On Fri, Feb 12, 2021 at 04:01:48PM -0600, Eric W. Biederman wrote: > Joe Perches <joe@xxxxxxxxxxx> writes: > > > Convert S_<FOO> permissions to the more readable octal. > > > > Done using: > > $ ./scripts/checkpatch.pl -f --fix-inplace --types=SYMBOLIC_PERMS fs/proc/*.[ch] > > > > No difference in generated .o files allyesconfig x86-64 > > > > Link: > > https://lore.kernel.org/lkml/CA+55aFw5v23T-zvDZp-MmD_EYxF8WbafwwB59934FV7g21uMGQ@xxxxxxxxxxxxxx/ > > > I will be frank. I don't know what 0644 means. I can never remember > which bit is read, write or execute. So I like symbolic constants. Heh, I'm the other way, I can't remember what S_IRUGO means. but I think there's another way which improves the information density: #define DIR_RO_ALL(NAME, iops, fops) DIR(NAME, 0555, iops, fops) ... (or S_IRUGO or whatever expands to 0555) There's really only a few combinations -- root read-only, everybody read-only root-write, others-read everybody-write and execute is only used by proc for directories, not files, so I think there's only 8 combinations we'd need (and everybody-write is almost unused ...) > Perhaps we can do something like: > > #define S_IRWX 7 > #define S_IRW_ 6 > #define S_IR_X 5 > #define S_IR__ 4 > #define S_I_WX 3 > #define S_I_W_ 2 > #define S_I__X 1 > #define S_I___ 0 > > #define MODE(TYPE, USER, GROUP, OTHER) \ > (((S_IF##TYPE) << 9) | \ > ((S_I##USER) << 6) | \ > ((S_I##GROUP) << 3) | \ > (S_I##OTHER)) > > Which would be used something like: > MODE(DIR, RWX, R_X, R_X) > MODE(REG, RWX, R__, R__) > > Something like that should be able to address the readability while > still using symbolic constants. I think that's been proposed before.
