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From:   Jason Wang <wangborong@cdjrlc.com>
To:     ley.foon.tan@intel.com
Cc:     akpm@linux-foundation.org, wangkefeng.wang@huawei.com,
        wangborong@cdjrlc.com, andreas.oetken@siemens.com,
        linux-kernel@vger.kernel.org
Subject: [PATCH] nios2: use strscpy to replace strlcpy
Date:   Sat,  7 Aug 2021 15:24:31 +0800
Message-Id: <20210807072431.66478-1-wangborong@cdjrlc.com>
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The strlcpy should not be used because it doesn't limit the source
length. As linus says, it's a completely useless function if you
can't implicitly trust the source string - but that is almost always
why people think they should use it! All in all the BSD function
will lead some potential bugs.

But the strscpy doesn't require reading memory from the src string
beyond the specified "count" bytes, and since the return value is
easier to error-check than strlcpy()'s. In addition, the implementation
is robust to the string changing out from underneath it, unlike the
current strlcpy() implementation.

Thus, We prefer using strscpy instead of strlcpy.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
---
 arch/nios2/kernel/setup.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c
index cf8d687a2644..02fe70b6d78e 100644
--- a/arch/nios2/kernel/setup.c
+++ b/arch/nios2/kernel/setup.c
@@ -121,7 +121,7 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
 		dtb_passed = r6;
 
 		if (r7)
-			strlcpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
+			strscpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
 	}
 #endif
 
@@ -129,10 +129,10 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
 
 #ifndef CONFIG_CMDLINE_FORCE
 	if (cmdline_passed[0])
-		strlcpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
+		strscpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
 #ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB
 	else
-		strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+		strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 #endif
 #endif
 
-- 
2.32.0