Kernel/tasking/signal.cpp
2024-11-20 03:49:15 +02:00

772 lines
17 KiB
C++

/*
This file is part of Fennix Kernel.
Fennix Kernel is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of
the License, or (at your option) any later version.
Fennix Kernel is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/
#include <signal.hpp>
#include <dumper.hpp>
#include <task.hpp>
#include <errno.h>
#if defined(a64)
#include "../arch/amd64/cpu/gdt.hpp"
#elif defined(a32)
#include "../arch/i386/cpu/gdt.hpp"
#elif defined(aa64)
#endif
#include "../kernel.h"
#ifdef DEBUG
const char *sigStr[] = {
/* 0 */ "INVALID",
/* 1 */ "SIGABRT",
/* 2 */ "SIGALRM",
/* 3 */ "SIGBUS",
/* 4 */ "SIGCHLD",
/* 5 */ "SIGCONT",
/* 6 */ "SIGFPE",
/* 7 */ "SIGHUP",
/* 8 */ "SIGILL",
/* 9 */ "SIGINT",
/* 10 */ "SIGKILL",
/* 11 */ "SIGPIPE",
/* 12 */ "SIGQUIT",
/* 13 */ "SIGSEGV",
/* 14 */ "SIGSTOP",
/* 15 */ "SIGTERM",
/* 16 */ "SIGTSTP",
/* 17 */ "SIGTTIN",
/* 18 */ "SIGTTOU",
/* 19 */ "SIGUSR1",
/* 20 */ "SIGUSR2",
/* 21 */ "SIGPOLL",
/* 22 */ "SIGPROF",
/* 23 */ "SIGSYS",
/* 24 */ "SIGTRAP",
/* 25 */ "SIGURG",
/* 26 */ "SIGVTALRM",
/* 27 */ "SIGXCPU",
/* 28 */ "SIGXFSZ",
/* 29 */ "SIGCOMP1",
/* 30 */ "SIGCOMP2",
/* 31 */ "SIGCOMP3",
/* 32 */ "SIGRTMIN",
/* 33 */ "SIGRT_1",
/* 34 */ "SIGRT_2",
/* 35 */ "SIGRT_3",
/* 36 */ "SIGRT_4",
/* 37 */ "SIGRT_5",
/* 38 */ "SIGRT_6",
/* 39 */ "SIGRT_7",
/* 40 */ "SIGRT_8",
/* 41 */ "SIGRT_9",
/* 42 */ "SIGRT_10",
/* 43 */ "SIGRT_11",
/* 44 */ "SIGRT_12",
/* 45 */ "SIGRT_13",
/* 46 */ "SIGRT_14",
/* 47 */ "SIGRT_15",
/* 48 */ "SIGRT_16",
/* 49 */ "SIGRT_17",
/* 50 */ "SIGRT_18",
/* 51 */ "SIGRT_19",
/* 52 */ "SIGRT_20",
/* 53 */ "SIGRT_21",
/* 54 */ "SIGRT_22",
/* 55 */ "SIGRT_23",
/* 56 */ "SIGRT_24",
/* 57 */ "SIGRT_25",
/* 58 */ "SIGRT_26",
/* 59 */ "SIGRT_27",
/* 60 */ "SIGRT_28",
/* 61 */ "SIGRT_29",
/* 62 */ "SIGRT_30",
/* 63 */ "SIGRT_31",
/* 64 */ "SIGRTMAX",
};
const char *dispStr[] = {
"SIG_TERM",
"SIG_IGN ",
"SIG_CORE",
"SIG_STOP",
"SIG_CONT",
};
#endif
extern "C" uintptr_t _sig_native_trampoline_start, _sig_native_trampoline_end;
extern "C" uintptr_t _sig_linux_trampoline_start, _sig_linux_trampoline_end;
static const struct
{
Signals Signal;
SignalDispositions Disposition;
} SignalDisposition[] = {
{SIGHUP, SIG_TERM},
{SIGINT, SIG_TERM},
{SIGQUIT, SIG_TERM},
{SIGILL, SIG_CORE},
{SIGTRAP, SIG_CORE},
{SIGABRT, SIG_CORE},
{SIGBUS, SIG_CORE},
{SIGFPE, SIG_CORE},
{SIGKILL, SIG_TERM},
{SIGUSR1, SIG_TERM},
{SIGSEGV, SIG_CORE},
{SIGUSR2, SIG_TERM},
{SIGPIPE, SIG_TERM},
{SIGALRM, SIG_TERM},
{SIGTERM, SIG_TERM},
{SIGCOMP1, SIG_IGN},
{SIGCHLD, SIG_IGN},
{SIGCONT, SIG_CONT},
{SIGSTOP, SIG_STOP},
