258 lines
10 KiB
C++
258 lines
10 KiB
C++
// Copyright 2014 The Crashpad Authors. All rights reserved.
|
||
//
|
||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
// you may not use this file except in compliance with the License.
|
||
// You may obtain a copy of the License at
|
||
//
|
||
// http://www.apache.org/licenses/LICENSE-2.0
|
||
//
|
||
// Unless required by applicable law or agreed to in writing, software
|
||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
// See the License for the specific language governing permissions and
|
||
// limitations under the License.
|
||
|
||
#include "client/simulate_crash_mac.h"
|
||
|
||
#include <string.h>
|
||
#include <sys/types.h>
|
||
|
||
#include "base/check_op.h"
|
||
#include "base/cxx17_backports.h"
|
||
#include "base/logging.h"
|
||
#include "base/mac/mach_logging.h"
|
||
#include "base/mac/scoped_mach_port.h"
|
||
#include "build/build_config.h"
|
||
#include "util/mach/exc_client_variants.h"
|
||
#include "util/mach/exception_behaviors.h"
|
||
#include "util/mach/exception_ports.h"
|
||
#include "util/mach/mach_extensions.h"
|
||
#include "util/misc/implicit_cast.h"
|
||
|
||
namespace crashpad {
|
||
|
||
namespace {
|
||
|
||
//! \brief Sends an exception message to an exception port in accordance with
|
||
//! the behavior and thread state flavor it’s registered to receive.
|
||
//!
|
||
//! \param[in] thread, task, exception, code, code_count These parameters will
|
||
//! be passed to the exception handler as appropriate.
|
||
//! \param[in] cpu_context The value to use for the thread state, if \a behavior
|
||
//! indicates that the handler should receive a thread state and if the
|
||
//! supplied thread state matches or can be converted to \a flavor. If \a
|
||
//! behavior requires a thread state but this argument cannot be converted
|
||
//! to match \a flavor, `thread_get_state()` will be called to obtain a
|
||
//! suitable thread state value.
|
||
//! \param[in] handler The Mach exception handler to deliver the exception to.
|
||
//! \param[in] set_state If `true` and \a behavior indicates that the handler
|
||
//! should receive and return a thread state, a new thread state will be set
|
||
//! by `thread_set_state()` upon successful completion of the exception
|
||
//! handler. If `false`, this will be suppressed, even when \a behavior
|
||
//! indicates that the handler receives and returns a thread state.
|
||
//!
|
||
//! \return `true` if the exception was delivered to the handler and the handler
|
||
//! indicated success. `false` otherwise, with a warning message logged.
|
||
bool DeliverException(thread_t thread,
|
||
task_t task,
|
||
exception_type_t exception,
|
||
const mach_exception_data_t code,
|
||
mach_msg_type_number_t code_count,
|
||
const NativeCPUContext& cpu_context,
|
||
const ExceptionPorts::ExceptionHandler& handler,
|
||
bool set_state) {
|
||
kern_return_t kr;
|
||
|
||
bool handler_wants_state = ExceptionBehaviorHasState(handler.behavior);
|
||
if (!handler_wants_state) {
|
||
// Regardless of the passed-in value of |set_state|, if the handler won’t be
|
||
// dealing with any state at all, no state should be set.
|
||
set_state = false;
|
||
}
|
||
|
||
// old_state is only used if the context already captured doesn’t match (or
|
||
// can’t be converted to) what’s registered for the handler.
