Implement I_SUID/I_SGID feature for binfs in the POSIX compliant way.
If set-user-ID bit is set in the file permissions, then the effective
user ID of process shall be set to UID of the new process image file.
test case:
hello example emulates to set uid and file set-user-ID bit, and call
geteuid and getegid API.
UID = 2000
GID = 3000
MODE = 06555
nsh> ls -l /bin/hello
-r-sr-sr-x 2000 3000 0 hello
nsh> hello
geteuid:2000
getegid:3000
Signed-off-by: fangxinyong <fangxinyong@xiaomi.com>
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
Squashed commit of the following:
Correct some additional compile-related issues.
Move include/nuttx/binfmt/builtin.h to include/nuttx/lib/builtin.h. Move apps/builtin/lib_builtin_forindex.c to libs/libc/builtin/lib_builtin_forindex.c.
Move binfmt/libbuiltin to libs/libc/builtin. There are calls made directly from apps/nshlib into this logic and hence, must be part of a library that can be shared between the OS and applications.
many locations: Change occurences of open() followed by file_detach() to file_open(). Change most non-controversion calls to open() to nx_open().
fs/inode/fs_fileopen.c: Flesh out file_open() with some interim, placeholder logic.
fs/inode/fs_fileopen.c: Add a framework for a file_open() implementation (no real logic in place yet).
fs/vfs/fs_open.c: Add nx_open() which is the same as open() except that it does not create a cancellation point nor does it modify the errno variable.
