hush: add leak detector helper; fix/add tests for it

function                                             old     new   delta
builtin_memleak                                        -      92     +92
bltins                                               288     300     +12

shell/hush.c

@@ -117,7 +117,10 @@
 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
 #endif
 
-/* Keep unconditionally on for now */
+/* Enable/disable sanity checks. Ok to enable in production,
+ * only adds a bit of bloat.
+ * Keeping unconditionally on for now.
+ */
 #define HUSH_DEBUG 1
 /* In progress... */
 #define ENABLE_HUSH_FUNCTIONS 0
@@ -524,6 +527,9 @@ struct globals {
 	char **traps; /* char *traps[NSIG] */
 	sigset_t blocked_set;
 	sigset_t inherited_set;
+#if HUSH_DEBUG
+	unsigned long memleak_value;
+#endif
 	char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
 #if ENABLE_FEATURE_SH_STANDALONE
 	struct nofork_save_area nofork_save;
@@ -555,14 +561,17 @@ static int builtin_jobs(char **argv);
 #if ENABLE_HUSH_HELP
 static int builtin_help(char **argv);
 #endif
+#if HUSH_DEBUG
+static int builtin_memleak(char **argv);
+#endif
 static int builtin_pwd(char **argv);
 static int builtin_read(char **argv);
-static int builtin_test(char **argv);
-static int builtin_trap(char **argv);
-static int builtin_true(char **argv);
 static int builtin_set(char **argv);
 static int builtin_shift(char **argv);
 static int builtin_source(char **argv);
+static int builtin_test(char **argv);
+static int builtin_trap(char **argv);
+static int builtin_true(char **argv);
 static int builtin_umask(char **argv);
 static int builtin_unset(char **argv);
 static int builtin_wait(char **argv);
@@ -617,6 +626,9 @@ static const struct built_in_command bltins[] = {
 #endif
 #if ENABLE_HUSH_JOB
 	BLTIN("jobs"    , builtin_jobs    , "List active jobs"),
+#endif
+#if HUSH_DEBUG
+	BLTIN("memleak" , builtin_memleak , "Debug tool"),
 #endif
 	BLTIN("pwd"     , builtin_pwd     , "Print current directory"),
 	BLTIN("read"    , builtin_read    , "Input environment variable"),
@@ -5962,6 +5974,36 @@ static int builtin_jobs(char **argv UNUSED_PARAM)
 }
 #endif
 
+#if HUSH_DEBUG
+static int builtin_memleak(char **argv UNUSED_PARAM)
+{
+	void *p;
+	unsigned long l;
+
+	/* Crude attempt to find where "free memory" starts,
+	 * sans fragmentation. */
+	p = malloc(240);
+	l = (unsigned long)p;
+	free(p);
+	p = malloc(3400);
+	if (l < (unsigned long)p) l = (unsigned long)p;
+	free(p);
+
+	if (!G.memleak_value)
+		G.memleak_value = l;
+	
+	l -= G.memleak_value;
+	if ((long)l < 0)
+		l = 0;
+	l /= 1024;
+	if (l > 127)
+		l = 127;
+
+	/* Exitcode is "how many kilobytes we leaked since 1st call" */
+	return l;
+}
+#endif
+
 static int builtin_pwd(char **argv UNUSED_PARAM)
 {
 	puts(set_cwd());

