On Fri, Oct 9, 2015 at 10:52 PM, Bruce Momjian <br...@momjian.us> wrote:
>
> Any news on this item from 2013, worked on again 2014?
>
> ---------------------------------------------------------------------------
>
> On Wed, Aug 6, 2014 at 12:55:59PM -0400, Bruce Momjian wrote:
>> On Fri, Nov 29, 2013 at 02:04:10AM +0000, Greg Stark wrote:
>> > Attached is what I have so far. I have to say I'm starting to come
>> > around to Tom's point of view. This is a lot of hassle for not much
>> > gain. i've noticed a number of other overflow checks that the llvm
>> > optimizer is not picking up on so even after this patch it's not clear
>> > that all the signed overflow checks that depend on -fwrapv will be
>> > gone.
>> >
>> > This patch still isn't quite finished though.
>> >
>> > a) It triggers a spurious gcc warning about overflows on constant
>> > expressions. These value of these expressions aren't actually being
>> > used as they're used in the other branch of the overflow test. I think
>> > I see how to work around it for gcc using __builtin_choose_expr but it
>> > might be pretty grotty.
>> >
>> > b) I'm concerned these checks depend on INT_MIN/MAX and SHRT_MIN/MAX
>> > which may not be exactly the right length. I'm kind of confused why
>> > c.h assumes long is 32 bits and short is 16 bits though so I don't
>> > think I'm making it any worse. It may be better for us to just define
>> > our own limits since we know exactly how large we expect these data
>> > types to be.
>> >
>> > c) I want to add regression tests that will ensure that the overflow
>> > checks are all working. So far I haven't been able to catch any being
>> > optimized away even with -fno-wrapv and -fstrict-overflow. I think I
>> > just didn't build with the right options though and it should be
>> > possible.
>> >
>> > The goal here imho is to allow building with -fno-wrapv
>> > -fstrict-overflow safely. Whether we actually do or not is another
>> > question but it means we would be able to use new compilers like clang
>> > without worrying about finding the equivalent of -fwrapv for them.
>>
>> Where are we on this?
Well, I have played a bit with this patch and rebased it as attached.
One major change is the use of the variables PG_INT* that have been
added in 62e2a8d. Some places were not updated with those new checks,
in majority a couple of routines in int.c (I haven't finished
monitoring the whole code though). Also, I haven't played yet with my
compilers to optimize away some of the checks and break them, but I'll
give it a try with clang and gcc. For now, I guess that this patch is
a good thing to begin with though, I have checked that code compiles
and regression tests pass.
Regards,
--
Michael
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c
index 29f058c..9b4b890 100644
--- a/src/backend/executor/execQual.c
+++ b/src/backend/executor/execQual.c
@@ -3185,7 +3185,8 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
/* Get sub-array details from first member */
elem_ndims = this_ndims;
ndims = elem_ndims + 1;
- if (ndims <= 0 || ndims > MAXDIM)
+
+ if (PG_INT32_ADD_OVERFLOWS(elem_ndims,1) || ndims > MAXDIM)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("number of array dimensions (%d) exceeds " \
diff --git a/src/backend/utils/adt/array_userfuncs.c b/src/backend/utils/adt/array_userfuncs.c
index c14ea23..a6b0d1b 100644
--- a/src/backend/utils/adt/array_userfuncs.c
+++ b/src/backend/utils/adt/array_userfuncs.c
@@ -113,8 +113,9 @@ array_append(PG_FUNCTION_ARGS)
ub = dimv[0] + lb[0] - 1;
indx = ub + 1;
- /* overflow? */
- if (indx < ub)
+ /* check for overflow in upper bound (indx+1) */
+ if (PG_INT32_ADD_OVERFLOWS(dimv[0],lb[0]) ||
+ PG_INT32_ADD_OVERFLOWS(dimv[0]+lb[0], 1))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
@@ -168,7 +169,7 @@ array_prepend(PG_FUNCTION_ARGS)
lb0 = lb[0];
/* overflow? */
- if (indx > lb[0])
+ if (PG_INT32_ADD_OVERFLOWS(lb[0], -1))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 4e927d8..cc4c570 100644
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -2763,12 +2763,12 @@ width_bucket_float8(PG_FUNCTION_ARGS)
result = 0;
else if (operand >= bound2)
{
- result = count + 1;
/* check for overflow */
- if (result < count)
+ if (PG_INT32_ADD_OVERFLOWS(count, 1))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
+ result = count + 1;
}
else
result = ((float8) count * (operand - bound1) / (bound2 - bound1)) + 1;
@@ -2779,12 +2779,12 @@ width_bucket_float8(PG_FUNCTION_ARGS)
result = 0;
else if (operand <= bound2)
{
- result = count + 1;
/* check for overflow */
- if (result < count)
+ if (PG_INT32_ADD_OVERFLOWS(count, 1))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
+ result = count + 1;
}
else
result = ((float8) count * (bound1 - operand) / (bound1 - bound2)) + 1;
diff --git a/src/backend/utils/adt/int.c b/src/backend/utils/adt/int.c
index 1a91b29..8790169 100644
--- a/src/backend/utils/adt/int.c
+++ b/src/backend/utils/adt/int.c
@@ -641,12 +641,8 @@ int4pl(PG_FUNCTION_ARGS)
result = arg1 + arg2;
- /*
- * Overflow check. If the inputs are of different signs then their sum
- * cannot overflow. If the inputs are of the same sign, their sum had
- * better be that sign too.
