[PATCH] random: inform about bootloader-provided randomness

[Dominik Brodowski]

Inform how many bits of randomness were provided by the bootloader,
and whether we trust that input.

Signed-off-by: Dominik Brodowski <li...@dominikbrodowski.net>
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
Cc: Hsin-Yi Wang <hsi...@chromium.org>
Cc: Stephen Boyd <swb...@chromium.org>
Cc: Rob Herring <r...@kernel.org>
Cc: Theodore Ts'o <ty...@mit.edu>
Cc: Will Deacon <w...@kernel.org>

diff --git a/drivers/char/random.c b/drivers/char/random.c
index de434feb873a..673375e05c0d 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -2515,6 +2515,10 @@ EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
  */
 void add_bootloader_randomness(const void *buf, unsigned int size)
 {
+       pr_notice("random: adding %u bits of %sbootloader-provided randomness",
+               size * 8,
+               IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER) ? "trusted " : "");
+
        if (IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER))
                add_hwgenerator_randomness(buf, size, size * 8);
        else