| // Copyright 2015 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 "util/mach/exception_types.h" |
| |
| #include <Availability.h> |
| #include <AvailabilityMacros.h> |
| #include <dlfcn.h> |
| #include <errno.h> |
| #include <libproc.h> |
| #include <kern/exc_resource.h> |
| |
| #include "base/logging.h" |
| #include "base/mac/mach_logging.h" |
| #include "util/mac/mac_util.h" |
| |
| #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_9 |
| |
| extern "C" { |
| |
| // proc_get_wakemon_params() is present in the OS X 10.9 SDK, but no declaration |
| // is provided. This provides a declaration and marks it for weak import if the |
| // deployment target is below 10.9. |
| int proc_get_wakemon_params(pid_t pid, int* rate_hz, int* flags) |
| __OSX_AVAILABLE_STARTING(__MAC_10_9, __IPHONE_7_0); |
| |
| // Redeclare the method without the availability annotation to suppress the |
| // -Wpartial-availability warning. |
| int proc_get_wakemon_params(pid_t pid, int* rate_hz, int* flags); |
| |
| } // extern "C" |
| |
| #else |
| |
| namespace { |
| |
| using ProcGetWakemonParamsType = int (*)(pid_t, int*, int*); |
| |
| // The SDK doesn’t have proc_get_wakemon_params() to link against, even with |
| // weak import. This function returns a function pointer to it if it exists at |
| // runtime, or nullptr if it doesn’t. proc_get_wakemon_params() is looked up in |
| // the same module that provides proc_pidinfo(). |
| ProcGetWakemonParamsType GetProcGetWakemonParams() { |
| Dl_info dl_info; |
| if (!dladdr(reinterpret_cast<void*>(proc_pidinfo), &dl_info)) { |
| return nullptr; |
| } |
| |
| void* dl_handle = |
| dlopen(dl_info.dli_fname, RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); |
| if (!dl_handle) { |
| return nullptr; |
| } |
| |
| ProcGetWakemonParamsType proc_get_wakemon_params = |
| reinterpret_cast<ProcGetWakemonParamsType>( |
| dlsym(dl_handle, "proc_get_wakemon_params")); |
| return proc_get_wakemon_params; |
| } |
| |
| } // namespace |
| |
| #endif |
| |
| namespace { |
| |
| // Wraps proc_get_wakemon_params(), calling it if the system provides it. It’s |
| // present on OS X 10.9 and later. If it’s not available, sets errno to ENOSYS |
| // and returns -1. |
| int ProcGetWakemonParams(pid_t pid, int* rate_hz, int* flags) { |
| #if MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_9 |
| // proc_get_wakemon_params() isn’t in the SDK. Look it up dynamically. |
| static ProcGetWakemonParamsType proc_get_wakemon_params = |
| GetProcGetWakemonParams(); |
| #endif |
| |
| #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_9 |
| // proc_get_wakemon_params() is definitely available if the deployment target |
| // is 10.9 or newer. |
| if (!proc_get_wakemon_params) { |
| errno = ENOSYS; |
| return -1; |
| } |
| #endif |
| |
| return proc_get_wakemon_params(pid, rate_hz, flags); |
| } |
| |
| } // namespace |
| |
| namespace crashpad { |
| |
| exception_type_t ExcCrashRecoverOriginalException( |
| mach_exception_code_t code_0, |
| mach_exception_code_t* original_code_0, |
| int* signal) { |
| // 10.9.4 xnu-2422.110.17/bsd/kern/kern_exit.c proc_prepareexit() sets code[0] |
| // based on the signal value, original exception type, and low 20 bits of the |
| // original code[0] before calling xnu-2422.110.17/osfmk/kern/exception.c |
| // task_exception_notify() to raise an EXC_CRASH. |
| // |
| // The list of core-generating signals (as used in proc_prepareexit()’s call |
| // to hassigprop()) is in 10.9.4 xnu-2422.110.17/bsd/sys/signalvar.h sigprop: |
| // entires with SA_CORE are in the set. These signals are SIGQUIT, SIGILL, |
| // SIGTRAP, SIGABRT, SIGEMT, SIGFPE, SIGBUS, SIGSEGV, and SIGSYS. Processes |
| // killed for code-signing reasons will be killed by SIGKILL and are also |
| // eligible for EXC_CRASH handling, but processes killed by SIGKILL for other |
| // reasons are not. |
