esp_vfs_unregister_with_id() scanned only the first VFS_MAX_COUNT
(default 8, max 20) slots of s_fd_table[MAX_FDS] (MAX_FDS = FD_SETSIZE,
64 on non-Cygwin targets) when clearing stale references to the
unregistered VFS. Every other loop over s_fd_table in this file
(and in vfs_calls.c) correctly bounds on MAX_FDS.
Any global fd >= VFS_MAX_COUNT that was still open against the VFS
being unregistered was left with a stale vfs_index pointing at a slot
that esp_get_free_index() can immediately hand out to the next
esp_vfs_register*() call, causing later operations on that fd to be
routed into an unrelated filesystem's context.
Signed-off-by: yi chen <94xhn1@gmail.com>
Rework the syscall interposition architecture so FreeRTOS works
standalone (without VFS) and VFS optionally overrides with strong
symbols. All kernel FDs are registered with VFS via
esp_vfs_register_fd_with_local_fd, so the application only sees
VFS-allocated FD numbers, preventing numerical collisions between
kernel FDs and VFS-internal FD slots.
FreeRTOS side:
- Create linux_port_coop_internal.h with LINUX_COOP_IO_LOOP,
LINUX_COOP_RESOLVE, linux_coop_yield and FD state table functions
- Export cooperative I/O primitives (freertos_linux_coop_read/write/
open/close/fcntl/select/pread/pwrite/readv/writev/recv/send/
recvfrom/sendto/recvmsg/sendmsg/connect/accept/pselect/poll/
socket/socketpair/pipe/pipe2/dup/dup2/syscalls_init)
- Define weak POSIX symbols calling through to the cooperative
primitives; keep nanosleep/sleep/usleep as strong (not FD-related)
- Refactor freertos_linux_coop_syscalls.h into a pure public API header
VFS side:
- Register the Linux host FS with esp_vfs_register_fs_with_id() as a
proper VFS driver; register stdin/stdout/stderr at init (priority 99)
- Rewrite vfs_linux.c with strong POSIX symbols dispatching through
esp_vfs_*
- Add strong overrides for FD-creating syscalls (open, pipe, pipe2,
socket, socketpair, dup, dup2, accept) that register returned FDs
with VFS
- Add strong overrides for FD-translating syscalls (readv, writev,
recv, send, recvfrom, sendto, recvmsg, sendmsg, connect, pselect,
poll) that translate VFS FD to kernel FD
- Delete vfs_coop_syscalls.c (absorbed into FreeRTOS weak + VFS strong)
- Update CMakeLists.txt: remove vfs_coop_syscalls.c, add linker hook
This fixes a potential race condition in select() if both a socket-fd
and non-socket fd trigger simultaneously to unblock this select.
In case of both fds, we use lwip's local thread semaphore, so we only
have to try return it (if it was taken/triggered more than once) when
we exit select().
Closes https://github.com/espressif/esp-idf/issues/8896
Calling "open" in CHECK_AND_CALL sets a perfectly correct errno.
There is no need to overwrite that with a value of ENOENT, since doing
so hides lower level errors like EIO.
Closes https://github.com/espressif/esp-idf/pull/8036