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Tue, 25 Oct 2022 04:44:23 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 16656AE045; Tue, 25 Oct 2022 04:44:23 +0000 (GMT) Received: from ozlabs.au.ibm.com (unknown [9.192.253.14]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 25 Oct 2022 04:44:23 +0000 (GMT) Received: from li-0d7fa1cc-2c9d-11b2-a85c-aed20764436d.ibm.com (haven.au.ibm.com [9.192.254.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id 4D47660807; Tue, 25 Oct 2022 15:44:21 +1100 (AEDT) From: Benjamin Gray To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v9 3/7] powerpc/code-patching: Use WARN_ON and fix check in poking_init Date: Tue, 25 Oct 2022 15:44:05 +1100 Message-Id: <20221025044409.448755-4-bgray@linux.ibm.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221025044409.448755-1-bgray@linux.ibm.com> References: <20221025044409.448755-1-bgray@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: NPowKcivTjjsaJwPj3lvooEqcdMTWyG5 X-Proofpoint-GUID: yoFCxoj5krI175lTs9KQ4arHvCu3hLKy X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-24_09,2022-10-21_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 phishscore=0 mlxscore=0 priorityscore=1501 adultscore=0 malwarescore=0 suspectscore=0 spamscore=0 clxscore=1015 mlxlogscore=999 impostorscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2210250024 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ajd@linux.ibm.com, jniethe5@gmail.com, Benjamin Gray , npiggin@gmail.com, cmr@bluescreens.de Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" BUG_ON() when failing to initialise the code patching window is excessive, as most critical patching happens during boot before strict RWX control is enabled. Failure to patch after boot is not inherently fatal, so aborting the kernel is better determined by the caller. The return value of cpuhp_setup_state() is also >= 0 on success, so check for < 0. Signed-off-by: Benjamin Gray Reviewed-by: Russell Currey --- v9: * Reword commit message to explain why init failure is not fatal --- arch/powerpc/lib/code-patching.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 54e145247643..3b3b09d5d2e1 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -82,16 +82,13 @@ static int text_area_cpu_down(unsigned int cpu) static __ro_after_init DEFINE_STATIC_KEY_FALSE(poking_init_done); -/* - * Although BUG_ON() is rude, in this case it should only happen if ENOMEM, and - * we judge it as being preferable to a kernel that will crash later when - * someone tries to use patch_instruction(). - */ void __init poking_init(void) { - BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, - "powerpc/text_poke:online", text_area_cpu_up, - text_area_cpu_down)); + WARN_ON(cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "powerpc/text_poke:online", + text_area_cpu_up, + text_area_cpu_down) < 0); + static_branch_enable(&poking_init_done); }