From 36226741f56ebb3a1d8902ebdc6e612a93975ff6 Mon Sep 17 00:00:00 2001 From: Retr0 Date: Tue, 20 Oct 2026 19:09:51 +0300 Subject: [PATCH] fix(libc): open a directory with fopen in a read mode on Windows FreeBSD 11 fopen opens the path with _open, and vn_open_vnode refuses a directory only for FWRITE or O_TRUNC, so fopen of a directory in a read mode succeeds; Linux hosts already open it. On Windows CreateFileW without FILE_FLAG_BACKUP_SEMANTICS refused it with EACCES. fopen now opens such a path as a libkernel directory descriptor, which libkernel registers in libc when it loads, and fclose and freopen remove it from libkernel's table. Reads on the stream fail with EISDIR and set the error indicator, as on a Linux host and FreeBSD's tmpfs: the Windows CRT fails them already but reports EINVAL. Writes fail with EBADF, and fseek, ftell and ungetc work, as on any read-only stream. --- core/libs/prx/libc/include/FileStream.hpp | 17 ++++ core/libs/prx/libc/src/FileAndHeap.cpp | 78 ++++++++++++++++--- core/libs/prx/libc/src/Formatting.cpp | 2 + core/libs/prx/libc/src/StandardStreams.cpp | 3 + .../File/src/DirectoryDescriptor.cpp | 14 ++++ core/libs/tests/FileStreams.cpp | 11 +-- core/libs/tests/GuestFilesystem.cpp | 46 +++++++++++ docs/dev/debt/libc.md | 2 +- 8 files changed, 151 insertions(+), 22 deletions(-) diff --git a/core/libs/prx/libc/include/FileStream.hpp b/core/libs/prx/libc/include/FileStream.hpp index 1b9954d873..7a81d29f07 100644 --- a/core/libs/prx/libc/include/FileStream.hpp +++ b/core/libs/prx/libc/include/FileStream.hpp @@ -23,6 +23,8 @@ struct UcrtStreamState { int count; long flags; }; +extern "C" void LibcRegisterDirectoryStreams_nid_no_patch(int (*open)(const wchar_t* path), void (*forget)(int descriptor)); +extern "C" void ForgetDirectoryStream_nid_no_patch(int descriptor); #else #include #endif @@ -66,6 +68,7 @@ class FileStream { bool _dynamic; bool guestError = false; bool randomDevice = false; + bool directory = false; public: explicit FileStream(std::FILE* handle, bool dynamic = false) : _handle(handle), _dynamic(dynamic) { @@ -130,6 +133,14 @@ public: return randomDevice; } + void MarkDirectory() { + directory = true; + } + + bool IsDirectory() const { + return directory; + } + bool Reopen(const std::filesystem::path& filename, const char* mode, [[maybe_unused]] std::FILE* (*open)(const std::filesystem::path&, const std::string&) = nullptr) { auto* previous = GetHandle(); @@ -140,6 +151,7 @@ public: std::wstring wideMode; for (const char character : std::string_view(mode)) wideMode.push_back(static_cast(character)); const int replaced = previous ? _fileno(previous) : -1; + if (std::exchange(directory, false)) ForgetDirectoryStream_nid_no_patch(replaced); auto* const standard = HostStandardHandle_nid_no_patch(replaced); GuestFileLockForget_nid_no_patch(replaced); if (open && !filename.empty()) { @@ -260,6 +272,10 @@ public: #endif } + void KeepDirectoryReadError(bool failed) { + if (failed && directory && (_guest.flags & 0x40) != 0) errno = 21; + } + void SetError() { guestError = true; SyncStatus(); @@ -276,6 +292,7 @@ public: GetHandle(); #ifdef _WIN32 GuestFileLockForget_nid_no_patch(::_fileno(_handle)); + if (std::exchange(directory, false)) ForgetDirectoryStream_nid_no_patch(::_fileno(_handle)); #endif const int result = std::fclose(std::exchange(_handle, nullptr)); _guest.flags = 0; diff --git a/core/libs/prx/libc/src/FileAndHeap.cpp b/core/libs/prx/libc/src/FileAndHeap.cpp index 410fa6f309..0b6e86284c 100644 --- a/core/libs/prx/libc/src/FileAndHeap.cpp +++ b/core/libs/prx/libc/src/FileAndHeap.cpp @@ -65,6 +65,19 @@ static std::optional ParseFileMode(const char* mode) { #ifdef _WIN32 static constexpr DWORD AppendOnlyAccess = FILE_GENERIC_WRITE & ~FILE_WRITE_DATA; + +static std::optional HostOpenName(const std::filesystem::path& path) { + auto filename = path.native(); + if (!filename.starts_with(L"\\\\?