linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: "Nicholas Piggin" <npiggin@gmail.com>
To: "Benjamin Gray" <bgray@linux.ibm.com>, <linuxppc-dev@lists.ozlabs.org>
Cc: linux-hardening@vger.kernel.org, ajd@linux.ibm.com,
	cmr@bluescreens.de, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 05/13] prctl: Define PowerPC DEXCR interface
Date: Tue, 07 Mar 2023 15:07:52 +1000	[thread overview]
Message-ID: <CQZW2Z6JU55U.2M24IU59IQZ4D@bobo> (raw)
In-Reply-To: <20221128024458.46121-6-bgray@linux.ibm.com>

On Mon Nov 28, 2022 at 12:44 PM AEST, Benjamin Gray wrote:
> Adds the definitions and generic handler for prctl control of the
> PowerPC Dynamic Execution Control Register (DEXCR).

Assuming we'd go with the later prctl patches, this prep patch
is nice way to split out some of the mechanism.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

>
> Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
> ---
>  include/uapi/linux/prctl.h | 14 ++++++++++++++
>  kernel/sys.c               | 16 ++++++++++++++++
>  2 files changed, 30 insertions(+)
>
> diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
> index a5e06dcbba13..b4720e8de6f3 100644
> --- a/include/uapi/linux/prctl.h
> +++ b/include/uapi/linux/prctl.h
> @@ -281,6 +281,20 @@ struct prctl_mm_map {
>  # define PR_SME_VL_LEN_MASK		0xffff
>  # define PR_SME_VL_INHERIT		(1 << 17) /* inherit across exec */
>  
> +/* PowerPC Dynamic Execution Control Register (DEXCR) controls */
> +#define PR_PPC_GET_DEXCR		65
> +#define PR_PPC_SET_DEXCR		66
> +/* DEXCR aspect to act on */
> +# define PR_PPC_DEXCR_SBHE		0 /* Speculative branch hint enable */
> +# define PR_PPC_DEXCR_IBRTPD		1 /* Indirect branch recurrent target prediction disable */
> +# define PR_PPC_DEXCR_SRAPD		2 /* Subroutine return address prediction disable */
> +# define PR_PPC_DEXCR_NPHIE		3 /* Non-privileged hash instruction enable */
> +/* Action to apply / return */
> +# define PR_PPC_DEXCR_PRCTL		(1 << 0)
> +# define PR_PPC_DEXCR_SET_ASPECT	(1 << 1)
> +# define PR_PPC_DEXCR_FORCE_SET_ASPECT	(1 << 2)
> +# define PR_PPC_DEXCR_CLEAR_ASPECT	(1 << 3)
> +
>  #define PR_SET_VMA		0x53564d41
>  # define PR_SET_VMA_ANON_NAME		0
>  
> diff --git a/kernel/sys.c b/kernel/sys.c
> index 5fd54bf0e886..55b8f7369059 100644
> --- a/kernel/sys.c
> +++ b/kernel/sys.c
> @@ -139,6 +139,12 @@
>  #ifndef GET_TAGGED_ADDR_CTRL
>  # define GET_TAGGED_ADDR_CTRL()		(-EINVAL)
>  #endif
> +#ifndef PPC_GET_DEXCR_ASPECT
> +# define PPC_GET_DEXCR_ASPECT(a, b)	(-EINVAL)
> +#endif
> +#ifndef PPC_SET_DEXCR_ASPECT
> +# define PPC_SET_DEXCR_ASPECT(a, b, c)	(-EINVAL)
> +#endif
>  
>  /*
>   * this is where the system-wide overflow UID and GID are defined, for
> @@ -2623,6 +2629,16 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
>  		error = sched_core_share_pid(arg2, arg3, arg4, arg5);
>  		break;
>  #endif
> +	case PR_PPC_GET_DEXCR:
> +		if (arg3 || arg4 || arg5)
> +			return -EINVAL;
> +		error = PPC_GET_DEXCR_ASPECT(me, arg2);
> +		break;
> +	case PR_PPC_SET_DEXCR:
> +		if (arg4 || arg5)
> +			return -EINVAL;
> +		error = PPC_SET_DEXCR_ASPECT(me, arg2, arg3);
> +		break;
>  	case PR_SET_VMA:
>  		error = prctl_set_vma(arg2, arg3, arg4, arg5);
>  		break;
> -- 
> 2.38.1


  reply	other threads:[~2023-03-07  5:08 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-28  2:44 [RFC PATCH 00/13] Add DEXCR support Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 01/13] powerpc/book3s: Add missing <linux/sched.h> include Benjamin Gray
2023-03-07  4:28   ` Nicholas Piggin
2022-11-28  2:44 ` [RFC PATCH 02/13] powerpc: Add initial Dynamic Execution Control Register (DEXCR) support Benjamin Gray
2023-03-07  4:45   ` Nicholas Piggin
2023-03-09 23:46     ` Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 03/13] powerpc/dexcr: Handle hashchk exception Benjamin Gray
2022-11-29 10:39   ` Nicholas Piggin
2022-11-29 22:04     ` Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 04/13] powerpc/dexcr: Support userspace ROP protection Benjamin Gray
2023-03-07  5:05   ` Nicholas Piggin
2023-03-07  5:37     ` Benjamin Gray
2023-03-21  4:51       ` Nicholas Piggin
2022-11-28  2:44 ` [RFC PATCH 05/13] prctl: Define PowerPC DEXCR interface Benjamin Gray
2023-03-07  5:07   ` Nicholas Piggin [this message]
2022-11-28  2:44 ` [RFC PATCH 06/13] powerpc/dexcr: Add prctl implementation Benjamin Gray
2023-03-07  5:12   ` Nicholas Piggin
2022-11-28  2:44 ` [RFC PATCH 07/13] powerpc/dexcr: Add sysctl entry for SBHE system override Benjamin Gray
2023-03-07  5:30   ` Nicholas Piggin
2023-03-07  5:58     ` Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 08/13] powerpc/dexcr: Add enforced userspace ROP protection config Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 09/13] selftests/powerpc: Add more utility macros Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 10/13] selftests/powerpc: Add hashst/hashchk test Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 11/13] selftests/powerpc: Add DEXCR prctl, sysctl interface test Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 12/13] selftests/powerpc: Add DEXCR status utility lsdexcr Benjamin Gray
2022-11-28  2:44 ` [RFC PATCH 13/13] Documentation: Document PowerPC kernel DEXCR interface Benjamin Gray
2023-03-07  5:40   ` Nicholas Piggin
2023-03-07  5:52     ` Benjamin Gray
2022-11-28  4:05 ` [RFC PATCH 00/13] Add DEXCR support Russell Currey

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CQZW2Z6JU55U.2M24IU59IQZ4D@bobo \
    --to=npiggin@gmail.com \
    --cc=ajd@linux.ibm.com \
    --cc=bgray@linux.ibm.com \
    --cc=cmr@bluescreens.de \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).