void*
nsPresArena::Allocate(uint32_t aCode, size_t aSize)
{
NS_ABORT_IF_FALSE(aSize > 0, "PresArena cannot allocate zero bytes");
// We only hand out aligned sizes
aSize = PL_ARENA_ALIGN(&mPool, aSize);
// If there is no free-list entry for this type already, we have
// to create one now, to record its size.
FreeList* list = mFreeLists.PutEntry(aCode);
nsTArray<void*>::index_type len = list->mEntries.Length();
if (list->mEntrySize == 0) {
NS_ABORT_IF_FALSE(len == 0, "list with entries but no recorded size");
list->mEntrySize = aSize;
} else {
NS_ABORT_IF_FALSE(list->mEntrySize == aSize,
"different sizes for same object type code");
}
void* result;
if (len > 0) {
// LIFO behavior for best cache utilization
result = list->mEntries.ElementAt(len - 1);
list->mEntries.RemoveElementAt(len - 1);
#if defined(DEBUG)
{
MOZ_MAKE_MEM_DEFINED(result, list->mEntrySize);
char* p = reinterpret_cast<char*>(result);
char* limit = p + list->mEntrySize;
for (; p < limit; p += sizeof(uintptr_t)) {
uintptr_t val = *reinterpret_cast<uintptr_t*>(p);
NS_ABORT_IF_FALSE(val == mozPoisonValue(),
nsPrintfCString("PresArena: poison overwritten; "
"wanted %.16llx "
"found %.16llx "
"errors in bits %.16llx",
uint64_t(mozPoisonValue()),
uint64_t(val),
uint64_t(mozPoisonValue() ^ val)
).get());
}
}
#endif
MOZ_MAKE_MEM_UNDEFINED(result, list->mEntrySize);
return result;
}
// Allocate a new chunk from the arena
list->mEntriesEverAllocated++;
PL_ARENA_ALLOCATE(result, &mPool, aSize);
if (!result) {
NS_ABORT_OOM(aSize);
}
return result;
}
MOZ_ASAN_BLACKLIST void
ThreadStackHelper::FillThreadContext(void* aContext)
{
#ifdef MOZ_THREADSTACKHELPER_NATIVE
if (!mContextToFill) {
return;
}
#if 0 // TODO: remove dependency on Breakpad structs.
#if defined(XP_LINUX)
const ucontext_t& context = *reinterpret_cast<ucontext_t*>(aContext);
#if defined(MOZ_THREADSTACKHELPER_X86)
mContextToFill->mContext.context_flags = MD_CONTEXT_X86_FULL;
mContextToFill->mContext.edi = context.uc_mcontext.gregs[REG_EDI];
mContextToFill->mContext.esi = context.uc_mcontext.gregs[REG_ESI];
mContextToFill->mContext.ebx = context.uc_mcontext.gregs[REG_EBX];
mContextToFill->mContext.edx = context.uc_mcontext.gregs[REG_EDX];
mContextToFill->mContext.ecx = context.uc_mcontext.gregs[REG_ECX];
mContextToFill->mContext.eax = context.uc_mcontext.gregs[REG_EAX];
mContextToFill->mContext.ebp = context.uc_mcontext.gregs[REG_EBP];
mContextToFill->mContext.eip = context.uc_mcontext.gregs[REG_EIP];
mContextToFill->mContext.eflags = context.uc_mcontext.gregs[REG_EFL];
mContextToFill->mContext.esp = context.uc_mcontext.gregs[REG_ESP];
#elif defined(MOZ_THREADSTACKHELPER_X64)
mContextToFill->mContext.context_flags = MD_CONTEXT_AMD64_FULL;
mContextToFill->mContext.eflags = uint32_t(context.uc_mcontext.gregs[REG_EFL]);
mContextToFill->mContext.rax = context.uc_mcontext.gregs[REG_RAX];
mContextToFill->mContext.rcx = context.uc_mcontext.gregs[REG_RCX];
