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Marchesi" , Beau Belgrave , Linus Torvalds , Andrew Morton , Florian Weimer , Kees Cook , "Carlos O'Donell" , Sam James , Dylan Hatch Subject: [PATCH v4 08/12] s390/ptrace: Provide frame_pointer() Date: Tue, 27 Jan 2026 16:19:21 +0100 Message-ID: <20260127151926.2805123-9-jremus@linux.ibm.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260127151926.2805123-1-jremus@linux.ibm.com> References: <20260127151926.2805123-1-jremus@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=Gr1PO01C c=1 sm=1 tr=0 ts=6978d78b cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=vUbySO9Y5rIA:10 a=VkNPw1HP01LnGYTKEx00:22 a=NEAV23lmAAAA:8 a=VnNF1IyMAAAA:8 a=qpzfwOR0HA9Q5Rrae1MA:9 X-Proofpoint-GUID: IOw5bD2h0m9jWjw8gNZmyNkz3GINDcA- X-Proofpoint-ORIG-GUID: N9u8KjS7k6vBnqvMoArQJBk1byJqa5tM X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMTI3MDEyNSBTYWx0ZWRfXynKNwWCmOQ7h sOwsj49HXJczAzUjwjeZnwuk2sVFIiryzHKdOJIVXZuKB4X68W7jKCjnu2EgKYiJMpbI50WvGRm IaIBFz4N+3+0paxms/vQh/2U5sB281jHIWkOZ6DYOVAOoyVzeQthcqmyT1/KuQxfLjm7nEB4v1Q n+uRp7a7hAUB5wsjD6+uhZzbc1xzZ8dSyrCCYGXOHKkTv7z1tW2jJMtb17tUllV3/ZfX8iyj708 SJ21nNWIE8ACvWfrB5f1tPtnk8Va1zYuwWDLNE/IYDxvLdI9MYBAEIYLDhZfdLdknyeEScgN4ni CuYFYASMy8Epl+fWH6iqMhlPlEXXIKVgRTENj4YBjLDJ6dKmoXokPdKZS3fUTz/VyJHY+HkXAiA 4st5S0IbNmje8v0rYBu/A2w9c78+lN+NbCDT8lnVoW5IHVfUzvw/PopbJrK1uRj8emq212ZrnVx c9ewJ/6dWWBQ2/BliSw== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-01-27_03,2026-01-27_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 clxscore=1015 lowpriorityscore=0 suspectscore=0 impostorscore=0 phishscore=0 malwarescore=0 adultscore=0 spamscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2601150000 definitions=main-2601270125 Content-Type: text/plain; charset="utf-8" On s390 64-bit the s390x ELF ABI [1] designates register 11 as the "preferred" frame pointer (FP) register in user space. [1]: s390x ELF ABI, https://github.com/IBM/s390x-abi/releases Signed-off-by: Jens Remus --- Notes (jremus): Changes in v4: - Split out "while at it" changes into separate commit that can go upstream independently. (Heiko) =20 Changes in RFC v2: - Separate provide frame_pointer() into this new commit. arch/s390/include/asm/ptrace.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h index e6ec0ccf3d73..8f18d00b5fdb 100644 --- a/arch/s390/include/asm/ptrace.h +++ b/arch/s390/include/asm/ptrace.h @@ -250,6 +250,12 @@ static __always_inline unsigned long user_stack_pointe= r(const struct pt_regs *re return regs->gprs[15]; } =20 +static __always_inline unsigned long frame_pointer(const struct pt_regs *r= egs) +{ + /* Return ABI-designated "preferred" frame-pointer register value. */ + return regs->gprs[11]; +} + static __always_inline unsigned long regs_get_register(const struct pt_reg= s *regs, unsigned int offset) { --=20 2.51.0