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#include <Kernel/Process.h>
#include <Kernel/Ptrace.h>
#include <Kernel/Thread.h>
#include <Kernel/ThreadTracer.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/VM/ProcessPagingScope.h>
namespace Ptrace {
KResultOr<u32> handle_syscall(const Kernel::Syscall::SC_ptrace_params& params, Process& caller)
{
if (params.request == PT_TRACE_ME) {
if (Thread::current->tracer())
return KResult(-EBUSY);
caller.set_wait_for_tracer_at_next_execve(true);
return KSuccess;
}
if (params.pid == caller.pid())
return KResult(-EINVAL);
Thread* peer = nullptr;
{
InterruptDisabler disabler;
peer = Thread::from_tid(params.pid);
}
if (!peer)
return KResult(-ESRCH);
if ((peer->process().uid() != caller.euid())
|| (peer->process().uid() != peer->process().euid())) // Disallow tracing setuid processes
return KResult(-EACCES);
if (params.request == PT_ATTACH) {
if (peer->tracer()) {
return KResult(-EBUSY);
}
peer->start_tracing_from(caller.pid());
if (peer->state() != Thread::State::Stopped && !(peer->has_blocker() && peer->blocker().is_reason_signal()))
peer->send_signal(SIGSTOP, &caller);
return KSuccess;
}
auto* tracer = peer->tracer();
if (!tracer)
return KResult(-EPERM);
if (tracer->tracer_pid() != caller.pid())
return KResult(-EBUSY);
if (peer->state() == Thread::State::Running)
return KResult(-EBUSY);
switch (params.request) {
case PT_CONTINUE:
peer->send_signal(SIGCONT, &caller);
break;
case PT_DETACH:
peer->stop_tracing();
peer->send_signal(SIGCONT, &caller);
break;
case PT_SYSCALL:
tracer->set_trace_syscalls(true);
peer->send_signal(SIGCONT, &caller);
break;
case PT_GETREGS: {
if (!tracer->has_regs())
return KResult(-EINVAL);
auto* regs = reinterpret_cast<PtraceRegisters*>(params.addr);
if (!caller.validate_write_typed(regs))
return KResult(-EFAULT);
copy_to_user(regs, &tracer->regs());
break;
}
case PT_SETREGS: {
if (!tracer->has_regs())
return KResult(-EINVAL);
PtraceRegisters regs;
if (!caller.validate_read_and_copy_typed(®s, (const PtraceRegisters*)params.addr))
return KResult(-EFAULT);
auto& peer_saved_registers = peer->get_register_dump_from_stack();
// Verify that the saved registers are in usermode context
if ((peer_saved_registers.cs & 0x03) != 3)
return KResult(-EFAULT);
tracer->set_regs(regs);
copy_ptrace_registers_into_kernel_registers(peer_saved_registers, regs);
break;
}
case PT_PEEK: {
Kernel::Syscall::SC_ptrace_peek_params peek_params;
if (!caller.validate_read_and_copy_typed(&peek_params, reinterpret_cast<Kernel::Syscall::SC_ptrace_peek_params*>(params.addr)))
return -EFAULT;
// read validation is done inside 'peek_user_data'
auto result = peer->process().peek_user_data(peek_params.address);
if (result.is_error())
return -EFAULT;
if (!caller.validate_write(peek_params.out_data, sizeof(u32)))
return -EFAULT;
copy_to_user(peek_params.out_data, &result.value());
break;
}
case PT_POKE: {
u32* addr = reinterpret_cast<u32*>(params.addr);
// write validation is done inside 'poke_user_data'
return peer->process().poke_user_data(addr, params.data);
}
default:
return -EINVAL;
}
return 0;
}
void copy_kernel_registers_into_ptrace_registers(PtraceRegisters& ptrace_regs, const RegisterState& kernel_regs)
{
ptrace_regs.eax = kernel_regs.eax,
ptrace_regs.ecx = kernel_regs.ecx,
ptrace_regs.edx = kernel_regs.edx,
ptrace_regs.ebx = kernel_regs.ebx,
ptrace_regs.esp = kernel_regs.userspace_esp,
ptrace_regs.ebp = kernel_regs.ebp,
ptrace_regs.esi = kernel_regs.esi,
ptrace_regs.edi = kernel_regs.edi,
ptrace_regs.eip = kernel_regs.eip,
ptrace_regs.eflags = kernel_regs.eflags,
ptrace_regs.cs = 0;
ptrace_regs.ss = 0;
ptrace_regs.ds = 0;
ptrace_regs.es = 0;
ptrace_regs.fs = 0;
ptrace_regs.gs = 0;
}
void copy_ptrace_registers_into_kernel_registers(RegisterState& kernel_regs, const PtraceRegisters& ptrace_regs)
{
kernel_regs.eax = ptrace_regs.eax;
kernel_regs.ecx = ptrace_regs.ecx;
kernel_regs.edx = ptrace_regs.edx;
kernel_regs.ebx = ptrace_regs.ebx;
kernel_regs.esp = ptrace_regs.esp;
kernel_regs.ebp = ptrace_regs.ebp;
kernel_regs.esi = ptrace_regs.esi;
kernel_regs.edi = ptrace_regs.edi;
kernel_regs.eip = ptrace_regs.eip;
kernel_regs.eflags = ptrace_regs.eflags;
}
}
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