{SIGTSTP, SIG_STOP},
{SIGTTIN, SIG_STOP},
{SIGTTOU, SIG_STOP},
{SIGURG, SIG_IGN},
{SIGXCPU, SIG_CORE},
{SIGXFSZ, SIG_CORE},
{SIGVTALRM, SIG_TERM},
{SIGPROF, SIG_TERM},
{SIGCOMP2, SIG_IGN},
{SIGPOLL, SIG_TERM},
{SIGCOMP3, SIG_IGN},
{SIGSYS, SIG_CORE},
{SIGRTMIN, SIG_IGN},
{SIGRT_1, SIG_IGN},
{SIGRT_2, SIG_IGN},
{SIGRT_3, SIG_IGN},
{SIGRT_4, SIG_IGN},
{SIGRT_5, SIG_IGN},
{SIGRT_6, SIG_IGN},
{SIGRT_7, SIG_IGN},
{SIGRT_8, SIG_IGN},
{SIGRT_9, SIG_IGN},
{SIGRT_10, SIG_IGN},
{SIGRT_11, SIG_IGN},
{SIGRT_12, SIG_IGN},
{SIGRT_13, SIG_IGN},
{SIGRT_14, SIG_IGN},
{SIGRT_15, SIG_IGN},
{SIGRT_16, SIG_IGN},
{SIGRT_17, SIG_IGN},
{SIGRT_18, SIG_IGN},
{SIGRT_19, SIG_IGN},
{SIGRT_20, SIG_IGN},
{SIGRT_21, SIG_IGN},
{SIGRT_22, SIG_IGN},
{SIGRT_23, SIG_IGN},
{SIGRT_24, SIG_IGN},
{SIGRT_25, SIG_IGN},
{SIGRT_26, SIG_IGN},
{SIGRT_27, SIG_IGN},
{SIGRT_28, SIG_IGN},
{SIGRT_29, SIG_IGN},
{SIGRT_30, SIG_IGN},
{SIGRT_31, SIG_IGN},
{SIGRTMAX, SIG_IGN},
};
SignalDispositions GetDefaultSignalDisposition(Signals sig)
{
foreach (auto var in SignalDisposition)
{
if (var.Signal == sig)
return var.Disposition;
}
error("Invalid signal: %d", sig);
return SIG_TERM;
}
/* subsystem/linux/syscall.cpp */
extern int ConvertSignalToLinux(Signals sig);
namespace Tasking
{
bool Signal::LinuxSig()
{
return ((PCB *)ctx)->Info.Compatibility == Linux;
}
int Signal::MakeExitCode(Signals sig)
{
if (this->LinuxSig())
return 128 + ConvertSignalToLinux(sig);
else
return 100 + sig;
}
void Signal::InitTrampoline()
{
if (unlikely(TrampAddr))
return;
PCB *pcb = (PCB *)ctx;
debug("Trampoline not set up yet");
switch (pcb->Info.Compatibility)
{
case Native:
{
debug("%#lx - %#lx",
&_sig_native_trampoline_end,
&_sig_native_trampoline_start);
TrampSz = (size_t)&_sig_native_trampoline_end -
(size_t)&_sig_native_trampoline_start;
TrampAddr = pcb->vma->RequestPages(TO_PAGES(TrampSz), true);
memcpy((void *)TrampAddr,
(void *)&_sig_native_trampoline_start,
TrampSz);
debug("Trampoline at %#lx with size %lld",
TrampAddr, TrampSz);
break;
}
case Linux:
{
debug("%#lx - %#lx",
&_sig_linux_trampoline_end,
&_sig_linux_trampoline_start);
TrampSz = (size_t)&_sig_linux_trampoline_end -
(size_t)&_sig_linux_trampoline_start;
TrampAddr = pcb->vma->RequestPages(TO_PAGES(TrampSz), true);
memcpy((void *)TrampAddr,
(void *)&_sig_linux_trampoline_start,
TrampSz);
debug("Trampoline at %#lx with size %lld",
TrampAddr, TrampSz);
break;
}
case Windows:
{
assert(!"Windows compatibility not implemented");
break;
}
default:
/* Process not fully initalized. */
return;
}
}
/* ------------------------------------------------------ */
int Signal::AddWatcher(Signal *who, Signals sig)
{
