
descr->tid = t->tid();
|
|
// Try to fetch precise stack frame for this access.
|
|
AsanThread::StackFrameAccess access;
|
|
if (!t->GetStackFrameAccessByAddr(addr, &access)) {
|
|
descr->frame_descr = nullptr;
|
|
return true;
|
|
}
|
|
|
|
descr->offset = access.offset;
|
|
descr->access_size = access_size;
|
|
descr->frame_pc = access.frame_pc;
|
|
descr->frame_descr = access.frame_descr;
|
|
|
|
#if SANITIZER_PPC64V1
|
|
// On PowerPC64 ELFv1, the address of a function actually points to a
|
|
// three-doubleword data structure with the first field containing
|
|
// the address of the function's code.
|
|
descr->frame_pc = *reinterpret_cast<uptr *>(descr->frame_pc);
|
|
#endif
|
|
descr->frame_pc += 16;
|
|
|
|
return true;
|
|
}
|
|
|
|
static void PrintAccessAndVarIntersection(const StackVarDescr &var, uptr addr,
|
|
uptr access_size, uptr prev_var_end,
|
|
uptr next_var_beg) {
|
|
uptr var_end = var.beg + var.size;
|
|
uptr addr_end = addr + access_size;
|
|
const char *pos_descr = nullptr;
|
|
// If the variable [var.beg, var_end) is the nearest variable to the
|
|
// current memory access, indicate it in the log.
|
|
if (addr >= var.beg) {
|
|
if (addr_end <= var_end)
|
|
pos_descr = "is inside"; // May happen if this is a use-after-return.
|
|
else if (addr < var_end)
|
|
pos_descr = "partially overflows";
|
|
else if (addr_end <= next_var_beg &&
|
|
next_var_beg - addr_end >= addr - var_end)
|
|
pos_descr = "overflows";
|
|
} else {
|
|
if (addr_end > var.beg)
|
|
pos_descr = "partially underflows";
|
|
else if (addr >= prev_var_end && addr - prev_var_end >= var.beg - addr_end)
|
|
pos_descr = "underflows";
|
|
}
|
|
InternalScopedString str(1024);
|
|
str.append(" [%zd, %zd)", var.beg, var_end);
|
|
// Render variable name.
|
|
str.append(" '");
|
|
for (uptr i = 0; i < var.name_len; ++i) {
|
|
str.append("%c", var.name_pos[i]);
|
|
}
|
|
str.append("'");
|
|
if (var.line > 0) {
|
|
str.append(" (line %d)", var.line);
|
|
}
|
|
if (pos_descr) {
|
|
Decorator d;
|
|
// FIXME: we may want to also print the size of the access here,
|
|
// but in case of accesses generated by memset it may be confusing.
|
|
str.append("%s <== Memory access at offset %zd %s this variable%s\n",
|
|
d.Location(), addr, pos_descr, d.Default());
|
|
} else {
|
|
str.append("\n");
|
|
}
|
|
Printf("%s", str.data());
|
|
}
|
|
|
|
bool DescribeAddressIfStack(uptr addr, uptr access_size) {
|
|
StackAddressDescription descr;
|
|
if (!GetStackAddressInformation(addr, access_size, &descr)) return false;
|
|
descr.Print();
|
|
return true;
|
|
}
|
|
|
|
// Global descriptions
|
|
static void DescribeAddressRelativeToGlobal(uptr addr, uptr access_size,
|
|
const __asan_global &g) {
|
|
InternalScopedString str(4096);
|
|
Decorator d;
|
|
str.append("%s", d.Location());
|
|
if (addr < g.beg) {
|
|
str.append("%p is located %zd bytes to the left", (void *)addr,
|
|
g.beg - addr);
|
|
} else if (addr + access_size > g.beg + g.size) {
|
|
if (addr < g.beg + g.size) addr = g.beg + g.size;
|
|
str.append("%p is located %zd bytes to the right", (void *)addr,
|
|
addr - (g.beg + g.size));
|
|
} else {
|
|
// Can it happen?
