Alexey Gladkov <gladkov.alexey@xxxxxxxxx> writes: > On Thu, Apr 02, 2020 at 11:05:21AM -0500, Eric W. Biederman wrote: >> Alexey Gladkov <gladkov.alexey@xxxxxxxxx> writes: >> >> > The hidepid parameter values are becoming more and more and it becomes >> > difficult to remember what each new magic number means. >> >> In principle I like this change. In practice I think you have just >> broken ABI compatiblity with the new mount ABI. >> >> In particular the following line seems broken. >> >> > diff --git a/fs/proc/root.c b/fs/proc/root.c >> > index dbcd96f07c7a..ba782d6e6197 100644 >> > --- a/fs/proc/root.c >> > +++ b/fs/proc/root.c >> > @@ -45,7 +45,7 @@ enum proc_param { >> > >> > static const struct fs_parameter_spec proc_fs_parameters[] = { >> > fsparam_u32("gid", Opt_gid), >> > - fsparam_u32("hidepid", Opt_hidepid), >> > + fsparam_string("hidepid", Opt_hidepid), >> > fsparam_string("subset", Opt_subset), >> > {} >> > }; >> >> As I read fs_parser.c fs_param_is_u32 handles string inputs and turns them >> into numbers, and it handles binary numbers. However fs_param_is_string >> appears to only handle strings. It appears to have not capacity to turn >> raw binary numbers into strings. > > I use result only with hidepid_u32_spec and nobody modifies param->string. > I do not use internal functions here. > > I don’t follow how a raw number can get here ? I may be wrong but last I looked you can input raw numbers using the new mount api. I have most of the details paged out at the moment, but I believe that is why when you set a parameter in the new mount api it takes a type. >> So I think we probably need to fix fs_param_is_string to raw binary >> numbers before we can safely make this change to fs/proc/root.c >> >> David am I reading the fs_parser.c code correctly? If I am are you ok >> with a change like the above? Eric