Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Tiezhu Yang <yangtiezhu@loongson.cn>
To:     Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc:     Xuefeng Li <lixuefeng@loongson.cn>, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/3] MIPS: Return -EINVAL if mem parameter is empty in early_parse_mem()
Date:   Fri, 18 Mar 2022 23:05:18 +0800
Message-Id: <1647615920-23103-2-git-send-email-yangtiezhu@loongson.cn>
In-Reply-To: <1647615920-23103-1-git-send-email-yangtiezhu@loongson.cn>
References: <1647615920-23103-1-git-send-email-yangtiezhu@loongson.cn>
Precedence: bulk

In the current code, the users usually need to make sure the value
of mem parameter is correct, but it is better to do some check to
avoid potential boot hangs.

This commit checks whether mem parameter is empty, if yes, return
-EINVAL before call memblock_remove() and memblock_add().

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 arch/mips/kernel/setup.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index f979adf..14aa8bd 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -344,6 +344,11 @@ static int __init early_parse_mem(char *p)
 {
 	phys_addr_t start, size;
 
+	if (!p) {
+		pr_err("mem parameter is empty, do nothing\n");
+		return -EINVAL;
+	}
+
 	/*
 	 * If a user specifies memory size, we
 	 * blow away any automatically generated
-- 
2.1.0