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/*
* 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 <Kernel/Process.h>
namespace Kernel {
int Process::sys$sigprocmask(int how, const sigset_t* set, sigset_t* old_set)
{
REQUIRE_PROMISE(sigaction);
auto current_thread = Thread::current();
if (old_set) {
if (!validate_write_typed(old_set))
return -EFAULT;
copy_to_user(old_set, ¤t_thread->m_signal_mask);
}
if (set) {
if (!validate_read_typed(set))
return -EFAULT;
sigset_t set_value;
copy_from_user(&set_value, set);
switch (how) {
case SIG_BLOCK:
current_thread->m_signal_mask &= ~set_value;
break;
case SIG_UNBLOCK:
current_thread->m_signal_mask |= set_value;
break;
case SIG_SETMASK:
current_thread->m_signal_mask = set_value;
break;
default:
return -EINVAL;
}
}
return 0;
}
int Process::sys$sigpending(sigset_t* set)
{
REQUIRE_PROMISE(stdio);
if (!validate_write_typed(set))
return -EFAULT;
copy_to_user(set, &Thread::current()->m_pending_signals);
return 0;
}
int Process::sys$sigaction(int signum, const sigaction* act, sigaction* old_act)
{
REQUIRE_PROMISE(sigaction);
if (signum < 1 || signum >= 32 || signum == SIGKILL || signum == SIGSTOP)
return -EINVAL;
if (!validate_read_typed(act))
return -EFAULT;
InterruptDisabler disabler; // FIXME: This should use a narrower lock. Maybe a way to ignore signals temporarily?
auto& action = Thread::current()->m_signal_action_data[signum];
if (old_act) {
if (!validate_write_typed(old_act))
return -EFAULT;
copy_to_user(&old_act->sa_flags, &action.flags);
copy_to_user(&old_act->sa_sigaction, &action.handler_or_sigaction, sizeof(action.handler_or_sigaction));
}
copy_from_user(&action.flags, &act->sa_flags);
copy_from_user(&action.handler_or_sigaction, &act->sa_sigaction, sizeof(action.handler_or_sigaction));
return 0;
}
int Process::sys$sigreturn(RegisterState& registers)
{
REQUIRE_PROMISE(stdio);
SmapDisabler disabler;
//Here, we restore the state pushed by dispatch signal and asm_signal_trampoline.
u32* stack_ptr = (u32*)registers.userspace_esp;
u32 smuggled_eax = *stack_ptr;
//pop the stored eax, ebp, return address, handler and signal code
stack_ptr += 5;
Thread::current()->m_signal_mask = *stack_ptr;
stack_ptr++;
//pop edi, esi, ebp, esp, ebx, edx, ecx and eax
memcpy(®isters.edi, stack_ptr, 8 * sizeof(FlatPtr));
stack_ptr += 8;
registers.eip = *stack_ptr;
stack_ptr++;
registers.eflags = *stack_ptr;
stack_ptr++;
registers.userspace_esp = registers.esp;
return smuggled_eax;
}
}
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