Currently if an attempt is made to print a pointer before there is enough entropy then '(____ptrval____)' is printed. This makes debugging stack traces during early boot difficult.
One partial solution to this problem is to use the hw RNG if it is available. Patch 1 - Whitespace fixes. Patch 2 - Fix get_random_bytes_arch() Patch 3 - Use hw RNG for pointer hashing if available (by default). thanks, Tobin. v4 -> v5 - Use 'upside-down-xmas-tree' style to declare local variables (Steve) - Added Reviewed-by tag from Steve (patch 2 and 3). v3 -> v4 - remove last patch of series (command line option patch) v2 -> v3 - Add __ro_after_init (suggested by Kees). v1 -> v2 - Use min_t() instead of min() (thanks checkpatch). - Add __must_check to function declaration (thanks Steve). - Use hw RNG by default if available (as originally suggested by Kees). - Add command line option to use cryptographically insecure hashing. If debug_early_boot is enabled use hash_long() instead of siphash (as requested by Steve, and solves original problem for Anna-Maria). - Added Acked-by tag from Ted (patch 1 and 2) *** BLURB HERE *** Tobin C. Harding (3): random: Fix whitespace pre random-bytes work random: Return nbytes filled from hw RNG vsprintf: Use hw RNG for ptr_key drivers/char/random.c | 19 ++++++++++--------- include/linux/random.h | 2 +- lib/vsprintf.c | 19 ++++++++++++++++--- 3 files changed, 27 insertions(+), 13 deletions(-) -- 2.7.4
