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 f81934af5e2d3564220ed071ba1555d69ca6c3c5..dd08dfcc222906955c8ac000f4a42ce772db0105 100644 (file)
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -1157,15 +1157,8 @@ 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")));
@@ -1189,15 +1182,8 @@ 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")));
@@ -1245,15 +1231,8 @@ 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")));
@@ -1277,15 +1256,8 @@ 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 40a029cc18bd2a6524add76c53db0b2ceffd6eb0..cfb094a4888092af49297a072780f61ec119b0cd 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 089657371bbf4c174c44f90a1f235067daafb542..972f481e59afbce6945e4c5fed617f8949c4e796 100644 (file)
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3410,7 +3410,7 @@ 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/include/c.h b/src/include/c.h
index 86e4b549754649fca1a17cc6641cc25abd22ffb6..32a804a7e8186a85678fa2a5cd352934070a2be5 100644 (file)
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -954,6 +954,30 @@ 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