- */
- if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT32_ADD_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
@@ -662,12 +658,8 @@ int4mi(PG_FUNCTION_ARGS)
result = arg1 - arg2;
- /*
- * Overflow check. If the inputs are of the same sign then their
- * difference cannot overflow. If they are of different signs then the
- * result should be of the same sign as the first input.
- */
- if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT32_SUB_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
@@ -683,22 +675,8 @@ int4mul(PG_FUNCTION_ARGS)
result = arg1 * arg2;
- /*
- * Overflow check. We basically check to see if result / arg2 gives arg1
- * again. There are two cases where this fails: arg2 = 0 (which cannot
- * overflow) and arg1 = INT_MIN, arg2 = -1 (where the division itself will
- * overflow and thus incorrectly match).
- *
- * Since the division is likely much more expensive than the actual
- * multiplication, we'd like to skip it where possible. The best bang for
- * the buck seems to be to check whether both inputs are in the int16
- * range; if so, no overflow is possible.
- */
- if (!(arg1 >= (int32) SHRT_MIN && arg1 <= (int32) SHRT_MAX &&
- arg2 >= (int32) SHRT_MIN && arg2 <= (int32) SHRT_MAX) &&
- arg2 != 0 &&
- ((arg2 == -1 && arg1 < 0 && result < 0) ||
- result / arg2 != arg1))
+ /* Overflow check */
+ if (PG_INT32_MUL_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
@@ -729,12 +707,12 @@ int4div(PG_FUNCTION_ARGS)
*/
if (arg2 == -1)
{
- result = -arg1;
/* overflow check (needed for INT_MIN) */
- if (arg1 != 0 && SAMESIGN(result, arg1))
+ if (arg1 == PG_INT32_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
+ result = -arg1;
PG_RETURN_INT32(result);
}
@@ -749,31 +727,25 @@ Datum
int4inc(PG_FUNCTION_ARGS)
{
int32 arg = PG_GETARG_INT32(0);
- int32 result;
- result = arg + 1;
- /* Overflow check */
- if (arg > 0 && result < 0)
+ if (PG_INT32_ADD_OVERFLOWS(arg, 1))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
- PG_RETURN_INT32(result);
+ PG_RETURN_INT32(arg + 1);
}
Datum
int2um(PG_FUNCTION_ARGS)
{
int16 arg = PG_GETARG_INT16(0);
- int16 result;
- result = -arg;
- /* overflow check (needed for SHRT_MIN) */
- if (arg != 0 && SAMESIGN(result, arg))
+ if (arg == SHRT_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("smallint out of range")));
- PG_RETURN_INT16(result);
+ PG_RETURN_INT16(-arg);
}
Datum
@@ -1151,12 +1123,12 @@ int4abs(PG_FUNCTION_ARGS)
int32 arg1 = PG_GETARG_INT32(0);
int32 result;
- result = (arg1 < 0) ? -arg1 : arg1;
/* overflow check (needed for INT_MIN) */
- if (result < 0)
+ if (arg1 == PG_INT32_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
+ result = (arg1 < 0) ? -arg1 : arg1;
PG_RETURN_INT32(result);
}
@@ -1166,12 +1138,13 @@ int2abs(PG_FUNCTION_ARGS)
int16 arg1 = PG_GETARG_INT16(0);
int16 result;
- result = (arg1 < 0) ? -arg1 : arg1;
/* overflow check (needed for SHRT_MIN) */