shell/hush_test/hush-z_slow/leak_all1.right

@@ -0,0 +1,3 @@
+Warm up
+Measuring memory leak...
+Ok

shell/hush_test/hush-z_slow/leak_all1.tests

@@ -0,0 +1,61 @@
+# "Check many leaks" test #1
+# Cramming all kinds of weird commands in here.
+# As you find leaks, please create separate, small test
+# for each leak.
+# Narrowing down the leak using this large test may be difficult.
+# It is intended to be a blanket "is everything ok?" test
+
+echo "Warm up"
+i=1
+l=1
+t=1
+export t
+while test $i != 99; do
+    t=value1_$i; t=value2_$i true; t=value3_$i /bin/true; t=value4_$i exec 1>&1
+    { t=value3_$i /bin/true; } </dev/null
+    if true; t=valueA_$i false >>/dev/null; true; then
+	: << HERE >/dev/null; true <<HERE
+Hello builtin :
+HERE
+Hello true
+HERE
+    elif false; then
+	true; echo Doesnt run
+    else
+	{ true; }; echo Doesnt run too >>/foo/bar
+    fi
+    : $((i++))
+done
+
+memleak
+
+echo "Measuring memory leak..."
+# Please copy the entire block from above verbatim
+i=1
+l=1
+t=1
+export t
+while test $i != 99; do
+    t=value1_$i; t=value2_$i true; t=value3_$i /bin/true; t=value4_$i exec 1>&1
+    { t=value3_$i /bin/true; } </dev/null
+    if true; t=valueA_$i false >>/dev/null; true; then
+	: << HERE >/dev/null; true <<HERE
+Hello builtin :
+HERE
+Hello true
+HERE
+    elif false; then
+	true; echo Doesnt run
+    else
+	{ true; }; echo Doesnt run too >>/foo/bar
+    fi
+    : $((i++))
+done
+
+memleak
+kb=$?
+if test $kb -le 4; then
+    echo Ok #$kb
+else
+    echo "Bad: $kb kb (or more) leaked"
+fi

shell/hush_test/hush-z_slow/leak_var.right

@@ -1,2 +1,2 @@
 Measuring memory leak...
-vsz does not grow
+Ok

shell/hush_test/hush-z_slow/leak_var.tests

@@ -1,96 +1,4 @@
-pid=$$
-
-# Warm up
-beg=`ps -o pid,vsz | grep "^ *$pid "`
-i=1
-while test $i != X; do
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    i=1$i
-    if test $i = 1111111111111111111111111111111111111111111111; then i=2; fi
-    if test $i = 1111111111111111111111111111111111111111111112; then i=3; fi
-    if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
-    if test $i = 1111111111111111111111111111111111111111111114; then i=5; fi
-    if test $i = 1111111111111111111111111111111111111111111115; then i=6; fi
-    if test $i = 1111111111111111111111111111111111111111111116; then i=7; fi
-    if test $i = 1111111111111111111111111111111111111111111117; then i=8; fi
-    if test $i = 1111111111111111111111111111111111111111111118; then i=9; fi
-    if test $i = 1111111111111111111111111111111111111111111119; then i=a; fi
-    if test $i = 111111111111111111111111111111111111111111111a; then i=b; fi
-    if test $i = 111111111111111111111111111111111111111111111b; then i=c; fi
-    if test $i = 111111111111111111111111111111111111111111111c; then i=d; fi
-    if test $i = 111111111111111111111111111111111111111111111d; then i=e; fi
-    if test $i = 111111111111111111111111111111111111111111111e; then i=f; fi
-    if test $i = 111111111111111111111111111111111111111111111f; then i=g; fi
-    if test $i = 111111111111111111111111111111111111111111111g; then i=h; fi
-    if test $i = 111111111111111111111111111111111111111111111h; then i=i; fi
-    if test $i = 111111111111111111111111111111111111111111111i; then i=j; fi
-    if test $i = 111111111111111111111111111111111111111111111j; then i=X; fi
-done
-end=`ps -o pid,vsz | grep "^ *$pid "`
-
-# Warm up again (I do need it on my machine)
-beg=`ps -o pid,vsz | grep "^ *$pid "`
-i=1
-while test $i != X; do
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    unset t
-    t=111111111111111111111111111111111111111111111111111111111111111111111111
-    export t
-    i=1$i
-    if test $i = 1111111111111111111111111111111111111111111111; then i=2; fi
-    if test $i = 1111111111111111111111111111111111111111111112; then i=3; fi
-    if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
-    if test $i = 1111111111111111111111111111111111111111111114; then i=5; fi
-    if test $i = 1111111111111111111111111111111111111111111115; then i=6; fi
-    if test $i = 1111111111111111111111111111111111111111111116; then i=7; fi
-    if test $i = 1111111111111111111111111111111111111111111117; then i=8; fi
-    if test $i = 1111111111111111111111111111111111111111111118; then i=9; fi
-    if test $i = 1111111111111111111111111111111111111111111119; then i=a; fi
-    if test $i = 111111111111111111111111111111111111111111111a; then i=b; fi
-    if test $i = 111111111111111111111111111111111111111111111b; then i=c; fi
-    if test $i = 111111111111111111111111111111111111111111111c; then i=d; fi
-    if test $i = 111111111111111111111111111111111111111111111d; then i=e; fi
-    if test $i = 111111111111111111111111111111111111111111111e; then i=f; fi
-    if test $i = 111111111111111111111111111111111111111111111f; then i=g; fi
-    if test $i = 111111111111111111111111111111111111111111111g; then i=h; fi
-    if test $i = 111111111111111111111111111111111111111111111h; then i=i; fi
-    if test $i = 111111111111111111111111111111111111111111111i; then i=j; fi
-    if test $i = 111111111111111111111111111111111111111111111j; then i=X; fi
-done
-end=`ps -o pid,vsz | grep "^ *$pid "`
-if test "$beg" != "$end"; then
-    true echo "vsz grows: $beg -> $end"
-else
-    true echo "vsz does not grow"
-fi
-
 echo "Measuring memory leak..."
-beg=`ps -o pid,vsz | grep "^ *$pid "`
 i=1
 while test $i != X; do
     unset t
@@ -128,11 +36,12 @@ while test $i != X; do
     if test $i = 111111111111111111111111111111111111111111111h; then i=i; fi
     if test $i = 111111111111111111111111111111111111111111111i; then i=j; fi
     if test $i = 111111111111111111111111111111111111111111111j; then i=X; fi
+    memleak
 done
-end=`ps -o pid,vsz | grep "^ *$pid "`
+memleak
-
+kb=$?
-if test "$beg" != "$end"; then
+if test $kb -le 4; then
-    echo "vsz grows: $beg -> $end"
+    echo Ok
 else
-    echo "vsz does not grow"
+    echo "Bad: $kb kb (or more) leaked"
 fi

