Fix integer-overflow edge case detection in interval_mul and pgbench.
authorTom Lane <[email protected]>
Thu, 7 Nov 2019 16:22:52 +0000 (11:22 -0500)
committerTom Lane <[email protected]>
Thu, 7 Nov 2019 16:22:58 +0000 (11:22 -0500)
This patch adopts the overflow check logic introduced by commit cbdb8b4c0
into two more places.  interval_mul() failed to notice if it computed a
new microseconds value that was one more than INT64_MAX, and pgbench's
double-to-int64 logic had the same sorts of edge-case problems that
cbdb8b4c0 fixed in the core code.

To make this easier to get right in future, put the guts of the checks
into new macros in c.h, and add commentary about how to use the macros
correctly.

Back-patch to all supported branches, as we did with the previous fix.

Yuya Watari

Discussion: https://postgr.es/m/CAJ2pMkbkkFw2hb9Qb1Zj8d06EhWAQXFLy73St4qWv6aX=vqnjw@mail.gmail.com

src/backend/utils/adt/float.c
src/backend/utils/adt/int8.c
src/backend/utils/adt/timestamp.c
src/bin/pgbench/pgbench.c
src/include/c.h
src/test/regress/expected/interval.out
src/test/regress/sql/interval.sql

index 77a5d7d42f82c4a0f68fd0f962beb645d9917e46..47c786f1267eea35d6b20daa6e90cdcbac8a0c8e 100644 (file)
@@ -1212,15 +1212,8 @@ dtoi4(PG_FUNCTION_ARGS)
         */
        num = rint(num);
 
-       /*
-        * Range check.  We must be careful here that the boundary values are
-        * expressed exactly in the float domain.  We expect PG_INT32_MIN to be an
-        * exact power of 2, so it will be represented exactly; but PG_INT32_MAX
-        * isn't, and might get rounded off, so avoid using it.
-        */
-       if (unlikely(num < (float8) PG_INT32_MIN ||
-                                num >= -((float8) PG_INT32_MIN) ||
-                                isnan(num)))
+       /* Range check */
+       if (unlikely(isnan(num) || !FLOAT8_FITS_IN_INT32(num)))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("integer out of range")));
@@ -1244,15 +1237,8 @@ dtoi2(PG_FUNCTION_ARGS)
         */
        num = rint(num);
 
-       /*
-        * Range check.  We must be careful here that the boundary values are
-        * expressed exactly in the float domain.  We expect PG_INT16_MIN to be an
-        * exact power of 2, so it will be represented exactly; but PG_INT16_MAX
-        * isn't, and might get rounded off, so avoid using it.
-        */
-       if (unlikely(num < (float8) PG_INT16_MIN ||
-                                num >= -((float8) PG_INT16_MIN) ||
-                                isnan(num)))
+       /* Range check */
+       if (unlikely(isnan(num) || !FLOAT8_FITS_IN_INT16(num)))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("smallint out of range")));
@@ -1300,15 +1286,8 @@ ftoi4(PG_FUNCTION_ARGS)
         */
        num = rint(num);
 
-       /*
-        * Range check.  We must be careful here that the boundary values are
-        * expressed exactly in the float domain.  We expect PG_INT32_MIN to be an
-        * exact power of 2, so it will be represented exactly; but PG_INT32_MAX
-        * isn't, and might get rounded off, so avoid using it.
-        */
-       if (unlikely(num < (float4) PG_INT32_MIN ||
-                                num >= -((float4) PG_INT32_MIN) ||
-                                isnan(num)))
+       /* Range check */
+       if (unlikely(isnan(num) || !FLOAT4_FITS_IN_INT32(num)))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("integer out of range")));
@@ -1332,15 +1311,8 @@ ftoi2(PG_FUNCTION_ARGS)
         */
        num = rint(num);
 
-       /*
-        * Range check.  We must be careful here that the boundary values are
-        * expressed exactly in the float domain.  We expect PG_INT16_MIN to be an
-        * exact power of 2, so it will be represented exactly; but PG_INT16_MAX
-        * isn't, and might get rounded off, so avoid using it.
-        */
-       if (unlikely(num < (float4) PG_INT16_MIN ||
-                                num >= -((float4) PG_INT16_MIN) ||
-                                isnan(num)))
+       /* Range check */
+       if (unlikely(isnan(num) || !FLOAT4_FITS_IN_INT16(num)))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("smallint out of range")));
index 0ff9394a2fb037ff6ac532dbcd149896e04f414b..93acabce42ca7e8b98d3cd2b4f69f703bd7253e7 100644 (file)
@@ -1216,15 +1216,8 @@ dtoi8(PG_FUNCTION_ARGS)
         */
        num = rint(num);
 
