Messages in this thread | | | From | Matteo Croce <> | Date | Tue, 30 Apr 2019 00:21:47 +0200 | Subject | Re: [PATCH v3] proc/sysctl: add shared variables for range check |
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On Tue, Apr 23, 2019 at 5:28 AM Matteo Croce <mcroce@redhat.com> wrote: > > On April 19, 2019 10:07:14 AM GMT+09:00, Matthew Wilcox <willy@infradead.org> wrote: > > On Fri, Apr 19, 2019 at 09:17:17AM +0900, Matteo Croce wrote: > > > > extern const int sysctl_zero; > > > > /* comment goes here */ > > > > #define SYSCTL_ZERO ((void *)&sysctl_zero) > > > > > > > > and then use SYSCTL_ZERO everywhere. That centralizes the > > ugliness > > > > and > > > > makes it easier to switch over if/when extra1&2 are constified. > > > > > > > > But it's all a bit sad and lame :( > > > > > > No, we didn't decide yet. I need to check for all extra1,2 > > assignment. Not an impossible task, anyway. > > > > > > I agree that the casts are ugly. Your suggested macro moves the > > ugliness in a single point, which is good. Or maybe we can do a single > > macro like: > > > > > > #define SYSCTL_VAL(x) ((void *)&sysctl_##x) > > > > > > to avoid defining one for every value. And when we decide that > > everything can be const, we just update the macro. > > > > If we're going to do that, we can save two EXPORTs and do: > > > > const int sysctl_vals[] = { 0, 1, -1 }; > > EXPORT_SYMBOL(sysctl_vals); > > > > #define SYSCTL_ZERO ((void *)&sysctl_vals[0]) > > Hi Matthew, > > I like this approach, regardless of the const or not const extra1. > > I'll be AFK for a few days, then I will investigate if extra1,2 can be made const and then prepare a v4 with the single export.
Hi all,
I turned extra{1,2) to const and I see no issues. I'm sending a v4 with extra{1,2} const, a single export for all vars as suggested by Matthew, and the define suggested by Andrew. Comments are welcome as usual.
Regards, -- Matteo Croce per aspera ad upstream
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