[PATCH v2 00/11] introduce random32_get_bytes() and random32_get_bytes_state()

[PATCH v2 00/11] introduce random32_get_bytes() and random32_get_bytes_state()

[Akinobu Mita]

This patchset introduces new functions into random32 library for
getting the requested number of pseudo-random bytes.

Before introducing these new functions into random32 library,
prandom32() and prandom32_seed() with "prandom32" prefix are
renamed to random32_state() and srandom32_state() respectively.

The purpose of this renaming is to prevent some kernel developers
from assuming that prandom32() and random32() might imply that only
prandom32() was the one using a pseudo-random number generator by
prandom32's "p", and the result may be a very embarassing security
exposure.

Changelog

* v2
- rename prandom32 to random32_state
- dropped lib/uuid.c patch
- add bnx2 and mtd_stresstest patches

Akinobu Mita (11):
  random32: rename prandom32 to random32_state
  random32: introduce random32_get_bytes() and
    random32_get_bytes_state()
  bnx2x: use random32_get_bytes()
  mtd: nandsim: use random32_get_bytes
  ubifs: use random32_get_bytes
  mtd: mtd_nandecctest: use random32_get_bytes instead of
    get_random_bytes()
  mtd: mtd_oobtest: convert to use random32_get_bytes_state()
  mtd: mtd_pagetest: convert to use random32_get_bytes_state()
  mtd: mtd_speedtest: use random32_get_bytes
  mtd: mtd_subpagetest: convert to use random32_get_bytes_state()
  mtd: mtd_stresstest: use random32_get_bytes()

 drivers/mtd/nand/nandsim.c                      |  5 +--
 drivers/mtd/tests/mtd_nandecctest.c             |  2 +-
 drivers/mtd/tests/mtd_oobtest.c                 | 49 +++++++-------------
 drivers/mtd/tests/mtd_pagetest.c                | 43 ++++++------------
 drivers/mtd/tests/mtd_speedtest.c               |  9 +---
 drivers/mtd/tests/mtd_stresstest.c              |  3 +-
 drivers/mtd/tests/mtd_subpagetest.c             | 42 +++++------------
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c |  5 +--
 drivers/scsi/fcoe/fcoe_ctlr.c                   |  4 +-
 fs/ubifs/debug.c                                |  8 ++--
 include/linux/random.h                          |  8 ++--
 lib/interval_tree_test_main.c                   |  7 +--
 lib/random32.c                                  | 60 ++++++++++++++++++++-----
 lib/rbtree_test.c                               |  6 +--
 14 files changed, 112 insertions(+), 139 deletions(-)

Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: netdev@vger.kernel.org
Cc: Robert Love <robert.w.love@intel.com>
Cc: devel@open-fcoe.org
Cc: Michel Lespinasse <walken@google.com>

-- 
1.7.11.7

[PATCH v2 02/11] random32: introduce random32_get_bytes() and random32_get_bytes_state()

[Akinobu Mita]

Add functions to get the requested number of pseudo-random bytes.

The difference from get_random_bytes() is that it generates pseudo-random
numbers by random32().  It is fast, suitable for generating random bytes
for testing, and reproducible if random32_get_bytes_state() is used.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: netdev@vger.kernel.org
---
* v2
- rename prandom32_get_bytes to random32_get_bytes_state

 include/linux/random.h |  2 ++
 lib/random32.c         | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/include/linux/random.h b/include/linux/random.h
index bb96f79..4176762 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -27,8 +27,10 @@ unsigned long randomize_range(unsigned long start, unsigned long end, unsigned l
 
 u32 random32(void);
 void srandom32(u32 seed);
+void random32_get_bytes(void *buf, int nbytes);
 
 u32 random32_state(struct rnd_state *);
+void random32_get_bytes_state(struct rnd_state *state, void *buf, int nbytes);
 
 /*
  * Handle minimum values for seeds
diff --git a/lib/random32.c b/lib/random32.c
index 7a3e0c7..9557417 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -61,6 +61,44 @@ u32 random32_state(struct rnd_state *state)
 EXPORT_SYMBOL(random32_state);
 
 /**
+ *	random32_get_bytes_state - get the pseudo-random bytes
+ *	@state: pointer to state structure holding seeded state.
+ *	@buf: where to copy the pseudo-random bytes to
+ *	@bytes: the requested number of bytes
+ *
+ *	This is used for pseudo-randomness with no outside seeding.
+ *	For more random results, use random32_get_bytes().
+ */
+void random32_get_bytes_state(struct rnd_state *state, void *buf, int bytes)
+{
+	unsigned char *p = buf;
+
+	for (; bytes > 0 && ((unsigned long)p) % sizeof(u32); bytes--, p++)
+		*p = random32_state(state);
+
+	for (; bytes > sizeof(u32) - 1; bytes -= sizeof(u32), p += sizeof(u32))
+		*(u32 *)p = random32_state(state);
+
+	for (; bytes > 0; bytes--, p++)
+		*p = random32_state(state);
+}
+EXPORT_SYMBOL(random32_get_bytes_state);
+
+/**
+ *	random32_get_bytes - get the requested number of pseudo-random bytes
+ *	@buf: where to copy the pseudo-random bytes to
+ *	@bytes: the requested number of bytes
+ */
+void random32_get_bytes(void *buf, int bytes)
+{
+	struct rnd_state *state = &get_cpu_var(net_rand_state);
+
+	random32_get_bytes_state(state, buf, bytes);
+	put_cpu_var(state);
+}
+EXPORT_SYMBOL(random32_get_bytes);
+
+/**
  *	random32 - pseudo random number generator
  *
  *	A 32 bit pseudo-random number is generated using a fast
-- 
1.7.11.7