\\") && !filename.starts_with(L"\\\\.\\")) { + std::error_code pathError; + auto absolutePath = std::filesystem::absolute(path, pathError); + if (pathError) { errno = pathError.default_error_condition().value(); return std::nullopt; } + const auto absolute = absolutePath.lexically_normal().make_preferred().native(); + if (absolute.size() >= MAX_PATH) + filename = absolute.starts_with(L"\\\\") ? L"\\\\?\\UNC\\" + absolute.substr(2) : L"\\\\?\\" + absolute; + } + return filename; +} #endif static std::FILE* OpenNative(const std::filesystem::path& path, const std::string& nativeMode) { @@ -76,16 +89,9 @@ static std::FILE* OpenNative(const std::filesystem::path& path, const std::strin const DWORD disposition = access == 'r' ? OPEN_EXISTING : nativeMode.find('x') != std::string::npos ? CREATE_NEW : access == 'w' ? CREATE_ALWAYS : OPEN_ALWAYS; SECURITY_ATTRIBUTES security{sizeof(SECURITY_ATTRIBUTES), nullptr, TRUE}; - auto filename = path.native(); - if (!filename.starts_with(L"\\\\?\\") && !filename.starts_with(L"\\\\.\\")) { - std::error_code pathError; - auto absolutePath = std::filesystem::absolute(path, pathError); - if (pathError) { errno = pathError.default_error_condition().value(); return nullptr; } - const auto absolute = absolutePath.lexically_normal().make_preferred().native(); - if (absolute.size() >= MAX_PATH) - filename = absolute.starts_with(L"\\\\") ? L"\\\\?\\UNC\\" + absolute.substr(2) : L"\\\\?\\" + absolute; - } - const auto handle = CreateFileW(filename.c_str(), desired, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, &security, + const auto filename = HostOpenName(path); + if (!filename) return nullptr; + const auto handle = CreateFileW(filename->c_str(), desired, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, &security, disposition, FILE_ATTRIBUTE_NORMAL, nullptr); if (handle == INVALID_HANDLE_VALUE) { errno = WindowsOpenError_nid_no_patch(GetLastError()); @@ -307,6 +313,47 @@ static int OpenFailure(const std::filesystem::path& path, bool writes, int hostE return writes && error == 13 && std::filesystem::is_directory(path, status) ? 21 : error; } +#ifdef _WIN32 +static int (*g_openDirectoryDescriptor)(const wchar_t*) = nullptr; +static void (*g_forgetDirectoryDescriptor)(int) = nullptr; + +void LibcRegisterDirectoryStreams_nid_no_patch(int (*open)(const wchar_t*), void (*forget)(int)) { + g_openDirectoryDescriptor = open; + g_forgetDirectoryDescriptor = forget; +} + +void ForgetDirectoryStream_nid_no_patch(int descriptor) { + if (!g_forgetDirectoryDescriptor) throw std::runtime_error("ForgetDirectoryStream: libkernel has not registered its directory descriptors"); + g_forgetDirectoryDescriptor(descriptor); +} + +static FileStream* OpenDirectoryStream(const std::filesystem::path& path) { + if (!g_openDirectoryDescriptor) throw std::runtime_error("fopen: libkernel has not registered its directory descriptors"); + const auto filename = HostOpenName(path); + if (!filename) { errno = GuestErrnoFromHost_nid_no_patch(errno); return nullptr; } + const auto release = [](void* pointer) { ::operator delete(pointer); }; + std::unique_ptr storage(::operator new(sizeof(FileStream)), release); + const int descriptor = g_openDirectoryDescriptor(filename->c_str()); + if (descriptor < 0) { + const int error = GuestErrnoFromHost_nid_no_patch(errno); + errno = error == 2 ? NotFoundError_nid_no_patch(path) : error; + return nullptr; + } + auto* native = ::_fdopen(descriptor, "rb"); + if (!native) { + const int error = GuestErrnoFromHost_nid_no_patch(errno); + ForgetDirectoryStream_nid_no_patch(descriptor); + ::_close(descriptor); + errno = error; + return nullptr; + } + auto* stream = new (storage.get()) FileStream(native, true); + storage.release(); + stream->MarkDirectory(); + return stream; +} +#endif + FileStream* APS5_VABI freopen_nid_postfix(const char* filename, const char* mode, FileStream* stream) { if (!stream || !mode) { errno = 22; return nullptr; } if (!filename) { errno = 45; return nullptr; } // Mode-only reopening is not supported. @@ -370,7 +417,13 @@ FileStream* APS5_VABI fopen_nid_postfix(const char* filename, const char* mode) if (const int error = ResolvePathError_nid_no_patch(filename, fpath)) { errno = error; return nullptr; } std::unique_ptr handle(OpenNative(fpath, parsed->native), std::fclose); if (!handle) { - errno = OpenFailure(fpath, parsed->writes, errno); + const int hostError = errno; +#ifdef _WIN32 + std::error_code status; + if (!parsed->writes && GuestErrnoFromHost_nid_no_patch(hostError) == 13 && std::filesystem::is_directory(fpath, status)) + return OpenDirectoryStream(fpath); +#endif + errno = OpenFailure(fpath, parsed->writes, hostError); if (errno == 2) errno = NotFoundError_nid_no_patch(fpath); return nullptr; } @@ -445,6 +498,7 @@ size_t APS5_VABI fread_nid_postfix(void* buffer, size_t size, size_t count, File if (!stream->SwitchToReading()) return 0; const auto result = std::fread(buffer, size, count, handle); stream->SyncStatus(); + stream->KeepDirectoryReadError(result < count); return result; } @@ -529,7 +583,7 @@ int APS5_VABI fputs_nid_postfix(const char* str, FileStream* stream) { int APS5_VABI fflush_nid_postfix(FileStream* stream) { if (stream && !stream->IsOpen()) { errno = 9; return -1; } std::FILE* native = stream ? GetStreamHandle(stream) : nullptr; - if (stream && stream->IsRandomDevice()) return 0; + if (stream && (stream->IsRandomDevice() || stream->IsDirectory())) return 0; #ifdef __linux__ if (native && !__fwriting(native)) return 0; #endif diff --git a/core/libs/prx/libc/src/Formatting.cpp b/core/libs/prx/libc/src/Formatting.cpp index 07fc5468a8..1ab1877529 100644 --- a/core/libs/prx/libc/src/Formatting.cpp +++ b/core/libs/prx/libc/src/Formatting.cpp @@ -378,6 +378,7 @@ int APS5_VABI fscanf_nid_postfix(FileStream* stream, const char* format, ...) { va_end(args); #endif stream->SyncStatus(); + stream->KeepDirectoryReadError(result == -1); return result; } @@ -656,6 +657,7 @@ int APS5_VABI vfscanf_nid_postfix(FileStream* stream, const char* format, VaList va_end(copy); #endif stream->SyncStatus(); + stream->KeepDirectoryReadError(result == -1); return result; } diff --git a/core/libs/prx/libc/src/StandardStreams.cpp b/core/libs/prx/libc/src/StandardStreams.cpp index 03cdaed4cd..2cd656f01f 100644 --- a/core/libs/prx/libc/src/StandardStreams.cpp +++ b/core/libs/prx/libc/src/StandardStreams.cpp @@ -39,6 +39,7 @@ int APS5_VABI fgetc_nid_postfix(FileStream* stream) { if (!stream->SwitchToReading()) return -1; const int result = std::fgetc(native); stream->SyncStatus(); + stream->KeepDirectoryReadError(result == -1); return result; } std::int32_t APS5_VABI fgetwc_nid_postfix(FileStream* stream) { @@ -94,6 +95,7 @@ int APS5_VABI getc_unlocked_nid_postfix(FileStream* stream) { const int