ladybird/Kernel/Syscalls/ptrace.cpp
Andreas Kling 19d3f8cab7 Kernel+LibC: Turn errno codes into a strongly typed enum
..and allow implicit creation of KResult and KResultOr from ErrnoCode.
This means that kernel functions that return those types can finally
do "return EINVAL;" and it will just work.

There's a handful of functions that still deal with signed integers
that should be converted to return KResults.
2021-01-20 23:20:02 +01:00

108 lines
3.8 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 <AK/ScopeGuard.h>
#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(ptrace);
Syscall::SC_ptrace_params params;
if (!copy_from_user(&params, user_params))
return -EFAULT;
auto result = Ptrace::handle_syscall(params, *this);
return result.is_error() ? result.error().error() : result.value();
}
/**
* "Does this process have a thread that is currently being traced by the provided process?"
*/
bool Process::has_tracee_thread(ProcessID tracer_pid)
{
if (auto tracer = this->tracer())
return tracer->tracer_pid() == tracer_pid;
return false;
}
KResultOr<u32> Process::peek_user_data(Userspace<const u32*> address)
{
uint32_t result;
// This function can be called from the context of another
// process that called PT_PEEK
ProcessPagingScope scope(*this);
if (!copy_from_user(&result, address)) {
dbgln("Invalid address for peek_user_data: {}", address.ptr());
return EFAULT;
}
return result;
}
KResult Process::poke_user_data(Userspace<u32*> address, u32 data)
{
Range range = { VirtualAddress(address), sizeof(u32) };
auto* region = find_region_containing(range);
if (!region)
return EFAULT;
ProcessPagingScope scope(*this);
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) {
region->set_writable(true);
region->remap();
}
ScopeGuard rollback([&]() {
if (!was_writable) {
region->set_writable(false);
region->remap();
}
});
if (!copy_to_user(address, &data)) {
dbgln("poke_user_data: Bad address {:p}", address.ptr());
return EFAULT;
}
return KSuccess;
}
}