[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 <linux@xxxxxxxxxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Cc: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>

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