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Commit 0891ad82 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random 

Pull /dev/random changes from Ted Ts'o:
 "The /dev/random changes for 3.13 including a number of improvements in
  the following areas: performance, avoiding waste of entropy, better
  tracking of entropy estimates, support for non-x86 platforms that have
  a register which can't be used for fine-grained timekeeping, but which
  might be good enough for the random driver.

  Also add some printk's so that we can see how quickly /dev/urandom can
  get initialized, and when programs try to use /dev/urandom before it
  is fully initialized (since this could be a security issue).  This
  shouldn't be an issue on x86 desktop/laptops --- a test on my Lenovo
  T430s laptop shows that /dev/urandom is getting fully initialized
  approximately two seconds before the root file system is mounted
  read/write --- this may be an issue with ARM and MIPS embedded/mobile
  systems, though.  These printk's will be a useful canary before
  potentially adding a future change to start blocking processes which
  try to read from /dev/urandom before it is initialized, which is
  something FreeBSD does already for security reasons, and which
  security folks have been agitating for Linux to also adopt"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: add debugging code to detect early use of get_random_bytes()
  random: initialize the last_time field in struct timer_rand_state
  random: don't zap entropy count in rand_initialize()
  random: printk notifications for urandom pool initialization
  random: make add_timer_randomness() fill the nonblocking pool first
  random: convert DEBUG_ENT to tracepoints
  random: push extra entropy to the output pools
  random: drop trickle mode
  random: adjust the generator polynomials in the mixing function slightly
  random: speed up the fast_mix function by a factor of four
  random: cap the rate which the /dev/urandom pool gets reseeded
  random: optimize the entropy_store structure
  random: optimize spinlock use in add_device_randomness()
  random: fix the tracepoint for get_random_bytes(_arch)
  random: account for entropy loss due to overwrites
  random: allow fractional bits to be tracked
  random: statically compute poolbitshift, poolbytes, poolbits
  random: mix in architectural randomness earlier in extract_buf()
parents f63c4824 392a546d

drivers/char/random.c

+405 −242

File changed.

Preview size limit exceeded, changes collapsed.

include/trace/events/random.h

+182 −1
Original line number Diff line number Diff line
@@ -7,6 +7,25 @@ 
#include <linux/writeback.h>

#include <linux/tracepoint.h>



TRACE_EVENT(add_device_randomness,

	TP_PROTO(int bytes, unsigned long IP),



	TP_ARGS(bytes, IP),



	TP_STRUCT__entry(

		__field(	  int,	bytes			)

		__field(unsigned long,	IP			)

	),



	TP_fast_assign(

		__entry->bytes		= bytes;

		__entry->IP		= IP;

	),



	TP_printk("bytes %d caller %pF",

		__entry->bytes, (void *)__entry->IP)

);



DECLARE_EVENT_CLASS(random__mix_pool_bytes,

	TP_PROTO(const char *pool_name, int bytes, unsigned long IP),
@@ -68,7 +87,112 @@ TRACE_EVENT(credit_entropy_bits, 
		  (void *)__entry->IP)

);



TRACE_EVENT(get_random_bytes,

TRACE_EVENT(push_to_pool,

	TP_PROTO(const char *pool_name, int pool_bits, int input_bits),



	TP_ARGS(pool_name, pool_bits, input_bits),



	TP_STRUCT__entry(

		__field( const char *,	pool_name		)

		__field(	  int,	pool_bits		)

		__field(	  int,	input_bits		)

	),



	TP_fast_assign(

		__entry->pool_name	= pool_name;

		__entry->pool_bits	= pool_bits;

		__entry->input_bits	= input_bits;

	),



	TP_printk("%s: pool_bits %d input_pool_bits %d",

		  __entry->pool_name, __entry->pool_bits,

		  __entry->input_bits)

);



TRACE_EVENT(debit_entropy,

	TP_PROTO(const char *pool_name, int debit_bits),



	TP_ARGS(pool_name, debit_bits),



	TP_STRUCT__entry(

		__field( const char *,	pool_name		)

		__field(	  int,	debit_bits		)

	),



	TP_fast_assign(

		__entry->pool_name	= pool_name;

		__entry->debit_bits	= debit_bits;

	),



	TP_printk("%s: debit_bits %d", __entry->pool_name,

		  __entry->debit_bits)

);



TRACE_EVENT(add_input_randomness,

	TP_PROTO(int input_bits),



	TP_ARGS(input_bits),



	TP_STRUCT__entry(

		__field(	  int,	input_bits		)

	),



	TP_fast_assign(

		__entry->input_bits	= input_bits;

	),



	TP_printk("input_pool_bits %d", __entry->input_bits)

