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Subject: Re: [PATCH v2 1/5] fs: Add support for an O_MAYEXEC flag on
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To:     James Morris <jmorris@namei.org>, Jeff Layton <jlayton@kernel.org>
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From:   =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= <mickael.salaun@ssi.gouv.fr>
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Date:   Mon, 9 Sep 2019 11:25:06 +0200
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On 06/09/2019 21:03, James Morris wrote:
> On Fri, 6 Sep 2019, Jeff Layton wrote:
>
>> The fact that open and openat didn't vet unknown flags is really a bug.
>>
>> Too late to fix it now, of course, and as Aleksa points out, we've
>> worked around that in the past. Now though, we have a new openat2
>> syscall on the horizon. There's little need to continue these sorts of
>> hacks.
>>
>> New open flags really have no place in the old syscalls, IMO.
>
> Agree here. It's unfortunate but a reality and Linus will reject any such
> changes which break existing userspace.

Do you mean that adding new flags to open(2) is not possible?

Does it means that unspecified behaviors are definitely part of the
Linux specification and can't be fixed?

As I said, O_MAYEXEC should be ignored if it is not supported by the
kernel, which perfectly fit with the current open(2) flags behavior, and
should also behave the same with openat2(2).


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