From: hpa@zytor.com
To: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
linux-kernel@vger.kernel.org, Song Liu <song@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-raid@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 18/23] init: open code setting up stdin/stdout/stderr
Date: Sun, 26 Jul 2020 23:36:15 -0700 [thread overview]
Message-ID: <366377E2-6F19-45E1-9285-CFA5E660C6B5@zytor.com> (raw)
In-Reply-To: <20200727062425.GA2005@lst.de>
On July 26, 2020 11:24:25 PM PDT, Christoph Hellwig <hch@lst.de> wrote:
>On Sun, Jul 26, 2020 at 11:20:41PM -0700, hpa@zytor.com wrote:
>> On July 26, 2020 8:05:34 PM PDT, Al Viro <viro@zeniv.linux.org.uk>
>wrote:
>> >On Tue, Jul 14, 2020 at 09:04:22PM +0200, Christoph Hellwig wrote:
>> >> Don't rely on the implicit set_fs(KERNEL_DS) for ksys_open to
>work,
>> >but
>> >> instead open a struct file for /dev/console and then install it as
>FD
>> >> 0/1/2 manually.
>> >
>> >I really hate that one. Every time we exposed the internal details
>to
>> >the fucking early init code, we paid for that afterwards. And this
>> >goes over the top wrt the level of details being exposed.
>> >
>> >_IF_ you want to keep that thing, move it to fs/file.c, with dire
>> >comment
>> >re that being very special shite for init and likely cause of
>> >subsequent
>> >trouble whenever anything gets changed, a gnat farts somewhere, etc.
>> >
>> > Do not leave that kind of crap sitting around init/*.c; KERNEL_DS
>> >may be a source of occasional PITA, but here you are trading it for
>a
>> >lot
>> >worse one in the future.
>>
>> Okay... here is a perhaps idiotic idea... even if we don't want to
>run stuff in actual user space, could we map initramfs into user space
>memory before running init (execing init will tear down those mappings
>anyway) so that we don't need KERNEL_DS at least?
>
>Err, why? The changes have been pretty simple, and I'd rather not come
>up with new crazy ways just to make things complicated.
Why? To avoid this neverending avalanche of special interfaces and layering violations. Neatly deals with non-contiguous contents and initramfs in device memory, etc. etc. etc.
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
next prev parent reply other threads:[~2020-07-27 6:36 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 19:04 decruft the early init / initrd / initramfs code v2 Christoph Hellwig
2020-07-14 19:04 ` [PATCH 01/23] fs: add a vfs_fchown helper Christoph Hellwig
2020-07-14 19:04 ` [PATCH 02/23] fs: add a vfs_fchmod helper Christoph Hellwig
2020-07-14 19:04 ` [PATCH 03/23] init: remove the bstat helper Christoph Hellwig
2020-07-15 23:14 ` NeilBrown
2020-07-14 19:04 ` [PATCH 04/23] md: move the early init autodetect code to drivers/md/ Christoph Hellwig
2020-07-14 19:04 ` [PATCH 05/23] md: replace the RAID_AUTORUN ioctl with a direct function call Christoph Hellwig
2020-07-15 23:33 ` NeilBrown
2020-07-14 19:04 ` [PATCH 06/23] md: remove the autoscan partition re-read Christoph Hellwig
2020-07-15 23:34 ` NeilBrown
2020-07-14 19:04 ` [PATCH 07/23] md: remove the kernel version of md_u.h Christoph Hellwig
2020-07-14 19:04 ` [PATCH 08/23] md: simplify md_setup_drive Christoph Hellwig
2020-07-15 23:37 ` NeilBrown
2020-07-14 19:04 ` [PATCH 09/23] md: rewrite md_setup_drive to avoid ioctls Christoph Hellwig
2020-07-15 23:50 ` NeilBrown
2020-07-16 13:38 ` Christoph Hellwig
2020-07-14 19:04 ` [PATCH 10/23] initrd: remove support for multiple floppies Christoph Hellwig
2020-07-14 19:04 ` [PATCH 11/23] initrd: remove the BLKFLSBUF call in handle_initrd Christoph Hellwig
2020-07-14 19:04 ` [PATCH 12/23] initrd: switch initrd loading to struct file based APIs Christoph Hellwig
2020-07-27 1:50 ` Al Viro
2020-07-14 19:04 ` [PATCH 13/23] initrd: mark init_linuxrc as __init Christoph Hellwig
2020-07-14 19:04 ` [PATCH 14/23] initrd: mark initrd support as deprecated Christoph Hellwig
2020-07-14 19:04 ` [PATCH 15/23] initramfs: remove the populate_initrd_image and clean_rootfs stubs Christoph Hellwig
2020-07-14 19:04 ` [PATCH 16/23] initramfs: simplify clean_rootfs Christoph Hellwig
[not found] ` <CGME20200717205549eucas1p13fca9a8496836faa71df515524743648@eucas1p1.samsung.com>
2020-07-17 20:55 ` Marek Szyprowski
2020-07-18 10:00 ` Christoph Hellwig
2020-07-23 9:22 ` Christoph Hellwig
2020-07-23 14:25 ` Lukasz Stelmach
2020-07-23 14:27 ` Christoph Hellwig
2020-07-27 2:41 ` Al Viro
2020-07-27 2:44 ` Matthew Wilcox
2020-07-14 19:04 ` [PATCH 17/23] initramfs: switch initramfs unpacking to struct file based APIs Christoph Hellwig
2020-07-14 19:31 ` Linus Torvalds
2020-07-15 6:27 ` Christoph Hellwig
2020-07-27 2:55 ` Al Viro
2020-07-14 19:04 ` [PATCH 18/23] init: open code setting up stdin/stdout/stderr Christoph Hellwig
2020-07-27 3:05 ` Al Viro
2020-07-27 5:46 ` Christoph Hellwig
2020-07-27 6:03 ` Al Viro
2020-07-27 6:48 ` Christoph Hellwig
2020-07-27 15:54 ` Al Viro
2020-07-27 15:58 ` Christoph Hellwig
2020-07-27 6:20 ` hpa
2020-07-27 6:24 ` Christoph Hellwig
2020-07-27 6:36 ` hpa [this message]
2020-07-27 6:49 ` Christoph Hellwig
2020-07-14 19:04 ` [PATCH 19/23] fs: remove ksys_getdents64 Christoph Hellwig
2020-07-14 19:04 ` [PATCH 20/23] fs: remove ksys_open Christoph Hellwig
2020-07-14 19:04 ` [PATCH 21/23] fs: remove ksys_dup Christoph Hellwig
2020-07-14 19:04 ` [PATCH 22/23] fs: remove ksys_fchmod Christoph Hellwig
2020-07-14 19:04 ` [PATCH 23/23] fs: remove ksys_ioctl Christoph Hellwig
2020-07-14 19:34 ` decruft the early init / initrd / initramfs code v2 Linus Torvalds
2020-07-15 6:51 ` Christoph Hellwig
2020-07-16 15:57 ` Guoqing Jiang
2020-07-16 16:00 ` Christoph Hellwig
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