Comment 16 for bug 1783362

From: Alex Bennée <email address hidden>

This adds a test to make sure we fail properly for a 0 length mmap.
There are most likely other failure conditions we should also check.

Signed-off-by: Alex Bennée <email address hidden>
Reviewed-by: Richard Henderson <email address hidden>
Cc: umarcor <email address hidden>
Message-Id: <email address hidden>
Signed-off-by: Laurent Vivier <email address hidden>
---
 tests/tcg/multiarch/test-mmap.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/tests/tcg/multiarch/test-mmap.c b/tests/tcg/multiarch/test-mmap.c
index 5c0afe6e49..11d0e777b1 100644
--- a/tests/tcg/multiarch/test-mmap.c
+++ b/tests/tcg/multiarch/test-mmap.c
@@ -27,7 +27,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <unistd.h>
-
+#include <errno.h>
 #include <sys/mman.h>

 #define D(x)
@@ -435,6 +435,25 @@ void checked_write(int fd, const void *buf, size_t count)
     fail_unless(rc == count);
 }

+void check_invalid_mmaps(void)
+{
+ unsigned char *addr;
+
+ /* Attempt to map a zero length page. */
+ addr = mmap(NULL, 0, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ fprintf(stdout, "%s addr=%p", __func__, (void *)addr);
+ fail_unless(addr == MAP_FAILED);
+ fail_unless(errno == EINVAL);
+
+ /* Attempt to map a over length page. */
+ addr = mmap(NULL, -4, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ fprintf(stdout, "%s addr=%p", __func__, (void *)addr);
+ fail_unless(addr == MAP_FAILED);
+ fail_unless(errno == ENOMEM);
+
+ fprintf(stdout, " passed\n");
+}
+
 int main(int argc, char **argv)
 {
  char tempname[] = "/tmp/.cmmapXXXXXX";
@@ -476,6 +495,7 @@ int main(int argc, char **argv)
  check_file_fixed_mmaps();
  check_file_fixed_eof_mmaps();
  check_file_unfixed_eof_mmaps();
+ check_invalid_mmaps();

  /* Fails at the moment. */
  /* check_aligned_anonymous_fixed_mmaps_collide_with_host(); */
--
2.17.1