Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [RFC] export module parameters even the permission is zero | Date | Tue, 20 Jan 2015 17:02:39 +1030 |
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"Wang, Yalin" <Yalin.Wang@sonymobile.com> writes: > This patch make sure to export module parameters even the permission > is zero, this is useful for some platforms like Android, > the init process can change the parameter mode/owner by > chmod/chown during bootup > > Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com>
Hi!
Unfortunately, this won't work. Various parts of the code assume that 0 permissions means "cannot be changed or read", so this change would introduce many bugs (eg. the parameter could be __initdata).
Since these are owned by root at boot, changing mode and owner should still work. However, you can't make a read-only field writable and expect it to work.
Hope that helps, Rusty.
> --- > kernel/params.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/kernel/params.c b/kernel/params.c > index bd65d136..aa80c04 100644 > --- a/kernel/params.c > +++ b/kernel/params.c > @@ -607,9 +607,6 @@ static __modinit int add_sysfs_param(struct module_kobject *mk, > struct attribute **new_attrs; > unsigned int i; > > - /* We don't bother calling this with invisible parameters. */ > - BUG_ON(!kp->perm); > - > if (!mk->mp) { > /* First allocation. */ > mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL); > @@ -812,9 +809,6 @@ static void __init param_sysfs_builtin(void) > for (kp = __start___param; kp < __stop___param; kp++) { > char *dot; > > - if (kp->perm == 0) > - continue; > - > dot = strchr(kp->name, '.'); > if (!dot) { > /* This happens for core_param() */ > -- > 2.1.3 > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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