- if (result < 0)
+ if (arg1 == PG_INT16_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("smallint out of range")));
+ result = (arg1 < 0) ? -arg1 : arg1;
+
PG_RETURN_INT16(result);
}
diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c
index 63a4fbb..8a0a05a 100644
--- a/src/backend/utils/adt/int8.c
+++ b/src/backend/utils/adt/int8.c
@@ -102,19 +102,19 @@ scanint8(const char *str, bool errorOK, int64 *result)
/* process digits */
while (*ptr && isdigit((unsigned char) *ptr))
{
- int64 newtmp = tmp * 10 + (*ptr++ - '0');
-
- if ((newtmp / 10) != tmp) /* overflow? */
+ if (PG_INT64_MUL_OVERFLOWS(tmp, 10) ||
+ PG_INT64_ADD_OVERFLOWS(tmp * 10, *ptr - '0'))
{
if (errorOK)
return false;
else
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
- errmsg("value \"%s\" is out of range for type bigint",
- str)));
+ errmsg("value \"%s\" is out of range for type bigint",
+ str)));
}
- tmp = newtmp;
+
+ tmp = tmp * 10 + (*ptr++ - '0');
}
gotdigits:
@@ -490,15 +490,12 @@ Datum
int8um(PG_FUNCTION_ARGS)
{
int64 arg = PG_GETARG_INT64(0);
- int64 result;
- result = -arg;
- /* overflow check (needed for INT64_MIN) */
- if (arg != 0 && SAMESIGN(result, arg))
+ if (arg == PG_INT64_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
- PG_RETURN_INT64(result);
+ PG_RETURN_INT64(-arg);
}
Datum
@@ -516,17 +513,13 @@ int8pl(PG_FUNCTION_ARGS)
int64 arg2 = PG_GETARG_INT64(1);
int64 result;
- result = arg1 + arg2;
-
- /*
- * Overflow check. If the inputs are of different signs then their sum
- * cannot overflow. If the inputs are of the same sign, their sum had
- * better be that sign too.
- */
- if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_ADD_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
+
+ result = arg1 + arg2;
PG_RETURN_INT64(result);
}
@@ -537,17 +530,13 @@ int8mi(PG_FUNCTION_ARGS)
int64 arg2 = PG_GETARG_INT64(1);
int64 result;
- result = arg1 - arg2;
-
- /*
- * Overflow check. If the inputs are of the same sign then their
- * difference cannot overflow. If they are of different signs then the
- * result should be of the same sign as the first input.
- */
- if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_SUB_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
+
+ result = arg1 - arg2;
PG_RETURN_INT64(result);
}
@@ -560,18 +549,8 @@ int8mul(PG_FUNCTION_ARGS)
result = arg1 * arg2;
- /*
- * Overflow check. We basically check to see if result / arg2 gives arg1
- * again. There are two cases where this fails: arg2 = 0 (which cannot
- * overflow) and arg1 = INT64_MIN, arg2 = -1 (where the division itself
- * will overflow and thus incorrectly match).
- *
- * Since the division is likely much more expensive than the actual
- * multiplication, we'd like to skip it where possible. The best bang for
- * the buck seems to be to check whether both inputs are in the int32
- * range; if so, no overflow is possible.
