ladybird/Kernel/Syscalls/open.cpp
Andrew Kaster f08e91f67e Kernel: Don't check pledges or veil against code coverage data files
Coverage tools like LLVM's source-based coverage or GNU's --coverage
need to be able to write out coverage files from any binary, regardless
of its security posture. Not ignoring these pledges and veils means we
can't get our coverage data out without playing some serious tricks.

However this is pretty terrible for normal exeuction, so only skip these
checks when we explicitly configured userspace for coverage.
2022-05-02 01:46:18 +02:00

94 lines
2.8 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/KLexicalPath.h>
#include <Kernel/Net/LocalSocket.h>
#include <Kernel/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$open(Userspace<Syscall::SC_open_params const*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto params = TRY(copy_typed_from_user(user_params));
int dirfd = params.dirfd;
int options = params.options;
u16 mode = params.mode;
if (options & O_NOFOLLOW_NOERROR)
return EINVAL;
if (options & O_UNLINK_INTERNAL)
return EINVAL;
auto path = TRY(get_syscall_path_argument(params.path));
// Disable checking open pledges when building userspace with coverage
// so that all processes can write out coverage data even with pledges
bool skip_pledge_verification = false;
#ifdef SKIP_PATH_VALIDATION_FOR_COVERAGE_INSTRUMENTATION
if (KLexicalPath::basename(path->view()).ends_with(".profraw"sv))
skip_pledge_verification = true;
#endif
if (!skip_pledge_verification) {
if (options & O_WRONLY)
TRY(require_promise(Pledge::wpath));
else if (options & O_RDONLY)
TRY(require_promise(Pledge::rpath));
if (options & O_CREAT)
TRY(require_promise(Pledge::cpath));
}
// Ignore everything except permission bits.
mode &= 0777;
dbgln_if(IO_DEBUG, "sys$open(dirfd={}, path='{}', options={}, mode={})", dirfd, path->view(), options, mode);
auto fd_allocation = TRY(allocate_fd());
RefPtr<Custody> base;
if (dirfd == AT_FDCWD) {
base = current_directory();
} else {
auto base_description = TRY(open_file_description(dirfd));
if (!base_description->is_directory())
return ENOTDIR;
if (!base_description->custody())
return EINVAL;
base = base_description->custody();
}
auto description = TRY(VirtualFileSystem::the().open(path->view(), options, mode & ~umask(), *base));
if (description->inode() && description->inode()->bound_socket())
return ENXIO;
return m_fds.with_exclusive([&](auto& fds) -> ErrorOr<FlatPtr> {
u32 fd_flags = (options & O_CLOEXEC) ? FD_CLOEXEC : 0;
fds[fd_allocation.fd].set(move(description), fd_flags);
return fd_allocation.fd;
});
}
ErrorOr<FlatPtr> Process::sys$close(int fd)
{
VERIFY_NO_PROCESS_BIG_LOCK(this)
TRY(require_promise(Pledge::stdio));
auto description = TRY(open_file_description(fd));
auto result = description->close();
m_fds.with_exclusive([fd](auto& fds) { fds[fd] = {}; });
if (result.is_error())
return result.release_error();
return 0;
}
}