ladybird/Kernel/ProcessSpecificExposed.cpp
Andreas Kling a412fd2ed8 Kernel/ProcFS: Avoid two unnecessary number-to-string conversions
We don't need to create a new string from a number in order to compare
an existing string to that number. Converting the existing string to a
number is much cheaper, since it does not require any heap allocations.

Ran into this while profiling "find /" :^)
2021-08-15 23:30:52 +02:00

288 lines
11 KiB
C++

/*
* Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/JsonArraySerializer.h>
#include <AK/JsonObjectSerializer.h>
#include <AK/JsonValue.h>
#include <Kernel/Arch/x86/InterruptDisabler.h>
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/ProcFS.h>
#include <Kernel/KBufferBuilder.h>
#include <Kernel/Memory/AnonymousVMObject.h>
#include <Kernel/Memory/MemoryManager.h>
#include <Kernel/Process.h>
#include <Kernel/ProcessExposed.h>
namespace Kernel {
KResultOr<size_t> Process::procfs_get_thread_stack(ThreadID thread_id, KBufferBuilder& builder) const
{
JsonArraySerializer array { builder };
auto thread = Thread::from_tid(thread_id);
if (!thread)
return KResult(ESRCH);
bool show_kernel_addresses = Process::current()->is_superuser();
bool kernel_address_added = false;
for (auto address : Processor::capture_stack_trace(*thread, 1024)) {
if (!show_kernel_addresses && !Memory::is_user_address(VirtualAddress { address })) {
if (kernel_address_added)
continue;
address = 0xdeadc0de;
kernel_address_added = true;
}
array.add(address);
}
array.finish();
return KSuccess;
}
KResult Process::traverse_stacks_directory(unsigned fsid, Function<bool(FileSystem::DirectoryEntryView const&)> callback) const
{
callback({ ".", { fsid, SegmentedProcFSIndex::build_segmented_index_for_main_property(pid(), SegmentedProcFSIndex::ProcessSubDirectory::Stacks, SegmentedProcFSIndex::MainProcessProperty::Reserved) }, 0 });
callback({ "..", { fsid, m_procfs_traits->component_index() }, 0 });
for_each_thread([&](const Thread& thread) {
int tid = thread.tid().value();
InodeIdentifier identifier = { fsid, SegmentedProcFSIndex::build_segmented_index_for_thread_stack(pid(), thread.tid()) };
callback({ String::number(tid), identifier, 0 });
});
return KSuccess;
}
KResultOr<NonnullRefPtr<Inode>> Process::lookup_stacks_directory(const ProcFS& procfs, StringView name) const
{
KResultOr<NonnullRefPtr<ProcFSProcessPropertyInode>> thread_stack_inode { ENOENT };
// FIXME: Try to exit the loop earlier
for_each_thread([&](const Thread& thread) {
int tid = thread.tid().value();
VERIFY(!(tid < 0));
if (name.to_int() == tid) {
auto maybe_inode = ProcFSProcessPropertyInode::try_create_for_thread_stack(procfs, thread.tid(), pid());
if (maybe_inode.is_error()) {
thread_stack_inode = maybe_inode.error();
return;
}
thread_stack_inode = maybe_inode.release_value();
}
});
if (thread_stack_inode.is_error())
return thread_stack_inode.error();
return thread_stack_inode.release_value();
}
KResultOr<size_t> Process::procfs_get_file_description_link(unsigned fd, KBufferBuilder& builder) const
{
auto file_description = m_fds.file_description(fd);
if (!file_description)
return EBADF;
auto data = file_description->absolute_path();
builder.append(data);
return data.length();
}
KResult Process::traverse_file_descriptions_directory(unsigned fsid, Function<bool(FileSystem::DirectoryEntryView const&)> callback) const
{
callback({ ".", { fsid, m_procfs_traits->component_index() }, 0 });
callback({ "..", { fsid, m_procfs_traits->component_index() }, 0 });
size_t count = 0;
fds().enumerate([&](auto& file_description_metadata) {
if (!file_description_metadata.is_valid()) {
count++;
return;
}
InodeIdentifier identifier = { fsid, SegmentedProcFSIndex::build_segmented_index_for_file_description(pid(), count) };
callback({ String::number(count), identifier, 0 });
count++;
});
return KSuccess;
}
KResultOr<NonnullRefPtr<Inode>> Process::lookup_file_descriptions_directory(const ProcFS& procfs, StringView name) const
{
KResultOr<NonnullRefPtr<ProcFSProcessPropertyInode>> file_description_link { ENOENT };
// FIXME: Try to exit the loop earlier
size_t count = 0;
fds().enumerate([&](auto& file_description_metadata) {
if (!file_description_metadata.is_valid()) {
count++;
return;
}
if (name.to_uint() == count) {
auto maybe_inode = ProcFSProcessPropertyInode::try_create_for_file_description_link(procfs, static_cast<unsigned>(count), pid());
if (maybe_inode.is_error()) {
file_description_link = maybe_inode.error();
return;
}
file_description_link = maybe_inode.release_value();
}
count++;
});
if (file_description_link.is_error())
return file_description_link.error();
return file_description_link.release_value();
}
KResult Process::procfs_get_pledge_stats(KBufferBuilder& builder) const
{
JsonObjectSerializer obj { builder };
#define __ENUMERATE_PLEDGE_PROMISE(x) \
