[PATCH v3 1/2] s390/uv: Fix loop condition in uv_find_secrets

[Steffen Eiden <seiden@linux.ibm.com>]

Systems with more than 85 UV secrets got -ENOENT for any secret past the
first page.

Fix this by setting the start index at the beginning of the loop in
uv_find_secret() and not at the end. First test if there are more
secrets left by comparing start_idx with list->next_secret_idx, and then
set the start index to the next secret index.

Fixes: 7c9137af2042 ("s390/uv: Retrieve UV secrets support")
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
 arch/s390/kernel/uv.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index a284f98d9716..d970b15ef126 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -781,11 +781,14 @@ int uv_find_secret(const u8 secret_id[UV_SECRET_ID_LEN],
 		   struct uv_secret_list *list,
 		   struct uv_secret_list_item_hdr *secret)
 {
-	u16 start_idx = 0;
+	u16 start_idx;
 	u16 list_rc;
 	int ret;
 
+	list->next_secret_idx = 0;
+
 	do {
+		start_idx = list->next_secret_idx;
 		uv_list_secrets(list, start_idx, &list_rc, NULL);
 		if (list_rc != UVC_RC_EXECUTED && list_rc != UVC_RC_MORE_DATA) {
 			if (list_rc == UVC_RC_INV_CMD)
@@ -796,7 +799,6 @@ int uv_find_secret(const u8 secret_id[UV_SECRET_ID_LEN],
 		ret = find_secret_in_page(secret_id, list, secret);
 		if (ret == 0)
 			return ret;
-		start_idx = list->next_secret_idx;
 	} while (list_rc == UVC_RC_MORE_DATA && start_idx < list->next_secret_idx);
 
 	return -ENOENT;

-- 
2.53.0