tunables signed/unsigned bug & patch

[DJ Delorie <dj at redhat dot com>]

The range check for size_t tunables was checking against
(signed)(0xfff...fff), which is -1, so never passed (val>0 && val<-1).
This means half the existing tunables would never work :-(

I couldn't think of a clean way to handle both signed and unsigned in
the same function, so I split it into separate functions.

As an aside, tunables_strtoul() parses signed values but returns
unsigned values.  Ideally that would be split out too, but that's a
lot more code duplication.

DJ

diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
index e0119d1..c2f487a 100644
--- a/elf/dl-tunables.c
+++ b/elf/dl-tunables.c
@@ -172,10 +172,10 @@ tunables_strtoul (const char *nptr)
    explicit constraints of the tunable or with the implicit constraints of its
    type.  */
 static void
-tunable_set_val_if_valid_range (tunable_t *cur, const char *strval,
+tunable_set_val_if_valid_range_signed (tunable_t *cur, const char *strval,
 				int64_t default_min, int64_t default_max)
 {
-  int64_t val = tunables_strtoul (strval);
+  int64_t val = (int64_t) tunables_strtoul (strval);
 
   int64_t min = cur->type.min;
   int64_t max = cur->type.max;
@@ -193,6 +193,28 @@ tunable_set_val_if_valid_range (tunable_t *cur, const char *strval,
     }
 }
 
+static void
+tunable_set_val_if_valid_range_unsigned (tunable_t *cur, const char *strval,
+					 uint64_t default_min, uint64_t default_max)
+{
+  uint64_t val = (uint64_t) tunables_strtoul (strval);
+
+  uint64_t min = cur->type.min;
+  uint64_t max = cur->type.max;
+
+  if (min == max)
+    {
+      min = default_min;
+      max = default_max;
+    }
+
+  if (val >= min && val <= max)
+    {
+      cur->val.numval = val;
+      cur->strval = strval;
+    }
+}
+
 /* Validate range of the input value and initialize the tunable CUR if it looks
    good.  */
 static void
@@ -202,12 +224,12 @@ tunable_initialize (tunable_t *cur, const char *strval)
     {
     case TUNABLE_TYPE_INT_32:
 	{
-	  tunable_set_val_if_valid_range (cur, strval, INT32_MIN, INT32_MAX);
+	  tunable_set_val_if_valid_range_signed (cur, strval, INT32_MIN, INT32_MAX);
 	  break;
 	}
     case TUNABLE_TYPE_SIZE_T:
 	{
-	  tunable_set_val_if_valid_range (cur, strval, 0, SIZE_MAX);
+	  tunable_set_val_if_valid_range_unsigned (cur, strval, 0, SIZE_MAX);
 	  break;
 	}
     case TUNABLE_TYPE_STRING: