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From: Ingo Molnar <mingo@kernel.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Brian Gerst <brgerst@gmail.com>, Borislav Petkov <bp@alien8.de>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 08/11] x86: Move uaccess_err and sig_on_uaccess_err to thread_struct
Date: Fri, 15 Jul 2016 10:14:43 +0200	[thread overview]
Message-ID: <20160715081443.GA10756@gmail.com> (raw)
In-Reply-To: <d0ac4d01c8e4d4d756264604e47445d5acc7900e.1468527351.git.luto@kernel.org>


* Andy Lutomirski <luto@kernel.org> wrote:

> thread_info is a legacy mess.  To prepare for its partial removal,
> move the uaccess control fields out -- they're straightforward.
> 
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
>  arch/x86/entry/vsyscall/vsyscall_64.c | 6 +++---
>  arch/x86/include/asm/processor.h      | 3 +++
>  arch/x86/include/asm/thread_info.h    | 2 --
>  arch/x86/include/asm/uaccess.h        | 4 ++--
>  arch/x86/mm/extable.c                 | 2 +-
>  arch/x86/mm/fault.c                   | 2 +-
>  6 files changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
> index 174c2549939d..3aba2b043050 100644
> --- a/arch/x86/entry/vsyscall/vsyscall_64.c
> +++ b/arch/x86/entry/vsyscall/vsyscall_64.c
> @@ -221,8 +221,8 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
>  	 * With a real vsyscall, page faults cause SIGSEGV.  We want to
>  	 * preserve that behavior to make writing exploits harder.
>  	 */
> -	prev_sig_on_uaccess_error = current_thread_info()->sig_on_uaccess_error;
> -	current_thread_info()->sig_on_uaccess_error = 1;
> +	prev_sig_on_uaccess_error = current->thread.sig_on_uaccess_error;
> +	current->thread.sig_on_uaccess_error = 1;
>  
>  	ret = -EFAULT;
>  	switch (vsyscall_nr) {
> @@ -243,7 +243,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
>  		break;
>  	}
>  
> -	current_thread_info()->sig_on_uaccess_error = prev_sig_on_uaccess_error;
> +	current->thread.sig_on_uaccess_error = prev_sig_on_uaccess_error;
>  
>  check_fault:
>  	if (ret == -EFAULT) {
> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> index 62c6cc3cc5d3..f53ae57bd985 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -419,6 +419,9 @@ struct thread_struct {
>  	/* Max allowed port in the bitmap, in bytes: */
>  	unsigned		io_bitmap_max;
>  
> +	unsigned int		sig_on_uaccess_error:1;
> +	unsigned int		uaccess_err:1;	/* uaccess failed */

Btw., while at it I've renamed 'sig_on_uaccess_error' to 'sig_on_uaccess_err' to 
make the two names consistent.

Thanks,

	Ingo

  reply	other threads:[~2016-07-15  8:15 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-14 20:22 [PATCH 00/11] x86: misc prep patches for virtually mapped stacks Andy Lutomirski
2016-07-14 20:22 ` [PATCH 01/11] x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() Andy Lutomirski
2016-07-15 11:59   ` [tip:x86/mm] " tip-bot for Ingo Molnar
2016-07-14 20:22 ` [PATCH 02/11] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski
2016-07-15 11:59   ` [tip:x86/mm] x86/mm/cpa: In populate_pgd(), don't set the PGD " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 03/11] x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables() Andy Lutomirski
2016-07-15 12:00   ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 04/11] x86/dumpstack: Try harder to get a call trace on stack overflow Andy Lutomirski
2016-07-15 12:00   ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 05/11] x86/dumpstack/64: Handle faults when printing the "Stack:" part of an OOPS Andy Lutomirski
2016-07-15 12:01   ` [tip:x86/mm] x86/dumpstack/64: Handle faults when printing the "Stack: " " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 06/11] x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm Andy Lutomirski
2016-07-15 12:01   ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 07/11] x86/dumpstack: When OOPSing, rewind the stack before do_exit() Andy Lutomirski
2016-07-15 12:02   ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 08/11] x86: Move uaccess_err and sig_on_uaccess_err to thread_struct Andy Lutomirski
2016-07-15  8:14   ` Ingo Molnar [this message]
2016-07-15 12:02   ` [tip:x86/mm] x86/uaccess: Move thread_info::uaccess_err and thread_info::sig_on_uaccess_err " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 09/11] x86: Move addr_limit " Andy Lutomirski
2016-07-15 12:03   ` [tip:x86/mm] x86/uaccess: Move thread_info::addr_limit " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 10/11] x86/smp: Remove stack_smp_processor_id() Andy Lutomirski
2016-07-15 12:04   ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 11/11] x86/smp: Remove unnecessary initialization of thread_info::cpu Andy Lutomirski
2016-07-15 12:04   ` [tip:x86/mm] " tip-bot for Andy Lutomirski

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