-       /*
-        * Range check.  We must be careful here that the boundary values are
-        * expressed exactly in the float domain.  We expect PG_INT64_MIN to be an
-        * exact power of 2, so it will be represented exactly; but PG_INT64_MAX
-        * isn't, and might get rounded off, so avoid using it.
-        */
-       if (unlikely(num < (float8) PG_INT64_MIN ||
-                                num >= -((float8) PG_INT64_MIN) ||
-                                isnan(num)))
+       /* Range check */
+       if (unlikely(isnan(num) || !FLOAT8_FITS_IN_INT64(num)))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("bigint out of range")));
@@ -1258,15 +1251,8 @@ ftoi8(PG_FUNCTION_ARGS)
         */
        num = rint(num);
 
-       /*
-        * Range check.  We must be careful here that the boundary values are
-        * expressed exactly in the float domain.  We expect PG_INT64_MIN to be an
-        * exact power of 2, so it will be represented exactly; but PG_INT64_MAX
-        * isn't, and might get rounded off, so avoid using it.
-        */
-       if (unlikely(num < (float4) PG_INT64_MIN ||
-                                num >= -((float4) PG_INT64_MIN) ||
-                                isnan(num)))
+       /* Range check */
+       if (unlikely(isnan(num) || !FLOAT4_FITS_IN_INT64(num)))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("bigint out of range")));
index 1dc4c820de25f7add521bdd0c9ca57fee276f632..31bdb37c55985936afb420aa7351d49266045da7 100644 (file)
@@ -3233,7 +3233,7 @@ interval_mul(PG_FUNCTION_ARGS)
        /* cascade units down */
        result->day += (int32) month_remainder_days;
        result_double = rint(span->time * factor + sec_remainder * USECS_PER_SEC);
-       if (result_double > PG_INT64_MAX || result_double < PG_INT64_MIN)
+       if (isnan(result_double) || !FLOAT8_FITS_IN_INT64(result_double))
                ereport(ERROR,
                                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                                 errmsg("interval out of range")));
index 14dbc4510ce9a4dced14954e5ed78b0a82dc4195..4a7ac1f82137580ae5953fe5384c65a1d559aef9 100644 (file)
@@ -1675,9 +1675,9 @@ coerceToInt(PgBenchValue *pval, int64 *ival)
        }
        else if (pval->type == PGBT_DOUBLE)
        {
-               double          dval = pval->u.dval;
+               double          dval = rint(pval->u.dval);
 
-               if (dval < PG_INT64_MIN || PG_INT64_MAX < dval)
+               if (isnan(dval) || !FLOAT8_FITS_IN_INT64(dval))
                {
                        fprintf(stderr, "double to int overflow for %f\n", dval);
                        return false;
index 16b428daa143052c01780c1e55a373efc1234cdd..c95acd35f7fec8a2eea082a8cb605ecba75044a9 100644 (file)
@@ -1030,6 +1030,30 @@ extern void ExceptionalCondition(const char *conditionName,
                        *_start++ = 0; \
        } while (0)
 
+/*
+ * Macros for range-checking float values before converting to integer.
+ * We must be careful here that the boundary values are expressed exactly
+ * in the float domain.  PG_INTnn_MIN is an exact power of 2, so it will
+ * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded
+ * off, so avoid using that.
+ * The input must be rounded to an integer beforehand, typically with rint(),
+ * else we might draw the wrong conclusion about close-to-the-limit values.
+ * These macros will do the right thing for Inf, but not necessarily for NaN,
+ * so check isnan(num) first if that's a possibility.
+ */
+#define FLOAT4_FITS_IN_INT16(num) \
+       ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN))
+#define FLOAT4_FITS_IN_INT32(num) \
+       ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN))
+#define FLOAT4_FITS_IN_INT64(num) \
+       ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN))
+#define FLOAT8_FITS_IN_INT16(num) \
+       ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN))
+#define FLOAT8_FITS_IN_INT32(num) \
+       ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN))
+#define FLOAT8_FITS_IN_INT64(num) \
+       ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN))
+
 
 /* ----------------------------------------------------------------
  *                             Section 8:      random stuff
index f88f34550ad56b44d37785a772e329a87c0eedb9..f772909e49ce949829fd15c80347c871f65cbc73 100644 (file)
@@ -232,6 +232,9 @@ INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483648 years');
 ERROR:  interval out of range
 LINE 1: INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483648 years'...
                                                  ^
+-- Test edge-case overflow detection in interval multiplication
+select extract(epoch from '256 microseconds'::interval * (2^55)::float8);
+ERROR:  interval out of range
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL_OF r1, INTERVAL_TBL_OF r2
    WHERE r1.f1 > r2.f1
index bc5537d1b9c008dc9b63e732b6b31b338880f8af..eb1e84f053e05ddc6d4448ec59a41911a1a8ed1e 100644 (file)
@@ -73,6 +73,9 @@ INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483647 years');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483648 years');
 
+-- Test edge-case overflow detection in interval multiplication
+select extract(epoch from '256 microseconds'::interval * (2^55)::float8);
+
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL_OF r1, INTERVAL_TBL_OF r2
    WHERE r1.f1 > r2.f1