3 files changed, 34 insertions, 33 deletions

diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb
index 2cfd2721f7ed..9b5d1d7f2ef7 100644
--- a/lib/Kconfig.kgdb
+++ b/lib/Kconfig.kgdb
@@ -4,14 +4,17 @@ config HAVE_ARCH_KGDB
 
 menuconfig KGDB
         bool "KGDB: kernel debugging with remote gdb"
-        select FRAME_POINTER
         depends on HAVE_ARCH_KGDB
         depends on DEBUG_KERNEL && EXPERIMENTAL
         help
           If you say Y here, it will be possible to remotely debug the
-          kernel using gdb.  Documentation of kernel debugger is available
-          at http://kgdb.sourceforge.net as well as in DocBook form
-          in Documentation/DocBook/.  If unsure, say N.
+          kernel using gdb.  It is recommended but not required, that
+          you also turn on the kernel config option
+          CONFIG_FRAME_POINTER to aid in producing more reliable stack
+          backtraces in the external debugger.  Documentation of
+          kernel debugger is available at http://kgdb.sourceforge.net
+          as well as in DocBook form in Documentation/DocBook/.  If
+          unsure, say N.
 
 if KGDB
 
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
index 889ddce2021e..a3b8d4c3f77a 100644
--- a/lib/iommu-helper.c
+++ b/lib/iommu-helper.c
@@ -80,11 +80,3 @@ void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr)
         }
 }
 EXPORT_SYMBOL(iommu_area_free);
-
-unsigned long iommu_num_pages(unsigned long addr, unsigned long len)
-{
-        unsigned long size = roundup((addr & ~PAGE_MASK) + len, PAGE_SIZE);
-
-        return size >> PAGE_SHIFT;
-}
-EXPORT_SYMBOL(iommu_num_pages);
diff --git a/lib/random32.c b/lib/random32.c
index ca87d86992bd..217d5c4b666d 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -56,23 +56,12 @@ static u32 __random32(struct rnd_state *state)
         return (state->s1 ^ state->s2 ^ state->s3);
 }
 
-static void __set_random32(struct rnd_state *state, unsigned long s)
+/*
+ * Handle minimum values for seeds
+ */
+static inline u32 __seed(u32 x, u32 m)
 {
-        if (s == 0)
-                s = 1;      /* default seed is 1 */
-
-#define LCG(n) (69069 * n)
-        state->s1 = LCG(s);
-        state->s2 = LCG(state->s1);
-        state->s3 = LCG(state->s2);
-
-        /* "warm it up" */
-        __random32(state);
-        __random32(state);
-        __random32(state);
-        __random32(state);
-        __random32(state);
-        __random32(state);
+        return (x < m) ? x + m : x;
 }
 
 /**
@@ -107,7 +96,7 @@ void srandom32(u32 entropy)
          */
         for_each_possible_cpu (i) {
                 struct rnd_state *state = &per_cpu(net_rand_state, i);
-                __set_random32(state, state->s1 ^ entropy);
+                state->s1 = __seed(state->s1 ^ entropy, 1);
         }
 }
 EXPORT_SYMBOL(srandom32);
@@ -122,7 +111,19 @@ static int __init random32_init(void)
 
         for_each_possible_cpu(i) {
                 struct rnd_state *state = &per_cpu(net_rand_state,i);
-                __set_random32(state, i + jiffies);
+
+#define LCG(x)  ((x) * 69069)   /* super-duper LCG */
+                state->s1 = __seed(LCG(i + jiffies), 1);
+                state->s2 = __seed(LCG(state->s1), 7);
+                state->s3 = __seed(LCG(state->s2), 15);
+
+                /* "warm it up" */
+                __random32(state);
+                __random32(state);
+                __random32(state);
+                __random32(state);
+                __random32(state);
+                __random32(state);
         }
         return 0;
 }
@@ -135,13 +136,18 @@ core_initcall(random32_init);
 static int __init random32_reseed(void)
 {
         int i;
-        unsigned long seed;
 
         for_each_possible_cpu(i) {
                 struct rnd_state *state = &per_cpu(net_rand_state,i);
+                u32 seeds[3];
+
+                get_random_bytes(&seeds, sizeof(seeds));
+                state->s1 = __seed(seeds[0], 1);
+                state->s2 = __seed(seeds[1], 7);
+                state->s3 = __seed(seeds[2], 15);
 
-                get_random_bytes(&seed, sizeof(seed));
-                __set_random32(state, seed);
+                /* mix it in */
+                __random32(state);
         }
         return 0;
 }