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From:   Yunfeng Ye <yeyunfeng@huawei.com>
Subject: [PATCH v2] arm64: armv8_deprecated: Checking return value for memory
 allocation
To:     <catalin.marinas@arm.com>, <will.deacon@arm.com>,
        <kstewart@linuxfoundation.org>, <gregkh@linuxfoundation.org>,
        <tglx@linutronix.de>, <info@metux.net>
CC:     <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
Message-ID: <bd558d56-18a9-3607-3db0-ad203ab12aa8@huawei.com>
Date:   Mon, 7 Oct 2019 18:06:35 +0800
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Sender: linux-kernel-owner@vger.kernel.org
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There are no return value checking when using kzalloc() and kcalloc() for
memory allocation. so add it.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
---
v1 -> v2:
 - return error code when memory allocation failure

 arch/arm64/kernel/armv8_deprecated.c | 57 +++++++++++++++++++++++++++---------
 1 file changed, 43 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index 2ec09de..2284fcb 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -168,12 +168,15 @@ static int update_insn_emulation_mode(struct insn_emulation *insn,
 	return ret;
 }

-static void __init register_insn_emulation(struct insn_emulation_ops *ops)
+static int __init register_insn_emulation(struct insn_emulation_ops *ops)
 {
 	unsigned long flags;
 	struct insn_emulation *insn;

 	insn = kzalloc(sizeof(*insn), GFP_KERNEL);
+	if (!insn)
+		return -ENOMEM;
+
 	insn->ops = ops;
 	insn->min = INSN_UNDEF;

@@ -197,6 +200,7 @@ static void __init register_insn_emulation(struct insn_emulation_ops *ops)

 	/* Register any handlers if required */
 	update_insn_emulation_mode(insn, INSN_UNDEF);
+	return 0;
 }

 static int emulation_proc_handler(struct ctl_table *table, int write,
@@ -224,7 +228,7 @@ static int emulation_proc_handler(struct ctl_table *table, int write,
 	return ret;
 }

-static void __init register_insn_emulation_sysctl(void)
+static int __init register_insn_emulation_sysctl(void)
 {
 	unsigned long flags;
 	int i = 0;
@@ -233,6 +237,8 @@ static void __init register_insn_emulation_sysctl(void)

 	insns_sysctl = kcalloc(nr_insn_emulated + 1, sizeof(*sysctl),
 			       GFP_KERNEL);
+	if (!insns_sysctl)
+		return -ENOMEM;

 	raw_spin_lock_irqsave(&insn_emulation_lock, flags);
 	list_for_each_entry(insn, &insn_emulation, node) {
@@ -251,6 +257,7 @@ static void __init register_insn_emulation_sysctl(void)
 	raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);

 	register_sysctl("abi", insns_sysctl);
+	return 0;
 }

 /*
@@ -617,25 +624,47 @@ static int t16_setend_handler(struct pt_regs *regs, u32 instr)
  */
 static int __init armv8_deprecated_init(void)
 {
-	if (IS_ENABLED(CONFIG_SWP_EMULATION))
-		register_insn_emulation(&swp_ops);
+	int ret = 0;
+	int err = 0;
+
+	if (IS_ENABLED(CONFIG_SWP_EMULATION)) {
+		ret = register_insn_emulation(&swp_ops);
+		if (ret) {
+			pr_err("register insn emulation swp: fail\n");
+			err = ret;
+		}
+	}

-	if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION))
-		register_insn_emulation(&cp15_barrier_ops);
+	if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION)) {
+		ret = register_insn_emulation(&cp15_barrier_ops);
+		if (ret) {
+			pr_err("register insn emulation cpu15_barrier: fail\n");
+			err = ret;
+		}
+	}

 	if (IS_ENABLED(CONFIG_SETEND_EMULATION)) {
-		if(system_supports_mixed_endian_el0())
-			register_insn_emulation(&setend_ops);
-		else
+		if (system_supports_mixed_endian_el0()) {
+			ret = register_insn_emulation(&setend_ops);
+			if (ret) {
+				pr_err("register insn emulation setend: fail\n");
+				err = ret;
+			}
+		} else {
 			pr_info("setend instruction emulation is not supported on this system\n");
+		}
 	}

-	cpuhp_setup_state_nocalls(CPUHP_AP_ARM64_ISNDEP_STARTING,
-				  "arm64/isndep:starting",
-				  run_all_insn_set_hw_mode, NULL);
-	register_insn_emulation_sysctl();
+	if (nr_insn_emulated) {
+		cpuhp_setup_state_nocalls(CPUHP_AP_ARM64_ISNDEP_STARTING,
+					  "arm64/isndep:starting",
+					  run_all_insn_set_hw_mode, NULL);
+		ret = register_insn_emulation_sysctl();
+		if (ret)
+			err = ret;
+	}

-	return 0;
+	return err;
 }

 core_initcall(armv8_deprecated_init);
-- 
1.8.3.1