move random bytes buffer to be part of mmaped pages; ok tedu@

1 files changed, 18 insertions, 21 deletions

diff --git a/src/lib/libc/stdlib/malloc.c b/src/lib/libc/stdlib/malloc.c
index 412d000a11..ba8bd3ad8f 100644
--- a/src/lib/libc/stdlib/malloc.c
+++ b/src/lib/libc/stdlib/malloc.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: malloc.c,v 1.166 2014/05/26 06:19:07 otto Exp $       */
+/*      $OpenBSD: malloc.c,v 1.167 2014/06/02 08:49:38 otto Exp $       */
 /*
  * Copyright (c) 2008, 2010, 2011 Otto Moerbeek <otto@drijf.net>
  * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org>
@@ -117,6 +117,8 @@ struct dir_info {
         struct region_info free_regions[MALLOC_MAXCACHE];
                                         /* delayed free chunk slots */
         void *delayed_chunks[MALLOC_DELAYED_CHUNK_MASK + 1];
+        size_t rbytesused;              /* random bytes used */
+        u_char rbytes[512];             /* random bytes */
         u_short chunk_start;
 #ifdef MALLOC_STATS
         size_t inserts;
@@ -191,14 +193,10 @@ static union {
 #define g_pool  mopts.g_pool
 
 char            *malloc_options;        /* compile-time options */
-
 static char     *malloc_func;           /* current function */
 static int      malloc_active;          /* status of malloc */
 
-
-static size_t rbytesused;               /* random bytes used */
-static u_char rbytes[512];              /* random bytes */
-static u_char getrbyte(void);
+static u_char getrbyte(struct dir_info *d);
 
 extern char     *__progname;
 
@@ -275,20 +273,20 @@ wrterror(char *msg, void *p)
 }
 
 static void
-rbytes_init(void)
+rbytes_init(struct dir_info *d)
 {
-        arc4random_buf(rbytes, sizeof(rbytes));
-        rbytesused = 0;
+        arc4random_buf(d->rbytes, sizeof(d->rbytes));
+        d->rbytesused = 0;
 }
 
 static inline u_char
-getrbyte(void)
+getrbyte(struct dir_info *d)
 {
         u_char x;
 
-        if (rbytesused >= sizeof(rbytes))
-                rbytes_init();
-        x = rbytes[rbytesused++];
+        if (d->rbytesused >= sizeof(d->rbytes))
+                rbytes_init(d);
+        x = d->rbytes[d->rbytesused++];
         return x;
 }
 
@@ -322,7 +320,7 @@ unmap(struct dir_info *d, void *p, size_t sz)
         rsz = mopts.malloc_cache - d->free_regions_size;
         if (psz > rsz)
                 tounmap = psz - rsz;
-        offset = getrbyte();
+        offset = getrbyte(d);
         for (i = 0; tounmap > 0 && i < mopts.malloc_cache; i++) {
                 r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)];
                 if (r->p != NULL) {
@@ -403,7 +401,7 @@ map(struct dir_info *d, size_t sz, int zero_fill)
                 /* zero fill not needed */
                 return p;
         }
-        offset = getrbyte();
+        offset = getrbyte(d);
         for (i = 0; i < mopts.malloc_cache; i++) {
                 r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)];
                 if (r->p != NULL) {
@@ -461,8 +459,6 @@ omalloc_init(struct dir_info **dp)
         size_t d_avail, regioninfo_size;
         struct dir_info *d;
 
-        rbytes_init();
-
         /*
          * Default options
          */
@@ -616,6 +612,7 @@ omalloc_init(struct dir_info **dp)
         d = (struct dir_info *)(p + MALLOC_PAGESIZE +
             (arc4random_uniform(d_avail) << MALLOC_MINSHIFT));
 
+        rbytes_init(d);
         d->regions_free = d->regions_total = MALLOC_INITIAL_REGIONS;
         regioninfo_size = d->regions_total * sizeof(struct region_info);
         d->r = MMAP(regioninfo_size);
@@ -914,7 +911,7 @@ malloc_bytes(struct dir_info *d, size_t size, void *f)
                         j++;
         }
 
-        listnum = getrbyte() % MALLOC_CHUNK_LISTS;
+        listnum = getrbyte(d) % MALLOC_CHUNK_LISTS;
         /* If it's empty, make a page more of that size chunks */
         if ((bp = LIST_FIRST(&d->chunk_dir[j][listnum])) == NULL) {
                 bp = omalloc_make_chunks(d, j, listnum);
@@ -927,7 +924,7 @@ malloc_bytes(struct dir_info *d, size_t size, void *f)
 
         i = d->chunk_start;
         if (bp->free > 1)
-                i += getrbyte();
+                i += getrbyte(d);
         if (i >= bp->total)
                 i &= bp->total - 1;
         for (;;) {
@@ -1016,7 +1013,7 @@ free_bytes(struct dir_info *d, struct region_info *r, void *ptr)
 
         if (info->free == 1) {
                 /* Page became non-full */
-                listnum = getrbyte() % MALLOC_CHUNK_LISTS;
+                listnum = getrbyte(d) % MALLOC_CHUNK_LISTS;
                 if (info->size != 0)
                         mp = &d->chunk_dir[info->shift][listnum];
                 else
@@ -1224,7 +1221,7 @@ ofree(void *p)
                 if (!mopts.malloc_freenow) {
                         if (find_chunknum(g_pool, r, p) == -1)
                                 return;
-                        i = getrbyte() & MALLOC_DELAYED_CHUNK_MASK;
+                        i = getrbyte(g_pool) & MALLOC_DELAYED_CHUNK_MASK;
                         tmp = p;
                         p = g_pool->delayed_chunks[i];
                         if (tmp == p) {