shell/hush_test/hush-z_slow/leak_var2.right

@@ -1,2 +1,3 @@
+Warm up
 Measuring memory leak...
-vsz does not grow
+Ok

shell/hush_test/hush-z_slow/leak_var2.tests

@@ -1,10 +1,7 @@
-pid=$$
-
 t=1
 export t
 
-# Warm up
+echo "Warm up"
-beg=`ps -o pid,vsz | grep "^ *$pid "`
 i=1
 while test $i != X; do
     t=111111111111111111111111111111111111111111111111111111111111111111111110$i
@@ -17,31 +14,10 @@ while test $i != X; do
     if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
     if test $i = 1111111111111111111111111111111111111111111114; then i=X; fi
 done
-end=`ps -o pid,vsz | grep "^ *$pid "`
 
-# Warm up again (I do need it on my machine)
+memleak
-beg=`ps -o pid,vsz | grep "^ *$pid "`
-i=1
-while test $i != X; do
-    t=111111111111111111111111111111111111111111111111111111111111111111111110$i
-    t=111111111111111111111111111111111111111111111111111111111111111111111111$i true
-    t=111111111111111111111111111111111111111111111111111111111111111111111112$i /bin/true
-    t=111111111111111111111111111111111111111111111111111111111111111111111113$i exec 1>&1
-    i=1$i
-    if test $i = 1111111111111111111111111111111111111111111111; then i=2; fi
-    if test $i = 1111111111111111111111111111111111111111111112; then i=3; fi
-    if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
-    if test $i = 1111111111111111111111111111111111111111111114; then i=X; fi
-done
-end=`ps -o pid,vsz | grep "^ *$pid "`
-if test "$beg" != "$end"; then
-    true echo "vsz grows: $beg -> $end"
-else
-    true echo "vsz does not grow"
-fi
 
 echo "Measuring memory leak..."
-beg=`ps -o pid,vsz | grep "^ *$pid "`
 i=1
 while test $i != X; do
     t=111111111111111111111111111111111111111111111111111111111111111111111110$i
@@ -54,10 +30,11 @@ while test $i != X; do
     if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
     if test $i = 1111111111111111111111111111111111111111111114; then i=X; fi
 done
-end=`ps -o pid,vsz | grep "^ *$pid "`
 
-if test "$beg" != "$end"; then
+memleak
-    echo "vsz grows: $beg -> $end"
+kb=$?
+if test $kb -le 4; then
+    echo Ok
 else
-    echo "vsz does not grow"
+    echo "Bad: $kb kb (or more) leaked"
 fi