pstore: Remove write_buf() callback
Now that write() and write_buf() are functionally identical, this removes
write_buf(), and renames write_buf_user() to write_user(). Additionally
adds sanity-checks for pstore_info's declared functions and flags at
registration time.
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 1e6642a..e79f170 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -604,7 +604,7 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
}
record.buf = (char *)s;
record.size = c;
- psinfo->write_buf(&record);
+ psinfo->write(&record);
spin_unlock_irqrestore(&psinfo->buf_lock, flags);
s += c;
c = e - s;
@@ -632,15 +632,8 @@ static void pstore_register_console(void) {}
static void pstore_unregister_console(void) {}
#endif
-static int pstore_write_compat(struct pstore_record *record)
-{
- record->buf = psinfo->buf;
-
- return record->psi->write_buf(record);
-}
-
-static int pstore_write_buf_user_compat(struct pstore_record *record,
- const char __user *buf)
+static int pstore_write_user_compat(struct pstore_record *record,
+ const char __user *buf)
{
unsigned long flags = 0;
size_t i, bufsize, total_size = record->size;
@@ -662,7 +655,7 @@ static int pstore_write_buf_user_compat(struct pstore_record *record,
break;
}
record->size = c;
- ret = record->psi->write_buf(record);
+ ret = record->psi->write(record);
if (unlikely(ret < 0))
break;
i += c;
@@ -687,6 +680,20 @@ int pstore_register(struct pstore_info *psi)
return -EPERM;
}
+ /* Sanity check flags. */
+ if (!psi->flags) {
+ pr_warn("backend '%s' must support at least one frontend\n",
+ psi->name);
+ return -EINVAL;
+ }
+
+ /* Check for required functions. */
+ if (!psi->read || !psi->write) {
+ pr_warn("backend '%s' must implement read() and write()\n",
+ psi->name);
+ return -EINVAL;
+ }
+
spin_lock(&pstore_lock);
if (psinfo) {
pr_warn("backend '%s' already loaded: ignoring '%s'\n",
@@ -695,10 +702,8 @@ int pstore_register(struct pstore_info *psi)
return -EBUSY;
}
- if (!psi->write)
- psi->write = pstore_write_compat;
- if (!psi->write_buf_user)
- psi->write_buf_user = pstore_write_buf_user_compat;
+ if (!psi->write_user)
+ psi->write_user = pstore_write_user_compat;
psinfo = psi;
mutex_init(&psinfo->read_mutex);
spin_unlock(&pstore_lock);