result = ::getc_unlocked(native); #endif stream->SyncUnlockedStatus(); + stream->KeepDirectoryReadError(result == -1); return result; } int APS5_VABI __srget_nid_postfix(FileStream* stream) { return fgetc_nid_postfix(stream); } @@ -140,6 +142,7 @@ char* APS5_VABI fgets_nid_postfix(char* buffer, int size, FileStream* stream) { if (!stream->SwitchToReading()) return nullptr; auto* result = std::fgets(buffer, size, native); stream->SyncStatus(); + stream->KeepDirectoryReadError(result == nullptr); return result; } int APS5_VABI feof_nid_postfix(FileStream* stream) { diff --git a/core/libs/prx/libkernel/File/src/DirectoryDescriptor.cpp b/core/libs/prx/libkernel/File/src/DirectoryDescriptor.cpp index 7727bb9000..e140a6b0f4 100644 --- a/core/libs/prx/libkernel/File/src/DirectoryDescriptor.cpp +++ b/core/libs/prx/libkernel/File/src/DirectoryDescriptor.cpp @@ -8,6 +8,7 @@ #ifdef _WIN32 +#include "prx/libc/include/FileStream.hpp" #include "prx/libc/include/General.hpp" #include @@ -63,6 +64,19 @@ void Load(DirectoryState& state, int fd) { } } +int OpenStreamDirectory(const wchar_t* path) { + return File::OpenDirectoryDescriptor(path); +} + +struct StreamRegistration { + StreamRegistration() { LibcRegisterDirectoryStreams_nid_no_patch(&OpenStreamDirectory, &File::ForgetDirectoryDescriptor); } + ~StreamRegistration() { LibcRegisterDirectoryStreams_nid_no_patch(nullptr, nullptr); } + StreamRegistration(const StreamRegistration&) = delete; + StreamRegistration& operator=(const StreamRegistration&) = delete; +}; + +const StreamRegistration g_streamRegistration; + } namespace File { diff --git a/core/libs/tests/FileStreams.cpp b/core/libs/tests/FileStreams.cpp index f53419748c..55445e2707 100644 --- a/core/libs/tests/FileStreams.cpp +++ b/core/libs/tests/FileStreams.cpp @@ -234,18 +234,11 @@ int main(int argc, char** argv) { errno = 0; Require(fopen_nid_postfix(argv[1], "rb") == nullptr); Require(errno == ENOENT); -#ifdef _WIN32 - const std::string directoryMode = "rb"; - constexpr int directoryError = EACCES; -#else - const std::string directoryMode = "wb"; - constexpr int directoryError = EISDIR; -#endif const std::string directoryName = std::string(argv[1]) + ".dir"; Require(std::filesystem::create_directory(directoryName)); errno = 0; - Require(fopen_nid_postfix(directoryName.c_str(), directoryMode.c_str()) == nullptr); - Require(errno == directoryError); + Require(fopen_nid_postfix(directoryName.c_str(), "wb") == nullptr); + Require(errno == EISDIR); Require(std::filesystem::remove(directoryName)); const std::u8string unicodeName = u8"セーブé.tmp"; const std::string guestName(unicodeName.begin(), unicodeName.end()); diff --git a/core/libs/tests/GuestFilesystem.cpp b/core/libs/tests/GuestFilesystem.cpp index c1a1a863bb..5faa99a95b 100644 --- a/core/libs/tests/GuestFilesystem.cpp +++ b/core/libs/tests/GuestFilesystem.cpp @@ -85,6 +85,13 @@ FileStream* APS5_VABI freopen_nid_postfix(const char*, const char*, FileStream*) std::size_t APS5_VABI fread_nid_postfix(void*, std::size_t, std::size_t, FileStream*); int APS5_VABI fclose_nid_postfix(FileStream*); int APS5_VABI fgetc_nid_postfix(FileStream*); +int APS5_VABI fileno_nid_postfix(FileStream*); +char* APS5_VABI fgets_nid_postfix(char*, int, FileStream*); +int APS5_VABI fscanf_nid_postfix(FileStream*, const char*, ...); +int APS5_VABI fputc_nid_postfix(int, FileStream*); +int APS5_VABI fseek_nid_postfix(FileStream*, std::int64_t, int); +std::int64_t APS5_VABI ftell_nid_postfix(FileStream*); +void APS5_VABI clearerr_nid_postfix(FileStream*); int APS5_VABI