SignalInfo info;
info.sig = sig;
info.val.sival_ptr = who;
SmartLock(SignalLock);
Watchers.push_back(info);
return 0;
}
int Signal::RemoveWatcher(Signal *who, Signals sig)
{
SmartLock(SignalLock);
forItr(itr, Watchers)
{
if (itr->sig == sig &&
itr->val.sival_ptr == who)
{
Watchers.erase(itr);
return 0;
}
}
return -ENOENT;
}
int Signal::AddSignal(Signals sig, union sigval val, pid_t tid)
{
SignalInfo info{.sig = sig, .val = val, .tid = tid};
Queue.push_back(info);
return 0;
}
int Signal::RemoveSignal(Signals sig)
{
size_t n = Queue.remove_if([sig](SignalInfo &info)
{ return info.sig == sig; });
debug("Removed %d signals", n);
return n ? 0 : -ENOENT;
}
Signal::SignalInfo Signal::GetAvailableSignal(void *thread)
{
forItr(itr, Queue)
{
// if (GlobalMask.test(itr->sig - 1))
// {
// debug("Signal %s is blocked by global mask",
// sigStr[itr->sig]);
// continue;
// }
if (((TCB *)thread)->Signals.Mask.test(itr->sig - 1))
{
debug("Signal %s is blocked by thread mask",
sigStr[itr->sig]);
continue;
}
if (((TCB *)thread)->ID != itr->tid && itr->tid != -1)
{
debug("Signal %s is not for this thread",
sigStr[itr->sig]);
continue;
}
assert(sa[itr->sig].sa_handler.Disposition != SAD_IGN);
assert(sa[itr->sig].sa_handler.Disposition != SAD_DFL);
Queue.erase(itr);
debug("Signal %s is available", sigStr[itr->sig]);
return *itr;
}
debug("No signal available");
return {};
}
bool Signal::HandleSignal(CPU::SchedulerFrame *tf, void *thread)
{
/* We don't want to do this in kernel mode */
if (tf->cs != GDT_USER_CODE)
return false;
if (Queue.empty())
return false;
debug("We have %d signals to handle", Queue.size());
SmartLock(SignalLock);
SignalInfo sigI = GetAvailableSignal(thread);
if (sigI.sig == SIG_NULL)
return false;
uintptr_t _p_rsp = ((PCB *)ctx)->PageTable->Get(tf->rsp);
uint64_t paRsp = _p_rsp;
paRsp &= ~0xF; /* Align */
paRsp -= 128; /* Red zone */
/* Calculate the virtual rsp */
uintptr_t _v_rsp = tf->rsp;
_v_rsp &= ~0xF; /* Align */
_v_rsp -= 128; /* Red zone */
uint64_t *vRsp = (uint64_t *)(_v_rsp - sizeof(StackInfo));
vRsp--; /* Alignment */
vRsp--; /* Handler Address */
assert(!((uintptr_t)vRsp & 0xF));
/* Add the stack info */
StackInfo si{};
CPU::x64::fxsave(&si.fx);
si.tf = *tf;
si.GSBase = CPU::x64::rdmsr(CPU::x64::MSR_GS_BASE);
si.FSBase = CPU::x64::rdmsr(CPU::x64::MSR_FS_BASE);
si.ShadowGSBase = CPU::x64::rdmsr(CPU::x64::MSR_SHADOW_GS_BASE);
si.SignalMask = ((TCB *)thread)->Signals.Mask.to_ulong();
si.Compatibility = ((PCB *)ctx)->Info.Compatibility;
debug("gs: %#lx fs: %#lx shadow: %#lx",
si.GSBase, si.FSBase, si.ShadowGSBase);
/* Copy the stack info */
uint64_t *pRsp = (uint64_t *)(paRsp - sizeof(StackInfo));