- */
- if (arg1 != (int64) ((int32) arg1) || arg2 != (int64) ((int32) arg2))
+ /* Overflow check */
+ if (PG_INT64_MUL_OVERFLOWS(arg1, arg2))
{
if (arg2 != 0 &&
((arg2 == -1 && arg1 < 0 && result < 0) ||
@@ -607,12 +586,12 @@ int8div(PG_FUNCTION_ARGS)
*/
if (arg2 == -1)
{
- result = -arg1;
- /* overflow check (needed for INT64_MIN) */
- if (arg1 != 0 && SAMESIGN(result, arg1))
+ if (arg1 == PG_INT64_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
+
+ result = -arg1;
PG_RETURN_INT64(result);
}
@@ -632,12 +611,12 @@ int8abs(PG_FUNCTION_ARGS)
int64 arg1 = PG_GETARG_INT64(0);
int64 result;
- result = (arg1 < 0) ? -arg1 : arg1;
- /* overflow check (needed for INT64_MIN) */
- if (result < 0)
+ if (arg1 == PG_INT64_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
+
+ result = (arg1 < 0) ? -arg1 : arg1;
PG_RETURN_INT64(result);
}
@@ -687,15 +666,13 @@ int8inc(PG_FUNCTION_ARGS)
if (AggCheckCallContext(fcinfo, NULL))
{
int64 *arg = (int64 *) PG_GETARG_POINTER(0);
- int64 result;
+ int64 result = *arg;
- result = *arg + 1;
- /* Overflow check */
- if (result < 0 && *arg > 0)
+ if (PG_INT64_ADD_OVERFLOWS(result, 1))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
-
+ result += 1;
*arg = result;
PG_RETURN_POINTER(arg);
}
@@ -704,16 +681,12 @@ int8inc(PG_FUNCTION_ARGS)
{
/* Not called as an aggregate, so just do it the dumb way */
int64 arg = PG_GETARG_INT64(0);
- int64 result;
- result = arg + 1;
- /* Overflow check */
- if (result < 0 && arg > 0)
+ if (PG_INT64_ADD_OVERFLOWS(arg, 1))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
-
- PG_RETURN_INT64(result);
+ PG_RETURN_INT64(arg + 1);
}
}
@@ -823,12 +796,8 @@ int84pl(PG_FUNCTION_ARGS)
result = arg1 + arg2;
- /*
- * Overflow check. If the inputs are of different signs then their sum
- * cannot overflow. If the inputs are of the same sign, their sum had
- * better be that sign too.
- */
- if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_ADD_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -844,12 +813,8 @@ int84mi(PG_FUNCTION_ARGS)
result = arg1 - arg2;
- /*
- * Overflow check. If the inputs are of the same sign then their
- * difference cannot overflow. If they are of different signs then the
- * result should be of the same sign as the first input.
- */
- if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_SUB_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -865,18 +830,8 @@ int84mul(PG_FUNCTION_ARGS)
result = arg1 * arg2;
- /*
- * Overflow check. We basically check to see if result / arg1 gives arg2
- * again. There is one case where this fails: arg1 = 0 (which cannot
- * overflow).
- *
- * Since the division is likely much more expensive than the actual
- * multiplication, we'd like to skip it where possible. The best bang for
- * the buck seems to be to check whether both inputs are in the int32
- * range; if so, no overflow is possible.
- */
- if (arg1 != (int64) ((int32) arg1) &&
- result / arg1 != arg2)
+ /* overflow check */
+ if (PG_INT64_MUL_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -907,13 +862,11 @@ int84div(PG_FUNCTION_ARGS)
*/
if (arg2 == -1)
{
- result = -arg1;
- /* overflow check (needed for INT64_MIN) */
- if (arg1 != 0 && SAMESIGN(result, arg1))
+ if (arg1 == PG_INT64_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
- PG_RETURN_INT64(result);
+ PG_RETURN_INT64(-arg1);
}
/* No overflow is possible */
@@ -932,12 +885,8 @@ int48pl(PG_FUNCTION_ARGS)
result = arg1 + arg2;
- /*
- * Overflow check. If the inputs are of different signs then their sum
- * cannot overflow. If the inputs are of the same sign, their sum had
- * better be that sign too.
- */
- if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_ADD_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -953,12 +902,8 @@ int48mi(PG_FUNCTION_ARGS)
result = arg1 - arg2;
- /*
- * Overflow check. If the inputs are of the same sign then their
- * difference cannot overflow. If they are of different signs then the
- * result should be of the same sign as the first input.
- */
- if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_SUB_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -974,18 +919,8 @@ int48mul(PG_FUNCTION_ARGS)
result = arg1 * arg2;
- /*
- * Overflow check. We basically check to see if result / arg2 gives arg1
- * again. There is one case where this fails: arg2 = 0 (which cannot
- * overflow).
- *
- * Since the division is likely much more expensive than the actual
- * multiplication, we'd like to skip it where possible. The best bang for
- * the buck seems to be to check whether both inputs are in the int32
- * range; if so, no overflow is possible.
- */
- if (arg2 != (int64) ((int32) arg2) &&
- result / arg2 != arg1)
+ /* overflow check */
+ if (PG_INT64_MUL_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -1018,17 +953,13 @@ int82pl(PG_FUNCTION_ARGS)
int16 arg2 = PG_GETARG_INT16(1);
int64 result;
- result = arg1 + arg2;
-
- /*
- * Overflow check. If the inputs are of different signs then their sum
- * cannot overflow. If the inputs are of the same sign, their sum had
- * better be that sign too.
