Messages in this thread | | | From | Masahiro Yamada <> | Date | Sat, 30 Mar 2019 21:52:46 +0900 | Subject | Re: [PATCH 4/4] CPER: Remove unnecessary use of user-space types |
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On Tue, Mar 26, 2019 at 3:26 AM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Mon, Mar 25, 2019 at 01:14:25PM -0500, helgaas@kernel.org wrote: > > From: Bjorn Helgaas <bhelgaas@google.com> > > > > "__u32" and similar types are intended for things exported to user-space, > > including structs used in ioctls; see include/uapi/asm-generic/int-l64.h. > > > > They are not needed for the CPER struct definitions, which not exported to > > user-space and not used in ioctls. Replace them with the typical "u32" and > > similar types. No functional change intended. > > > > The reason for changing this is to remove the question of "why do we use > > __u32 here instead of u32?" We should use __u32 when there's a reason for > > it; otherwise, we should prefer u32 for consistency. > > > > Reference: Documentation/process/coding-style.rst > > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> > > CC: Masahiro Yamada <yamada.masahiro@socionext.com> > > CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > CC: Andrew Morton <akpm@linux-foundation.org> > > I cc'd you folks because you were part of this conversation: > > https://lore.kernel.org/lkml/1526350925-14922-3-git-send-email-yamada.masahiro@socionext.com/T/#u > > I *think* the conclusion there was that this sort of change makes > sense, but I want to make sure. If it does make sense, I'm surprised > at how much stuff in include/linux/ still uses __u32 when it doesn't > appear to need it.
This patch looks good to me.
I still fail to understand Greg's comment in the referred URL, though.
"__u32" and similar types are intended for things exported to user-space.
This is clearly documented.
Documentation/process/coding-style.rst:
(e) Types safe for use in userspace.
In certain structures which are visible to userspace, we cannot require C99 types and cannot use the ``u32`` form above. Thus, we use __u32 and similar types in all structures which are shared with userspace.
I'd be eager to see a document that suggests __u32 and similar types in ioctl structures.
-- Best Regards Masahiro Yamada
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