[PATCH v3 4/8] random: Ignore GRND_RANDOM in getentropy(2)

Andy Lutomirski
2019-12-23T08:21:19Z

The separate blocking pool is going away. Start by ignoring
GRND_RANDOM in getentropy(2).

This should not materially break any API. Any code that worked
without this change should work at least as well with this change.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
drivers/char/random.c | 3 ---
include/uapi/linux/random.h | 2 +-
2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 675b8a48e18a..c0a3032b30ca 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -2206,9 +2206,6 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
if (count > INT_MAX)
count = INT_MAX;

- if (flags & GRND_RANDOM)
- return _random_read(flags & GRND_NONBLOCK, buf, count);
-
if (!(flags & GRND_INSECURE) && !crng_ready()) {
if (flags & GRND_NONBLOCK)
return -EAGAIN;
diff --git a/include/uapi/linux/random.h b/include/uapi/linux/random.h
index c092d20088d3..dcc1b3e6106f 100644
--- a/include/uapi/linux/random.h
+++ b/include/uapi/linux/random.h
@@ -48,7 +48,7 @@ struct rand_pool_info {
* Flags for getrandom(2)
*
* GRND_NONBLOCK Don't block and return EAGAIN instead
- * GRND_RANDOM Use the /dev/random pool instead of /dev/urandom
+ * GRND_RANDOM No effect
* GRND_INSECURE Return non-cryptographic random bytes
*/
#define GRND_NONBLOCK 0x0001
--
2.23.0