[OpenBIOS] [PATCH] herewrite: check for dictionary overflow

[Igor V. Kovalenko]

From: Igor V. Kovalenko <igor.v.kovalenko at gmail.com>

- add dictlimit variable to store dictionary memory size
- change herewrite() to check for overflow if dictlimit is set
- sparc64: set dictlimit to allocated amount

Signed-off-by: Igor V. Kovalenko <igor.v.kovalenko at gmail.com>
---
 arch/sparc64/openbios.c |    2 ++
 kernel/dict.c           |    1 +
 kernel/forth.c          |    8 ++++++++
 kernel/include/dict.h   |    1 +
 4 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/arch/sparc64/openbios.c b/arch/sparc64/openbios.c
index 2f1a955..67849e1 100644
--- a/arch/sparc64/openbios.c
+++ b/arch/sparc64/openbios.c
@@ -519,6 +519,8 @@ int openbios(void)
         collect_sys_info(&sys_info);
 
         dict = malloc(DICTIONARY_SIZE);
+        dictlimit = DICTIONARY_SIZE;
+
 	load_dictionary((char *)sys_info.dict_start,
 			(unsigned long)sys_info.dict_end
                         - (unsigned long)sys_info.dict_start);
diff --git a/kernel/dict.c b/kernel/dict.c
index 34b97f3..822c923 100644
--- a/kernel/dict.c
+++ b/kernel/dict.c
@@ -21,6 +21,7 @@
 unsigned char *dict = NULL;
 ucell *last;
 cell dicthead = 0;
+ucell dictlimit = 0;
 
 /* lfa2nfa
  * converts a link field address to a name field address,
diff --git a/kernel/forth.c b/kernel/forth.c
index 5fc53d3..2876709 100644
--- a/kernel/forth.c
+++ b/kernel/forth.c
@@ -851,6 +851,14 @@ static void herewrite(void)
 #ifdef CONFIG_DEBUG_INTERNAL
 	printk("here!: new value: %x\n", tmp);
 #endif
+
+	if (dictlimit && dicthead >= dictlimit) {
+	    printk("Dictionary space overflow:"
+	            " dicthead=" FMT_ucellx
+	            " dictlimit=" FMT_ucellx
+	            "\n",
+	            dicthead, dictlimit);
+	}
 }
 
 
diff --git a/kernel/include/dict.h b/kernel/include/dict.h
index 7e8c320..cc30f99 100644
--- a/kernel/include/dict.h
+++ b/kernel/include/dict.h
@@ -50,6 +50,7 @@ extern ucell 		PC;
 
 extern unsigned char	*dict;
 extern cell 		dicthead;
+extern ucell		dictlimit;
 extern ucell		*last;
 #ifdef FCOMPILER
 extern ucell *trampoline;