feof_nid_postfix(FileStream*); int APS5_VABI ferror_nid_postfix(FileStream*); int APS5_VABI setvbuf_nid_postfix(FileStream*, char*, int, std::size_t); @@ -604,6 +611,45 @@ int main() { for (const char* openMode : {"w", "wb", "r+", "a"}) { Require(fopen_nid_postfix(root.string().c_str(), openMode) == nullptr && *__error_nid_postfix() == 21); } + { + const auto listed = root / "listed.txt"; + std::ofstream(listed, std::ios::binary) << "listed"; + for (const char* openMode : {"r", "rb", "re"}) { + auto* directoryStream = fopen_nid_postfix(root.string().c_str(), openMode); + Require(directoryStream != nullptr); + const int directoryDescriptor = fileno_nid_postfix(directoryStream); + FileStat directoryStatus{}; + Require(directoryDescriptor >= 0 && sceKernelFstat(directoryDescriptor, &directoryStatus) == 0 && (directoryStatus.st_mode & 0170000) == 0040000); + Require(feof_nid_postfix(directoryStream) == 0 && ferror_nid_postfix(directoryStream) == 0 && fflush_nid_postfix(directoryStream) == 0); + char unread[8] = {}; + int scanned = 0; + *__error_nid_postfix() = 0; + Require(fread_nid_postfix(unread, 1, sizeof(unread), directoryStream) == 0 && *__error_nid_postfix() == 21); + Require(ferror_nid_postfix(directoryStream) != 0 && feof_nid_postfix(directoryStream) == 0); + clearerr_nid_postfix(directoryStream); + Require(ferror_nid_postfix(directoryStream) == 0); + *__error_nid_postfix() = 0; + Require(fgetc_nid_postfix(directoryStream) == -1 && *__error_nid_postfix() == 21 && ferror_nid_postfix(directoryStream) != 0); + clearerr_nid_postfix(directoryStream); + *__error_nid_postfix() = 0; + Require(fgets_nid_postfix(unread, sizeof(unread), directoryStream) == nullptr && *__error_nid_postfix() == 21 && ferror_nid_postfix(directoryStream) != 0); + clearerr_nid_postfix(directoryStream); + *__error_nid_postfix() = 0; + Require(fscanf_nid_postfix(directoryStream, "%d", &scanned) == -1 && *__error_nid_postfix() == 21 && ferror_nid_postfix(directoryStream) != 0); + clearerr_nid_postfix(directoryStream); + Require(fseek_nid_postfix(directoryStream, 0, 0) == 0 && ftell_nid_postfix(directoryStream) == 0); + *__error_nid_postfix() = 0; + Require(fputc_nid_postfix('x', directoryStream) == -1 && *__error_nid_postfix() == 9 && ferror_nid_postfix(directoryStream) != 0); + Require(fclose_nid_postfix(directoryStream) == 0); +#ifdef _WIN32 + const int reused = open_nid_postfix(listed.string().c_str(), 0, 0); + char text[6]{}; + Require(reused == directoryDescriptor && read_nid_postfix(reused, text, sizeof(text)) == 6 && std::memcmp(text, "listed", 6) == 0); + Require(close_nid_postfix(reused) == 0); +#endif + } + Require(std::filesystem::remove(listed)); + } Require(mkdir_nid_postfix((root / "missing" / "child").string().c_str(), 0700) == -1 && *__error_nid_postfix() == 2); Require(mkdir_nid_postfix(nullptr, 0700) == -1 && *__error_nid_postfix() == 14); const auto file = root / "file.txt"; diff --git a/docs/dev/debt/libc.md b/docs/dev/debt/libc.md index 581f589299..0805d05317 100644 --- a/docs/dev/debt/libc.md +++ b/docs/dev/debt/libc.md @@ -95,7 +95,7 @@ - On macOS the [guest arena](../../../core/libs/prx/libc/src/GuestArena.cpp) finds host regions with `mach_vm_region` and reserves the rest with a fixed `mach_vm_map`, which fails instead of replacing, as macOS has no `/proc/self/maps` or `MAP_FIXED_NOREPLACE`. The kernel keeps the range up to 0x70_0000_0000 unmappable for every process (max protection none). It starts at 0x10_0000_0000 on macOS 26.5 (M1 Pro, arm64 and x86_64 under Rosetta) and at 0xF_C000_0000 on macOS 27 (27.0.1 