From: Rich Felker <dalias@libc.org>
To: Palmer Dabbelt <palmer@sifive.com>
Cc: viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
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Subject: Re: [PATCH v2 2/4] Add fchmodat4(), a new syscall
Date: Tue, 16 Jul 2019 22:40:46 -0400 [thread overview]
Message-ID: <20190717024046.GI1506@brightrain.aerifal.cx> (raw)
In-Reply-To: <20190717012719.5524-3-palmer@sifive.com>
On Tue, Jul 16, 2019 at 06:27:17PM -0700, Palmer Dabbelt wrote:
> man 3p says that fchmodat() takes a flags argument, but the Linux
> syscall does not. There doesn't appear to be a good userspace
> workaround for this issue but the implementation in the kernel is pretty
> straight-forward. The specific use case where the missing flags came up
> was WRT a fuse filesystem implemenation, but the functionality is pretty
> generic so I'm assuming there would be other use cases.
Note that we do have a workaround in musl libc with O_PATH and
/proc/self/fd, but a syscall that allows a proper fix with the ugly
workaround only in the fallback path for old kernels will be much
appreciated!
What about also doing a new SYS_faccessat4 with working AT_EACCESS
flag? The workaround we have to do for it is far worse.
Rich
next prev parent reply other threads:[~2019-07-17 2:51 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-17 1:27 Add a new fchmodat4() syscall, v2 Palmer Dabbelt
2019-07-17 1:27 ` [PATCH v2 1/4] Non-functional cleanup of a "__user * filename" Palmer Dabbelt
2019-07-17 1:27 ` [PATCH v2 2/4] Add fchmodat4(), a new syscall Palmer Dabbelt
2019-07-17 1:48 ` Al Viro
2019-07-17 2:12 ` Palmer Dabbelt
2019-07-17 2:40 ` Rich Felker [this message]
2019-07-17 3:02 ` Al Viro
2019-07-17 1:27 ` [PATCH v2 3/4] arch: Register fchmodat4, usually as syscall 434 Palmer Dabbelt
2019-07-17 1:27 ` [PATCH v2 4/4] tools: Add fchmodat4 Palmer Dabbelt
2019-07-17 12:39 ` Arnaldo Carvalho de Melo
2020-06-09 13:52 ` Add a new fchmodat4() syscall, v2 Florian Weimer
2023-07-11 11:25 ` [PATCH v3 0/5] Add a new fchmodat4() syscall Alexey Gladkov
2023-07-11 11:25 ` [PATCH v3 1/5] Non-functional cleanup of a "__user * filename" Alexey Gladkov
2023-07-11 11:32 ` Arnd Bergmann
2023-07-11 11:25 ` [PATCH v3 2/5] fs: Add fchmodat4() Alexey Gladkov
2023-07-11 11:42 ` Arnd Bergmann
2023-07-11 11:52 ` Christian Brauner
2023-07-11 12:51 ` Alexey Gladkov
2023-07-11 14:01 ` Christian Brauner
2023-07-11 15:23 ` Alexey Gladkov
2023-07-11 12:28 ` Matthew Wilcox
2023-07-11 12:49 ` Alexey Gladkov
2023-07-11 11:25 ` [PATCH v3 3/5] arch: Register fchmodat4, usually as syscall 451 Alexey Gladkov
2023-07-11 11:31 ` Arnd Bergmann
2023-07-11 11:25 ` [PATCH v3 4/5] tools headers UAPI: Sync files changed by new fchmodat4 syscall Alexey Gladkov
2023-07-11 11:25 ` [PATCH v3 5/5] selftests: add fchmodat4(2) selftest Alexey Gladkov
2023-07-11 12:10 ` Florian Weimer
2023-07-11 13:38 ` Alexey Gladkov
2023-07-11 12:24 ` [PATCH v3 0/5] Add a new fchmodat4() syscall Florian Weimer
2023-07-11 15:14 ` Christian Brauner
2023-07-25 11:05 ` Alexey Gladkov
2023-07-25 12:05 ` Christian Brauner
2023-07-11 16:16 ` [PATCH v4 0/5] Add a new fchmodat2() syscall Alexey Gladkov
2023-07-11 16:16 ` [PATCH v4 1/5] Non-functional cleanup of a "__user * filename" Alexey Gladkov
2023-07-11 16:16 ` [PATCH v4 2/5] fs: Add fchmodat2() Alexey Gladkov
2023-07-11 17:05 ` Christian Brauner
2023-07-25 16:36 ` Aleksa Sarai
2023-07-26 13:45 ` Alexey Gladkov
2023-07-27 10:26 ` Christian Brauner
2023-07-27 17:12 ` Aleksa Sarai
2023-07-27 17:39 ` Aleksa Sarai
2023-07-28 8:43 ` David Laight
2023-07-28 18:42 ` dalias
2023-07-27 9:01 ` David Laight
2023-07-27 16:28 ` Andreas Schwab
2023-07-27 17:02 ` Christian Brauner
2023-07-27 17:13 ` dalias
2023-07-27 17:36 ` Christian Brauner
2023-07-27 16:31 ` dalias
2023-07-11 16:16 ` [PATCH v4 3/5] arch: Register fchmodat2, usually as syscall 452 Alexey Gladkov
2023-07-11 16:26 ` Arnd Bergmann
2023-07-25 7:16 ` Geert Uytterhoeven
2023-07-25 16:43 ` Aleksa Sarai
2023-07-27 10:37 ` Christian Brauner
2023-07-27 17:42 ` Aleksa Sarai
2023-07-11 16:16 ` [PATCH v4 4/5] tools headers UAPI: Sync files changed by new fchmodat2 syscall Alexey Gladkov
2023-07-11 17:19 ` Namhyung Kim
2023-07-11 17:23 ` Alexey Gladkov
2023-07-11 16:16 ` [PATCH v4 5/5] selftests: Add fchmodat2 selftest Alexey Gladkov
2023-07-11 17:36 ` (subset) [PATCH v4 0/5] Add a new fchmodat2() syscall Christian Brauner
2023-07-12 2:42 ` Rich Felker
2023-07-25 15:58 ` Add fchmodat2() - or add a more general syscall? David Howells
2023-07-25 16:10 ` Florian Weimer
2023-07-25 16:50 ` Aleksa Sarai
2023-07-25 18:39 ` David Howells
2023-07-25 18:44 ` Rich Felker
2023-07-26 13:30 ` Christian Brauner
2023-07-27 3:57 ` Eric Biggers
2023-07-27 10:27 ` Christian Brauner
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