lib/vfscore: Fix wrong application of umask

[andreittr]

Description of changes

Previously vfscore would apply the umask to the mode bits in the emulated libc functions open and openat, instead of within the open/openat syscall implementation where it would be correct to do so. This lead to the umask being ignored when a real libc was in use. This change fixes this bug, restoring expected behavior with or without a libc.

Prerequisite checklist

• Read the contribution guidelines regarding submitting new changes to the project;
• Tested your changes against relevant architectures and platforms;
• Ran the checkpatch.uk on your commit series before opening this PR;
• Updated relevant documentation.

Base target

• Architecture(s): N/A
• Platform(s): N/A
• Application(s): N/A

Additional configuration

Test with:

umask(0027);
f = open("file", O_WRONLY|O_CREAT, 0775);
fstat(f, &st);
printf("Should be: %o, is %o\n", 0775 & (~0027), st.st_mode);

[RaduNichita]

All good from my side. Thanks @andreittr!

Reviewed-by: Radu Nichita radunichita99@gmail.com

[eduardvintila]

All good, thanks.

Reviewed-by: Eduard Vintilă eduard.vintila47@gmail.com

[razvand]

Approved-by: Razvan Deaconescu razvand@unikraft.io

[unikraft-bot]

✅ Checkpatch passed

Beep boop! I ran Unikraft's checkpatch.pl support script on your pull request and it all looks good!

SHA	commit	checkpatch
75f42ed	lib/vfscore: Fix wrong application of umask	✅