- */
- if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_ADD_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
+
+ result = arg1 + arg2;
PG_RETURN_INT64(result);
}
@@ -1039,17 +970,13 @@ int82mi(PG_FUNCTION_ARGS)
int16 arg2 = PG_GETARG_INT16(1);
int64 result;
- result = arg1 - arg2;
-
- /*
- * Overflow check. If the inputs are of the same sign then their
- * difference cannot overflow. If they are of different signs then the
- * result should be of the same sign as the first input.
- */
- if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_SUB_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
+
+ result = arg1 - arg2;
PG_RETURN_INT64(result);
}
@@ -1060,23 +987,13 @@ int82mul(PG_FUNCTION_ARGS)
int16 arg2 = PG_GETARG_INT16(1);
int64 result;
- result = arg1 * arg2;
-
- /*
- * Overflow check. We basically check to see if result / arg1 gives arg2
- * again. There is one case where this fails: arg1 = 0 (which cannot
- * overflow).
- *
- * Since the division is likely much more expensive than the actual
- * multiplication, we'd like to skip it where possible. The best bang for
- * the buck seems to be to check whether both inputs are in the int32
- * range; if so, no overflow is possible.
- */
- if (arg1 != (int64) ((int32) arg1) &&
- result / arg1 != arg2)
+ /* Overflow check */
+ if (PG_INT64_MUL_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
+
+ result = arg1 * arg2;
PG_RETURN_INT64(result);
}
@@ -1129,12 +1046,8 @@ int28pl(PG_FUNCTION_ARGS)
result = arg1 + arg2;
- /*
- * Overflow check. If the inputs are of different signs then their sum
- * cannot overflow. If the inputs are of the same sign, their sum had
- * better be that sign too.
- */
- if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ /* Overflow check */
+ if (PG_INT64_ADD_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -1155,7 +1068,7 @@ int28mi(PG_FUNCTION_ARGS)
* difference cannot overflow. If they are of different signs then the
* result should be of the same sign as the first input.
*/
- if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+ if (PG_INT64_SUB_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -1171,18 +1084,8 @@ int28mul(PG_FUNCTION_ARGS)
result = arg1 * arg2;
- /*
- * Overflow check. We basically check to see if result / arg2 gives arg1
- * again. There is one case where this fails: arg2 = 0 (which cannot
- * overflow).
- *
- * Since the division is likely much more expensive than the actual
- * multiplication, we'd like to skip it where possible. The best bang for
- * the buck seems to be to check whether both inputs are in the int32
- * range; if so, no overflow is possible.
- */
- if (arg2 != (int64) ((int32) arg2) &&
- result / arg2 != arg1)
+ /* Overflow check */
+ if (PG_INT64_MUL_OVERFLOWS(arg1, arg2))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 1667d80..df866b4 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -5197,8 +5197,7 @@ numericvar_to_int64(NumericVar *var, int64 *result)
int ndigits;
int weight;
int i;
- int64 val,
- oldval;
+ int64 val;
bool neg;
NumericVar rounded;
@@ -5224,37 +5223,34 @@ numericvar_to_int64(NumericVar *var, int64 *result)
weight = rounded.weight;
Assert(weight >= 0 && ndigits <= weight + 1);
- /* Construct the result */
+ /*
+ * Construct the result by accumulating the absolute value in "val" as
+ * a negative value to avoid overflow with PG_INT64_MIN.
+ */
digits = rounded.digits;
neg = (rounded.sign == NUMERIC_NEG);
- val = digits[0];
+ val = -digits[0];
for (i = 1; i <= weight; i++)
{
- oldval = val;
- val *= NBASE;
- if (i < ndigits)
- val += digits[i];
-
- /*
- * The overflow check is a bit tricky because we want to accept
- * INT64_MIN, which will overflow the positive accumulator. We can
- * detect this case easily though because INT64_MIN is the only
- * nonzero value for which -val == val (on a two's complement machine,
- * anyway).
