From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, luto@kernel.org
Subject: [PATCH 3/3] x86/mpx: remove MPX APIs
Date: Fri, 05 Jul 2019 10:53:21 -0700 [thread overview]
Message-ID: <20190705175321.DB42F0AD@viggo.jf.intel.com> (raw)
In-Reply-To: <20190705175317.1B3C9C52@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
MPX is being removed from the kernel due to a lack of support
in the toolchain going forward (gcc).
The first thing we need to do is remove the userspace-visible
ABIs so that applications will stop using it. The most visible
one are the enable/disable prctl()s. Remove them first.
This is the most minimal and least invasive patch needed to
ensure that apps stop using MPX with new kernels.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: Andy Lutomirski <luto@kernel.org>
---
b/include/uapi/linux/prctl.h | 2 +-
b/kernel/sys.c | 16 ++--------------
2 files changed, 3 insertions(+), 15 deletions(-)
diff -puN include/uapi/linux/prctl.h~mpx-remove-apis include/uapi/linux/prctl.h
--- a/include/uapi/linux/prctl.h~mpx-remove-apis 2019-07-05 10:40:49.441907046 -0700
+++ b/include/uapi/linux/prctl.h 2019-07-05 10:40:49.447907046 -0700
@@ -181,7 +181,7 @@ struct prctl_mm_map {
#define PR_GET_THP_DISABLE 42
/*
- * Tell the kernel to start/stop helping userspace manage bounds tables.
+ * No longer implemented, but left here to ensure the numbers stay reserved:
*/
#define PR_MPX_ENABLE_MANAGEMENT 43
#define PR_MPX_DISABLE_MANAGEMENT 44
diff -puN kernel/sys.c~mpx-remove-apis kernel/sys.c
--- a/kernel/sys.c~mpx-remove-apis 2019-07-05 10:40:49.444907046 -0700
+++ b/kernel/sys.c 2019-07-05 10:40:49.448907046 -0700
@@ -103,12 +103,6 @@
#ifndef SET_TSC_CTL
# define SET_TSC_CTL(a) (-EINVAL)
#endif
-#ifndef MPX_ENABLE_MANAGEMENT
-# define MPX_ENABLE_MANAGEMENT() (-EINVAL)
-#endif
-#ifndef MPX_DISABLE_MANAGEMENT
-# define MPX_DISABLE_MANAGEMENT() (-EINVAL)
-#endif
#ifndef GET_FP_MODE
# define GET_FP_MODE(a) (-EINVAL)
#endif
@@ -2456,15 +2450,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsi
up_write(&me->mm->mmap_sem);
break;
case PR_MPX_ENABLE_MANAGEMENT:
- if (arg2 || arg3 || arg4 || arg5)
- return -EINVAL;
- error = MPX_ENABLE_MANAGEMENT();
- break;
case PR_MPX_DISABLE_MANAGEMENT:
- if (arg2 || arg3 || arg4 || arg5)
- return -EINVAL;
- error = MPX_DISABLE_MANAGEMENT();
- break;
+ /* No longer implemented: */
+ return -EINVAL;
case PR_SET_FP_MODE:
error = SET_FP_MODE(me, arg2);
break;
_
next prev parent reply other threads:[~2019-07-05 18:06 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-05 17:53 [PATCH 0/3] [RFC] x86: start the MPX removal process Dave Hansen
2019-07-05 17:53 ` [PATCH 1/3] x86/mpx: remove selftests Makefile entry Dave Hansen
2019-07-22 9:58 ` [tip:x86/cleanups] x86/mpx: Remove " tip-bot for Dave Hansen
2019-07-05 17:53 ` [PATCH 2/3] x86/mpx: remove selftests themselves Dave Hansen
2019-07-22 9:58 ` [tip:x86/cleanups] x86/mpx: Remove " tip-bot for Dave Hansen
2019-07-05 17:53 ` Dave Hansen [this message]
2019-07-22 9:59 ` [tip:x86/cleanups] x86/mpx: Remove MPX APIs tip-bot for Dave Hansen
2020-01-22 13:09 ` [PATCH 0/3] [RFC] x86: start the MPX removal process Borislav Petkov
2020-01-22 18:14 ` Dave Hansen
2020-01-23 11:23 ` Borislav Petkov
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