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Tue, 15 Oct 2024 08:21:38 +0000 Received: from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com [10.20.54.104]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 49F8LXnF34275944 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 15 Oct 2024 08:21:33 GMT Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AFAD020040; Tue, 15 Oct 2024 08:21:33 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D939520043; Tue, 15 Oct 2024 08:21:32 +0000 (GMT) Received: from ltcd97-lp3.aus.stglabs.ibm.com (unknown [9.40.194.171]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 15 Oct 2024 08:21:32 +0000 (GMT) From: Sachin Monga To: libc-alpha@sourceware.org Cc: bergner@linux.ibm.com, murphyp@linux.ibm.com, Sachin Monga Subject: [PATCH v2] powerpc64: Obviate the need for ROP protection in clone/clone3 Date: Tue, 15 Oct 2024 03:21:21 -0500 Message-ID: <20241015082121.2484410-1-smonga@linux.ibm.com> X-Mailer: git-send-email 2.43.5 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: FQUtPDDQtXFPdaX5wvJPJ6m-QU2fAixb X-Proofpoint-ORIG-GUID: FQUtPDDQtXFPdaX5wvJPJ6m-QU2fAixb X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 phishscore=0 lowpriorityscore=0 priorityscore=1501 bulkscore=0 mlxlogscore=506 mlxscore=0 adultscore=0 impostorscore=0 spamscore=0 suspectscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410150052 X-Spam-Status: No, score=-11.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, GIT_PATCH_0, KAM_NUMSUBJECT, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libc-alpha-bounces~patchwork=sourceware.org@sourceware.org Spilling lr in a non-volatile before scv. The non-volatile was unused and already saved/restored. Removed the dead code from clone. Signed-off-by: Sachin Monga --- sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S | 7 ++----- sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S | 6 ++---- 2 files changed, 4 insertions(+), 9 deletions(-) diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S index 164311d2bd..e57cb6e82e 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S @@ -56,7 +56,6 @@ ENTRY (__clone) /* Save fn, args, stack across syscall. */ mr r30,r3 /* Function in r30. */ - mr r29,r5 /* Flags in r29. */ mr r31,r6 /* Argument in r31. */ /* 'flags' argument is first parameter to clone syscall. @@ -77,14 +76,12 @@ ENTRY (__clone) CHECK_SCV_SUPPORT r28 0f /* This is equivalent to DO_CALL_SCV, but we cannot use the macro here because it uses CFI directives and we just called cfi_endproc. */ - mflr r9 - std r9,FRAME_LR_SAVE(r1) + mflr r29 .machine "push" .machine "power9" scv 0 .machine "pop" - ld r9,FRAME_LR_SAVE(r1) - mtlr r9 + mtlr r29 /* Check for child process. */ /* When using scv, error is indicated by negative r3. */ diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S index 900c354c9c..a48e0115ab 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone3.S @@ -39,14 +39,12 @@ because it uses CFI directives and we just called cfi_endproc. */ # define DO_CLONE3_SVC_CALL(jumpfalse) \ CHECK_SCV_SUPPORT r28 jumpfalse; \ - mflr r9; \ - std r9, FRAME_LR_SAVE(r1); \ + mflr r31; \ .machine "push"; \ .machine "power9"; \ scv 0; \ .machine "pop"; \ - ld r9, FRAME_LR_SAVE(r1); \ - mtlr r9; \ + mtlr r31; \ /* With scv an, an error is a value -4095 <= x < 0. */ \ cmpdi cr1, r3, 0; \ b 1f;