From 196f0bb081db462bc0f9a9462f47c9639101204b Mon Sep 17 00:00:00 2001
From: Michael Brown <mcb30@ipxe.org>
Date: Sun, 18 Mar 2012 16:45:04 +0000
Subject: [PATCH] [rng] Allow entropy_enable() to return an error

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/arch/i386/interface/pcbios/rtc_entropy.c | 5 ++++-
 src/crypto/entropy.c                         | 3 ++-
 src/include/ipxe/entropy.h                   | 3 ++-
 src/include/ipxe/null_entropy.h              | 3 ++-
 src/tests/entropy_sample.c                   | 3 ++-
 5 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/arch/i386/interface/pcbios/rtc_entropy.c b/src/arch/i386/interface/pcbios/rtc_entropy.c
index 03189659e..257cf08a0 100644
--- a/src/arch/i386/interface/pcbios/rtc_entropy.c
+++ b/src/arch/i386/interface/pcbios/rtc_entropy.c
@@ -165,12 +165,15 @@ static void rtc_disable_int ( void ) {
 /**
  * Enable entropy gathering
  *
+ * @ret rc		Return status code
  */
-static void rtc_entropy_enable ( void ) {
+static int rtc_entropy_enable ( void ) {
 
 	rtc_hook_isr();
 	enable_irq ( RTC_IRQ );
 	rtc_enable_int();
+
+	return 0;
 }
 
 /**
diff --git a/src/crypto/entropy.c b/src/crypto/entropy.c
index cb3d54d8f..03e7290a3 100644
--- a/src/crypto/entropy.c
+++ b/src/crypto/entropy.c
@@ -422,7 +422,8 @@ int get_entropy_input_tmp ( unsigned int num_samples, uint8_t *tmp,
 	int rc;
 
 	/* Enable entropy gathering */
-	entropy_enable();
+	if ( ( rc = entropy_enable() ) != 0 )
+		return rc;
 
 	/* Perform mandatory startup tests, if not yet performed */
 	for ( ; startup_tested < startup_test_count() ; startup_tested++ ) {
diff --git a/src/include/ipxe/entropy.h b/src/include/ipxe/entropy.h
index 02dde2f1d..50ba4fc63 100644
--- a/src/include/ipxe/entropy.h
+++ b/src/include/ipxe/entropy.h
@@ -61,8 +61,9 @@ typedef uint8_t entropy_sample_t;
 /**
  * Enable entropy gathering
  *
+ * @ret rc		Return status code
  */
-void entropy_enable ( void );
+int entropy_enable ( void );
 
 /**
  * Disable entropy gathering
diff --git a/src/include/ipxe/null_entropy.h b/src/include/ipxe/null_entropy.h
index 0bfec802d..646d1a17e 100644
--- a/src/include/ipxe/null_entropy.h
+++ b/src/include/ipxe/null_entropy.h
@@ -19,9 +19,10 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define ENTROPY_PREFIX_null __null_
 #endif
 
-static inline __always_inline void
+static inline __always_inline int
 ENTROPY_INLINE ( null, entropy_enable ) ( void ) {
 	/* Do nothing */
+	return 0;
 }
 
 static inline __always_inline void
diff --git a/src/tests/entropy_sample.c b/src/tests/entropy_sample.c
index e00bb484e..9e75b4e9b 100644
--- a/src/tests/entropy_sample.c
+++ b/src/tests/entropy_sample.c
@@ -48,7 +48,8 @@ static void entropy_sample_test_exec ( void ) {
 	for ( i = 0 ; i < ( SAMPLE_COUNT / SAMPLE_BLOCKSIZE ) ; i++ ) {
 
 		/* Collect one block of samples */
-		entropy_enable();
+		rc = entropy_enable();
+		ok ( rc == 0 );
 		for ( j = 0 ; j < SAMPLE_BLOCKSIZE ; j++ ) {
 			rc = get_noise ( &samples[j] );
 			ok ( rc == 0 );