on an M4 Pro, arm64 and x86_64 under Rosetta; 27.2 on an M2 Max, arm64). With dyld and the Rosetta runtime near 0x2_0200_0000 and 0x3_0400_0000, a guest mapping fixed inside those ranges fails where the console places it; mappings without a fixed address are placed around them. - [sceKernelSync](../../../core/libs/prx/libc/src/General.cpp) (libkernel) flushes only the host files and directories recorded through `RecordWrittenPath_nid_no_patch` (the libc, libkernel, save data and app content file functions) and their changed parent directories. A host write in a library that does not record its path is not flushed by `sceKernelSync` - [sceKernelSync](../../../core/libs/prx/libc/src/General.cpp) (libkernel) on Windows skips a recorded file it cannot open for writing (read-only, or held open by a handle that denies write sharing), since `FlushFileBuffers` needs a writable handle. On Linux, it skips a recorded file it cannot open for reading. Such a file's data may not reach the disk before a host crash; the guest reads the same data either way -- [`fopen` and `freopen`](../../../core/libs/prx/libc/src/FileAndHeap.cpp) (libc) on Windows fail to open a directory in a read mode with `EACCES`, where FreeBSD opens it; directory streams are not emulated +- [`fopen` and `freopen`](../../../core/libs/prx/libc/src/FileAndHeap.cpp) (libc) on Windows: `freopen` onto a directory in a read mode fails with `EACCES`, where FreeBSD opens it. Reading a directory stream from `fopen` fails with `EISDIR` and sets the error indicator on every host, as FreeBSD 11 tmpfs does; FreeBSD 11 FFS returns the directory's raw blocks instead, and what the console's filesystems return is unverified - [readdir and readdir_r](../../../core/libs/prx/libc/src/Directory.cpp) (libc) on Windows report, on a file system whose directory listing carries no file ID (the entry's ID is 0, or the volume refuses `FileIdBothDirectoryInfo`), a nonzero `d_fileno` hashed from the entry name and the directory's file index, which differs from `lstat`'s `st_ino`. Not reproduced: NTFS lists an ID for every entry - [Writes on an update stream](../../../core/libs/prx/libc/src/FileAndHeap.cpp) (libc) on Windows go through the UCRT, which drops a write that directly follows a read without `fflush`, `fseek`, `fsetpos` or `rewind` unless the read reached end of file: `fwrite` returns 0, and `fputc` and `fprintf` report success, without the error indicator. FreeBSD 11.4's [`__swsetup`](https://github.com/freebsd/freebsd-src/blob/d106002967eff712894ab8b5337bbbff106ce5e0/lib/libc/stdio/wsetup.c#L59-L74) discards the read buffer and writes at the descriptor's offset, past a read-ahead of `st_blksize` bytes for a regular file, so where the console writes depends on its block size. Reads directly after writes follow FreeBSD's `__srefill` - [`fopen` of /dev/random and /dev/urandom](../../../core/libs/prx/libc/src/FileAndHeap.cpp) (libc) in a read mode returns a stream over the host null device whose `fread` fills the buffer with host OS entropy, as the libkernel [random device](../../../core/libs/prx/libkernel/File/src/RandomDevice.cpp) descriptors do. Only the exact paths are recognised, the stream has no descriptor, `setvbuf`, `feof`, `ferror`, `clearerr`, `flockfile`, `ftrylockfile`, `funlockfile` and `fclose` work on it, `fflush` returns 0 as on a FreeBSD read-only stream, and every other stream function throws, as does opening the paths for writing. `freopen` onto these paths still fails with `ENOENT`. ProsperoTV (PPSA99003) reads its phone pairing code this way