PM / sleep: declare __tracedata symbols as char[] rather than char

Accessing more than one byte from a symbol declared simply 'char' is undefined
behavior, as reported by UBSAN:

	UBSAN: Undefined behaviour in drivers/base/power/trace.c:178:18
	load of address ffffffff8203fc78 with insufficient space
	for an object of type 'char'

Avoid this by declaring the symbols as arrays.

Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c
index a311cfa..a697579 100644 (file)
--- a/drivers/base/power/trace.c
+++ b/drivers/base/power/trace.c
@@ -166,14 +166,14 @@ void generate_pm_trace(const void *tracedata, unsigned int user)
 }
 EXPORT_SYMBOL(generate_pm_trace);
 
-extern char __tracedata_start, __tracedata_end;
+extern char __tracedata_start[], __tracedata_end[];
 static int show_file_hash(unsigned int value)
 {
        int match;
        char *tracedata;
 
        match = 0;
-       for (tracedata = &__tracedata_start ; tracedata < &__tracedata_end ;
+       for (tracedata = __tracedata_start ; tracedata < __tracedata_end ;
                        tracedata += 2 + sizeof(unsigned long)) {
                unsigned short lineno = *(unsigned short *)tracedata;
                const char *file = *(const char **)(tracedata + 2);