linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Matt Mackall <mpm@selenic.com>
To: Herbert Xu <herbert@gondor.hengli.com.au>
Cc: Linux Mailing List <linux-kernel@vger.kernel.org>,
	Steven Liu <lingjiujianke@gmail.com>
Subject: [PATCH] random: simplify fips mode
Date: Thu, 20 May 2010 00:44:17 -0500	[thread overview]
Message-ID: <1274334257.11603.1438.camel@calx> (raw)

Rather than dynamically allocate 10 bytes, move it to static allocation.
This saves space and avoids the need for error checking.

Signed-off-by: Matt Mackall <mpm@selenic.com>

diff -r a12387bbcc93 drivers/char/random.c
--- a/drivers/char/random.c	Thu Apr 08 10:02:02 2010 -0700
+++ b/drivers/char/random.c	Thu May 20 00:43:13 2010 -0500
@@ -257,6 +257,7 @@
 #define INPUT_POOL_WORDS 128
 #define OUTPUT_POOL_WORDS 32
 #define SEC_XFER_SIZE 512
+#define EXTRACT_SIZE 10
 
 /*
  * The minimum number of bits of entropy before we wake up a read on
@@ -414,7 +415,7 @@
 	unsigned add_ptr;
 	int entropy_count;
 	int input_rotate;
-	__u8 *last_data;
+	__u8 last_data[EXTRACT_SIZE];
 };
 
 static __u32 input_pool_data[INPUT_POOL_WORDS];
@@ -714,8 +715,6 @@
 }
 #endif
 
-#define EXTRACT_SIZE 10
-
 /*********************************************************************
  *
  * Entropy extraction routines
@@ -862,7 +861,7 @@
 	while (nbytes) {
 		extract_buf(r, tmp);
 
-		if (r->last_data) {
+		if (fips_enabled) {
 			spin_lock_irqsave(&r->lock, flags);
 			if (!memcmp(tmp, r->last_data, EXTRACT_SIZE))
 				panic("Hardware RNG duplicated output!\n");
@@ -951,9 +950,6 @@
 	now = ktime_get_real();
 	mix_pool_bytes(r, &now, sizeof(now));
 	mix_pool_bytes(r, utsname(), sizeof(*(utsname())));
-	/* Enable continuous test in fips mode */
-	if (fips_enabled)
-		r->last_data = kmalloc(EXTRACT_SIZE, GFP_KERNEL);
 }
 
 static int rand_initialize(void)

-- 
Mathematics is the supreme nostalgia of our time.



             reply	other threads:[~2010-05-20  5:44 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-20  5:44 Matt Mackall [this message]
2010-05-20  9:55 ` [PATCH] random: simplify fips mode Herbert Xu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1274334257.11603.1438.camel@calx \
    --to=mpm@selenic.com \
    --cc=herbert@gondor.hengli.com.au \
    --cc=lingjiujianke@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).