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>
This commit is contained in:
Kees Cook
2017-03-05 22:41:10 -08:00
parent fdd0311863
commit 4c9ec21976
5 changed files with 39 additions and 43 deletions

View File

@@ -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);