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Kernel: Make UserOrKernelBuffer R/W helpers return KResultOr<size_t>

This makes error propagation less cumbersome (and also exposed some
places where we were not doing it.)
This commit is contained in:
Andreas Kling 2021-05-13 09:08:44 +02:00
parent 25a45e639a
commit e46343bf9a
15 changed files with 64 additions and 85 deletions

View file

@ -57,14 +57,11 @@ Kernel::KResultOr<size_t> Console::write(FileDescription&, u64, const Kernel::Us
if (!size)
return 0;
ssize_t nread = data.read_buffered<256>(size, [&](const u8* bytes, size_t bytes_count) {
return data.read_buffered<256>(size, [&](u8 const* bytes, size_t bytes_count) {
for (size_t i = 0; i < bytes_count; i++)
put_char((char)bytes[i]);
return (ssize_t)bytes_count;
return bytes_count;
});
if (nread < 0)
return Kernel::KResult((ErrnoCode)-nread);
return (size_t)nread;
}
void Console::put_char(char ch)

View file

@ -90,7 +90,7 @@ public:
}
template<size_t BUFFER_BYTES, typename... Args>
[[nodiscard]] bool write_to_buffer_buffered(UserOrKernelBuffer& buffer, Args... args)
[[nodiscard]] KResultOr<size_t> write_to_buffer_buffered(UserOrKernelBuffer& buffer, Args... args)
{
if (in_target_context(buffer))
return buffer.write_buffered<BUFFER_BYTES>(forward<Args>(args)...);
@ -108,7 +108,7 @@ public:
}
template<size_t BUFFER_BYTES, typename... Args>
[[nodiscard]] bool read_from_buffer_buffered(const UserOrKernelBuffer& buffer, Args... args)
[[nodiscard]] KResultOr<size_t> read_from_buffer_buffered(const UserOrKernelBuffer& buffer, Args... args)
{
if (in_target_context(buffer))
return buffer.read_buffered<BUFFER_BYTES>(forward<Args>(args)...);

View file

@ -298,13 +298,13 @@ KResultOr<size_t> KeyboardDevice::read(FileDescription&, u64, UserOrKernelBuffer
lock.unlock();
ssize_t n = buffer.write_buffered<sizeof(Event)>(sizeof(Event), [&](u8* data, size_t data_bytes) {
auto result = buffer.write_buffered<sizeof(Event)>(sizeof(Event), [&](u8* data, size_t data_bytes) {
memcpy(data, &event, sizeof(Event));
return (ssize_t)data_bytes;
return data_bytes;
});
if (n < 0)
return KResult((ErrnoCode)-n);
VERIFY((size_t)n == sizeof(Event));
if (result.is_error())
return result.error();
VERIFY(result.value() == sizeof(Event));
nread += sizeof(Event);
lock.lock();

View file

@ -25,13 +25,10 @@ bool RandomDevice::can_read(const FileDescription&, size_t) const
KResultOr<size_t> RandomDevice::read(FileDescription&, u64, UserOrKernelBuffer& buffer, size_t size)
{
bool success = buffer.write_buffered<256>(size, [&](u8* data, size_t data_size) {
return buffer.write_buffered<256>(size, [&](u8* data, size_t data_size) {
get_good_random_bytes(data, data_size);
return (ssize_t)data_size;
return data_size;
});
if (!success)
return EFAULT;
return size;
}
KResultOr<size_t> RandomDevice::write(FileDescription&, u64, const UserOrKernelBuffer&, size_t size)