);



TRACE_EVENT(add_disk_randomness,

	TP_PROTO(dev_t dev, int input_bits),



	TP_ARGS(dev, input_bits),



	TP_STRUCT__entry(

		__field(	dev_t,	dev			)

		__field(	  int,	input_bits		)

	),



	TP_fast_assign(

		__entry->dev		= dev;

		__entry->input_bits	= input_bits;

	),



	TP_printk("dev %d,%d input_pool_bits %d", MAJOR(__entry->dev),

		  MINOR(__entry->dev), __entry->input_bits)

);



TRACE_EVENT(xfer_secondary_pool,

	TP_PROTO(const char *pool_name, int xfer_bits, int request_bits,

		 int pool_entropy, int input_entropy),



	TP_ARGS(pool_name, xfer_bits, request_bits, pool_entropy,

		input_entropy),



	TP_STRUCT__entry(

		__field( const char *,	pool_name		)

		__field(	  int,	xfer_bits		)

		__field(	  int,	request_bits		)

		__field(	  int,	pool_entropy		)

		__field(	  int,	input_entropy		)

	),



	TP_fast_assign(

		__entry->pool_name	= pool_name;

		__entry->xfer_bits	= xfer_bits;

		__entry->request_bits	= request_bits;

		__entry->pool_entropy	= pool_entropy;

		__entry->input_entropy	= input_entropy;

	),



	TP_printk("pool %s xfer_bits %d request_bits %d pool_entropy %d "

		  "input_entropy %d", __entry->pool_name, __entry->xfer_bits,

		  __entry->request_bits, __entry->pool_entropy,

		  __entry->input_entropy)

);



DECLARE_EVENT_CLASS(random__get_random_bytes,

	TP_PROTO(int nbytes, unsigned long IP),



	TP_ARGS(nbytes, IP),
@@ -86,6 +210,18 @@ TRACE_EVENT(get_random_bytes, 
	TP_printk("nbytes %d caller %pF", __entry->nbytes, (void *)__entry->IP)

);



DEFINE_EVENT(random__get_random_bytes, get_random_bytes,

	TP_PROTO(int nbytes, unsigned long IP),



	TP_ARGS(nbytes, IP)

);



DEFINE_EVENT(random__get_random_bytes, get_random_bytes_arch,

	TP_PROTO(int nbytes, unsigned long IP),



	TP_ARGS(nbytes, IP)

);



DECLARE_EVENT_CLASS(random__extract_entropy,

	TP_PROTO(const char *pool_name, int nbytes, int entropy_count,

		 unsigned long IP),
@@ -126,7 +262,52 @@ DEFINE_EVENT(random__extract_entropy, extract_entropy_user, 
	TP_ARGS(pool_name, nbytes, entropy_count, IP)

);



TRACE_EVENT(random_read,

	TP_PROTO(int got_bits, int need_bits, int pool_left, int input_left),



	TP_ARGS(got_bits, need_bits, pool_left, input_left),



	TP_STRUCT__entry(

		__field(	  int,	got_bits		)

		__field(	  int,	need_bits		)

		__field(	  int,	pool_left		)

		__field(	  int,	input_left		)

	),



	TP_fast_assign(

		__entry->got_bits	= got_bits;

		__entry->need_bits	= need_bits;

		__entry->pool_left	= pool_left;

		__entry->input_left	= input_left;

	),



	TP_printk("got_bits %d still_needed_bits %d "

		  "blocking_pool_entropy_left %d input_entropy_left %d",

		  __entry->got_bits, __entry->got_bits, __entry->pool_left,

		  __entry->input_left)

);



TRACE_EVENT(urandom_read,

	TP_PROTO(int got_bits, int pool_left, int input_left),



	TP_ARGS(got_bits, pool_left, input_left),



	TP_STRUCT__entry(

		__field(	  int,	got_bits		)

		__field(	  int,	pool_left		)

		__field(	  int,	input_left		)

	),



	TP_fast_assign(

		__entry->got_bits	= got_bits;

		__entry->pool_left	= pool_left;

		__entry->input_left	= input_left;

	),



	TP_printk("got_bits %d nonblocking_pool_entropy_left %d "

		  "input_entropy_left %d", __entry->got_bits,

		  __entry->pool_left, __entry->input_left)

);



#endif /* _TRACE_RANDOM_H */