|
|
str.append("%p is located %zd bytes inside", (void *)addr, addr - g.beg);
|
|
}
|
|
str.append(" of global variable '%s' defined in '",
|
|
MaybeDemangleGlobalName(g.name));
|
|
PrintGlobalLocation(&str, g);
|
|
str.append("' (0x%zx) of size %zu\n", g.beg, g.size);
|
|
str.append("%s", d.Default());
|
|
PrintGlobalNameIfASCII(&str, g);
|
|
Printf("%s", str.data());
|
|
}
|
|
|
|
bool GetGlobalAddressInformation(uptr addr, uptr access_size,
|
|
GlobalAddressDescription *descr) {
|
|
descr->addr = addr;
|
|
int globals_num = GetGlobalsForAddress(addr, descr->globals, descr->reg_sites,
|
|
ARRAY_SIZE(descr->globals));
|
|
descr->size = globals_num;
|
|
descr->access_size = access_size;
|
|
return globals_num != 0;
|
|
}
|
|
|
|
bool DescribeAddressIfGlobal(uptr addr, uptr access_size,
|
|
const char *bug_type) {
|
|
GlobalAddressDescription descr;
|
|
if (!GetGlobalAddressInformation(addr, access_size, &descr)) return false;
|
|
|
|
descr.Print(bug_type);
|
|
return true;
|
|
}
|
|
|
|
void ShadowAddressDescription::Print() const {
|
|
Printf("Address %p is located in the %s area.\n", addr, ShadowNames[kind]);
|
|
}
|
|
|
|
void GlobalAddressDescription::Print(const char *bug_type) const {
|
|
for (int i = 0; i < size; i++) {
|
|
DescribeAddressRelativeToGlobal(addr, access_size, globals[i]);
|
|
if (bug_type &&
|
|
0 == internal_strcmp(bug_type, "initialization-order-fiasco") &&
|
|
reg_sites[i]) {
|
|
Printf(" registered at:\n");
|
|
StackDepotGet(reg_sites[i]).Print();
|
|
}
|
|
}
|
|
}
|
|
|
|
bool GlobalAddressDescription::PointsInsideTheSameVariable(
|
|
const GlobalAddressDescription &other) const {
|
|
if (size == 0 || other.size == 0) return false;
|
|
|
|
for (uptr i = 0; i < size; i++) {
|
|
const __asan_global &a = globals[i];
|
|
for (uptr j = 0; j < other.size; j++) {
|
|
const __asan_global &b = other.globals[j];
|
|
if (a.beg == b.beg &&
|
|
a.beg <= addr &&
|
|
b.beg <= other.addr &&
|
|
(addr + access_size) < (a.beg + a.size) &&
|
|
(other.addr + other.access_size) < (b.beg + b.size))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
void StackAddressDescription::Print() const {
|
|
Decorator d;
|
|
Printf("%s", d.Location());
|
|
Printf("Address %p is located in stack of thread %s", addr,
|
|
AsanThreadIdAndName(tid).c_str());
|
|
|
|
if (!frame_descr) {
|
|
Printf("%s\n", d.Default());
|
|
return;
|
|
}
|
|
Printf(" at offset %zu in frame%s\n", offset, d.Default());
|
|
|
|
// Now we print the frame where the alloca has happened.
|
|
// We print this frame as a stack trace with one element.
|
|
// The symbolizer may print more than one frame if inlining was involved.
|
|
// The frame numbers may be different than those in the stack trace printed
|
|
// previously. That's unfortunate, but I have no better solution,
|
|
// especially given that the alloca may be from entirely different place
|
|
// (e.g. use-after-scope, or different thread's stack).
|
|
Printf("%s", d.Default());
|
|
StackTrace alloca_stack(&frame_pc, 1);
|
|
alloca_stack.Print();
|
|
|
|
InternalMmapVector<StackVarDescr> vars;
|
|
vars.reserve(16);
|
|
if (!ParseFrameDescription(frame_descr, &vars)) {
|
|
Printf(
|
|
"AddressSanitizer can't parse the stack frame "
|
|
"descriptor: |%s|\n",
|
|
frame_descr);
|
|
// 'addr' is a stack address, so return true even if we can't parse frame
|
|
return;
|
|
}
|
|
uptr n_objects = vars.size();
|
|
// Report the number of stack objects.
|
|
Printf(" This frame has %zu object(s):\n", n_objects);
|
|
|
|
// Report all objects in this frame.
