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
next prev parent 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
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