ladybird/Kernel/Syscalls/clock.cpp
Andreas Kling cf16b2c8e6 Kernel: Wrap process address spaces in SpinlockProtected
This forces anyone who wants to look into and/or manipulate an address
space to lock it. And this replaces the previous, more flimsy, manual
spinlock use.

Note that pointers *into* the address space are not safe to use after
you unlock the space. We've got many issues like this, and we'll have
to track those down as wlel.
2022-08-24 14:57:51 +02:00

138 lines
4 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Time.h>
#include <Kernel/Process.h>
#include <Kernel/Time/TimeManagement.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$map_time_page()
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
auto& vmobject = TimeManagement::the().time_page_vmobject();
return address_space().with([&](auto& space) -> ErrorOr<FlatPtr> {
auto* region = TRY(space->allocate_region_with_vmobject(Memory::RandomizeVirtualAddress::Yes, {}, PAGE_SIZE, PAGE_SIZE, vmobject, 0, "Kernel time page"sv, PROT_READ, true));
return region->vaddr().get();
});
}
ErrorOr<FlatPtr> Process::sys$clock_gettime(clockid_t clock_id, Userspace<timespec*> user_ts)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::stdio));
TRY(TimeManagement::validate_clock_id(clock_id));
auto ts = TimeManagement::the().current_time(clock_id).to_timespec();
TRY(copy_to_user(user_ts, &ts));
return 0;
}
ErrorOr<FlatPtr> Process::sys$clock_settime(clockid_t clock_id, Userspace<timespec const*> user_ts)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::settime));
auto credentials = this->credentials();
if (!credentials->is_superuser())
return EPERM;
auto time = TRY(copy_time_from_user(user_ts));
switch (clock_id) {
case CLOCK_REALTIME:
TimeManagement::the().set_epoch_time(time);
break;
default:
return EINVAL;
}
return 0;
}
ErrorOr<FlatPtr> Process::sys$clock_nanosleep(Userspace<Syscall::SC_clock_nanosleep_params const*> user_params)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
TRY(require_promise(Pledge::stdio));
auto params = TRY(copy_typed_from_user(user_params));
auto requested_sleep = TRY(copy_time_from_user(params.requested_sleep));
bool is_absolute;
switch (params.flags) {
case 0:
is_absolute = false;
break;
case TIMER_ABSTIME:
is_absolute = true;
break;
default:
return EINVAL;
}
TRY(TimeManagement::validate_clock_id(params.clock_id));
bool was_interrupted;
if (is_absolute) {
was_interrupted = Thread::current()->sleep_until(params.clock_id, requested_sleep).was_interrupted();
} else {
Time remaining_sleep;
was_interrupted = Thread::current()->sleep(params.clock_id, requested_sleep, &remaining_sleep).was_interrupted();
timespec remaining_sleep_ts = remaining_sleep.to_timespec();
if (was_interrupted && params.remaining_sleep) {
TRY(copy_to_user(params.remaining_sleep, &remaining_sleep_ts));
}
}
if (was_interrupted)
return EINTR;
return 0;
}
ErrorOr<FlatPtr> Process::sys$clock_getres(Userspace<Syscall::SC_clock_getres_params const*> user_params)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
auto params = TRY(copy_typed_from_user(user_params));
timespec ts {};
switch (params.clock_id) {
case CLOCK_REALTIME:
ts.tv_sec = 0;
ts.tv_nsec = 1000000000 / _SC_CLK_TCK;
TRY(copy_to_user(params.result, &ts));
break;
default:
return EINVAL;
}
return 0;
}
ErrorOr<FlatPtr> Process::sys$adjtime(Userspace<timeval const*> user_delta, Userspace<timeval*> user_old_delta)
{
VERIFY_NO_PROCESS_BIG_LOCK(this);
if (user_old_delta) {
timespec old_delta_ts = TimeManagement::the().remaining_epoch_time_adjustment();
timeval old_delta;
timespec_to_timeval(old_delta_ts, old_delta);
TRY(copy_to_user(user_old_delta, &old_delta));
}
if (user_delta) {
TRY(require_promise(Pledge::settime));
auto credentials = this->credentials();
if (!credentials->is_superuser())
return EPERM;
auto delta = TRY(copy_time_from_user(user_delta));
// FIXME: Should use AK::Time internally
TimeManagement::the().set_remaining_epoch_time_adjustment(delta.to_timespec());
}
return 0;
}
}