|
||
thread_state_data_t old_state;
|
||
|
||
thread_state_flavor_t flavor = handler.flavor;
|
||
ConstThreadState state;
|
||
mach_msg_type_number_t state_count;
|
||
switch (flavor) {
|
||
#if defined(ARCH_CPU_X86_FAMILY)
|
||
case x86_THREAD_STATE:
|
||
state = reinterpret_cast<ConstThreadState>(&cpu_context);
|
||
state_count = x86_THREAD_STATE_COUNT;
|
||
break;
|
||
#if defined(ARCH_CPU_X86)
|
||
case x86_THREAD_STATE32:
|
||
state = reinterpret_cast<ConstThreadState>(&cpu_context.uts.ts32);
|
||
state_count = cpu_context.tsh.count;
|
||
break;
|
||
#elif defined(ARCH_CPU_X86_64)
|
||
case x86_THREAD_STATE64:
|
||
state = reinterpret_cast<ConstThreadState>(&cpu_context.uts.ts64);
|
||
state_count = cpu_context.tsh.count;
|
||
break;
|
||
#endif
|
||
#elif defined(ARCH_CPU_ARM64)
|
||
case ARM_UNIFIED_THREAD_STATE:
|
||
state = reinterpret_cast<ConstThreadState>(&cpu_context);
|
||
state_count = ARM_UNIFIED_THREAD_STATE_COUNT;
|
||
break;
|
||
case ARM_THREAD_STATE64:
|
||
state = reinterpret_cast<ConstThreadState>(&cpu_context.ts_64);
|
||
state_count = cpu_context.ash.count;
|
||
break;
|
||
#else
|
||
#error Port to your CPU architecture
|
||
#endif
|
||
|
||
case THREAD_STATE_NONE:
|
||
// This is only acceptable if the handler doesn’t have one of the “state”
|
||
// behaviors. Otherwise, if the kernel were attempting to send an
|
||
// exception message to this port, it would call thread_getstatus() (known
|
||
// outside the kernel as thread_get_state()) which would fail because
|
||
// THREAD_STATE_NONE is not a valid state to get. See 10.9.5
|
||
// xnu-2422.115.4/osfmk/kern/exception.c exception_deliver() and
|
||
// xnu-2422.115.4/osfmk/i386/pcb.c machine_thread_get_state().
|
||
if (!handler_wants_state) {
|
||
state = nullptr;
|
||
state_count = 0;
|
||
break;
|
||
}
|
||
|
||
LOG(WARNING) << "exception handler has unexpected state flavor" << flavor;
|
||
return false;
|
||
|
||
default:
|
||
if (!handler_wants_state) {
|
||
// Don’t bother getting any thread state if the handler’s not actually
|
||
// going to use it.
|
||
state = nullptr;
|
||
state_count = 0;
|
||
} else {
|
||
state = old_state;
|
||
state_count = THREAD_STATE_MAX;
|
||
kr = thread_get_state(thread, flavor, old_state, &state_count);
|
||
if (kr != KERN_SUCCESS) {
|
||
MACH_LOG(WARNING, kr) << "thread_get_state";
|
||
return false;
|
||
}
|
||
}
|
||
break;
|
||
}
|
||
|
||
// new_state is supposed to be an out parameter only, but in case the handler
|
||
// doesn't touch it, make sure it's initialized to a valid thread state.
|
||
// Otherwise, the thread_set_state() call below would set a garbage thread
|
||
// state.
|
||
thread_state_data_t new_state;
|
||
size_t state_size =
|
||
sizeof(natural_t) *
|
||
std::min(state_count, implicit_cast<unsigned int>(THREAD_STATE_MAX));
|
||
memcpy(new_state, state, state_size);
|
||
mach_msg_type_number_t new_state_count = THREAD_STATE_MAX;
|
||
|
||
kr = UniversalExceptionRaise(handler.behavior,
|
||
handler.port,
|
||
thread,
|
||
task,
|
||
exception,
|
||
code,
|
||
code_count,
|
||
&flavor,
|
||
state,
|
||
state_count,
|
||
new_state,
|
||
&new_state_count);
|
||
|
||
// The kernel treats a return value of MACH_RCV_PORT_DIED as successful,
|
||
// although it will not set a new thread state in that case. See 10.9.5
|
||
// xnu-2422.115.4/osfmk/kern/exception.c exception_deliver(), and the more
|
||
// elaborate comment at util/mach/exc_server_variants.h
|
||
// ExcServerSuccessfulReturnValue(). Duplicate that behavior.
