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Rao" , Mark Rutland , Daniel Borkmann , Masahiro Yamada , Nicholas Piggin , Alexei Starovoitov , Steven Rostedt , Andrii Nakryiko , Christophe Leroy , Vishal Chourasia , Mahesh J Salgaonkar , Masami Hiramatsu Subject: [PATCH v5 07/17] powerpc/ftrace: Skip instruction patching if the instructions are the same Date: Mon, 16 Sep 2024 02:26:38 +0530 Message-ID: <20240915205648.830121-8-hbathini@linux.ibm.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240915205648.830121-1-hbathini@linux.ibm.com> References: <20240915205648.830121-1-hbathini@linux.ibm.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: -xhLp2SQbwzr2h4N68QqUOI8_hACQXJt X-Proofpoint-GUID: 8-HrT9gb5nKTgblEAuOAfxvk7VMxngb9 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-15_12,2024-09-13_02,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxlogscore=832 priorityscore=1501 phishscore=0 clxscore=1015 malwarescore=0 bulkscore=0 impostorscore=0 spamscore=0 suspectscore=0 mlxscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2408220000 definitions=main-2409150159 From: Naveen N Rao To simplify upcoming changes to ftrace, add a check to skip actual instruction patching if the old and new instructions are the same. We still validate that the instruction is what we expect, but don't actually patch the same instruction again. Signed-off-by: Naveen N Rao --- arch/powerpc/kernel/trace/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index fe0546fbac8e..719517265d39 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -82,7 +82,7 @@ static inline int ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_ { int ret = ftrace_validate_inst(ip, old); - if (!ret) + if (!ret && !ppc_inst_equal(old, new)) ret = patch_instruction((u32 *)ip, new); return ret;