Post Syndicated from corbet original https://lwn.net/Articles/939217/

The fchmodat()
system call on Linux hides a little secret: it does not actually implement
all of the functionality that the man page claims (and that POSIX
calls for). As a result, C libraries have to do a bit of a complicated
workaround to provide the API that applications expect. That situation
looks likely to change with the 6.6 kernel, though, as the result of this patch
series posted by Alexey Gladkov.