|
||
bool success = kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED;
|
||
MACH_LOG_IF(WARNING, !success, kr) << "UniversalExceptionRaise";
|
||
|
||
if (kr == KERN_SUCCESS && set_state) {
|
||
kr = thread_set_state(thread, flavor, new_state, new_state_count);
|
||
MACH_LOG_IF(WARNING, kr != KERN_SUCCESS, kr) << "thread_set_state";
|
||
}
|
||
|
||
return success;
|
||
}
|
||
|
||
} // namespace
|
||
|
||
void SimulateCrash(const NativeCPUContext& cpu_context) {
|
||
#if defined(ARCH_CPU_X86)
|
||
DCHECK_EQ(implicit_cast<thread_state_flavor_t>(cpu_context.tsh.flavor),
|
||
implicit_cast<thread_state_flavor_t>(x86_THREAD_STATE32));
|
||
DCHECK_EQ(implicit_cast<mach_msg_type_number_t>(cpu_context.tsh.count),
|
||
x86_THREAD_STATE32_COUNT);
|
||
#elif defined(ARCH_CPU_X86_64)
|
||
DCHECK_EQ(implicit_cast<thread_state_flavor_t>(cpu_context.tsh.flavor),
|
||
implicit_cast<thread_state_flavor_t>(x86_THREAD_STATE64));
|
||
DCHECK_EQ(implicit_cast<mach_msg_type_number_t>(cpu_context.tsh.count),
|
||
x86_THREAD_STATE64_COUNT);
|
||
#elif defined(ARCH_CPU_ARM64)
|
||
DCHECK_EQ(implicit_cast<thread_state_flavor_t>(cpu_context.ash.flavor),
|
||
implicit_cast<thread_state_flavor_t>(ARM_THREAD_STATE64));
|
||
DCHECK_EQ(implicit_cast<mach_msg_type_number_t>(cpu_context.ash.count),
|
||
ARM_THREAD_STATE64_COUNT);
|
||
#else
|
||
#error Port to your CPU architecture
|
||
#endif
|
||
|
||
base::mac::ScopedMachSendRight thread(mach_thread_self());
|
||
exception_type_t exception = kMachExceptionSimulated;
|
||
mach_exception_data_type_t codes[] = {0, 0};
|
||
mach_msg_type_number_t code_count = base::size(codes);
|
||
|
||
// Look up the handler for EXC_CRASH exceptions in the same way that the
|
||
// kernel would: try a thread handler, then a task handler, and finally a host
|
||
// handler. 10.9.5 xnu-2422.115.4/osfmk/kern/exception.c exception_triage().
|
||
static constexpr ExceptionPorts::TargetType kTargetTypes[] = {
|
||
ExceptionPorts::kTargetTypeThread,
|
||
ExceptionPorts::kTargetTypeTask,
|
||
|
||
// This is not expected to succeed, because mach_host_self() doesn’t
|
||
// return the host_priv port to non-root users, and this is the port
|
||
// that’s required for host_get_exception_ports().
|
||
//
|
||
// See 10.9.5 xnu-2422.115.4/bsd/kern/kern_prot.c set_security_token(),
|
||
// xnu-2422.115.4/osfmk/kern/task.c host_security_set_task_token(), and
|
||
// xnu-2422.115.4/osfmk/kern/ipc_host.c host_get_exception_ports().
|
||
ExceptionPorts::kTargetTypeHost,
|
||
};
|
||
|
||
bool success = false;
|
||
|
||
for (size_t target_type_index = 0;
|
||
!success && target_type_index < base::size(kTargetTypes);
|
||
++target_type_index) {
|
||
ExceptionPorts::ExceptionHandlerVector handlers;
|
||
ExceptionPorts exception_ports(kTargetTypes[target_type_index],
|
||
MACH_PORT_NULL);
|
||
if (exception_ports.GetExceptionPorts(EXC_MASK_CRASH, &handlers)) {
|
||
DCHECK_LE(handlers.size(), 1u);
|
||
if (handlers.size() == 1) {
|
||
DCHECK(handlers[0].mask & EXC_MASK_CRASH);
|
||
success = DeliverException(thread.get(),
|
||
mach_task_self(),
|
||
exception,
|
||
codes,
|
||
code_count,
|
||
cpu_context,
|
||
handlers[0],
|
||
false);
|
||
}
|
||
}
|
||
}
|
||
|
||
LOG_IF(WARNING, !success)
|
||
<< "SimulateCrash did not find an appropriate exception handler";
|
||
}
|
||
|
||
} // namespace crashpad
|