From: Johannes Berg <johannes.berg@xxxxxxxxx>
On newer hardware, the tx_queue debugfs file would need to
allocate 37.5kib data since there are 512 queues, which is
too much. Rather than resorting to kludges like kvmalloc(),
use the seq_file API to print out the data.
While at it, also fix a NULL pointer dereference here, the
txq pointer from trans_pcie->txqs[] may be NULL if that
queue hasn't been allocated.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
---
.../net/wireless/intel/iwlwifi/pcie/trans.c | 121 +++++++++++++-----
1 file changed, 89 insertions(+), 32 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index e4cbd8daa7c6..3c33c01cda60 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -70,6 +70,7 @@
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/wait.h>
+#include <linux/seq_file.h>
#include "iwl-drv.h"
#include "iwl-trans.h"
@@ -2544,44 +2545,94 @@ static const struct file_operations iwl_dbgfs_##name##_ops = { \
.llseek = generic_file_llseek, \
};
-static ssize_t iwl_dbgfs_tx_queue_read(struct file *file,
- char __user *user_buf,
- size_t count, loff_t *ppos)
+struct iwl_dbgfs_tx_queue_priv {
+ struct iwl_trans *trans;
+};
+
+struct iwl_dbgfs_tx_queue_state {
+ loff_t pos;
+};
+
+static void *iwl_dbgfs_tx_queue_seq_start(struct seq_file *seq, loff_t *pos)
{
- struct iwl_trans *trans = file->private_data;
+ struct iwl_dbgfs_tx_queue_priv *priv = seq->private;
+ struct iwl_dbgfs_tx_queue_state *state;
+
+ if (*pos >= priv->trans->trans_cfg->base_params->num_of_queues)
+ return NULL;
+
+ state = kmalloc(sizeof(*state), GFP_KERNEL);
+ if (!state)
+ return NULL;
+ state->pos = *pos;
+ return state;
+}
+
+static void *iwl_dbgfs_tx_queue_seq_next(struct seq_file *seq,
+ void *v, loff_t *pos)
+{
+ struct iwl_dbgfs_tx_queue_priv *priv = seq->private;
+ struct iwl_dbgfs_tx_queue_state *state = v;
+
+ *pos = ++state->pos;
+
+ if (*pos >= priv->trans->trans_cfg->base_params->num_of_queues)
+ return NULL;
+
+ return state;
+}
+
+static void iwl_dbgfs_tx_queue_seq_stop(struct seq_file *seq, void *v)
+{
+ kfree(v);
+}
+
+static int iwl_dbgfs_tx_queue_seq_show(struct seq_file *seq, void *v)
+{
+ struct iwl_dbgfs_tx_queue_priv *priv = seq->private;
+ struct iwl_dbgfs_tx_queue_state *state = v;
+ struct iwl_trans *trans = priv->trans;
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
- struct iwl_txq *txq;
- char *buf;
- int pos = 0;
- int cnt;
- int ret;
- size_t bufsz;
+ struct iwl_txq *txq = trans_pcie->txq[state->pos];
+
+ seq_printf(seq, "hwq %.3u: used=%d stopped=%d ",
+ (unsigned int)state->pos,
+ !!test_bit(state->pos, trans_pcie->queue_used),
+ !!test_bit(state->pos, trans_pcie->queue_stopped));
+ if (txq)
+ seq_printf(seq,
+ "read=%u write=%u need_update=%d frozen=%d",
+ txq->read_ptr, txq->write_ptr,
+ txq->need_update, txq->frozen);
+ else
+ seq_puts(seq, "(unallocated)");
- bufsz = sizeof(char) * 75 *
- trans->trans_cfg->base_params->num_of_queues;
+ if (state->pos == trans_pcie->cmd_queue)
+ seq_puts(seq, " (HCMD)");
+ seq_puts(seq, "\n");
- if (!trans_pcie->txq_memory)
- return -EAGAIN;
+ return 0;
+}
- buf = kzalloc(bufsz, GFP_KERNEL);
- if (!buf)
+static const struct seq_operations iwl_dbgfs_tx_queue_seq_ops = {
+ .start = iwl_dbgfs_tx_queue_seq_start,
+ .next = iwl_dbgfs_tx_queue_seq_next,
+ .stop = iwl_dbgfs_tx_queue_seq_stop,
+ .show = iwl_dbgfs_tx_queue_seq_show,
+};
+
+static int iwl_dbgfs_tx_queue_open(struct inode *inode, struct file *filp)
+{
+ struct iwl_dbgfs_tx_queue_priv *priv;
+
+ priv = __seq_open_private(filp, &iwl_dbgfs_tx_queue_seq_ops,
+ sizeof(*priv));
+
+ if (!priv)
return -ENOMEM;
- for (cnt = 0;
- cnt < trans->trans_cfg->base_params->num_of_queues;
- cnt++) {
- txq = trans_pcie->txq[cnt];
- pos += scnprintf(buf + pos, bufsz - pos,
- "hwq %.2d: read=%u write=%u use=%d stop=%d need_update=%d frozen=%d%s\n",
- cnt, txq->read_ptr, txq->write_ptr,
- !!test_bit(cnt, trans_pcie->queue_used),
- !!test_bit(cnt, trans_pcie->queue_stopped),
- txq->need_update, txq->frozen,
- (cnt == trans_pcie->cmd_queue ? " HCMD" : ""));
- }
- ret = simple_read_from_buffer(user_buf, count, ppos, buf, pos);
- kfree(buf);
- return ret;
+ priv->trans = inode->i_private;
+ return 0;
}
static ssize_t iwl_dbgfs_rx_queue_read(struct file *file,
@@ -2914,9 +2965,15 @@ static ssize_t iwl_dbgfs_monitor_data_read(struct file *file,
DEBUGFS_READ_WRITE_FILE_OPS(interrupt);
DEBUGFS_READ_FILE_OPS(fh_reg);
DEBUGFS_READ_FILE_OPS(rx_queue);
-DEBUGFS_READ_FILE_OPS(tx_queue);
DEBUGFS_WRITE_FILE_OPS(csr);
DEBUGFS_READ_WRITE_FILE_OPS(rfkill);
+static const struct file_operations iwl_dbgfs_tx_queue_ops = {
+ .owner = THIS_MODULE,
+ .open = iwl_dbgfs_tx_queue_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
static const struct file_operations iwl_dbgfs_monitor_data_ops = {
.read = iwl_dbgfs_monitor_data_read,
--
2.25.1
