[PATCH RFC v1 02/10] m68k: use sched_clock() for random_get_entropy() instead of zero

[Jason A. Donenfeld]

In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling sched_clock() would be preferable, because
that always needs to return _something_, even falling back to jiffies
eventually. It's not as though sched_clock() is super high precision or
guaranteed to be entropic, but basically anything that's not zero all
the time is better than returning zero all the time.

Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
 arch/m68k/include/asm/timex.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/m68k/include/asm/timex.h b/arch/m68k/include/asm/timex.h
index 6a21d9358280..2cd0942097f8 100644
--- a/arch/m68k/include/asm/timex.h
+++ b/arch/m68k/include/asm/timex.h
@@ -7,6 +7,8 @@
 #ifndef _ASMm68K_TIMEX_H
 #define _ASMm68K_TIMEX_H
 
+#include <linux/sched/clock.h>
+
 #ifdef CONFIG_COLDFIRE
 /*
  * CLOCK_TICK_RATE should give the underlying frequency of the tick timer
@@ -35,7 +37,7 @@ static inline unsigned long random_get_entropy(void)
 {
 	if (mach_random_get_entropy)
 		return mach_random_get_entropy();
-	return 0;
+	return sched_clock();
 }
 #define random_get_entropy	random_get_entropy
 
-- 
2.35.1