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| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-04-08 18:03:13 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-30 09:33:41 +0200 |
| commit | 0b93f40cbe9712563bb15329768bd73c9c19ac03 (patch) | |
| tree | 1361f30b0de742a2720923e025d9feedc0bbbb56 /arch/nios2 | |
| parent | fdca775081527364621857957655207d83035376 (diff) | |
| download | linux-stable-0b93f40cbe9712563bb15329768bd73c9c19ac03.tar.gz linux-stable-0b93f40cbe9712563bb15329768bd73c9c19ac03.tar.bz2 linux-stable-0b93f40cbe9712563bb15329768bd73c9c19ac03.zip | |
nios2: use fallback for random_get_entropy() instead of zero
commit c04e72700f2293013dab40208e809369378f224c 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>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/nios2')
| -rw-r--r-- | arch/nios2/include/asm/timex.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/nios2/include/asm/timex.h b/arch/nios2/include/asm/timex.h index a769f871b28d..40a1adc9bd03 100644 --- a/arch/nios2/include/asm/timex.h +++ b/arch/nios2/include/asm/timex.h @@ -8,5 +8,8 @@ typedef unsigned long cycles_t; extern cycles_t get_cycles(void); +#define get_cycles get_cycles + +#define random_get_entropy() (((unsigned long)get_cycles()) ?: random_get_entropy_fallback()) #endif |