[PATCH 20/28] parisc: Refactor strlcat() to seq_buf in setup_cmdline()

setup_cmdline() uses multiple strlcat() calls to conditionally append
default console and earlycon parameters to boot_command_line.

In preparation for removing the deprecated strlcat() API[1], initialize a
struct seq_buf with the existing boot_command_line contents and use
seq_buf_printf() to append the console parameters.

Link: https://github.com/KSPP/linux/issues/370 [1]
Cc: codemender-patching+linux@google.com
Assisted-by: CoPilot:Gemini-1.5-Pro [editor_update_file, shell_command_run]
Signed-off-by: Bill Wendling <morbo@google.com>
---
Cc: Russell King <linux@armlinux.org.uk>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
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---
 arch/parisc/kernel/setup.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c
index d3e17a7a8901..fa3efc82ad87 100644
--- a/arch/parisc/kernel/setup.c
+++ b/arch/parisc/kernel/setup.c

@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/console.h>
 #include <linux/seq_file.h>
+#include <linux/seq_buf.h>
 #define PCI_DEBUG
 #include <linux/pci.h>
 #undef PCI_DEBUG

@@ -42,6 +43,7 @@ static char __initdata command_line[COMMAND_LINE_SIZE];
 static void __init setup_cmdline(char **cmdline_p)
 {
 	extern unsigned int boot_args[];
+	struct seq_buf s;
 	char *p;
 
 	*cmdline_p = command_line;

@@ -54,19 +56,21 @@ static void __init setup_cmdline(char **cmdline_p)
 	strscpy(boot_command_line, (char *)__va(boot_args[1]),
 		COMMAND_LINE_SIZE);
 
+	s.buffer = boot_command_line;
+	s.size = COMMAND_LINE_SIZE;
+	s.len = strlen(boot_command_line);
+
 	/* autodetect console type (if not done by palo yet) */
 	p = boot_command_line;
 	if (!str_has_prefix(p, "console=") && !strstr(p, " console=")) {
-		strlcat(p, " console=", COMMAND_LINE_SIZE);
-		if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
-			strlcat(p, "ttyS0", COMMAND_LINE_SIZE);
-		else
-			strlcat(p, "tty0", COMMAND_LINE_SIZE);
+		seq_buf_printf(&s, " console=%s",
+			       PAGE0->mem_cons.cl_class == CL_DUPLEX ?
+			       "ttyS0" : "tty0");
 	}
 
 	/* default to use early console */
 	if (!strstr(p, "earlycon"))
-		strlcat(p, " earlycon=pdc", COMMAND_LINE_SIZE);
+		seq_buf_printf(&s, " earlycon=pdc");
 
 #ifdef CONFIG_BLK_DEV_INITRD
 	/* did palo pass us a ramdisk? */

-- 
2.55.0.1032.g73a4cd73de-goog