mContextToFill->mContext.rdx = context.uc_mcontext.gregs[REG_RDX];
mContextToFill->mContext.rbx = context.uc_mcontext.gregs[REG_RBX];
mContextToFill->mContext.rsp = context.uc_mcontext.gregs[REG_RSP];
mContextToFill->mContext.rbp = context.uc_mcontext.gregs[REG_RBP];
mContextToFill->mContext.rsi = context.uc_mcontext.gregs[REG_RSI];
mContextToFill->mContext.rdi = context.uc_mcontext.gregs[REG_RDI];
memcpy(&mContextToFill->mContext.r8,
&context.uc_mcontext.gregs[REG_R8], 8 * sizeof(int64_t));
mContextToFill->mContext.rip = context.uc_mcontext.gregs[REG_RIP];
#elif defined(MOZ_THREADSTACKHELPER_ARM)
mContextToFill->mContext.context_flags = MD_CONTEXT_ARM_FULL;
memcpy(&mContextToFill->mContext.iregs[0],
&context.uc_mcontext.arm_r0, 17 * sizeof(int32_t));
#else
#error "Unsupported architecture"
#endif // architecture
#elif defined(XP_WIN)
// Breakpad context struct is based off of the Windows CONTEXT struct,
// so we assume they are the same; do some sanity checks to make sure.
static_assert(sizeof(ThreadContext::Context) == sizeof(::CONTEXT),
"Context struct mismatch");
static_assert(offsetof(ThreadContext::Context, context_flags) ==
offsetof(::CONTEXT, ContextFlags),
"Context struct mismatch");
mContextToFill->mContext.context_flags = CONTEXT_FULL;
NS_ENSURE_TRUE_VOID(::GetThreadContext(mThreadID,
reinterpret_cast<::CONTEXT*>(&mContextToFill->mContext)));
#elif defined(XP_MACOSX)
#if defined(MOZ_THREADSTACKHELPER_X86)
const thread_state_flavor_t flavor = x86_THREAD_STATE32;
x86_thread_state32_t state = {};
mach_msg_type_number_t count = x86_THREAD_STATE32_COUNT;
#elif defined(MOZ_THREADSTACKHELPER_X64)
const thread_state_flavor_t flavor = x86_THREAD_STATE64;
x86_thread_state64_t state = {};
mach_msg_type_number_t count = x86_THREAD_STATE64_COUNT;
#elif defined(MOZ_THREADSTACKHELPER_ARM)
const thread_state_flavor_t flavor = ARM_THREAD_STATE;
arm_thread_state_t state = {};
mach_msg_type_number_t count = ARM_THREAD_STATE_COUNT;
#endif
NS_ENSURE_TRUE_VOID(KERN_SUCCESS == ::thread_get_state(
mThreadID, flavor, reinterpret_cast<thread_state_t>(&state), &count));
#if __DARWIN_UNIX03
#define GET_REGISTER(s, r) ((s).__##r)
#else
#define GET_REGISTER(s, r) ((s).r)
#endif
#if defined(MOZ_THREADSTACKHELPER_X86)
mContextToFill->mContext.context_flags = MD_CONTEXT_X86_FULL;
mContextToFill->mContext.edi = GET_REGISTER(state, edi);
mContextToFill->mContext.esi = GET_REGISTER(state, esi);
mContextToFill->mContext.ebx = GET_REGISTER(state, ebx);
mContextToFill->mContext.edx = GET_REGISTER(state, edx);
mContextToFill->mContext.ecx = GET_REGISTER(state, ecx);
mContextToFill->mContext.eax = GET_REGISTER(state, eax);
mContextToFill->mContext.ebp = GET_REGISTER(state, ebp);
mContextToFill->mContext.eip = GET_REGISTER(state, eip);
mContextToFill->mContext.eflags = GET_REGISTER(state, eflags);
mContextToFill->mContext.esp = GET_REGISTER(state, esp);
#elif defined(MOZ_THREADSTACKHELPER_X64)
