preadv2/pwritev2: Handle offset == -1 [BZ #22753]

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

3 files changed, 40 insertions, 0 deletions

diff --git a/misc/tst-preadvwritev-common.c b/misc/tst-preadvwritev-common.c
index 560c8f8..b59a3de 100644
--- a/misc/tst-preadvwritev-common.c
+++ b/misc/tst-preadvwritev-common.c
@@ -16,6 +16,7 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <array_length.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <errno.h>
@@ -25,6 +26,7 @@
 
 #include <support/check.h>
 #include <support/temp_file.h>
+#include <support/xunistd.h>
 
 static char *temp_filename;
 static int temp_fd;
@@ -50,6 +52,42 @@ do_prepare (int argc, char **argv)
   pwritev (__fd, __iov, __iovcnt, __offset)
 #endif
 
+static __attribute__ ((unused)) void
+do_test_without_offset (void)
+{
+  xftruncate (temp_fd, 0);
+
+  xwrite (temp_fd, "123", 3);
+  xlseek (temp_fd, 2, SEEK_SET);
+  {
+    struct iovec iov[] =
+      {
+        { (void *) "abc", 3 },
+        { (void *) "xyzt", 4 },
+      };
+    TEST_COMPARE (PWRITEV (temp_fd, iov, array_length (iov), -1), 7);
+  }
+  TEST_COMPARE (xlseek (temp_fd, 0, SEEK_CUR), 9);
+
+  xlseek (temp_fd, 1, SEEK_SET);
+  char buf1[3];
+  char buf2[2];
+  {
+    struct iovec iov[] =
+      {
+        { buf1, sizeof (buf1) },
+        { buf2, sizeof (buf2) },
+      };
+    TEST_COMPARE (PREADV (temp_fd, iov, array_length (iov), -1),
+                  sizeof (buf1) + sizeof (buf2));
+    TEST_COMPARE (memcmp ("2ab", buf1, sizeof (buf1)), 0);
+    TEST_COMPARE (memcmp ("cx", buf2, sizeof (buf2)), 0);
+    TEST_COMPARE (xlseek (temp_fd, 0, SEEK_CUR), 6);
+  }
+
+  xftruncate (temp_fd, 0);
+}
+
 static int
 do_test_with_offset (off_t offset)
 {
diff --git a/misc/tst-preadvwritev2.c b/misc/tst-preadvwritev2.c
index d8a9daf..be22802 100644
--- a/misc/tst-preadvwritev2.c
+++ b/misc/tst-preadvwritev2.c
@@ -29,6 +29,7 @@ static int
 do_test (void)
 {
   do_test_with_invalid_flags ();
+  do_test_without_offset ();
 
   return do_test_with_offset (0);
 }
diff --git a/misc/tst-preadvwritev64v2.c b/misc/tst-preadvwritev64v2.c
index 2c656ae..8d3cc32 100644
--- a/misc/tst-preadvwritev64v2.c
+++ b/misc/tst-preadvwritev64v2.c
@@ -31,6 +31,7 @@ static int
 do_test (void)
 {
   do_test_with_invalid_flags ();
+  do_test_without_offset ();
 
   return do_test_with_offset (0);
 }