- */
- if ((val / NBASE) != oldval) /* possible overflow? */
- {
- if (!neg || (-val) != val || val == 0 || oldval < 0)
+ NumericDigit digit = (i < ndigits) ? digits[i] : 0;
+ if (PG_INT64_MUL_OVERFLOWS(val, NBASE) ||
+ PG_INT64_SUB_OVERFLOWS(val * NBASE, digit))
{
free_var(&rounded);
return false;
}
- }
+ val = val * NBASE - digit;
}
free_var(&rounded);
- *result = neg ? -val : val;
+ if (!neg && val == PG_INT64_MIN)
+ /* overflows signed int64 */
+ return false;
+ else if (!neg)
+ *result = -val;
+ else
+ *result = val;
return true;
}
diff --git a/src/backend/utils/adt/oracle_compat.c b/src/backend/utils/adt/oracle_compat.c
index 8e896eb..afdbd44 100644
--- a/src/backend/utils/adt/oracle_compat.c
+++ b/src/backend/utils/adt/oracle_compat.c
@@ -175,14 +175,14 @@ lpad(PG_FUNCTION_ARGS)
if (s2len <= 0)
len = s1len; /* nothing to pad with, so don't pad */
- bytelen = pg_database_encoding_max_length() * len;
-
/* check for integer overflow */
- if (len != 0 && bytelen / pg_database_encoding_max_length() != len)
+ if (len > PG_INT32_MAX / pg_database_encoding_max_length() - VARHDRSZ)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("requested length too large")));
+ bytelen = pg_database_encoding_max_length() * len;
+
ret = (text *) palloc(VARHDRSZ + bytelen);
m = len - s1len;
@@ -1041,24 +1041,25 @@ repeat(PG_FUNCTION_ARGS)
char *cp,
*sp;
+ slen = VARSIZE_ANY_EXHDR(string);
+
if (count < 0)
count = 0;
- slen = VARSIZE_ANY_EXHDR(string);
- tlen = VARHDRSZ + (count * slen);
-
- /* Check for integer overflow */
- if (slen != 0 && count != 0)
+ else if (slen != 0 &&
+ count > (PG_INT32_MAX - VARHDRSZ) / slen)
{
- int check = count * slen;
- int check2 = check + VARHDRSZ;
-
- if ((check / slen) != count || check2 <= check)
- ereport(ERROR,
- (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
- errmsg("requested length too large")));
+ /*
+ * The palloc will actually fail at a lower value but we must protect
+ * against signed integer overflow separately
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("requested length too large")));
}
+ tlen = VARHDRSZ + (count * slen);
+
result = (text *) palloc(tlen);
SET_VARSIZE(result, tlen);
diff --git a/src/backend/utils/adt/varbit.c b/src/backend/utils/adt/varbit.c
index 77b05c8..2583ab4 100644
--- a/src/backend/utils/adt/varbit.c
+++ b/src/backend/utils/adt/varbit.c
@@ -1054,16 +1054,12 @@ bitsubstring(VarBit *arg, int32 s, int32 l, bool length_not_specified)
}
else
{
- e = s + l;
-
- /*
- * A negative value for L is the only way for the end position to be
- * before the start. SQL99 says to throw an error.
- */
- if (e < s)
+ /* SQL99 says to throw an error. */
+ if (l < 0)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
+ e = s + l;
e1 = Min(e, bitlen + 1);
}
if (s1 > bitlen || e1 <= s1)
@@ -1166,12 +1162,14 @@ bit_overlay(VarBit *t1, VarBit *t2, int sp, int sl)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
- sp_pl_sl = sp + sl;
- if (sp_pl_sl <= sl)
+
+ if (PG_INT32_ADD_OVERFLOWS(sp, sl))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
+ sp_pl_sl = sp + sl;
+
s1 = bitsubstring(t1, 1, sp - 1, false);
s2 = bitsubstring(t1, sp_pl_sl, -1, true);
result = bit_catenate(s1, t2);
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index d545c34..7d8bf99 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -818,32 +818,36 @@ text_substring(Datum str, int32 start, int32 length, bool length_not_specified)
{
S1 = Max(S, 1);
- if (length_not_specified) /* special case - get length to end of
- * string */
+ /* special case - get length to end of string */
+ if (length_not_specified)
L1 = -1;
+ else if (length < 0)
+ {
+ /* SQL99 says to throw an error. */
+ ereport(ERROR,
+ (errcode(ERRCODE_SUBSTRING_ERROR),
+ errmsg("negative substring length not allowed")));
+ }
+ else if (PG_INT32_MAX - length < start)
+ {
+ /*
+ * overflow (but the string can't be that large so just get length
+ * to end of string) */
+ L1 = -1;
+ }
else
{
- /* end position */
- int E = S + length;
-
/*
- * A negative value for L is the only way for the end position to
- * be before the start. SQL99 says to throw an error.