memcpy(pRsp, &si, sizeof(StackInfo));
/* Set the handler address */
pRsp--; /* Alignment */
pRsp--;
*pRsp = uint64_t(sa[sigI.sig].sa_handler.Handler);
assert(!((uintptr_t)pRsp & 0xF));
int cSig = LinuxSig() ? ConvertSignalToLinux((Signals)sigI.sig) : sigI.sig;
#ifdef DEBUG
DumpData("Stack Data", (void *)pRsp,
paRsp - uint64_t(pRsp));
debug("initial stack tf->rsp: %#lx after: %#lx",
tf->rsp, uint64_t(vRsp));
debug("sig: %d -> %d", sigI.sig, cSig);
#endif
tf->rsp = uint64_t(vRsp);
tf->rip = uint64_t(TrampAddr);
/* void func(int signo); */
/* void func(int signo, siginfo_t *info, void *context); */
tf->rdi = cSig;
if (sa[sigI.sig].Flags & SA_SIGINFO)
{
fixme("SA_SIGINFO not implemented");
siginfo_t *info = 0;
void *context = 0;
tf->rsi = uint64_t(info);
tf->rdx = uint64_t(context);
tf->rcx = 0;
tf->r8 = 0;
tf->r9 = 0;
}
else
{
tf->rsi = 0;
tf->rdx = 0;
tf->rcx = 0;
tf->r8 = 0;
tf->r9 = 0;
}
((TCB *)thread)->Signals.Mask = sa[sigI.sig].Mask;
assert(TrampAddr != nullptr);
return true;
}
void Signal::RestoreHandleSignal(SyscallsFrame *sf, void *thread)
{
debug("Restoring signal handler");
SmartLock(SignalLock);
gsTCB *gs = (gsTCB *)CPU::x64::rdmsr(CPU::x64::MSR_GS_BASE);
uint64_t *sp = (uint64_t *)((PCB *)ctx)->PageTable->Get(gs->TempStack);
sp++; /* Alignment */
sp++; /* Handler Address */
assert(!((uintptr_t)sp & 0xF));
StackInfo *si = (StackInfo *)sp;
assert(si != nullptr);
sf->r15 = si->tf.r15;
sf->r14 = si->tf.r14;
sf->r13 = si->tf.r13;
sf->r12 = si->tf.r12;
sf->r11 = si->tf.r11;
sf->r10 = si->tf.r10;
sf->r9 = si->tf.r9;
sf->r8 = si->tf.r8;
sf->rbp = si->tf.rbp;
sf->rdi = si->tf.rdi;
sf->rsi = si->tf.rsi;
sf->rdx = si->tf.rdx;
sf->rcx = si->tf.rcx;
sf->rbx = si->tf.rbx;
sf->rax = si->tf.rax;
sf->Flags = si->tf.rflags.raw;
sf->ReturnAddress = si->tf.rip;
gs->TempStack = (void *)si->tf.rsp;
((TCB *)thread)->Signals.Mask = si->SignalMask;
CPU::x64::fxrstor(&si->fx);
CPU::x64::wrmsr(CPU::x64::MSR_GS_BASE, si->ShadowGSBase);
CPU::x64::wrmsr(CPU::x64::MSR_FS_BASE, si->FSBase);
CPU::x64::wrmsr(CPU::x64::MSR_SHADOW_GS_BASE, si->GSBase);
debug("gs: %#lx fs: %#lx shadow: %#lx",
si->GSBase, si->FSBase, si->ShadowGSBase);
// ((PCB *)ctx)->GetContext()->Yield();
// __builtin_unreachable();
/* Return because we will restore at sysretq */
}
int Signal::SetAction(Signals sig, const SignalAction *act)
{
SmartLock(SignalLock);
if ((size_t)sig > sizeof(sa) / sizeof(sa[0]))
{
debug("Invalid signal: %d", sig);
return -EINVAL;
}
if ((long)act->sa_handler.Disposition == SAD_IGN)
{
Disposition[sig] = SIG_IGN;
debug("Set disposition for %s to SIG_IGN", sigStr[sig]);
debug("Discarding pending signals %s", sigStr[sig]);
