Unknown open() flag passed by execve()

Question

When executing a bash script located on my FUSE filesystem, an open() call is made with these flags:

debug,cpfsfuse.c(62),cpfs_fuse_open: path "/make.sh", flags 0100040

The flags (0100040) should correspond to those passed in parameter 2 of open(). The unknown flag originates from an execve() call:

matt@stanley:~/cpfs/dir$ strace -f ./make.sh 
execve("./make.sh", ["./make.sh"], [/* 37 vars */]

My code recognises #define O_LARGEFILE 00100000, but the other flag appears to arise only when execve() is called.

Grepping for the flag does not find it:

matt@stanley:~/cpfs$ grep -RP '\b00*40\b' /usr/include/ | less

Mostly terminal flags are found. Can anyone shed some light on either how to track down the origin and meaning of this flag, or where to find its definition?

Answer 1

/usr/include/linux/fs.h:

/* File is opened for execution with sys_execve / sys_uselib */
#define FMODE_EXEC              ((fmode_t)32)

Answer 2

This might be a combination of flags. (ORed).