+ * Calculate length adjusted to actual start of string (input
+ * start could have been negative) and note that according to
+ * SQL99 we should return an empty string if the entire string is
+ * left of 1.
*/
- if (E < S)
- ereport(ERROR,
- (errcode(ERRCODE_SUBSTRING_ERROR),
- errmsg("negative substring length not allowed")));
- /*
- * A zero or negative value for the end position can happen if the
- * start was negative or one. SQL99 says to return a zero-length
- * string.
- */
- if (E < 1)
- return cstring_to_text("");
+ L1 = S + length - S1;
- L1 = E - S1;
+ if (L1 <= 0)
+ return cstring_to_text("");
}
/*
@@ -883,21 +887,29 @@ text_substring(Datum str, int32 start, int32 length, bool length_not_specified)
*/
slice_start = 0;
- if (length_not_specified) /* special case - get length to end of
- * string */
+ if (length_not_specified)
+ {
+ /* special case - get length to end of string */
slice_size = L1 = -1;
- else
+ }
+ else if (length < 0)
+ {
+ /* SQL99 says to throw an error. */
+ ereport(ERROR,
+ (errcode(ERRCODE_SUBSTRING_ERROR),
+ errmsg("negative substring length not allowed")));
+ }
+ else if (PG_INT32_MAX - length < start)
{
- int E = S + length;
-
/*
- * A negative value for L is the only way for the end position to
- * be before the start. SQL99 says to throw an error.
+ * Overflow but the string can't be that large so just get length
+ * to end of string.
*/
- if (E < S)
- ereport(ERROR,
- (errcode(ERRCODE_SUBSTRING_ERROR),
- errmsg("negative substring length not allowed")));
+ slice_size = L1 = -1;
+ }
+ else
+ {
+ int E = S + length;
/*
* A zero or negative value for the end position can happen if the
@@ -1042,12 +1054,14 @@ text_overlay(text *t1, text *t2, int sp, int sl)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
- sp_pl_sl = sp + sl;
- if (sp_pl_sl <= sl)
+
+ if (PG_INT32_MAX - sp < sl)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
+ sp_pl_sl = sp + sl;
+
s1 = text_substring(PointerGetDatum(t1), 1, sp - 1, false);
s2 = text_substring(PointerGetDatum(t1), sp_pl_sl, -1, true);
result = text_catenate(s1, t2);
@@ -2573,21 +2587,27 @@ bytea_substring(Datum str,
*/
L1 = -1;
}
+ else if (L < 0)
+ {
+ /* SQL99 says to throw an error. */
+ ereport(ERROR,
+ (errcode(ERRCODE_SUBSTRING_ERROR),
+ errmsg("negative substring length not allowed")));
+ }
+ else if (PG_INT32_MAX - L < S)
+ {
+ /*
+ * Overflow, but the string can't be so large so just fetch to end of
+ * the string.
+ */
+ L1 = -1;
+ }
else
{
/* end position */
int E = S + L;
/*
- * A negative value for L is the only way for the end position to be
- * before the start. SQL99 says to throw an error.
- */
- if (E < S)
- ereport(ERROR,
- (errcode(ERRCODE_SUBSTRING_ERROR),
- errmsg("negative substring length not allowed")));
-
- /*
* A zero or negative value for the end position can happen if the
* start was negative or one. SQL99 says to return a zero-length
* string.
@@ -2653,12 +2673,14 @@ bytea_overlay(bytea *t1, bytea *t2, int sp, int sl)
ereport(ERROR,
(errcode(ERRCODE_SUBSTRING_ERROR),
errmsg("negative substring length not allowed")));
- sp_pl_sl = sp + sl;
- if (sp_pl_sl <= sl)
+
+ if (PG_INT32_MAX - sp < sl)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
+ sp_pl_sl = sp + sl;
+
s1 = bytea_substring(PointerGetDatum(t1), 1, sp - 1, false);
s2 = bytea_substring(PointerGetDatum(t1), sp_pl_sl, -1, true);
result = bytea_catenate(s1, t2);
diff --git a/src/include/c.h b/src/include/c.h
index 8163b00..bb01121 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -793,6 +793,68 @@ typedef NameData *Name;
#define Abs(x) ((x) >= 0 ? (x) : -(x))
/*
+ * Detect overflow for signed INT32 and INT64
+ *
+ * Note that this has to be done before doing the suspect arithmetic rather
+ * than afterwards by examining the signs because signed overflow is not well
+ * defined and compilers take liberties to optimize away the checks.