bool found = false;
forItr(itr, Queue)
{
if (itr->sig == sig)
{
Queue.erase(itr);
found = true;
break;
}
}
if (!found)
{
debug("No pending signal %s", sigStr[sig]);
}
}
if ((long)act->sa_handler.Disposition == SAD_DFL)
{
Disposition[sig] = GetDefaultSignalDisposition(sig);
debug("Set disposition for %s to %s (default)", sigStr[sig],
dispStr[Disposition[sig]]);
}
sa[sig].sa_handler.Handler = act->sa_handler.Handler;
sa[sig].Mask = act->Mask;
sa[sig].Flags = act->Flags;
sa[sig].Restorer = act->Restorer;
debug("Set action for %s with handler %#lx, mask %#lx and flags %#lx",
sigStr[sig], sa[sig].sa_handler.Handler, sa[sig].Mask, sa[sig].Flags);
return 0;
}
int Signal::GetAction(Signals sig, SignalAction *act)
{
SmartLock(SignalLock);
if ((size_t)sig > sizeof(sa) / sizeof(sa[0]))
{
debug("Invalid signal: %d", sig);
return -EINVAL;
}
act->sa_handler.Handler = sa[sig].sa_handler.Handler;
act->Mask = sa[sig].Mask;
act->Flags = sa[sig].Flags;
act->Restorer = sa[sig].Restorer;
debug("Got action for %s with handler %#lx, mask %#lx and flags %#lx",
sigStr[sig], sa[sig].sa_handler.Handler, sa[sig].Mask, sa[sig].Flags);
return 0;
}
int Signal::SendSignal(Signals sig, sigval val, pid_t tid)
{
SmartLock(SignalLock);
PCB *pcb = (PCB *)ctx;
LastSignal = sig;
debug("Sending signal %s to %s(%d)",
sigStr[sig], pcb->Name, pcb->ID);
if (sa[sig].sa_handler.Handler)
{
if (pcb->Security.ExecutionMode == Kernel)
{
info("Kernel processes cannot have signal handlers");
return -EINVAL;
}
if (sa[sig].sa_handler.Disposition == SAD_IGN)
{
debug("Ignoring signal %s", sigStr[sig]);
return 0;
}
debug("sa_handler: %#lx", sa[sig].sa_handler.Handler);
debug("Adding signal %s to queue", sigStr[sig]);
goto CompleteSignal;
}
else
{
debug("No handler for signal %s", sigStr[sig]);
}
if (thisThread->Signals.Mask.test(sig - 1))
{
debug("Signal %s is blocked by thread mask",
sigStr[sig]);
return 0;
}
debug("Signal disposition: %s", dispStr[Disposition[sig]]);
switch (Disposition[sig])
{
case SIG_TERM:
{
if (unlikely(pcb->Security.IsCritical))
{
debug("Critical process %s received signal %s(%d): Terminated",
pcb->Name, sigStr[sig], sig);
// int3;
}
pcb->SetExitCode(MakeExitCode(sig));
debug("We have %d watchers", this->Watchers.size());
if (this->Watchers.size() > 0)
pcb->SetState(Zombie);
else
pcb->SetState(Terminated);
return val.sival_int == Tasking::KILL_CRASH ? -EFAULT : 0;
}
case SIG_IGN:
{
debug("Ignoring signal %d", sig);
return 0;
}
case SIG_CORE:
{
fixme("core dump");
if (unlikely(pcb->Security.IsCritical))
{
debug("Critical process %s received signal %s(%d): Core dumped",
pcb->Name, sigStr[sig], sig);
// int3;
}
pcb->SetExitCode(MakeExitCode(sig));
