linux-kernel - Re: [GIT PULL] hash addresses printed with %p

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Date:   Thu, 30 Nov 2017 18:17:47 -0500
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     "Tobin C. Harding" <me@...in.cc>,
        Matt Fleming <matt@...eblueprint.co.uk>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        LKML <linux-kernel@...r.kernel.org>,
        "linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>
Subject: Re: [GIT PULL] hash addresses printed with %p

On Thu, Nov 30, 2017 at 12:10 PM, Greg Kroah-Hartman
<gregkh@...uxfoundation.org> wrote:
>
> So changing it to use __ATTR() should fix this remaning leakage up.
> That is if we even really need to export these values at all.  What does
> userspace do with them?  Shouldn't they just be in debugfs instead?

So what I find distasteful here is how sysfs has these "helper" macros
that are clearly designed to over-share.

The __ATTR macro is a lot  more complicated to use than the
__ATTR_RO/WO/RW macros, but those macros end up giving everybody read
access (ok, not the WO one)

So honestly, I think the "helper" functions should be deprecated
simply because they basically encourage people to make everything
world-readable.

Which is why most of sysfs is world-readable, whether it makes sense or not.

It would have been better had they just taken the actual mode, I suspect.

(And it would be better yet if the code didn't use that disgusting
S_IRUGO, which pretty much everybody has to think about to figure out
it's 0444)

               Linus