+ *
+ * Also note that SUB_OVERFLOWS is not just the same as doing ADD_OVERFLOWS
+ * with -b because if b = INT_MIN then that would itself cause an overflow...
+ */
+
+#define PG_INT32_ADD_OVERFLOWS(a,b) ( \
+ ((a)>0 && (b)>0 && (a) > PG_INT32_MAX - (b)) || \
+ ((a)<0 && (b)<0 && (a) < PG_INT32_MIN - (b)))
+
+#define PG_INT32_SUB_OVERFLOWS(a,b) ( \
+ ((a)<0 && (b)>0 && (a) < PG_INT32_MIN + (b)) || \
+ ((a)>0 && (b)<0 && (a) > PG_INT32_MAX + (b)))
+
+#define PG_INT64_ADD_OVERFLOWS(a,b) ( \
+ ((a)>0 && (b)>0 && (a) > PG_INT64_MAX - (b)) || \
+ ((a)<0 && (b)<0 && (a) < PG_INT64_MIN - (b)))
+
+#define PG_INT64_SUB_OVERFLOWS(a,b) ( \
+ ((a)<0 && (b)>0 && (a) < PG_INT64_MIN + (b)) || \
+ ((a)>0 && (b)<0 && (a) > PG_INT64_MAX + (b)))
+
+/*
+ * Overflow can only happen if at least one value is outside the range
+ * sqrt(min)..sqrt(max) so check that first as the division can be quite a bit
+ * more expensive than the multiplication.
+ *
+ * Multiplying by 0 or 1 can't overflow of course and checking for 0
+ * separately avoids any risk of dividing by 0. Be careful about dividing
+ * PG_INT32_MIN by -1 also, note reversing the a and b to ensure we're always
+ * dividing it by a positive value.
+ */
+
+#define PG_INT32_MUL_OVERFLOWS(a,b) ( \
+ ((a) > SHRT_MAX || (a) < SHRT_MIN || \
+ (b) > SHRT_MAX || (b) < SHRT_MIN) && \
+ (a) != 0 && (a) != 1 && (b) != 0 && (b) != 1 && \
+ ( \
+ ((a) > 0 && (b) > 0 && (a) > PG_INT32_MAX / (b)) || \
+ ((a) > 0 && (b) < 0 && (b) < PG_INT32_MIN / (a)) || \
+ ((a) < 0 && (b) > 0 && (a) < PG_INT32_MIN / (b)) || \
+ ((a) < 0 && (b) < 0 && (a) < PG_INT32_MAX / (b)) \
+ ) \
+ )
+
+#define PG_INT64_MUL_OVERFLOWS(a,b) ( \
+ ((a) > PG_INT32_MAX || (a) < PG_INT32_MIN || \
+ (b) > PG_INT32_MAX || (b) < PG_INT32_MIN) && \
+ (a) != 0 && (a) != 1 && (b) != 0 && (b) != 1 && \
+ ( \
+ ((a) > 0 && (b) > 0 && (a) > PG_INT64_MAX / (b)) || \
+ ((a) > 0 && (b) < 0 && (b) < PG_INT64_MIN / (a)) || \
+ ((a) < 0 && (b) > 0 && (a) < PG_INT64_MIN / (b)) || \
+ ((a) < 0 && (b) < 0 && (a) < PG_INT64_MAX / (b)) \
+ ) \
+ )
+
+/*
* StrNCpy
* Like standard library function strncpy(), except that result string
* is guaranteed to be null-terminated --- that is, at most N-1 bytes
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index c73f20b..77ad1a4 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -2068,13 +2068,13 @@ exec_stmt_fori(PLpgSQL_execstate *estate, PLpgSQL_stmt_fori *stmt)
*/
if (stmt->reverse)
{
- if ((int32) (loop_value - step_value) > loop_value)
+ if (PG_INT32_SUB_OVERFLOWS(loop_value, step_value))
break;
loop_value -= step_value;
}
else
{
- if ((int32) (loop_value + step_value) < loop_value)
+ if (PG_INT32_ADD_OVERFLOWS(loop_value, step_value))
break;
loop_value += step_value;
}
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