[CRIU] zdtm test build failure on s390x (s390x_regs_check.c)

[Michael Holzheu]

On Tue, 5 Sep 2017 17:56:08 +0200
Adrian Reber <adrian at lisas.de> wrote:

> When running 'make zdtm' on s390x it fails on my RHEL kernel with:
> 
> make[3]: Leaving directory `/tmp/criu/test/zdtm/lib'
>  CC        s390x_regs_check.o
> s390x_regs_check.c: In function ‘util_hexdump_grp’:
> s390x_regs_check.c:214:7: error: ‘ptr’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
>    ptr += sprintf(ptr, "%02x", buf[i]);
>        ^

Obviously the compiler does not understand the "if (first)" construct.

I assume the following will fix the problem:
---
[CRIU][PATCH] zdtm/s390x_regs_check: Fix compiler warning

When running 'make zdtm' on s390x it fails on RHEL7 with:

 make[3]: Leaving directory `/tmp/criu/test/zdtm/lib'
  CC        s390x_regs_check.o
 s390x_regs_check.c: In function "util_hexdump_grp":
 s390x_regs_check.c:214:7: error: "ptr" may be used uninitialized
 in this function [-Werror=maybe-uninitialized]
    ptr += sprintf(ptr, "%02x", buf[i]);

Fix this and assign ptr from the beginning to help gcc.

Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>
---
 test/zdtm/static/s390x_regs_check.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/zdtm/static/s390x_regs_check.c b/test/zdtm/static/s390x_regs_check.c
index a92679a..1a7e841 100644
--- a/test/zdtm/static/s390x_regs_check.c
+++ b/test/zdtm/static/s390x_regs_check.c
@@ -198,8 +198,8 @@ struct reg_set *reg_set_vec[] = {
 void util_hexdump_grp(const char *tag, const void *data, int grp,
 		      int count, int indent)
 {
+	char str[1024], *ptr = str;
 	const char *buf = data;
-	char str[1024], *ptr;
 	int i, first = 1;
 
 	for (i = 0; i < count; i++) {
-- 
2.7.4