[LTP] [PATCH 2/2] ioctl_sg01: Print buffer contents on failure

Martin Doucha
2025-10-22T09:58:40Z

Signed-off-by: Martin Doucha <mdoucha@suse.cz>
---

This patch is a convenience feature. Feel free to reject it.

testcases/kernel/syscalls/ioctl/ioctl_sg01.c | 24 +++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/testcases/kernel/syscalls/ioctl/ioctl_sg01.c b/testcases/kernel/syscalls/ioctl/ioctl_sg01.c
index 66ff980ce..dada174e0 100644
--- a/testcases/kernel/syscalls/ioctl/ioctl_sg01.c
+++ b/testcases/kernel/syscalls/ioctl/ioctl_sg01.c
@@ -36,7 +36,7 @@
#define CMD_SIZE 6

static int devfd = -1;
-static char buffer[BUF_SIZE];
+static char buffer[BUF_SIZE + 1];
static unsigned char command[CMD_SIZE];
static struct sg_io_hdr query;

@@ -100,6 +100,25 @@ static const char *find_generic_scsi_device(int access_flags, int skip_usb)
return NULL;
}

+static void dump_hex(const char *str, size_t size)
+{
+ size_t i;
+
+ for (; size && !str[size - 1]; size--)
+ ;
+
+ for (i = 0; i < size; i++) {
+ if (i && (i % 32) == 0)
+ printf("\n");
+ else if (i && (i % 4) == 0)
+ printf(" ");
+
+ printf("%02x", (unsigned int)str[i]);
+ }
+
+ printf("\n");
+}
+
static void setup(void)
{
const char *devpath = find_generic_scsi_device(O_RDONLY, 1);
@@ -135,6 +154,7 @@ static void run(void)

for (i = 0; i < 100; i++) {
TEST(ioctl(devfd, SG_IO, &query));
+ buffer[BUF_SIZE] = '\0';

if (TST_RET != 0 && TST_RET != -1)
tst_brk(TBROK|TTERRNO, "Invalid ioctl() return value");
@@ -143,6 +163,8 @@ static void run(void)
for (j = 0; j < BUF_SIZE; j++) {
if (buffer[j]) {
tst_res(TFAIL, "Kernel memory leaked");
+ tst_res(TINFO, "Buffer contents: %s", buffer);
+ dump_hex(buffer, BUF_SIZE);
return;
}
}
--
2.51.0