attack the biggest stack users:

[platform/upstream/busybox.git] / util-linux / mkfs_minix.c

diff --git a/util-linux/mkfs_minix.c b/util-linux/mkfs_minix.c
index de9dde3..35c0ccf 100644 (file)
--- a/util-linux/mkfs_minix.c
+++ b/util-linux/mkfs_minix.c
@@ -109,16 +109,22 @@ struct globals {
        unsigned long req_nr_inodes;
        unsigned currently_testing;
 
-
        char root_block[BLOCK_SIZE];
        char super_block_buffer[BLOCK_SIZE];
        char boot_block_buffer[512];
        unsigned short good_blocks_table[MAX_GOOD_BLOCKS];
        /* check_blocks(): buffer[] was the biggest static in entire bbox */
        char check_blocks_buffer[BLOCK_SIZE * TEST_BUFFER_BLOCKS];
-};
 
+       unsigned short ind_block1[BLOCK_SIZE >> 1];
+       unsigned short dind_block1[BLOCK_SIZE >> 1];
+       unsigned long ind_block2[BLOCK_SIZE >> 2];
+       unsigned long dind_block2[BLOCK_SIZE >> 2];
+};
 #define G (*ptr_to_globals)
+#define INIT_G() do { \
+       PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
+} while (0)
 
 static ALWAYS_INLINE unsigned div_roundup(unsigned size, unsigned n)
 {
@@ -306,8 +312,12 @@ static void make_bad_inode(void)
        struct minix1_inode *inode = &INODE_BUF1[MINIX_BAD_INO];
        int i, j, zone;
        int ind = 0, dind = 0;
+       /* moved to globals to reduce stack usage
        unsigned short ind_block[BLOCK_SIZE >> 1];
        unsigned short dind_block[BLOCK_SIZE >> 1];
+       */
+#define ind_block (G.ind_block1)
+#define dind_block (G.dind_block1)
 
 #define NEXT_BAD (zone = next(zone))
 
@@ -351,6 +361,8 @@ static void make_bad_inode(void)
                write_block(ind, (char *) ind_block);
        if (dind)
                write_block(dind, (char *) dind_block);
+#undef ind_block
+#undef dind_block
 }
 
 #if ENABLE_FEATURE_MINIX2
@@ -359,8 +371,12 @@ static void make_bad_inode2(void)
        struct minix2_inode *inode = &INODE_BUF2[MINIX_BAD_INO];
        int i, j, zone;
        int ind = 0, dind = 0;
+       /* moved to globals to reduce stack usage
        unsigned long ind_block[BLOCK_SIZE >> 2];
        unsigned long dind_block[BLOCK_SIZE >> 2];
+       */
+#define ind_block (G.ind_block2)
+#define dind_block (G.dind_block2)
 
        if (!G.badblocks)
                return;
@@ -401,6 +417,8 @@ static void make_bad_inode2(void)
                write_block(ind, (char *) ind_block);
        if (dind)
                write_block(dind, (char *) dind_block);
+#undef ind_block
+#undef dind_block
 }
 #else
 void make_bad_inode2(void);
@@ -613,7 +631,7 @@ int mkfs_minix_main(int argc, char **argv)
        char *str_i, *str_n;
        char *listfile = NULL;
 
-       PTR_TO_GLOBALS = xzalloc(sizeof(G));
+       INIT_G();
 /* default (changed to 30, per Linus's suggestion, Sun Nov 21 08:05:07 1993) */
        G.namelen = 30;
        G.dirsize = 32;