|
|
for (uptr i = 0; i < n_objects; i++) {
|
|
uptr prev_var_end = i ? vars[i - 1].beg + vars[i - 1].size : 0;
|
|
uptr next_var_beg = i + 1 < n_objects ? vars[i + 1].beg : ~(0UL);
|
|
PrintAccessAndVarIntersection(vars[i], offset, access_size, prev_var_end,
|
|
next_var_beg);
|
|
}
|
|
Printf(
|
|
"HINT: this may be a false positive if your program uses "
|
|
"some custom stack unwind mechanism, swapcontext or vfork\n");
|
|
if (SANITIZER_WINDOWS)
|
|
Printf(" (longjmp, SEH and C++ exceptions *are* supported)\n");
|
|
else
|
|
Printf(" (longjmp and C++ exceptions *are* supported)\n");
|
|
|
|
DescribeThread(GetThreadContextByTidLocked(tid));
|
|
}
|
|
|
|
void HeapAddressDescription::Print() const {
|
|
PrintHeapChunkAccess(addr, chunk_access);
|
|
|
|
asanThreadRegistry().CheckLocked();
|
|
AsanThreadContext *alloc_thread = GetThreadContextByTidLocked(alloc_tid);
|
|
StackTrace alloc_stack = GetStackTraceFromId(alloc_stack_id);
|
|
|
|
Decorator d;
|
|
AsanThreadContext *free_thread = nullptr;
|
|
if (free_tid != kInvalidTid) {
|
|
free_thread = GetThreadContextByTidLocked(free_tid);
|
|
Printf("%sfreed by thread %s here:%s\n", d.Allocation(),
|
|
AsanThreadIdAndName(free_thread).c_str(), d.Default());
|
|
StackTrace free_stack = GetStackTraceFromId(free_stack_id);
|
|
free_stack.Print();
|
|
Printf("%spreviously allocated by thread %s here:%s\n", d.Allocation(),
|
|
AsanThreadIdAndName(alloc_thread).c_str(), d.Default());
|
|
} else {
|
|
Printf("%sallocated by thread %s here:%s\n", d.Allocation(),
|
|
AsanThreadIdAndName(alloc_thread).c_str(), d.Default());
|
|
}
|
|
alloc_stack.Print();
|
|
DescribeThread(GetCurrentThread());
|
|
if (free_thread) DescribeThread(free_thread);
|
|
DescribeThread(alloc_thread);
|
|
}
|
|
|
|
AddressDescription::AddressDescription(uptr addr, uptr access_size,
|
|
bool shouldLockThreadRegistry) {
|
|
if (GetShadowAddressInformation(addr, &data.shadow)) {
|
|
data.kind = kAddressKindShadow;
|
|
return;
|
|
}
|
|
if (GetHeapAddressInformation(addr, access_size, &data.heap)) {
|
|
data.kind = kAddressKindHeap;
|
|
return;
|
|
}
|
|
|
|
bool isStackMemory = false;
|
|
if (shouldLockThreadRegistry) {
|
|
ThreadRegistryLock l(&asanThreadRegistry());
|
|
isStackMemory = GetStackAddressInformation(addr, access_size, &data.stack);
|
|
} else {
|
|
isStackMemory = GetStackAddressInformation(addr, access_size, &data.stack);
|
|
}
|
|
if (isStackMemory) {
|
|
data.kind = kAddressKindStack;
|
|
return;
|
|
}
|
|
|
|
if (GetGlobalAddressInformation(addr, access_size, &data.global)) {
|
|
data.kind = kAddressKindGlobal;
|
|
return;
|
|
}
|
|
data.kind = kAddressKindWild;
|
|
addr = 0;
|
|
}
|
|
|
|
void PrintAddressDescription(uptr addr, uptr access_size,
|
|
const char *bug_type) {
|
|
ShadowAddressDescription shadow_descr;
|
|
if (GetShadowAddressInformation(addr, &shadow_descr)) {
|
|
shadow_descr.Print();
|
|
return;
|
|
}
|
|
|
|
GlobalAddressDescription global_descr;
|
|
if (GetGlobalAddressInformation(addr, access_size, &global_descr)) {
|
|
global_descr.Print(bug_type);
|
|
return;
|
|
}
|
|
|
|
StackAddressDescription stack_descr;
|
|
if (GetStackAddressInformation(addr, access_size, &stack_descr)) {
|
|
stack_descr.Print();
|
|
return;
|
|
}
|
|
|
|
HeapAddressDescription heap_descr;
|
|
if (GetHeapAddressInformation(addr, access_size, &heap_descr)) {
|
|
heap_descr.Print();
|
|
return;
|
|
}
|
|
|
|
// We exhausted our possibilities. Bail out.
|
|
Printf(
|
|
"AddressSanitizer can not describe address in more detail "
|
|
"(wild memory access suspected).\n");
|
|
}
|
|
} // namespace __asan
|