blob: f078f1041a87f059f20a9d61be8285378eed2b0e [file] [log] [blame]
//===-- asan_debugging.cpp ------------------------------------------------===//
//
// 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.
//
// This file contains various functions that are generally useful to call when
// using a debugger (LLDB, GDB).
//===----------------------------------------------------------------------===//
#include "asan_allocator.h"
#include "asan_descriptions.h"
#include "asan_flags.h"
#include "asan_internal.h"
#include "asan_mapping.h"
#include "asan_report.h"
#include "asan_thread.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
namespace {
using namespace __asan;
static void FindInfoForStackVar(uptr addr, const char *frame_descr, uptr offset,
char *name, uptr name_size,
uptr *region_address, uptr *region_size) {
InternalMmapVector<StackVarDescr> vars;
vars.reserve(16);
if (!ParseFrameDescription(frame_descr, &vars)) {
return;
}
for (uptr i = 0; i < vars.size(); i++) {
if (offset <= vars[i].beg + vars[i].size) {
// We use name_len + 1 because strlcpy will guarantee a \0 at the end, so
// if we're limiting the copy due to name_len, we add 1 to ensure we copy
// the whole name and then terminate with '\0'.
internal_strlcpy(name, vars[i].name_pos,
Min(name_size, vars[i].name_len + 1));
*region_address = addr - (offset - vars[i].beg);
*region_size = vars[i].size;
return;
}
}
}
uptr AsanGetStack(uptr addr, uptr *trace, u32 size, u32 *thread_id,
bool alloc_stack) {
AsanChunkView chunk = FindHeapChunkByAddress(addr);
if (!chunk.IsValid()) return 0;
StackTrace stack(nullptr, 0);
if (alloc_stack) {
if (chunk.AllocTid() == kInvalidTid) return 0;
stack = StackDepotGet(chunk.GetAllocStackId());
if (thread_id) *thread_id = chunk.AllocTid();
} else {
if (chunk.FreeTid() == kInvalidTid) return 0;
stack = StackDepotGet(chunk.GetFreeStackId());
if (thread_id) *thread_id = chunk.FreeTid();
}
if (trace && size) {
size = Min(size, Min(stack.size, kStackTraceMax));
for (uptr i = 0; i < size; i++)
trace[i] = StackTrace::GetPreviousInstructionPc(stack.trace[i]);
return size;
}
return 0;
}
} // namespace
SANITIZER_INTERFACE_ATTRIBUTE
const char *__asan_locate_address(uptr addr, char *name, uptr name_size,
uptr *region_address_ptr,
uptr *region_size_ptr) {
AddressDescription descr(addr);
uptr region_address = 0;
uptr region_size = 0;
const char *region_kind = nullptr;
if (name && name_size > 0) name[0] = 0;
if (auto shadow = descr.AsShadow()) {
// region_{address,size} are already 0
switch (shadow->kind) {
case kShadowKindLow:
region_kind = "low shadow";
break;
case kShadowKindGap:
region_kind = "shadow gap";
break;
case kShadowKindHigh:
region_kind = "high shadow";
break;
}
} else if (auto heap = descr.AsHeap()) {
region_kind = "heap";
region_address = heap->chunk_access.chunk_begin;
region_size = heap->chunk_access.chunk_size;
} else if (auto stack = descr.AsStack()) {
region_kind = "stack";
if (!stack->frame_descr) {
// region_{address,size} are already 0
} else {
FindInfoForStackVar(addr, stack->frame_descr, stack->offset, name,
name_size, &region_address, &region_size);
}
} else if (auto global = descr.AsGlobal()) {
region_kind = "global";
auto &g = global->globals[0];
internal_strlcpy(name, g.name, name_size);
region_address = g.beg;
region_size = g.size;
} else {
// region_{address,size} are already 0
region_kind = "heap-invalid";
}
CHECK(region_kind);
if (region_address_ptr) *region_address_ptr = region_address;
if (region_size_ptr) *region_size_ptr = region_size;
return region_kind;
}
SANITIZER_INTERFACE_ATTRIBUTE
uptr __asan_get_alloc_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {
return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ true);
}
SANITIZER_INTERFACE_ATTRIBUTE
uptr __asan_get_free_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {
return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ false);
}
SANITIZER_INTERFACE_ATTRIBUTE
void __asan_get_shadow_mapping(uptr *shadow_scale, uptr *shadow_offset) {
if (shadow_scale)
*shadow_scale = ASAN_SHADOW_SCALE;
if (shadow_offset)
*shadow_offset = ASAN_SHADOW_OFFSET;
}