From: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
To: Rich Felker <dalias@aerifal.cx>
Cc: libc-alpha <libc-alpha@sourceware.org>, musl@lists.openwall.com
Subject: Re: O_EXEC and O_SEARCH
Date: Sat, 23 Feb 2013 00:21:01 -0500 [thread overview]
Message-ID: <CAHGf_=p7TmWkVbC1WcOYUOsfJxJqra_WPnvNHwC4NVmT-gX5kg@mail.gmail.com> (raw)
In-Reply-To: <20130223050542.GX20323@brightrain.aerifal.cx>
On Sat, Feb 23, 2013 at 12:05 AM, Rich Felker <dalias@aerifal.cx> wrote:
> On Sat, Feb 23, 2013 at 12:01:39AM -0500, KOSAKI Motohiro wrote:
>> > 1. Try to open with O_RDONLY. If it succeeds, we're done. This is
>> > REALLY nice because it means O_SEARCH and O_EXEC "just work" even on
>> > ancient or broken kernels as long as the target file is readable.
>>
>> Hmm..
>> This algorithm seems slightly strange to me. Why do you want to try O_RDONLY at
>> first?
>> O_RDONLY require read permission and O_SEARCH, if i understand correctly,
>> doesn't.
>> I think you should try O_PATH at first.
>
> If the file is readable, O_RDONLY will succeed and provides the
> necessary semantics for O_EXEC and O_SEARCH. The only time O_EXEC or
> O_SEARCH needs special support is when the file is not readable; these
> modes were specifically designed for supporting that case.
Ah, ok. got it.
next prev parent reply other threads:[~2013-02-23 5:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-22 0:45 Rich Felker
2013-02-23 3:05 ` KOSAKI Motohiro
2013-02-23 3:17 ` Rich Felker
2013-02-23 3:58 ` KOSAKI Motohiro
2013-02-23 4:33 ` Rich Felker
2013-02-23 5:01 ` KOSAKI Motohiro
2013-02-23 5:05 ` Rich Felker
2013-02-23 5:21 ` KOSAKI Motohiro [this message]
2013-02-23 4:54 ` KOSAKI Motohiro
2013-02-23 5:03 ` Rich Felker
2013-02-23 5:20 ` KOSAKI Motohiro
2013-02-23 5:28 ` KOSAKI Motohiro
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