View file

@ -33,15 +33,11 @@ KResultOr<size_t> SerialDevice::read(FileDescription&, u64, UserOrKernelBuffer&
if (!(get_line_status() & DataReady))
return 0;
ssize_t nwritten = buffer.write_buffered<128>(size, [&](u8* data, size_t data_size) {
return buffer.write_buffered<128>(size, [&](u8* data, size_t data_size) {
for (size_t i = 0; i < data_size; i++)
data[i] = IO::in8(m_base_addr);
return (ssize_t)data_size;
return data_size;
});
if (nwritten < 0)
return KResult((ErrnoCode)-nwritten);
return size;
}
bool SerialDevice::can_write(const FileDescription&, size_t) const
@ -57,14 +53,11 @@ KResultOr<size_t> SerialDevice::write(FileDescription&, u64, const UserOrKernelB
if (!(get_line_status() & EmptyTransmitterHoldingRegister))
return 0;
ssize_t nread = buffer.read_buffered<128>(size, [&](const u8* data, size_t data_size) {
return buffer.read_buffered<128>(size, [&](u8 const* data, size_t data_size) {
for (size_t i = 0; i < data_size; i++)
IO::out8(m_base_addr, data[i]);
return (ssize_t)data_size;
return data_size;
});
if (nread < 0)
return KResult((ErrnoCode)-nread);
return (size_t)nread;
}
String SerialDevice::device_name() const

View file

@ -48,7 +48,7 @@ KResultOr<size_t> InodeWatcher::read(FileDescription&, u64, UserOrKernelBuffer&
if (buffer_size < bytes_to_write)
return EINVAL;
ssize_t nwritten = buffer.write_buffered<MAXIMUM_EVENT_SIZE>(bytes_to_write, [&](u8* data, size_t data_bytes) {
auto result = buffer.write_buffered<MAXIMUM_EVENT_SIZE>(bytes_to_write, [&](u8* data, size_t data_bytes) {
size_t offset = 0;
memcpy(data + offset, &event.wd, sizeof(InodeWatcherEvent::watch_descriptor));
@ -64,12 +64,10 @@ KResultOr<size_t> InodeWatcher::read(FileDescription&, u64, UserOrKernelBuffer&
memset(data + offset, 0, sizeof(InodeWatcherEvent::name_length));
}
return (ssize_t)data_bytes;
return data_bytes;
});
if (nwritten < 0)
return KResult((ErrnoCode)-nwritten);
evaluate_block_conditions();
return bytes_to_write;
return result;
}
KResult InodeWatcher::close()

View file

@ -903,17 +903,17 @@ static ssize_t write_sys_bool(InodeIdentifier inode_id, const UserOrKernelBuffer
char value = 0;
bool did_read = false;
ssize_t nread = buffer.read_buffered<1>(1, [&](const u8* data, size_t) {
auto result = buffer.read_buffered<1>(1, [&](u8 const* data, size_t) {
if (did_read)
return 0;
value = (char)data[0];
did_read = true;
return 1;
});
if (nread < 0)
return nread;
VERIFY(nread == 0 || (nread == 1 && did_read));
if (nread == 0 || !(value == '0' || value == '1'))
if (result.is_error())
return result.error();
VERIFY(result.value() == 0 || (result.value() == 1 && did_read));
if (result.value() == 0 || !(value == '0' || value == '1'))
return (ssize_t)size;
auto* lockable_bool = reinterpret_cast<Lockable<bool>*>(variable.address);

View file

@ -255,7 +255,7 @@ public:
KResultOr<int> sys$inode_watcher_add_watch(Userspace<const Syscall::SC_inode_watcher_add_watch_params*> user_params);
KResultOr<int> sys$inode_watcher_remove_watch(int fd, int wd);
KResultOr<int> sys$dbgputch(u8);
KResultOr<int> sys$dbgputstr(Userspace<const u8*>, int length);
KResultOr<size_t> sys$dbgputstr(Userspace<const u8*>, int length);
KResultOr<int> sys$dump_backtrace();
KResultOr<pid_t> sys$gettid();
KResultOr<int> sys$donate(pid_t tid);
@ -372,7 +372,7 @@ public:
KResultOr<int> sys$halt();
KResultOr<int> sys$reboot();
KResultOr<int> sys$realpath(Userspace<const Syscall::SC_realpath_params*>);
KResultOr<ssize_t> sys$getrandom(Userspace<void*>, size_t, unsigned int);
KResultOr<size_t> sys$getrandom(Userspace<void*>, size_t, unsigned int);
KResultOr<int> sys$getkeymap(Userspace<const Syscall::SC_getkeymap_params*>);
KResultOr<int> sys$setkeymap(Userspace<const Syscall::SC_setkeymap_params*>);
KResultOr<int> sys$module_load(Userspace<const char*> path, size_t path_length);

