lkml.org 
[lkml]   [2022]   [Nov]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 05/13] prctl: Define PowerPC DEXCR interface
Date
Adds the definitions and generic handler for prctl control of the
PowerPC Dynamic Execution Control Register (DEXCR).

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
\
 
 \ /
  Last update: 2022-11-28 03:48    [W:0.195 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site