ladybird/Kernel/Syscalls/pledge.cpp
Ralf Donau 8ee3a5e09e Kernel: Logic fix in the pledge syscall
Pledge should check m_has_promises. Calling pledge("", nullptr)
does not fail on an already pledged process anymore.
2021-07-10 21:59:29 +02:00

77 lines
2.0 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StringView.h>
#include <Kernel/Process.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$pledge(Userspace<const Syscall::SC_pledge_params*> user_params)
{
Syscall::SC_pledge_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
if (params.promises.length > 1024 || params.execpromises.length > 1024)
return E2BIG;
String promises;
if (params.promises.characters) {
promises = copy_string_from_user(params.promises);
if (promises.is_null())
return EFAULT;
}
String execpromises;
if (params.execpromises.characters) {
execpromises = copy_string_from_user(params.execpromises);
if (execpromises.is_null())
return EFAULT;
}
auto parse_pledge = [&](auto& pledge_spec, u32& mask) {
auto parts = pledge_spec.split_view(' ');
for (auto& part : parts) {
#define __ENUMERATE_PLEDGE_PROMISE(x) \
if (part == #x) { \
mask |= (1u << (u32)Pledge::x); \
continue; \
}
ENUMERATE_PLEDGE_PROMISES
#undef __ENUMERATE_PLEDGE_PROMISE
return false;
}
return true;
};
ProtectedDataMutationScope scope { *this };
if (!promises.is_null()) {
u32 new_promises = 0;
if (!parse_pledge(promises, new_promises))
return EINVAL;
if (m_has_promises && (new_promises & ~m_promises))
return EPERM;
m_has_promises = true;
m_promises = new_promises;
}
if (!execpromises.is_null()) {
u32 new_execpromises = 0;
if (!parse_pledge(execpromises, new_execpromises))
return EINVAL;
if (m_has_execpromises && (new_execpromises & ~m_execpromises))
return EPERM;
m_has_execpromises = true;
m_execpromises = new_execpromises;
}
return 0;
}
}