[PATCH v2 03/11] bnx2x: use random32_get_bytes()

[Akinobu Mita]

Use random32_get_bytes() to fill rss key with pseudo-random bytes.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: netdev@vger.kernel.org
---
new patch from v2

 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 4833b6a..9a25658 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -1741,7 +1741,6 @@ int bnx2x_config_rss_pf(struct bnx2x *bp, struct bnx2x_rss_config_obj *rss_obj,
 			bool config_hash)
 {
 	struct bnx2x_config_rss_params params = {NULL};
-	int i;
 
 	/* Although RSS is meaningless when there is a single HW queue we
 	 * still need it enabled in order to have HW Rx hash generated.
@@ -1773,9 +1772,7 @@ int bnx2x_config_rss_pf(struct bnx2x *bp, struct bnx2x_rss_config_obj *rss_obj,
 
 	if (config_hash) {
 		/* RSS keys */
-		for (i = 0; i < sizeof(params.rss_key) / 4; i++)
-			params.rss_key[i] = random32();
-
+		random32_get_bytes(params.rss_key, sizeof(params.rss_key));
 		__set_bit(BNX2X_RSS_SET_SRCH, &params.rss_flags);
 	}
 
-- 
1.7.11.7

Re: [PATCH v2 00/11] introduce random32_get_bytes() and random32_get_bytes_state()

[Valdis.Kletnieks]

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On Sun, 04 Nov 2012 00:43:31 +0900, Akinobu Mita said:
> This patchset introduces new functions into random32 library for
> getting the requested number of pseudo-random bytes.
>
> Before introducing these new functions into random32 library,
> prandom32() and prandom32_seed() with "prandom32" prefix are
> renamed to random32_state() and srandom32_state() respectively.
>
> The purpose of this renaming is to prevent some kernel developers
> from assuming that prandom32() and random32() might imply that only
> prandom32() was the one using a pseudo-random number generator by
> prandom32's "p", and the result may be a very embarassing security
> exposure.

Out of curiosity, why the '32'?  I'm just waiting for some kernel developer to
do something stupid with this on a 64-bit arch because they think it's a 32-bit API. ;)

Should we bite the bullet and lose the 32, as long as we're churning the code *anyhow*?


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RE: [PATCH v2 00/11] introduce random32_get_bytes() and random32_get_bytes_state()

[David Laight]

> On Sun, 04 Nov 2012 00:43:31 +0900, Akinobu Mita said:
> > This patchset introduces new functions into random32 library for
> > getting the requested number of pseudo-random bytes.
> >
> > Before introducing these new functions into random32 library,
> > prandom32() and prandom32_seed() with "prandom32" prefix are
> > renamed to random32_state() and srandom32_state() respectively.
> >
> > The purpose of this renaming is to prevent some kernel developers
> > from assuming that prandom32() and random32() might imply that only
> > prandom32() was the one using a pseudo-random number generator by
> > prandom32's "p", and the result may be a very embarassing security
> > exposure.
> 
> Out of curiosity, why the '32'?  I'm just waiting for some kernel developer to
> do something stupid with this on a 64-bit arch because they think it's a 32-bit API. ;)
> 
> Should we bite the bullet and lose the 32, as long as we're churning the code *anyhow*?

Also why remove the 'pseudo' part of the name?
It is an important part of the name.

	David

Re: [PATCH v2 00/11] introduce random32_get_bytes() and random32_get_bytes_state()

[Akinobu Mita]

2012/11/6 David Laight <David.Laight@aculab.com>:
>> On Sun, 04 Nov 2012 00:43:31 +0900, Akinobu Mita said:
>> > This patchset introduces new functions into random32 library for
>> > getting the requested number of pseudo-random bytes.
>> >
>> > Before introducing these new functions into random32 library,
>> > prandom32() and prandom32_seed() with "prandom32" prefix are
>> > renamed to random32_state() and srandom32_state() respectively.
>> >
>> > The purpose of this renaming is to prevent some kernel developers
>> > from assuming that prandom32() and random32() might imply that only
>> > prandom32() was the one using a pseudo-random number generator by
>> > prandom32's "p", and the result may be a very embarassing security
>> > exposure.
>>
>> Out of curiosity, why the '32'?  I'm just waiting for some kernel developer to
>> do something stupid with this on a 64-bit arch because they think it's a 32-bit API. ;)
>>
>> Should we bite the bullet and lose the 32, as long as we're churning the code *anyhow*?
>
> Also why remove the 'pseudo' part of the name?
> It is an important part of the name.

Thanks for the heads-up.  Then, what is the ideal function name for
pseudo-random library?

I propose the following renaming, 'p' prefix is restored and '32' is
removed for not returning 32bit pseudo-random number functions.

void prandom_seed(u32 seed);    /* rename from srandom32() */
u32 prandom32(void);            /* rename from random32() */
void prandom_get_byte(void *buf, int bytes);

void prandom_seed_state(struct rnd_state *state, u64 seed);
                                        /* rename from prandom32_seed() */
u32 prandom32_state(struct rnd_state *state);   /* rename from prandom32() */
void prandom_get_byte_state(struct rnd_state *state, void *buf, int bytes);