debug("We have %d watchers", this->Watchers.size());
if (this->Watchers.size() > 0)
pcb->SetState(CoreDump);
else
pcb->SetState(Terminated);
return val.sival_int == Tasking::KILL_CRASH ? -EFAULT : 0;
}
case SIG_STOP:
{
debug("Stopping process %s(%d) with signal %s(%d)",
pcb->Name, pcb->ID, sigStr[sig], sig);
pcb->SetState(Stopped);
return 0;
}
case SIG_CONT:
{
debug("Continuing process %s(%d) with signal %s(%d)",
pcb->Name, pcb->ID, sigStr[sig], sig);
pcb->SetState(Ready);
return 0;
}
default:
assert(!"Invalid signal disposition");
return -EINVAL;
};
CompleteSignal:
if (pcb->Security.ExecutionMode == Kernel)
{
debug("Kernel process %s received signal %s(%d)! Ignoring... (with exceptions)",
pcb->Name, sigStr[sig], sig);
return 0;
}
this->InitTrampoline();
debug("Signal %s(%d) completed", sigStr[sig], sig);
if (Disposition[sig] != SIG_IGN)
{
foreach (auto info in Watchers)
{
Signal *who = (Signal *)info.val.sival_ptr;
assert(who != nullptr);
debug("Sending SIGCHLD to %s(%d)",
((PCB *)who->GetContext())->Name,
((PCB *)who->GetContext())->ID);
who->SendSignal(SIGCHLD, val);
}
}
debug("Adding signal to queue");
Queue.push_back({.sig = sig, .val = val, .tid = tid});
return 0;
}
int Signal::WaitAnySignal()
{
debug("Waiting for any signal");
size_t oldSize = Queue.size();
Reset:
while (Queue.size() == oldSize)
TaskManager->Yield();
if (Queue.size() > oldSize)
{
debug("Added signal to queue %d > %d",
Queue.size(), oldSize);
oldSize = Queue.size();
goto Reset;
}
debug("Signal received");
return -EINTR;
}
int Signal::WaitSignal(Signals sig, union sigval *val)
{
assert(!"WaitSignal not implemented");
return 0;
}
int Signal::WaitSignalTimeout(Signals sig, union sigval *val, uint64_t timeout)
{
assert(!"WaitSignalTimeout not implemented");
return 0;
}
Signal::Signal(void *_ctx)
{
assert(_ctx != nullptr);
this->ctx = _ctx;
// for (int i = 1; i < SIGNAL_MAX; i++)
// Disposition[i] = GetDefaultSignalDisposition(i);
#ifdef DEBUG
static int once = 0;
if (!once++)
{
for (int i = 1; i < SIGNAL_MAX; i++)
debug("%s: %s",
sigStr[i],
dispStr[Disposition[(Signals)i]]);
}
#endif
}
Signal::~Signal() {}
sigset_t ThreadSignal::Block(sigset_t sig)
{
sigset_t oldMask = Mask.to_ulong();
Mask |= sig;
debug("%#lx -> %#lx", oldMask, Mask);
return oldMask;
}
sigset_t ThreadSignal::Unblock(sigset_t sig)
{
sigset_t oldMask = Mask.to_ulong();
Mask &= ~sig;
debug("%#lx -> %#lx", oldMask, Mask);
return oldMask;
}
sigset_t ThreadSignal::SetMask(sigset_t sig)
{
sigset_t oldMask = Mask.to_ulong();
Mask = sig;
debug("%#lx -> %#lx", oldMask, Mask);
return oldMask;
}
sigset_t ThreadSignal::GetMask()
{
return Mask.to_ulong();
}
}