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 random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() 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: Thomas Gleixner <t...@linutronix.de>
Cc: Arnd Bergmann <a...@arndb.de>
Cc: Paul Walmsley <paul.walms...@sifive.com>
Cc: Palmer Dabbelt <pal...@dabbelt.com>
Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com>
---
arch/riscv/include/asm/timex.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/include/asm/timex.h b/arch/riscv/include/asm/timex.h
index 507cae273bc6..d6a7428f6248 100644
--- a/arch/riscv/include/asm/timex.h
+++ b/arch/riscv/include/asm/timex.h
@@ -41,7 +41,7 @@ static inline u32 get_cycles_hi(void)
static inline unsigned long random_get_entropy(void)
{
if (unlikely(clint_time_val == NULL))
- return 0;
+ return random_get_entropy_fallback();
return get_cycles();
}
#define random_get_entropy() random_get_entropy()
--
2.35.1
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