[PATCH v2 02/11] block: sed-opal: unify space check in add_token_*

From: Jonas Rabenstein
Date: Mon Mar 19 2018 - 14:40:15 EST


All add_token_* functions have a common set of conditions that have to
be checked. Use a common function for those checks in order to avoid
different behaviour as well as code duplication.

Signed-off-by: Jonas Rabenstein <jonas.rabenstein@xxxxxxxxxxxxxxxxxxxxxxx>

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 5aa41744b8f1..771b4cfff95c 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -510,15 +510,24 @@ static int opal_discovery0(struct opal_dev *dev, void *data)
return opal_discovery0_end(dev);
}

-static void add_token_u8(int *err, struct opal_dev *cmd, u8 tok)
+static bool can_add(int *err, struct opal_dev *cmd, size_t len)
{
if (*err)
- return;
- if (cmd->pos >= IO_BUFFER_LENGTH - 1) {
- pr_debug("Error adding u8: end of buffer.\n");
+ return false;
+
+ if (len > IO_BUFFER_LENGTH || cmd->pos >= IO_BUFFER_LENGTH - len) {
+ pr_debug("Error adding %zu bytes: end of buffer.\n", len);
*err = -ERANGE;
- return;
+ return false;
}
+
+ return true;
+}
+
+static void add_token_u8(int *err, struct opal_dev *cmd, u8 tok)
+{
+ if (!can_add(err, cmd, 1))
+ return;
cmd->cmd[cmd->pos++] = tok;
}

@@ -563,9 +572,8 @@ static void add_token_u64(int *err, struct opal_dev *cmd, u64 number)
msb = fls64(number);
len = DIV_ROUND_UP(msb, 8);

- if (cmd->pos >= IO_BUFFER_LENGTH - len - 1) {
+ if (!can_add(err, cmd, len + 1)) {
pr_debug("Error adding u64: end of buffer.\n");
- *err = -ERANGE;
return;
}
add_short_atom_header(cmd, false, false, len);
@@ -587,9 +595,8 @@ static void add_token_bytestring(int *err, struct opal_dev *cmd,
is_short_atom = false;
}

- if (len >= IO_BUFFER_LENGTH - cmd->pos - header_len) {
+ if (!can_add(err, cmd, header_len + len)) {
pr_debug("Error adding bytestring: end of buffer.\n");
- *err = -ERANGE;
return;
}

--
2.16.1