[3/8] tunables: Add support for tunables of uint64_t type
Commit Message
Recognize the uint64_t type in addition to the current int32_t and
size_t. This allows addition of tunables of uint64_t types. In
addition to adding the uint64_t type, this patch also consolidates
validation and reading of integer types in tunables.
One notable change is that of overflow computation in
tunables_strtoul. The function was lifted from __internal_strtoul,
but it does not need the boundary condition check (i.e. result ==
ULONG_MAX) since it does not need to set errno. As a result the check
can be simplified, which I have now done.
* elf/dl-tunable-types.h (tunable_type_code_t): New type
TUNABLE_TYPE_UINT_64.
* elf/dl-tunables.c (tunables_strtoul): Return uint64_t.
Simplify computation of overflow.
(tunable_set_val_if_valid_range_signed,
tunable_set_val_if_valid_range_unsigned): Remove and replace
with this...
(TUNABLE_SET_VAL_IF_VALID_RANGE): ... New macro.
(tunable_initialize): Adjust. Add uint64_t support.
(__tunable_set_val): Add uint64_t support.
---
elf/dl-tunable-types.h | 1 +
elf/dl-tunables.c | 94 +++++++++++++++++++++-----------------------------
2 files changed, 41 insertions(+), 54 deletions(-)
@@ -24,6 +24,7 @@
typedef enum
{
TUNABLE_TYPE_INT_32,
+ TUNABLE_TYPE_UINT_64,
TUNABLE_TYPE_SIZE_T,
TUNABLE_TYPE_STRING
} tunable_type_code_t;
@@ -105,10 +105,10 @@ get_next_env (char **envp, char **name, size_t *namelen, char **val,
/* A stripped down strtoul-like implementation for very early use. It does not
set errno if the result is outside bounds because it gets called before
errno may have been set up. */
-static unsigned long int
+static uint64_t
tunables_strtoul (const char *nptr)
{
- unsigned long int result = 0;
+ uint64_t result = 0;
long int sign = 1;
unsigned max_digit;
@@ -144,7 +144,7 @@ tunables_strtoul (const char *nptr)
while (1)
{
- unsigned long int digval;
+ int digval;
if (*nptr >= '0' && *nptr <= '0' + max_digit)
digval = *nptr - '0';
else if (base == 16)
@@ -159,9 +159,8 @@ tunables_strtoul (const char *nptr)
else
break;
- if (result > ULONG_MAX / base
- || (result == ULONG_MAX / base && digval > ULONG_MAX % base))
- return ULONG_MAX;
+ if (result >= (UINT64_MAX - digval) / base)
+ return UINT64_MAX;
result *= base;
result += digval;
++nptr;
@@ -170,68 +169,50 @@ tunables_strtoul (const char *nptr)
return result * sign;
}
-/* Initialize the internal type if the value validates either using the
- explicit constraints of the tunable or with the implicit constraints of its
- type. */
-static void
-tunable_set_val_if_valid_range_signed (tunable_t *cur, const char *strval,
- int64_t default_min, int64_t default_max)
-{
- int64_t val = (int64_t) tunables_strtoul (strval);
-
- int64_t min = cur->type.min;
- int64_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;
- }
-}
-
-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;
- }
-}
+#define TUNABLE_SET_VAL_IF_VALID_RANGE(__cur, __val, __type, __default_min, \
+ __default_max) \
+({ \
+ __type min = (__cur)->type.min; \
+ __type max = (__cur)->type.max; \
+ \
+ if (min == max) \
+ { \
+ min = __default_min; \
+ max = __default_max; \
+ } \
+ \
+ if ((__type) (__val) >= min && (__type) (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
tunable_initialize (tunable_t *cur, const char *strval)
{
+ uint64_t val;
+
+ if (cur->type.type_code != TUNABLE_TYPE_STRING)
+ val = tunables_strtoul (strval);
+
switch (cur->type.type_code)
{
case TUNABLE_TYPE_INT_32:
{
- tunable_set_val_if_valid_range_signed (cur, strval, INT32_MIN, INT32_MAX);
+ TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, int64_t, INT32_MIN, INT32_MAX);
+ break;
+ }
+ case TUNABLE_TYPE_UINT_64:
+ {
+ TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, uint64_t, 0, UINT64_MAX);
break;
}
case TUNABLE_TYPE_SIZE_T:
{
- tunable_set_val_if_valid_range_unsigned (cur, strval, 0, SIZE_MAX);
+ TUNABLE_SET_VAL_IF_VALID_RANGE (cur, val, uint64_t, 0, SIZE_MAX);
break;
}
case TUNABLE_TYPE_STRING:
@@ -461,6 +442,11 @@ __tunable_set_val (tunable_id_t id, void *valp, tunable_callback_t callback)
switch (cur->type.type_code)
{
+ case TUNABLE_TYPE_UINT_64:
+ {
+ *((uint64_t *) valp) = (uint64_t) cur->val.numval;
+ break;
+ }
case TUNABLE_TYPE_INT_32:
{
*((int32_t *) valp) = (int32_t) cur->val.numval;