4 files changed, 37 insertions, 6 deletions

diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c
index d04e9b89d14a..f584d7da29cb 100644
--- a/arch/s390/boot/ipl_parm.c
+++ b/arch/s390/boot/ipl_parm.c
@@ -179,7 +179,7 @@ void setup_boot_command_line(void)
 	if (has_ebcdic_char(parmarea.command_line))
 		EBCASC(parmarea.command_line, COMMAND_LINE_SIZE);
 	/* copy arch command line */
-	strcpy(early_command_line, strim(parmarea.command_line));
+	strscpy(early_command_line, strim(parmarea.command_line));
 
 	/* append IPL PARM data to the boot command line */
 	if (!is_prot_virt_guest() && ipl_block_valid)
@@ -253,7 +253,8 @@ void parse_boot_command_line(void)
 	int rc;
 
 	__kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
-	args = strcpy(command_line_buf, early_command_line);
+	strscpy(command_line_buf, early_command_line);
+	args = command_line_buf;
 	while (*args) {
 		args = next_arg(args, &param, &val);
 
@@ -309,7 +310,7 @@ void parse_boot_command_line(void)
 		if (!strcmp(param, "bootdebug")) {
 			bootdebug = true;
 			if (val)
-				strncpy(bootdebug_filter, val, sizeof(bootdebug_filter) - 1);
+				strscpy(bootdebug_filter, val);
 		}
 		if (!strcmp(param, "quiet"))
 			boot_console_loglevel = CONSOLE_LOGLEVEL_QUIET;
diff --git a/arch/s390/boot/printk.c b/arch/s390/boot/printk.c
index 8cf6331bc060..4bb6bc95704e 100644
--- a/arch/s390/boot/printk.c
+++ b/arch/s390/boot/printk.c
@@ -29,7 +29,8 @@ static void boot_rb_add(const char *str, size_t len)
 	/* store strings separated by '\0' */
 	if (len + 1 > avail)
 		boot_rb_off = 0;
-	strcpy(boot_rb + boot_rb_off, str);
+	avail = sizeof(boot_rb) - boot_rb_off - 1;
+	strscpy(boot_rb + boot_rb_off, str, avail);
 	boot_rb_off += len + 1;
 }
 
@@ -158,10 +159,10 @@ static noinline char *strsym(char *buf, void *ip)
 
 	p = findsym((unsigned long)ip, &off, &len);
 	if (p) {
-		strncpy(buf, p, MAX_SYMLEN);
+		strscpy(buf, p, MAX_SYMLEN);
 		/* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */
 		p = buf + strnlen(buf, MAX_SYMLEN - 15);
-		strcpy(p, "+0x");
+		strscpy(p, "+0x", MAX_SYMLEN - (p - buf));
 		as_hex(p + 3, off, 0);
 		strcat(p, "/0x");
 		as_hex(p + strlen(p), len, 0);
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 06316fb8e0fa..da8337e63a3e 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -6,6 +6,7 @@
 #include <asm/boot_data.h>
 #include <asm/extmem.h>
 #include <asm/sections.h>
+#include <asm/diag288.h>
 #include <asm/maccess.h>
 #include <asm/machine.h>
 #include <asm/sysinfo.h>
@@ -71,6 +72,20 @@ static void detect_machine_type(void)
 		set_machine_feature(MFEATURE_VM);
 }
 
+static void detect_diag288(void)
+{
+	/* "BEGIN" in EBCDIC character set */
+	static const char cmd[] = "\xc2\xc5\xc7\xc9\xd5";
+	unsigned long action, len;
+
+	action = machine_is_vm() ? (unsigned long)cmd : LPARWDT_RESTART;
+	len = machine_is_vm() ? sizeof(cmd) : 0;
+	if (__diag288(WDT_FUNC_INIT, MIN_INTERVAL, action, len))
+		return;
+	__diag288(WDT_FUNC_CANCEL, 0, 0, 0);
+	set_machine_feature(MFEATURE_DIAG288);
+}
+
 static void detect_diag9c(void)
 {
 	unsigned int cpu;
@@ -519,6 +534,8 @@ void startup_kernel(void)
 	detect_facilities();
 	detect_diag9c();
 	detect_machine_type();
+	/* detect_diag288() needs machine type */
+	detect_diag288();
 	cmma_init();
 	sanitize_prot_virt_host();
 	max_physmem_end = detect_max_physmem_end();
diff --git a/arch/s390/boot/string.c b/arch/s390/boot/string.c
index f6b9b1df48a8..bd68161434a6 100644
--- a/arch/s390/boot/string.c
+++ b/arch/s390/boot/string.c
@@ -29,6 +29,18 @@ int strncmp(const char *cs, const char *ct, size_t count)
 	return 0;
 }
 
+ssize_t sized_strscpy(char *dst, const char *src, size_t count)
+{
+	size_t len;
+
+	if (count == 0)
+		return -E2BIG;
+	len = strnlen(src, count - 1);
+	memcpy(dst, src, len);
+	dst[len] = '\0';
+	return src[len] ? -E2BIG : len;
+}
+
 void *memset64(uint64_t *s, uint64_t v, size_t count)
 {
 	uint64_t *xs = s;