From ab753f625e1dd77d388d1db6b9ecae54e871de84 Mon Sep 17 00:00:00 2001
From: "Paul E. Murphy" <murphyp@linux.vnet.ibm.com>
Date: Fri, 21 Aug 2015 14:39:01 -0500
Subject: [PATCH 58/65] powerpc: Fix tabort usage in syscalls
Fix usage of tabort in generated syscalls. r0 has special meaning
when used with this instruction, thus it will not generate
persistent errors, nor return an error code. This mitigates poor
CPU usage when performing elided critical sections.
Additionally, transactions should be aborted when entering a user
invoked syscall. Otherwise the results of the transaction may be
undefined.
2015-08-25 Paul E. Murphy <murphyp@linux.vnet.ibm.com>
* sysdeps/powerpc/powerpc32/sysdep.h (ABORT_TRANSACTION): Use
register other than r0 for tabort, it has special meaning.
* sysdeps/powerpc/powerpc64/sysdep.h (ABORT_TRANSACTION): Likewise
* sysdeps/unix.sysv/linux/powerpc/syscall.S (syscall): Abort
transaction before starting syscall.
(cherry picked from commit 18173559a23e28055640b152e623d9f0d40ecca8)
---
ChangeLog | 8 ++++++++
sysdeps/powerpc/powerpc32/sysdep.h | 4 ++--
sysdeps/powerpc/powerpc64/sysdep.h | 4 ++--
sysdeps/unix/sysv/linux/powerpc/syscall.S | 1 +
4 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 6c8f1ad..0b6deab 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2015-08-25 Paul E. Murphy <murphyp@linux.vnet.ibm.com>
+
+ * sysdeps/powerpc/powerpc32/sysdep.h (ABORT_TRANSACTION): Use
+ register other than r0 for tabort, it has special meaning.
+ * sysdeps/powerpc/powerpc64/sysdep.h (ABORT_TRANSACTION): Likewise
+ * sysdeps/unix.sysv/linux/powerpc/syscall.S (syscall): Abort
+ transaction before starting syscall.
+
2016-04-04 Stefan Liebler <stli@linux.vnet.ibm.com>
* sysdeps/s390/bits/link.h: (La_s390_vr) New typedef.
diff --git a/sysdeps/powerpc/powerpc32/sysdep.h b/sysdeps/powerpc/powerpc32/sysdep.h
index e16fe3e..ecb492a 100644
--- a/sysdeps/powerpc/powerpc32/sysdep.h
+++ b/sysdeps/powerpc/powerpc32/sysdep.h
@@ -95,8 +95,8 @@ GOT_LABEL: ; \
lwz 0,TM_CAPABLE(2); \
cmpwi 0,0; \
beq 1f; \
- li 0,_ABORT_SYSCALL; \
- tabort. 0; \
+ li 11,_ABORT_SYSCALL; \
+ tabort. 11; \
.align 4; \
1:
#else
diff --git a/sysdeps/powerpc/powerpc64/sysdep.h b/sysdeps/powerpc/powerpc64/sysdep.h
index bf2a884..a9d37ad 100644
--- a/sysdeps/powerpc/powerpc64/sysdep.h
+++ b/sysdeps/powerpc/powerpc64/sysdep.h
@@ -279,8 +279,8 @@ LT_LABELSUFFIX(name,_name_end): ; \
lwz 0,TM_CAPABLE(13); \
cmpwi 0,0; \
beq 1f; \
- li 0,_ABORT_SYSCALL; \
- tabort. 0; \
+ li 11,_ABORT_SYSCALL; \
+ tabort. 11; \
.align 4; \
1:
#else
diff --git a/sysdeps/unix/sysv/linux/powerpc/syscall.S b/sysdeps/unix/sysv/linux/powerpc/syscall.S
index 157e3e3..4477303 100644
--- a/sysdeps/unix/sysv/linux/powerpc/syscall.S
+++ b/sysdeps/unix/sysv/linux/powerpc/syscall.S
@@ -18,6 +18,7 @@
#include <sysdep.h>
ENTRY (syscall)
+ ABORT_TRANSACTION
mr r0,r3
mr r3,r4
mr r4,r5
--
2.7.4
