tests: Check lseek, read and malloc results with correct types in test.

When compiling dwfl-report-offline-memory.c on some systems (latest
gcc/glibc and --enable-sanitize-undefined) we might get:

In file included from /usr/include/features.h:490,
                 from /usr/include/assert.h:35,
                 from dwfl-report-offline-memory.c:18:
In function ‘read’,
    inlined from ‘main’ at dwfl-report-offline-memory.c:68:23:
/usr/include/bits/unistd.h:38:10: error: ‘__read_alias’ specified size 18446744073709551615
  exceeds maximum object size 9223372036854775807 [-Werror=stringop-overflow=]
   38 |   return __glibc_fortify (read, __nbytes, sizeof (char),
      |          ^~~~~~~~~~~~~~~
/usr/include/bits/unistd.h: In function ‘main’:
/usr/include/bits/unistd.h:26:16: note: in a call to function ‘__read_alias’ declared with
  attribute ‘access (write_only, 2, 3)’
   26 | extern ssize_t __REDIRECT (__read_alias, (int __fd, void *__buf,
      |                ^~~~~~~~~~
cc1: all warnings being treated as errors
make[2]: *** [Makefile:2461: dwfl-report-offline-memory.o] Error 1

Fix by using the correct types and checking all return values.

Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/tests/ChangeLog b/tests/ChangeLog
index 6ac2c1e..d07a910 100644 (file)
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,8 @@
+2022-10-16  Mark Wielaard  <mark@klomp.org>
+
+       * dwfl-report-offline-memory.c (main): Check lseek, read and malloc
+       results with correct types.
+
 2022-09-13  Aleksei Vetrov  <vvvvvv@google.com>
 
        * Makefile.am (check_PROGRAMS): Add dwfl-report-offline-memory.

diff --git a/tests/dwfl-report-offline-memory.c b/tests/dwfl-report-offline-memory.c
index 837aca5..81fa136 100644 (file)
--- a/tests/dwfl-report-offline-memory.c
+++ b/tests/dwfl-report-offline-memory.c
@@ -62,10 +62,14 @@ main (int argc, char **argv)
   int fd = open (fname, O_RDONLY);
   if (fd < 0)
     error (-1, 0, "can't open file %s: %s", fname, strerror (errno));
-  size_t size = lseek (fd, 0, SEEK_END);
+  off_t size = lseek (fd, 0, SEEK_END);
+  if (size < 0)
+    error (-1, 0, "can't lseek file %s: %s", fname, strerror (errno));
   lseek (fd, 0, SEEK_SET);
   char *data = malloc (size);
-  size_t bytes_read = read (fd, data, size);
+  if (data == NULL)
+    error (-1, 0, "can't malloc: %s", strerror (errno));
+  ssize_t bytes_read = read (fd, data, size);
   assert (bytes_read == size);
   close (fd);