| if (signal) { |
| *signal = (code_0 >> 24) & 0xff; |
| } |
| |
| if (original_code_0) { |
| *original_code_0 = code_0 & 0xfffff; |
| } |
| |
| return (code_0 >> 20) & 0xf; |
| } |
| |
| bool IsExceptionNonfatalResource(exception_type_t exception, |
| mach_exception_code_t code_0, |
| pid_t pid) { |
| if (exception != EXC_RESOURCE) { |
| return false; |
| } |
| |
| const int resource_type = EXC_RESOURCE_DECODE_RESOURCE_TYPE(code_0); |
| const int resource_flavor = EXC_RESOURCE_DECODE_FLAVOR(code_0); |
| |
| if (resource_type == RESOURCE_TYPE_CPU && |
| (resource_flavor == FLAVOR_CPU_MONITOR || |
| resource_flavor == FLAVOR_CPU_MONITOR_FATAL)) { |
| // These exceptions may be fatal. They are not fatal by default at task |
| // creation but can be made fatal by calling proc_rlimit_control() with |
| // RLIMIT_CPU_USAGE_MONITOR as the second argument and CPUMON_MAKE_FATAL set |
| // in the flags. |
| if (MacOSXMinorVersion() >= 10) { |
| // In OS X 10.10, the exception code indicates whether the exception is |
| // fatal. See 10.10 xnu-2782.1.97/osfmk/kern/thread.c |
| // THIS_THREAD_IS_CONSUMING_TOO_MUCH_CPU__SENDING_EXC_RESOURCE(). |
| return resource_flavor == FLAVOR_CPU_MONITOR; |
| } |
| |
| // In OS X 10.9, there’s no way to determine whether the exception is fatal. |
| // Unlike RESOURCE_TYPE_WAKEUPS below, there’s no way to determine this |
| // outside the kernel. proc_rlimit_control()’s RLIMIT_CPU_USAGE_MONITOR is |
| // the only interface to modify CPUMON_MAKE_FATAL, but it’s only able to set |
| // this bit, not obtain its current value. |
| // |
| // Default to assuming that these exceptions are nonfatal. They are nonfatal |
| // by default and no users of proc_rlimit_control() were found on 10.9.5 |
| // 13F1066 in /System and /usr outside of Metadata.framework and associated |
| // tools. |
| return true; |
| } |
| |
| if (resource_type == RESOURCE_TYPE_WAKEUPS && |
| resource_flavor == FLAVOR_WAKEUPS_MONITOR) { |
| // These exceptions may be fatal. They are not fatal by default at task |
| // creation, but can be made fatal by calling proc_rlimit_control() with |
| // RLIMIT_WAKEUPS_MONITOR as the second argument and WAKEMON_MAKE_FATAL set |
| // in the flags. |
| // |
| // proc_get_wakemon_params() (which calls |
| // through to proc_rlimit_control() with RLIMIT_WAKEUPS_MONITOR) determines |
| // whether these exceptions are fatal. See 10.10 |
| // xnu-2782.1.97/osfmk/kern/task.c |
| // THIS_PROCESS_IS_CAUSING_TOO_MANY_WAKEUPS__SENDING_EXC_RESOURCE(). |
| // |
| // If proc_get_wakemon_params() fails, default to assuming that these |
| // exceptions are nonfatal. They are nonfatal by default and no users of |
| // proc_rlimit_control() were found on 10.9.5 13F1066 in /System and /usr |
| // outside of Metadata.framework and associated tools. |
| int wm_rate; |
| int wm_flags; |
| int rv = ProcGetWakemonParams(pid, &wm_rate, &wm_flags); |
| if (rv < 0) { |
| PLOG(WARNING) << "ProcGetWakemonParams"; |
| return true; |
| } |
| |
| return !(wm_flags & WAKEMON_MAKE_FATAL); |
| } |
| |
| if (resource_type == RESOURCE_TYPE_MEMORY && |
| resource_flavor == FLAVOR_HIGH_WATERMARK) { |
| // These exceptions are never fatal. See 10.10 |
| // xnu-2782.1.97/osfmk/kern/task.c |
| // THIS_PROCESS_CROSSED_HIGH_WATERMARK__SENDING_EXC_RESOURCE(). |
| return true; |
| } |
| |
| if (resource_type == RESOURCE_TYPE_IO) { |
| // These exceptions don’t ever appear to be fatal. See |
| // https://crashpad.chromium.org/bug/124. |
| return true; |
| } |
| |
| // Treat unknown exceptions as fatal. This is the conservative approach: it |
| // may result in more crash reports being generated, but the type-flavor |
| // combinations can be evaluated to determine appropriate handling. |
| LOG(WARNING) << "unknown resource type " << resource_type << " flavor " |
| << resource_flavor; |
| return false; |
| } |
| |
| } // namespace crashpad |