Changeset 3621 in MondoRescue for branches/3.3/mindi-busybox/shell/math.c

Timestamp:

Dec 20, 2016, 4:07:32 PM (7 years ago)

Author:

Bruno Cornec

Message:

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.

Location:

branches/3.3

Files:

• . (copied) (copied from branches/3.2 )
• mindi-busybox/shell/math.c (modified) (2 diffs)

branches/3.3/mindi-busybox/shell/math.c

@@ -416 +416 @@
         else if (right_side_val == 0)
             return "divide by zero";
-        else if (op == TOK_DIV || op == TOK_DIV_ASSIGN)
-            rez /= right_side_val;
-        else if (op == TOK_REM || op == TOK_REM_ASSIGN)
-            rez %= right_side_val;
+        else if (op == TOK_DIV || op == TOK_DIV_ASSIGN
+              || op == TOK_REM || op == TOK_REM_ASSIGN) {
+            /*
+             * bash 4.2.45 x86 64bit: SEGV on 'echo $((2**63 / -1))'
+             *
+             * MAX_NEGATIVE_INT / -1 = MAX_POSITIVE_INT+1
+             * and thus is not representable.
+             * Some CPUs segfault trying such op.
+             * Others overflow MAX_POSITIVE_INT+1 to
+             * MAX_NEGATIVE_INT (0x7fff+1 = 0x8000).
+             * Make sure to at least not SEGV here:
+             */
+            if (right_side_val == -1
+             && rez << 1 == 0 /* MAX_NEGATIVE_INT or 0 */
+            ) {
+                right_side_val = 1;
+            }
+            if (op == TOK_DIV || op == TOK_DIV_ASSIGN)
+                rez /= right_side_val;
+            else {
+                rez %= right_side_val;
+            }
+        }
     }
 
@@ -495 +514 @@
 #define ptr_to_rparen (&op_tokens[sizeof(op_tokens)-7])
 
-const char* FAST_FUNC
-endofname(const char *name)
-{
-    if (!is_name(*name))
-        return name;
-    while (*++name) {
-        if (!is_in_name(*name))
-            break;
-    }
-    return name;
-}
-
 static arith_t FAST_FUNC
 evaluate_string(arith_state_t *math_state, const char *expr)