if (has_promised(Pledge::x)) { \
if (!builder.is_empty()) \
builder.append(' '); \
builder.append(#x); \
}
if (has_promises()) {
StringBuilder builder;
ENUMERATE_PLEDGE_PROMISES
obj.add("promises", builder.build());
}
#undef __ENUMERATE_PLEDGE_PROMISE
obj.finish();
return KSuccess;
}
KResult Process::procfs_get_unveil_stats(KBufferBuilder& builder) const
{
JsonArraySerializer array { builder };
for (auto& unveiled_path : unveiled_paths()) {
if (!unveiled_path.was_explicitly_unveiled())
continue;
auto obj = array.add_object();
obj.add("path", unveiled_path.path());
StringBuilder permissions_builder;
if (unveiled_path.permissions() & UnveilAccess::Read)
permissions_builder.append('r');
if (unveiled_path.permissions() & UnveilAccess::Write)
permissions_builder.append('w');
if (unveiled_path.permissions() & UnveilAccess::Execute)
permissions_builder.append('x');
if (unveiled_path.permissions() & UnveilAccess::CreateOrRemove)
permissions_builder.append('c');
if (unveiled_path.permissions() & UnveilAccess::Browse)
permissions_builder.append('b');
obj.add("permissions", permissions_builder.to_string());
}
array.finish();
return KSuccess;
}
KResult Process::procfs_get_perf_events(KBufferBuilder& builder) const
{
InterruptDisabler disabler;
if (!const_cast<Process&>(*this).perf_events()) {
dbgln("ProcFS: No perf events for {}", pid());
return KResult(ENOBUFS);
}
return const_cast<Process&>(*this).perf_events()->to_json(builder) ? KSuccess : KResult(EINVAL);
}
KResult Process::procfs_get_fds_stats(KBufferBuilder& builder) const
{
JsonArraySerializer array { builder };
if (fds().open_count() == 0) {
array.finish();
return KSuccess;
}
size_t count = 0;
fds().enumerate([&](auto& file_description_metadata) {
if (!file_description_metadata.is_valid()) {
count++;
return;
}
bool cloexec = file_description_metadata.flags() & FD_CLOEXEC;
RefPtr<FileDescription> description = file_description_metadata.description();
auto description_object = array.add_object();
description_object.add("fd", count);
description_object.add("absolute_path", description->absolute_path());
description_object.add("seekable", description->file().is_seekable());
description_object.add("class", description->file().class_name());
description_object.add("offset", description->offset());
description_object.add("cloexec", cloexec);
description_object.add("blocking", description->is_blocking());
description_object.add("can_read", description->can_read());
description_object.add("can_write", description->can_write());
count++;
});
array.finish();
return KSuccess;
}
KResult Process::procfs_get_virtual_memory_stats(KBufferBuilder& builder) const
{
JsonArraySerializer array { builder };
{
ScopedSpinLock lock(address_space().get_lock());
for (auto& region : address_space().regions()) {
if (!region->is_user() && !Process::current()->is_superuser())
continue;
auto region_object = array.add_object();
region_object.add("readable", region->is_readable());
region_object.add("writable", region->is_writable());
region_object.add("executable", region->is_executable());
region_object.add("stack", region->is_stack());
region_object.add("shared", region->is_shared());
region_object.add("syscall", region->is_syscall_region());
region_object.add("purgeable", region->vmobject().is_anonymous());
if (region->vmobject().is_anonymous()) {
region_object.add("volatile", static_cast<Memory::AnonymousVMObject const&>(region->vmobject()).is_volatile());
}
region_object.add("cacheable", region->is_cacheable());
region_object.add("address", region->vaddr().get());
region_object.add("size", region->size());
region_object.add("amount_resident", region->amount_resident());
region_object.add("amount_dirty", region->amount_dirty());
region_object.add("cow_pages", region->cow_pages());
region_object.add("name", region->name());
region_object.add("vmobject", region->vmobject().class_name());
StringBuilder pagemap_builder;
for (size_t i = 0; i < region->page_count(); ++i) {
auto* page = region->physical_page(i);
if (!page)
pagemap_builder.append('N');
else if (page->is_shared_zero_page() || page->is_lazy_committed_page())
pagemap_builder.append('Z');
else
pagemap_builder.append('P');
}
region_object.add("pagemap", pagemap_builder.to_string());
}
}
array.finish();
return KSuccess;
}
KResult Process::procfs_get_current_work_directory_link(KBufferBuilder& builder) const
{
builder.append_bytes(const_cast<Process&>(*this).current_directory().absolute_path().bytes());
return KSuccess;
}
mode_t Process::binary_link_required_mode() const
{
if (!executable())
return 0;
return m_procfs_traits->required_mode();
}
KResult Process::procfs_get_binary_link(KBufferBuilder& builder) const
{
auto* custody = executable();
if (!custody)
return KResult(ENOEXEC);
builder.append(custody->absolute_path().bytes());
return KSuccess;
}
}