Re: [PATCH v6 11/11] arm64: annotate user pointers casts detected by sparse
From: Andrey Konovalov <hidden>
Date: 2018-09-03 12:34:31
Also in:
linux-arch, linux-arm-kernel, linux-kselftest, linux-mm, lkml
On Fri, Aug 31, 2018 at 3:42 PM, Al Viro [off-list ref] wrote:
On Fri, Aug 31, 2018 at 10:11:24AM +0200, Luc Van Oostenryck wrote:quoted
On Thu, Aug 30, 2018 at 01:41:16PM +0200, Andrey Konovalov wrote:quoted
This patch adds __force annotations for __user pointers casts detected by sparse with the -Wcast-from-as flag enabled (added in [1]). [1] https://github.com/lucvoo/sparse-dev/commit/5f960cb10f56ec2017c128ef9d16060e0145f292Hi, It would be nice to have some explanation for why these added __force are useful.
I'll add this in the next version, thanks!
It would be even more useful if that series would either deal with
the noise for real ("that's what we intend here, that's what we intend there,
here's a primitive for such-and-such kind of cases, here we actually
ought to pass __user pointer instead of unsigned long", etc.) or left it
unmasked.
As it is, __force says only one thing: "I know the code is doing
the right thing here". That belongs in primitives, and I do *not* mean the
#define cast_to_ulong(x) ((__force unsigned long)(x))
kind.
Folks, if you don't want to deal with that - leave the warnings be.
They do carry more information than "someone has slapped __force in that place".
Al, very annoyed by that kind of information-hiding crap...This patch only adds __force to hide the reports I've looked at and decided that the code does the right thing. The cases where this is not the case are handled by the previous patches in the patchset. I'll this to the patch description as well. Is that OK?