diff options
| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-04-08 18:03:13 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-30 09:29:13 +0200 |
| commit | 2ab416043a94087a8bc28ce748db0d7bce850b43 (patch) | |
| tree | 702b964f9c291097dbd5a5763f6b9ed911b718c8 /arch/riscv | |
| parent | a1428cd7e194740fdd11048b5ba6ab66f31fe7e1 (diff) | |
riscv: use fallback for random_get_entropy() instead of zero
commit 6d01238623faa9425f820353d2066baf6c9dc872 upstream.
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 <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/include/asm/timex.h | 2 |
1 files changed, 1 insertions, 1 deletions
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() |