View file

@ -476,12 +476,12 @@ bool IDEChannel::ata_do_read_sector()
dbgln_if(PATA_DEBUG, "IDEChannel::ata_do_read_sector");
auto& request = *m_current_request;
auto out_buffer = request.buffer().offset(m_current_request_block_index * 512);
ssize_t nwritten = request.write_to_buffer_buffered<512>(out_buffer, 512, [&](u8* buffer, size_t buffer_bytes) {
auto result = request.write_to_buffer_buffered<512>(out_buffer, 512, [&](u8* buffer, size_t buffer_bytes) {
for (size_t i = 0; i < buffer_bytes; i += sizeof(u16))
*(u16*)&buffer[i] = IO::in16(m_io_group.io_base().offset(ATA_REG_DATA).get());
return (ssize_t)buffer_bytes;
return buffer_bytes;
});
if (nwritten < 0) {
if (result.is_error()) {
// TODO: Do we need to abort the PATA read if this wasn't the last block?
complete_current_request(AsyncDeviceRequest::MemoryFault);
return false;
@ -518,12 +518,12 @@ void IDEChannel::ata_do_write_sector()
auto in_buffer = request.buffer().offset(m_current_request_block_index * 512);
dbgln_if(PATA_DEBUG, "IDEChannel: Writing 512 bytes (part {}) (status={:#02x})...", m_current_request_block_index, status);
ssize_t nread = request.read_from_buffer_buffered<512>(in_buffer, 512, [&](const u8* buffer, size_t buffer_bytes) {
auto result = request.read_from_buffer_buffered<512>(in_buffer, 512, [&](u8 const* buffer, size_t buffer_bytes) {
for (size_t i = 0; i < buffer_bytes; i += sizeof(u16))
IO::out16(m_io_group.io_base().offset(ATA_REG_DATA).get(), *(const u16*)&buffer[i]);
return (ssize_t)buffer_bytes;
return buffer_bytes;
});
if (nread < 0)
if (result.is_error())
complete_current_request(AsyncDeviceRequest::MemoryFault);
}

View file

@ -23,7 +23,7 @@ KResultOr<int> Process::sys$dbgputch(u8 ch)
return 0;
}
KResultOr<int> Process::sys$dbgputstr(Userspace<const u8*> characters, int length)
KResultOr<size_t> Process::sys$dbgputstr(Userspace<const u8*> characters, int length)
{
if (length <= 0)
return 0;
@ -31,14 +31,11 @@ KResultOr<int> Process::sys$dbgputstr(Userspace<const u8*> characters, int lengt
auto buffer = UserOrKernelBuffer::for_user_buffer(characters, length);
if (!buffer.has_value())
return EFAULT;
ssize_t nread = buffer.value().read_buffered<1024>(length, [&](const u8* buffer, size_t buffer_size) {
return buffer.value().read_buffered<1024>(length, [&](u8 const* buffer, size_t buffer_size) {
for (size_t i = 0; i < buffer_size; ++i)
IO::out8(0xe9, buffer[i]);
return (ssize_t)buffer_size;
return buffer_size;
});
if (nread < 0)
return (int)nread;
return 0;
}
}

