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// Copyright 2017 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 "snapshot/linux/thread_snapshot_linux.h"
#include <sched.h>
#include "base/logging.h"
#include "snapshot/linux/cpu_context_linux.h"
#include "util/misc/reinterpret_bytes.h"
namespace crashpad {
namespace internal {
namespace {
int ComputeThreadPriority(int static_priority,
int sched_policy,
int nice_value) {
// Map Linux scheduling policy, static priority, and nice value into a
// single int value.
//
// The possible policies in order of approximate priority (low to high) are
// SCHED_IDLE
// SCHED_BATCH
// SCHED_OTHER
// SCHED_RR
// SCHED_FIFO
//
// static_priority is not used for OTHER, BATCH, or IDLE and should be 0.
// For FIFO and RR, static_priority should range from 1 to 99 with 99 being
// the highest priority.
//
// nice value ranges from -20 to 19, with -20 being highest priority
enum class Policy : uint8_t {
kUnknown = 0,
kIdle,
kBatch,
kOther,
kRR,
kFIFO
};
struct LinuxPriority {
#if defined(ARCH_CPU_LITTLE_ENDIAN)
// nice values affect how dynamic priorities are updated, which only
// matters for threads with the same static priority.
uint8_t nice_value = 0;
// The scheduling policy also affects how threads with the same static
// priority are ordered, but has greater impact than nice value.
Policy policy = Policy::kUnknown;
// The static priority is the most significant in determining overall
// priority.
uint8_t static_priority = 0;
// Put this in the most significant byte position to prevent negative
// priorities.
uint8_t unused = 0;
#elif defined(ARCH_CPU_BIG_ENDIAN)
uint8_t unused = 0;
uint8_t static_priority = 0;
Policy policy = Policy::kUnknown;
uint8_t nice_value = 0;
#endif // ARCH_CPU_LITTLE_ENDIAN
};
static_assert(sizeof(LinuxPriority) <= sizeof(int), "priority is too large");
LinuxPriority prio;
// Lower nice values have higher priority, so negate them and add 20 to put
// them in the range 1-40 with 40 being highest priority.
if (nice_value < -20 || nice_value > 19) {
LOG(WARNING) << "invalid nice value " << nice_value;
prio.nice_value = 0;
} else {
prio.nice_value = -1 * nice_value + 20;
}
switch (sched_policy) {
case SCHED_IDLE:
prio.policy = Policy::kIdle;
break;
case SCHED_BATCH:
prio.policy = Policy::kBatch;
break;
case SCHED_OTHER:
prio.policy = Policy::kOther;
break;
case SCHED_RR:
prio.policy = Policy::kRR;
break;
case SCHED_FIFO:
prio.policy = Policy::kFIFO;
break;
default:
prio.policy = Policy::kUnknown;
LOG(WARNING) << "Unknown scheduling policy " << sched_policy;
}
if (static_priority < 0 || static_priority > 99) {
LOG(WARNING) << "invalid static priority " << static_priority;
}
prio.static_priority = static_priority;
int priority;
if (!ReinterpretBytes(prio, &priority)) {
LOG(ERROR) << "Couldn't set priority";
return -1;
}
return priority;
}
} // namespace
ThreadSnapshotLinux::ThreadSnapshotLinux()
: ThreadSnapshot(),
context_union_(),
context_(),
stack_(),
thread_specific_data_address_(0),
thread_id_(-1),
priority_(-1),
initialized_() {}
ThreadSnapshotLinux::~ThreadSnapshotLinux() {}
bool ThreadSnapshotLinux::Initialize(ProcessReaderLinux* process_reader,
const ProcessReaderLinux::Thread& thread) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
#if defined(ARCH_CPU_X86_FAMILY)
if (process_reader->Is64Bit()) {
context_.architecture = kCPUArchitectureX86_64;
context_.x86_64 = &context_union_.x86_64;
InitializeCPUContextX86_64(thread.thread_info.thread_context.t64,
thread.thread_info.float_context.f64,
context_.x86_64);
} else {
context_.architecture = kCPUArchitectureX86;
context_.x86 = &context_union_.x86;
InitializeCPUContextX86(thread.thread_info.thread_context.t32,
thread.thread_info.float_context.f32,
context_.x86);
}
#elif defined(ARCH_CPU_ARM_FAMILY)
if (process_reader->Is64Bit()) {
context_.architecture = kCPUArchitectureARM64;
context_.arm64 = &context_union_.arm64;
InitializeCPUContextARM64(thread.thread_info.thread_context.t64,
thread.thread_info.float_context.f64,
context_.arm64);
} else {
context_.architecture = kCPUArchitectureARM;
context_.arm = &context_union_.arm;
InitializeCPUContextARM(thread.thread_info.thread_context.t32,
thread.thread_info.float_context.f32,
context_.arm);
}
#elif defined(ARCH_CPU_MIPS_FAMILY)
if (process_reader->Is64Bit()) {
context_.architecture = kCPUArchitectureMIPS64EL;
context_.mips64 = &context_union_.mips64;
InitializeCPUContextMIPS<ContextTraits64>(
thread.thread_info.thread_context.t64,
thread.thread_info.float_context.f64,
context_.mips64);
} else {
context_.architecture = kCPUArchitectureMIPSEL;
context_.mipsel = &context_union_.mipsel;
InitializeCPUContextMIPS<ContextTraits32>(
SignalThreadContext32(thread.thread_info.thread_context.t32),
thread.thread_info.float_context.f32,
context_.mipsel);
}
#else
#error Port.
#endif
stack_.Initialize(process_reader->Memory(),
thread.stack_region_address,
thread.stack_region_size);
thread_specific_data_address_ =
thread.thread_info.thread_specific_data_address;
thread_id_ = thread.tid;
priority_ =
thread.have_priorities
? ComputeThreadPriority(
thread.static_priority, thread.sched_policy, thread.nice_value)
: -1;
INITIALIZATION_STATE_SET_VALID(initialized_);
return true;
}
const CPUContext* ThreadSnapshotLinux::Context() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return &context_;
}
const MemorySnapshot* ThreadSnapshotLinux::Stack() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return &stack_;
}
uint64_t ThreadSnapshotLinux::ThreadID() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return thread_id_;
}
int ThreadSnapshotLinux::SuspendCount() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return 0;
}
int ThreadSnapshotLinux::Priority() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return priority_;
}
uint64_t ThreadSnapshotLinux::ThreadSpecificDataAddress() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return thread_specific_data_address_;
}
std::vector<const MemorySnapshot*> ThreadSnapshotLinux::ExtraMemory() const {
return std::vector<const MemorySnapshot*>();
}
} // namespace internal
} // namespace crashpad