mContextToFill->mContext.context_flags = MD_CONTEXT_AMD64_FULL;
mContextToFill->mContext.eflags = uint32_t(GET_REGISTER(state, rflags));
mContextToFill->mContext.rax = GET_REGISTER(state, rax);
mContextToFill->mContext.rcx = GET_REGISTER(state, rcx);
mContextToFill->mContext.rdx = GET_REGISTER(state, rdx);
mContextToFill->mContext.rbx = GET_REGISTER(state, rbx);
mContextToFill->mContext.rsp = GET_REGISTER(state, rsp);
mContextToFill->mContext.rbp = GET_REGISTER(state, rbp);
mContextToFill->mContext.rsi = GET_REGISTER(state, rsi);
mContextToFill->mContext.rdi = GET_REGISTER(state, rdi);
memcpy(&mContextToFill->mContext.r8,
&GET_REGISTER(state, r8), 8 * sizeof(int64_t));
mContextToFill->mContext.rip = GET_REGISTER(state, rip);
#elif defined(MOZ_THREADSTACKHELPER_ARM)
mContextToFill->mContext.context_flags = MD_CONTEXT_ARM_FULL;
memcpy(mContextToFill->mContext.iregs,
GET_REGISTER(state, r), 17 * sizeof(int32_t));
#else
#error "Unsupported architecture"
#endif // architecture
#undef GET_REGISTER
#else
#error "Unsupported platform"
#endif // platform
intptr_t sp = 0;
#if defined(MOZ_THREADSTACKHELPER_X86)
sp = mContextToFill->mContext.esp;
#elif defined(MOZ_THREADSTACKHELPER_X64)
sp = mContextToFill->mContext.rsp;
#elif defined(MOZ_THREADSTACKHELPER_ARM)
sp = mContextToFill->mContext.iregs[13];
#else
#error "Unsupported architecture"
#endif // architecture
NS_ENSURE_TRUE_VOID(sp);
NS_ENSURE_TRUE_VOID(mThreadStackBase);
size_t stackSize = std::min(intptr_t(ThreadContext::kMaxStackSize),
std::abs(sp - mThreadStackBase));
if (mContextToFill->mStackEnd) {
// Limit the start of stack to a certain location if specified.
stackSize = std::min(intptr_t(stackSize),
std::abs(sp - intptr_t(mContextToFill->mStackEnd)));
}
#ifndef MOZ_THREADSTACKHELPER_STACK_GROWS_DOWN
// If if the stack grows upwards, and we need to recalculate our
// stack copy's base address. Subtract sizeof(void*) so that the
// location pointed to by sp is included.
sp -= stackSize - sizeof(void*);
#endif
#ifndef MOZ_ASAN
memcpy(mContextToFill->mStack.get(), reinterpret_cast<void*>(sp), stackSize);
// Valgrind doesn't care about the access outside the stack frame, but
// the presence of uninitialised values on the stack does cause it to
// later report a lot of false errors when Breakpad comes to unwind it.
// So mark the extracted data as defined.
MOZ_MAKE_MEM_DEFINED(mContextToFill->mStack.get(), stackSize);
#else
// ASan will flag memcpy for access outside of stack frames,
// so roll our own memcpy here.
intptr_t* dst = reinterpret_cast<intptr_t*>(&mContextToFill->mStack[0]);
const intptr_t* src = reinterpret_cast<intptr_t*>(sp);
for (intptr_t len = stackSize; len > 0; len -= sizeof(*src)) {
*(dst++) = *(src++);
}
#endif
mContextToFill->mStackBase = uintptr_t(sp);
mContextToFill->mStackSize = stackSize;
mContextToFill->mValid = true;
#endif
#endif // MOZ_THREADSTACKHELPER_NATIVE
}