View file

@ -13,7 +13,7 @@ namespace Kernel {
// We don't use the flag yet, but we could use it for distinguishing
// random source like Linux, unlike the OpenBSD equivalent. However, if we
// do, we should be able of the caveats that Linux has dealt with.
KResultOr<ssize_t> Process::sys$getrandom(Userspace<void*> buffer, size_t buffer_size, [[maybe_unused]] unsigned flags)
KResultOr<size_t> Process::sys$getrandom(Userspace<void*> buffer, size_t buffer_size, [[maybe_unused]] unsigned flags)
{
REQUIRE_PROMISE(stdio);
if (buffer_size <= 0)
@ -22,11 +22,10 @@ KResultOr<ssize_t> Process::sys$getrandom(Userspace<void*> buffer, size_t buffer
auto data_buffer = UserOrKernelBuffer::for_user_buffer(buffer, buffer_size);
if (!data_buffer.has_value())
return EFAULT;
ssize_t nwritten = data_buffer.value().write_buffered<1024>(buffer_size, [&](u8* buffer, size_t buffer_bytes) {
return data_buffer.value().write_buffered<1024>(buffer_size, [&](u8* buffer, size_t buffer_bytes) {
get_good_random_bytes(buffer, buffer_bytes);
return (ssize_t)buffer_bytes;
return buffer_bytes;
});
return nwritten;
}
}

View file

@ -46,12 +46,12 @@ void SlavePTY::echo(u8 ch)
void SlavePTY::on_master_write(const UserOrKernelBuffer& buffer, ssize_t size)
{
ssize_t nread = buffer.read_buffered<128>(size, [&](const u8* data, size_t data_size) {
auto result = buffer.read_buffered<128>(size, [&](u8 const* data, size_t data_size) {
for (size_t i = 0; i < data_size; ++i)
emit(data[i], false);
return (ssize_t)data_size;
return data_size;
});
if (nread > 0)
if (!result.is_error())
evaluate_block_conditions();
}

View file

@ -43,10 +43,10 @@ KResultOr<size_t> TTY::read(FileDescription&, u64, UserOrKernelBuffer& buffer, s
if (m_input_buffer.size() < static_cast<size_t>(size))
size = m_input_buffer.size();
ssize_t nwritten;
KResultOr<size_t> result = 0;
bool need_evaluate_block_conditions = false;
if (in_canonical_mode()) {
nwritten = buffer.write_buffered<512>(size, [&](u8* data, size_t data_size) {
result = buffer.write_buffered<512>(size, [&](u8* data, size_t data_size) {
size_t i = 0;
for (; i < data_size; i++) {
u8 ch = m_input_buffer.dequeue();
@ -64,10 +64,10 @@ KResultOr<size_t> TTY::read(FileDescription&, u64, UserOrKernelBuffer& buffer, s
}
data[i] = ch;
}
return (ssize_t)i;
return i;
});
} else {
nwritten = buffer.write_buffered<512>(size, [&](u8* data, size_t data_size) {
result = buffer.write_buffered<512>(size, [&](u8* data, size_t data_size) {
for (size_t i = 0; i < data_size; i++) {
auto ch = m_input_buffer.dequeue();
if (ch == '\r' && m_termios.c_iflag & ICRNL)
@ -76,14 +76,12 @@ KResultOr<size_t> TTY::read(FileDescription&, u64, UserOrKernelBuffer& buffer, s
ch = '\r';
data[i] = ch;
}
return (ssize_t)data_size;
return data_size;
});
}
if (nwritten < 0)
return KResult((ErrnoCode)-nwritten);
if (nwritten > 0 || need_evaluate_block_conditions)
if ((!result.is_error() && result.value() > 0) || need_evaluate_block_conditions)
evaluate_block_conditions();
return (size_t)nwritten;
return result;
}
KResultOr<size_t> TTY::write(FileDescription&, u64, const UserOrKernelBuffer& buffer, size_t size)
@ -93,8 +91,8 @@ KResultOr<size_t> TTY::write(FileDescription&, u64, const UserOrKernelBuffer& bu
return EINTR;
}
const size_t num_chars = 256;
ssize_t nread = buffer.read_buffered<num_chars>((size_t)size, [&](const u8* data, size_t buffer_bytes) {
constexpr size_t num_chars = 256;
return buffer.read_buffered<num_chars>(size, [&](u8 const* data, size_t buffer_bytes) {
u8 modified_data[num_chars * 2];
size_t extra_chars = 0;
for (size_t i = 0; i < buffer_bytes; ++i) {
@ -106,10 +104,8 @@ KResultOr<size_t> TTY::write(FileDescription&, u64, const UserOrKernelBuffer& bu
modified_data[i + extra_chars] = ch;
}
on_tty_write(UserOrKernelBuffer::for_kernel_buffer(modified_data), buffer_bytes + extra_chars);
return (ssize_t)buffer_bytes;
return buffer_bytes;
});
return nread;
}
bool TTY::can_read(const FileDescription&, size_t) const

