iwlwifi: fix flow handler debug code

commit 94543a8d4fb302817014981489f15cb3b92ec3c2 upstream.

iwl_dbgfs_fh_reg_read() can cause crashes and/or
BUG_ON in slub because the ifdefs are wrong, the
code in iwl_dump_fh() should use DEBUGFS, not
DEBUG to protect the buffer writing code.

Also, while at it, clean up the arguments to the
function, some code and make it generally safer.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2: adjust filenames and context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[wujg: Backported to 3.4: adjust context]
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-int.h b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-int.h
index 3b844b7..dfa0d80 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-int.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-int.h
@@ -352,7 +352,7 @@ int iwl_queue_space(const struct iwl_queue *q);
 ******************************************************/
 int iwl_dump_nic_event_log(struct iwl_trans *trans, bool full_log,
                            char **buf, bool display);
-int iwl_dump_fh(struct iwl_trans *trans, char **buf, bool display);
+int iwl_dump_fh(struct iwl_trans *trans, char **buf);
 void iwl_dump_csr(struct iwl_trans *trans);
 
 /*****************************************************

diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
index aa7aea1..bc3dd34 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
@@ -695,7 +695,7 @@ static void iwl_irq_handle_error(struct iwl_trans *trans)
 
        iwl_dump_nic_error_log(trans);
        iwl_dump_csr(trans);
-       iwl_dump_fh(trans, NULL, false);
+       iwl_dump_fh(trans, NULL);
        iwl_dump_nic_event_log(trans, false, NULL, false);
 
        iwl_op_mode_nic_error(trans->op_mode);

diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
index 8741048..1780d3f 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
@@ -1768,13 +1768,9 @@ static const char *get_fh_string(int cmd)
        }
 }
 
-int iwl_dump_fh(struct iwl_trans *trans, char **buf, bool display)
+int iwl_dump_fh(struct iwl_trans *trans, char **buf)
 {
        int i;
-#ifdef CONFIG_IWLWIFI_DEBUG
-       int pos = 0;
-       size_t bufsz = 0;
-#endif
        static const u32 fh_tbl[] = {
                FH_RSCSR_CHNL0_STTS_WPTR_REG,
                FH_RSCSR_CHNL0_RBDCB_BASE_REG,
@@ -1786,29 +1782,34 @@ int iwl_dump_fh(struct iwl_trans *trans, char **buf, bool display)
                FH_TSSR_TX_STATUS_REG,
                FH_TSSR_TX_ERROR_REG
        };
-#ifdef CONFIG_IWLWIFI_DEBUG
-       if (display) {
+
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+       if (buf) {
+               int pos = 0;
+               size_t bufsz = ARRAY_SIZE(fh_tbl) * 48 + 40;
+
                bufsz = ARRAY_SIZE(fh_tbl) * 48 + 40;
                *buf = kmalloc(bufsz, GFP_KERNEL);
                if (!*buf)
                        return -ENOMEM;
                pos += scnprintf(*buf + pos, bufsz - pos,
                                "FH register values:\n");
-               for (i = 0; i < ARRAY_SIZE(fh_tbl); i++) {
+
+               for (i = 0; i < ARRAY_SIZE(fh_tbl); i++)
                        pos += scnprintf(*buf + pos, bufsz - pos,
                                "  %34s: 0X%08x\n",
                                get_fh_string(fh_tbl[i]),
                                iwl_read_direct32(trans, fh_tbl[i]));
-               }
+
                return pos;
        }
 #endif
        IWL_ERR(trans, "FH register values:\n");
-       for (i = 0; i <  ARRAY_SIZE(fh_tbl); i++) {
+       for (i = 0; i <  ARRAY_SIZE(fh_tbl); i++)
                IWL_ERR(trans, "  %34s: 0X%08x\n",
                        get_fh_string(fh_tbl[i]),
                        iwl_read_direct32(trans, fh_tbl[i]));
-       }
+
        return 0;
 }
 
@@ -2152,11 +2153,11 @@ static ssize_t iwl_dbgfs_fh_reg_read(struct file *file,
                                         size_t count, loff_t *ppos)
 {
        struct iwl_trans *trans = file->private_data;
-       char *buf;
+       char *buf = NULL;
        int pos = 0;
        ssize_t ret = -EFAULT;
 
-       ret = pos = iwl_dump_fh(trans, &buf, true);
+       ret = pos = iwl_dump_fh(trans, &buf);
        if (buf) {
                ret = simple_read_from_buffer(user_buf,
                                              count, ppos, buf, pos);