diff options
| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2017-08-25 17:50:16 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-26 09:20:33 +0200 |
| commit | c2ceb5fd4e921506e86208b82fca716a2c3aad59 (patch) | |
| tree | 960b9e5412ea59b8326b83939104f1c1ada0cab1 /drivers/firmware/efi/efi.c | |
| parent | efi/libstub: Enable reset attack mitigation (diff) | |
| download | linux-c2ceb5fd4e921506e86208b82fca716a2c3aad59.tar.xz linux-c2ceb5fd4e921506e86208b82fca716a2c3aad59.zip | |
efi/random: Increase size of firmware supplied randomness
The crng code requires at least 64 bytes (2 * CHACHA20_BLOCK_SIZE)
to complete the fast boot-time init, so provide that many bytes
when invoking UEFI protocols to seed the entropy pool. Also, add
a notice so we can tell from the boot log when the seeding actually
took place.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170825155019.6740-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/firmware/efi/efi.c')
| -rw-r--r-- | drivers/firmware/efi/efi.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index a32e1460ade8..c8a27a2c30c1 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -541,6 +541,7 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz, if (seed != NULL) { add_device_randomness(seed->bits, seed->size); early_memunmap(seed, sizeof(*seed) + size); + pr_notice("seeding entropy pool\n"); } else { pr_err("Could not map UEFI random seed!\n"); } @@ -900,7 +901,7 @@ static int update_efi_random_seed(struct notifier_block *nb, seed = memremap(efi.rng_seed, sizeof(*seed), MEMREMAP_WB); if (seed != NULL) { - size = min(seed->size, 32U); + size = min(seed->size, EFI_RANDOM_SEED_SIZE); memunmap(seed); } else { pr_err("Could not map UEFI random seed!\n"); |