On 7/10/23 13:15, Thomas Huth wrote:
From: Ilya Leoshkevich <i...@linux.ibm.com>
Add a small test to prevent regressions.
Signed-off-by: Ilya Leoshkevich <i...@linux.ibm.com>
Reviewed-by: David Hildenbrand <da...@redhat.com>
Message-Id: <20230704081506.276055-13-...@linux.ibm.com>
Signed-off-by: Thomas Huth <th...@redhat.com>
---
tests/tcg/s390x/mie3-mvcrl.c | 46 ++++++++++++++++++++++++++++--------
1 file changed, 36 insertions(+), 10 deletions(-)
diff --git a/tests/tcg/s390x/mie3-mvcrl.c b/tests/tcg/s390x/mie3-mvcrl.c
index 93c7b0a290..ec78dd1d49 100644
--- a/tests/tcg/s390x/mie3-mvcrl.c
+++ b/tests/tcg/s390x/mie3-mvcrl.c
@@ -1,29 +1,55 @@
+#include <stdbool.h>
#include <stdint.h>
+#include <stdlib.h>
#include <string.h>
-
-static inline void mvcrl_8(const char *dst, const char *src)
+static void mvcrl(const char *dst, const char *src, size_t len)
{
+ register long r0 asm("r0") = len;
+
asm volatile (
- "llill %%r0, 8\n"
".insn sse, 0xE50A00000000, 0(%[dst]), 0(%[src])"
- : : [dst] "d" (dst), [src] "d" (src)
- : "r0", "memory");
+ : : [dst] "d" (dst), [src] "d" (src), "r" (r0)
+ : "memory");
}
-
-int main(int argc, char *argv[])
+static bool test(void)
{
const char *alpha = "abcdefghijklmnop";
/* array missing 'i' */
- char tstr[17] = "abcdefghjklmnop\0" ;
+ char tstr[17] = "abcdefghjklmnop\0";
/* mvcrl reference use: 'open a hole in an array' */
- mvcrl_8(tstr + 9, tstr + 8);
+ mvcrl(tstr + 9, tstr + 8, 8);
/* place missing 'i' */
tstr[8] = 'i';
- return strncmp(alpha, tstr, 16ul);
+ return strncmp(alpha, tstr, 16ul) == 0;
+}
+
+static bool test_bad_r0(void)
+{
+ char src[256];
+
+ /*
+ * PoP says: Bits 32-55 of general register 0 should contain zeros;
+ * otherwise, the program may not operate compatibly in the future.
+ *
+ * Try it anyway in order to check whether this would crash QEMU itself.
+ */
+ mvcrl(src, src, (size_t)-1);
+
+ return true;
+}
gcc 11 doesn't like this:
https://gitlab.com/qemu-project/qemu/-/jobs/4623964826#L3921
/home/gitlab-runner/builds/E8PpwMky/0/qemu-project/qemu/tests/tcg/s390x/mie3-mvcrl.c: In
function ‘test_bad_r0’:
/home/gitlab-runner/builds/E8PpwMky/0/qemu-project/qemu/tests/tcg/s390x/mie3-mvcrl.c:42:5:
error: ‘src’ may be used uninitialized [-Werror=maybe-uninitialized]
42 | mvcrl(src, src, (size_t)-1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/gitlab-runner/builds/E8PpwMky/0/qemu-project/qemu/tests/tcg/s390x/mie3-mvcrl.c:6:13:
note: by argument 1 of type ‘const char *’ to ‘mvcrl’ declared here
6 | static void mvcrl(const char *dst, const char *src, size_t len)
| ^~~~~
/home/gitlab-runner/builds/E8PpwMky/0/qemu-project/qemu/tests/tcg/s390x/mie3-mvcrl.c:34:10:
note: ‘src’ declared here
34 | char src[256];
| ^~~
/home/gitlab-runner/builds/E8PpwMky/0/qemu-project/qemu/tests/tcg/s390x/mie3-mvcrl.c:42:5:
error: ‘src’ may be used uninitialized [-Werror=maybe-uninitialized]
42 | mvcrl(src, src, (size_t)-1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/gitlab-runner/builds/E8PpwMky/0/qemu-project/qemu/tests/tcg/s390x/mie3-mvcrl.c:6:13:
note: by argument 2 of type ‘const char *’ to ‘mvcrl’ declared here
6 | static void mvcrl(const char *dst, const char *src, size_t len)
| ^~~~~
/home/gitlab-runner/builds/E8PpwMky/0/qemu-project/qemu/tests/tcg/s390x/mie3-mvcrl.c:34:10:
note: ‘src’ declared here
34 | char src[256];
| ^~~
cc1: all warnings being treated as errors
How it sees any use of the structure, initialized or otherwise, I don't know -- it's all
hidden within the asm. However, src[256] = { } is enough to silence the error.
r~
