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From: Al Viro <[email protected]>
To: Christoph Hellwig <[email protected]>
Cc: Andrew Morton <[email protected]>,
	Jens Axboe <[email protected]>, Arnd Bergmann <[email protected]>,
	David Howells <[email protected]>,
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected]
Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
Date: Fri, 18 Sep 2020 14:40:12 +0100	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

On Fri, Sep 18, 2020 at 02:45:25PM +0200, Christoph Hellwig wrote:
> Add a flag to force processing a syscall as a compat syscall.  This is
> required so that in_compat_syscall() works for I/O submitted by io_uring
> helper threads on behalf of compat syscalls.
> 
> Signed-off-by: Christoph Hellwig <[email protected]>
> ---
>  arch/sparc/include/asm/compat.h | 3 ++-
>  arch/x86/include/asm/compat.h   | 2 +-
>  fs/io_uring.c                   | 9 +++++++++
>  include/linux/compat.h          | 5 ++++-
>  include/linux/sched.h           | 1 +
>  5 files changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
> index 40a267b3bd5208..fee6c51d36e869 100644
> --- a/arch/sparc/include/asm/compat.h
> +++ b/arch/sparc/include/asm/compat.h
> @@ -211,7 +211,8 @@ static inline int is_compat_task(void)
>  static inline bool in_compat_syscall(void)
>  {
>  	/* Vector 0x110 is LINUX_32BIT_SYSCALL_TRAP */
> -	return pt_regs_trap_type(current_pt_regs()) == 0x110;
> +	return pt_regs_trap_type(current_pt_regs()) == 0x110 ||
> +		(current->flags & PF_FORCE_COMPAT);

Can't say I like that approach ;-/  Reasoning about the behaviour is much
harder when it's controlled like that - witness set_fs() shite...

  reply	other threads:[~2020-09-18 13:40 UTC|newest]

Thread overview: 67+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-18 12:45 let import_iovec deal with compat_iovecs as well Christoph Hellwig
2020-09-18 12:45 ` [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Christoph Hellwig
2020-09-18 13:40   ` Al Viro [this message]
2020-09-18 13:44     ` Christoph Hellwig
2020-09-18 13:58       ` Al Viro
2020-09-18 15:16         ` Christoph Hellwig
2020-09-19 16:21           ` Andy Lutomirski
2020-09-19 21:16             ` Arnd Bergmann
2020-09-19 21:52               ` Finn Thain
2020-09-19 22:22               ` Andy Lutomirski
2020-09-21 16:10                 ` Pavel Begunkov
2020-09-21 16:13                   ` Pavel Begunkov
2020-09-21 23:51                     ` Andy Lutomirski
2020-09-22  0:22                       ` Pavel Begunkov
2020-09-22  0:58                         ` Andy Lutomirski
2020-09-22  6:30                           ` Pavel Begunkov
2020-09-22  7:23                             ` Arnd Bergmann
2020-09-22  7:57                               ` Pavel Begunkov
2020-09-22  9:01                                 ` Arnd Bergmann
2020-09-22 16:20                                   ` Andy Lutomirski
2020-09-23  8:01                                   ` Pavel Begunkov
2020-09-23 13:22                                     ` Al Viro
2020-09-19 22:09           ` Al Viro
2020-09-19 22:23             ` Andy Lutomirski
2020-09-19 22:41               ` Al Viro
2020-09-19 22:53                 ` Andy Lutomirski
2020-09-19 23:24                   ` Al Viro
2020-09-20  0:14                     ` Andy Lutomirski
2020-09-20  2:57                       ` Al Viro
2020-09-20 16:59                         ` Andy Lutomirski
2020-09-20 18:12                           ` Al Viro
2020-09-20 13:55             ` Arnd Bergmann
2020-09-20 15:02               ` Al Viro
2020-09-19 14:53         ` David Laight
2020-09-18 13:59       ` Arnd Bergmann
2020-09-20 15:15   ` Matthew Wilcox
2020-09-20 15:55     ` William Kucharski
2020-09-21 16:20       ` Pavel Begunkov
2020-09-20 16:00     ` Arnd Bergmann
2020-09-20 18:07     ` Al Viro
2020-09-20 18:41       ` Al Viro
2020-09-20 19:01       ` Matthew Wilcox
2020-09-20 19:10         ` Al Viro
2020-09-20 19:22           ` Matthew Wilcox
2020-09-20 19:28             ` Andy Lutomirski
2020-09-20 20:49               ` Arnd Bergmann
2020-09-20 21:13                 ` David Laight
2020-09-21 16:31                   ` Pavel Begunkov
2020-09-20 21:42             ` Al Viro
2020-09-21 16:26             ` Pavel Begunkov
2020-09-20 19:14       ` Andy Lutomirski
2020-09-21  4:28         ` Christoph Hellwig
2020-09-18 12:45 ` [PATCH 2/9] compat.h: fix a spelling error in <linux/compat.h> Christoph Hellwig
2020-09-18 13:37   ` Johannes Thumshirn
2020-09-18 12:45 ` [PATCH 3/9] fs: explicitly check for CHECK_IOVEC_ONLY in rw_copy_check_uvector Christoph Hellwig
2020-09-18 12:56   ` Matthew Wilcox
2020-09-18 13:39   ` Johannes Thumshirn
2020-09-18 12:45 ` [PATCH 4/9] fs: handle the compat case in import_iovec Christoph Hellwig
2020-09-18 12:45 ` [PATCH 5/9] fs: remove various compat readv/writev helpers Christoph Hellwig
2020-09-18 12:45 ` [PATCH 6/9] fs: remove the compat readv/writev syscalls Christoph Hellwig
2020-09-18 12:45 ` [PATCH 7/9] fs: remove compat_sys_vmsplice Christoph Hellwig
2020-09-18 12:45 ` [PATCH 8/9] mm: remove compat_process_vm_{readv,writev} Christoph Hellwig
2020-09-18 13:48   ` Arnd Bergmann
2020-09-18 12:45 ` [PATCH 9/9] security/keys: remove compat_keyctl_instantiate_key_iov Christoph Hellwig
2020-09-19 14:24 ` let import_iovec deal with compat_iovecs as well David Laight
2020-09-21  4:41   ` 'Christoph Hellwig'
2020-09-21 11:11     ` David Laight

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