Fix integer-overflow edge case detection in interval_mul and pgbench.

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

diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 79573f14d589f4f2b746a4c3f6b8f344b9aa7536..8b81d123bf7826f5db70400c8a3f29c7f59e2fc0 100644 (file)
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -1227,15 +1227,8 @@ 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 (num < (float8) PG_INT32_MIN ||
-               num >= -((float8) PG_INT32_MIN) ||
-               isnan(num))
+       /* Range check */
+       if (isnan(num) || !FLOAT8_FITS_IN_INT32(num))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("integer out of range")));
@@ -1259,15 +1252,8 @@ 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 (num < (float8) PG_INT16_MIN ||
-               num >= -((float8) PG_INT16_MIN) ||
-               isnan(num))
+       /* Range check */
+       if (isnan(num) || !FLOAT8_FITS_IN_INT16(num))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("smallint out of range")));
@@ -1315,15 +1301,8 @@ 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 (num < (float4) PG_INT32_MIN ||
-               num >= -((float4) PG_INT32_MIN) ||
-               isnan(num))
+       /* Range check */
+       if (isnan(num) || !FLOAT4_FITS_IN_INT32(num))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("integer out of range")));
@@ -1347,15 +1326,8 @@ 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 (num < (float4) PG_INT16_MIN ||
-               num >= -((float4) PG_INT16_MIN) ||
-               isnan(num))
+       /* Range check */
+       if (isnan(num) || !FLOAT4_FITS_IN_INT16(num))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("smallint out of range")));

diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c
index 62f54c12d503380556907c18351f73efdfaa42a3..c04d3abcef880a0707a477e6e84f396a654de7b2 100644 (file)
--- a/src/backend/utils/adt/int8.c
+++ b/src/backend/utils/adt/int8.c
@@ -1351,15 +1351,8 @@ 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 (num < (float8) PG_INT64_MIN ||
-               num >= -((float8) PG_INT64_MIN) ||
-               isnan(num))
+       /* Range check */
+       if (isnan(num) || !FLOAT8_FITS_IN_INT64(num))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("bigint out of range")));
@@ -1393,15 +1386,8 @@ 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 (num < (float4) PG_INT64_MIN ||
-               num >= -((float4) PG_INT64_MIN) ||
-               isnan(num))
+       /* Range check */
+       if (isnan(num) || !FLOAT4_FITS_IN_INT64(num))
                ereport(ERROR,
                                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                 errmsg("bigint out of range")));

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index f211bd05e0ab14dbfa7bb759b818cfe6ab121d57..5c0fdb7d3b77da673e2e45486fb8450727431519 100644 (file)
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3504,7 +3504,7 @@ interval_mul(PG_FUNCTION_ARGS)
        result->day += (int32) month_remainder_days;
 #ifdef HAVE_INT64_TIMESTAMP
        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")));

diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 43841e8eb4b70983f23092f70916055361e7e684..2ccab93fbe8298a1fa89b329c05de3c42fbb4236 100644 (file)
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -1160,10 +1160,11 @@ coerceToInt(PgBenchValue *pval, int64 *ival)
        }
        else
        {
-               double          dval = pval->u.dval;
+               double          dval;
 
                Assert(pval->type == PGBT_DOUBLE);
-               if (dval < PG_INT64_MIN || PG_INT64_MAX < dval)
+               dval = rint(pval->u.dval);
+               if (isnan(dval) || !FLOAT8_FITS_IN_INT64(dval))
                {
                        fprintf(stderr, "double to int overflow for %f\n", dval);
                        return false;

diff --git a/src/include/c.h b/src/include/c.h
index 3199be3054e624dc5325dfed8f5928f72a3f525c..bbd28701347c58326eabb032434ea4830188c0aa 100644 (file)
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -943,6 +943,30 @@ typedef NameData *Name;
                        *_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

diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index f88f34550ad56b44d37785a772e329a87c0eedb9..f772909e49ce949829fd15c80347c871f65cbc73 100644 (file)
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -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

diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index bc5537d1b9c008dc9b63e732b6b31b338880f8af..eb1e84f053e05ddc6d4448ec59a41911a1a8ed1e 100644 (file)
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -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