On Wed, 13 Oct 2021 at 09:30, Ivan T. Ivanov [off-list ref] wrote:

Hi,

Quoting Dominik Brodowski (2021-10-12 11:40:34)

quoted

Am Tue, Oct 12, 2021 at 11:27:08AM +0300 schrieb Ivan T. Ivanov:

quoted

This reverts commit 18b915ac6b0ac5ba7ded03156860f60a9f16df2b.

When CONFIG_RANDOM_TRUST_BOOTLOADER is enabled add_bootloader_randomness()
calls add_hwgenerator_randomness() which might sleep,

Wouldn't it be better to fix add_bootloader_randomness(), considering
that
calls to that function are likely to happen quite early during kernel
initialization? Especially as it seems to have worked beforehand?

I have tried. I made wait_event_interruptible() optional, but then
crng_reseed() segfault badly. And I don't think crng_reseed() is
something that I could fix easily. Suggestions are welcomed ;-)

How about

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 605969ed0f96..1828dc691ebf 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c

@@ -2297,9 +2297,8 @@ EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
  */
 void add_bootloader_randomness(const void *buf, unsigned int size)
 {
+       add_device_randomness(buf, size);
        if (IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER))
-               add_hwgenerator_randomness(buf, size, size * 8);
-       else
-               add_device_randomness(buf, size);
+               credit_entropy(&input_pool, size * 8);
 }
 EXPORT_SYMBOL_GPL(add_bootloader_randomness);