View file

@ -226,14 +226,16 @@ void VirtualConsole::on_key_pressed(KeyEvent event)
ssize_t VirtualConsole::on_tty_write(const UserOrKernelBuffer& data, ssize_t size)
{
ScopedSpinLock lock(s_lock);
ssize_t nread = data.read_buffered<512>((size_t)size, [&](const u8* buffer, size_t buffer_bytes) {
auto result = data.read_buffered<512>((size_t)size, [&](u8 const* buffer, size_t buffer_bytes) {
for (size_t i = 0; i < buffer_bytes; ++i)
m_terminal.on_input(buffer[i]);
return (ssize_t)buffer_bytes;
return buffer_bytes;
});
if (m_active)
flush_dirty_lines();
return nread;
if (result.is_error())
return result.error();
return (ssize_t)result.value();
}
void VirtualConsole::set_vga_start_row(u16 row)

View file

@ -82,10 +82,10 @@ public:
}
template<size_t BUFFER_BYTES, typename F>
[[nodiscard]] ssize_t write_buffered(size_t offset, size_t len, F f)
[[nodiscard]] KResultOr<size_t> write_buffered(size_t offset, size_t len, F f)
{
if (!m_buffer)
return -EFAULT;
return EFAULT;
if (is_kernel_buffer()) {
// We're transferring directly to a kernel buffer, bypass
return f(m_buffer + offset, len);
@ -102,24 +102,24 @@ public:
return copied;
VERIFY((size_t)copied <= to_copy);
if (!write(buffer, nwritten, (size_t)copied))
return -EFAULT;
return EFAULT;
nwritten += (size_t)copied;
if ((size_t)copied < to_copy)
break;
}
return (ssize_t)nwritten;
return nwritten;
}
template<size_t BUFFER_BYTES, typename F>
[[nodiscard]] ssize_t write_buffered(size_t len, F f)
[[nodiscard]] KResultOr<size_t> write_buffered(size_t len, F f)
{
return write_buffered<BUFFER_BYTES, F>(0, len, f);
}
template<size_t BUFFER_BYTES, typename F>
[[nodiscard]] ssize_t read_buffered(size_t offset, size_t len, F f) const
[[nodiscard]] KResultOr<size_t> read_buffered(size_t offset, size_t len, F f) const
{
if (!m_buffer)
return -EFAULT;
return EFAULT;
if (is_kernel_buffer()) {
// We're transferring directly from a kernel buffer, bypass
return f(m_buffer + offset, len);
@ -132,7 +132,7 @@ public:
while (nread < len) {
auto to_copy = min(sizeof(buffer), len - nread);
if (!read(buffer, nread, to_copy))
return -EFAULT;
return EFAULT;
ssize_t copied = f(buffer, to_copy);
if (copied < 0)
return copied;
@ -144,7 +144,7 @@ public:
return nread;
}
template<size_t BUFFER_BYTES, typename F>
[[nodiscard]] ssize_t read_buffered(size_t len, F f) const
[[nodiscard]] KResultOr<size_t> read_buffered(size_t len, F f) const
{
return read_buffered<BUFFER_BYTES, F>(0, len, f);
}