ladybird/Kernel/Syscalls/ptrace.cpp
2020-08-02 00:29:04 +02:00

113 lines
4.2 KiB
C++

/*
* 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>
#include <Kernel/Ptrace.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/VM/PrivateInodeVMObject.h>
#include <Kernel/VM/ProcessPagingScope.h>
#include <Kernel/VM/Region.h>
#include <Kernel/VM/SharedInodeVMObject.h>
namespace Kernel {
int Process::sys$ptrace(Userspace<const Syscall::SC_ptrace_params*> user_params)
{
REQUIRE_PROMISE(proc);
Syscall::SC_ptrace_params params;
if (!validate_read_and_copy_typed(&params, user_params))
return -EFAULT;
auto result = Ptrace::handle_syscall(params, *this);
return result.is_error() ? result.error() : result.value();
}
bool Process::has_tracee_thread(int tracer_pid) const
{
bool has_tracee = false;
for_each_thread([&](Thread& t) {
if (t.tracer() && t.tracer()->tracer_pid() == tracer_pid) {
has_tracee = true;
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
return has_tracee;
}
KResultOr<u32> Process::peek_user_data(Userspace<const u32*> address)
{
if (!MM.validate_user_read(*this, VirtualAddress(address), sizeof(u32))) {
dbg() << "Invalid address for peek_user_data: " << address.ptr();
return KResult(-EFAULT);
}
uint32_t result;
// This function can be called from the context of another
// process that called PT_PEEK
ProcessPagingScope scope(*this);
copy_from_user(&result, address);
return result;
}
KResult Process::poke_user_data(Userspace<u32*> address, u32 data)
{
// We validate for read (rather than write) because PT_POKE can write to readonly pages.
// So we effectively only care that the poke operation is trying to write to user pages.
if (!MM.validate_user_read(*this, VirtualAddress(address), sizeof(u32))) {
dbg() << "Invalid address for poke_user_data: " << address.ptr();
return KResult(-EFAULT);
}
ProcessPagingScope scope(*this);
Range range = { VirtualAddress(address), sizeof(u32) };
auto* region = find_region_containing(range);
ASSERT(region != nullptr);
if (region->is_shared()) {
// If the region is shared, we change its vmobject to a PrivateInodeVMObject
// to prevent the write operation from changing any shared inode data
ASSERT(region->vmobject().is_shared_inode());
region->set_vmobject(PrivateInodeVMObject::create_with_inode(static_cast<SharedInodeVMObject&>(region->vmobject()).inode()));
region->set_shared(false);
}
const bool was_writable = region->is_writable();
if (!was_writable) //TODO refactor into scopeguard
{
region->set_writable(true);
region->remap();
}
copy_to_user(address, &data);
if (!was_writable) {
region->set_writable(false);
region->remap();
}
return KResult(KSuccess);
}
}