ladybird/Kernel/Profiling.cpp
Andreas Kling 79e79ad1d2 Kernel: Don't blindly dereference Process::executable()
When setting up profiling, don't assume that the profiled process has
a valid executable.
2020-02-27 10:41:32 +01:00

109 lines
3.0 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Demangle.h>
#include <AK/StringBuilder.h>
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/KBuffer.h>
#include <Kernel/KSyms.h>
#include <Kernel/Process.h>
#include <Kernel/Profiling.h>
#include <LibELF/ELFLoader.h>
namespace Kernel {
namespace Profiling {
static KBufferImpl* s_profiling_buffer;
static size_t s_slot_count;
static size_t s_next_slot_index;
static u32 s_pid;
String& executable_path()
{
static String* path;
if (!path)
path = new String;
return *path;
}
u32 pid()
{
return s_pid;
}
void start(Process& process)
{
if (process.executable())
executable_path() = process.executable()->absolute_path().impl();
else
executable_path() = {};
s_pid = process.pid();
if (!s_profiling_buffer) {
s_profiling_buffer = RefPtr<KBufferImpl>(KBuffer::create_with_size(8 * MB).impl()).leak_ref();
s_profiling_buffer->region().commit();
s_slot_count = s_profiling_buffer->size() / sizeof(Sample);
}
s_next_slot_index = 0;
}
static Sample& sample_slot(size_t index)
{
return ((Sample*)s_profiling_buffer->data())[index];
}
Sample& next_sample_slot()
{
auto& slot = sample_slot(s_next_slot_index++);
if (s_next_slot_index >= s_slot_count)
s_next_slot_index = 0;
return slot;
}
void stop()
{
}
void did_exec(const String& new_executable_path)
{
executable_path() = new_executable_path;
s_next_slot_index = 0;
}
void for_each_sample(Function<void(Sample&)> callback)
{
for (size_t i = 0; i < s_next_slot_index; ++i) {
auto& sample = sample_slot(i);
callback(sample);
}
}
}
}