2021-01-12 13:35:59

by Florian Weimer

[permalink] [raw]
Subject: Re: Aarch64 EXT4FS inode checksum failures - seems to be weak memory ordering issues

* Lukas Wunner:

> On Fri, Jan 08, 2021 at 12:02:53PM -0800, Linus Torvalds wrote:
>> I appreciate Arnd pointing out "--std=gnu11", though. What are the
>> actual relevant language improvements?
>>
>> Variable declarations in for-loops is the only one I can think of. I
>> think that would clean up some code (and some macros), but might not
>> be compelling on its own.
>
> Anonymous structs/unions. I used to have a use case for that in
> struct efi_dev_path in include/linux/efi.h, but Ard Biesheuvel
> refactored it in a gnu89-compatible way for v5.7 with db8952e7094f.

Aren't those a GNU extension supported since GCC 3.0?

Thanks,
Florian
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2021-01-12 13:48:51

by David Laight

[permalink] [raw]
Subject: RE: Aarch64 EXT4FS inode checksum failures - seems to be weak memory ordering issues

From: Florian Weimer
> Sent: 12 January 2021 13:32
>
> * Lukas Wunner:
>
> > On Fri, Jan 08, 2021 at 12:02:53PM -0800, Linus Torvalds wrote:
> >> I appreciate Arnd pointing out "--std=gnu11", though. What are the
> >> actual relevant language improvements?
> >>
> >> Variable declarations in for-loops is the only one I can think of. I
> >> think that would clean up some code (and some macros), but might not
> >> be compelling on its own.
> >
> > Anonymous structs/unions. I used to have a use case for that in
> > struct efi_dev_path in include/linux/efi.h, but Ard Biesheuvel
> > refactored it in a gnu89-compatible way for v5.7 with db8952e7094f.
>
> Aren't those a GNU extension supported since GCC 3.0?

They are certainly pretty old.
The 15 year old gcc we use for release builds (so binaries work
on old distributions) supports them.

David

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