xtensa: use strscpy to copy strings

The strlcpy should not be used because it doesn't limit the source
length. So that it 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, replace strlcpy with strscpy.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Message-Id: <20211220084756.955307-1-wangborong@cdjrlc.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index 8db20cfb44ab8836db40547f311ca7b64b7aae64..3f18428914821ba85936fab143e774bdf6ae5331 100644 (file)
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -140,7 +140,7 @@ __tagtable(BP_TAG_FDT, parse_tag_fdt);
 
 static int __init parse_tag_cmdline(const bp_tag_t* tag)
 {
-       strlcpy(command_line, (char *)(tag->data), COMMAND_LINE_SIZE);
+       strscpy(command_line, (char *)(tag->data), COMMAND_LINE_SIZE);
        return 0;
 }
 
@@ -230,7 +230,7 @@ void __init early_init_devtree(void *params)
        of_scan_flat_dt(xtensa_dt_io_area, NULL);
 
        if (!command_line[0])
-               strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
+               strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
 }
 
 #endif /* CONFIG_USE_OF */
@@ -260,7 +260,7 @@ void __init init_arch(bp_tag_t *bp_start)
 
 #ifdef CONFIG_CMDLINE_BOOL
        if (!command_line[0])
-               strlcpy(command_line, default_command_line, COMMAND_LINE_SIZE);
+               strscpy(command_line, default_command_line, COMMAND_LINE_SIZE);
 #endif
 
        /* Early hook for platforms */
@@ -289,7 +289,7 @@ void __init setup_arch(char **cmdline_p)
 
        *cmdline_p = command_line;
        platform_setup(cmdline_p);
-       strlcpy(boot_command_line, *cmdline_p, COMMAND_LINE_SIZE);
+       strscpy(boot_command_line, *cmdline_p, COMMAND_LINE_SIZE);
 
        /* Reserve some memory regions */