iwlwifi: fix flow handler debug code

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.

Cc: stable@vger.kernel.org
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>
This commit is contained in:
Johannes Berg 2012-08-21 18:57:10 +02:00 committed by John W. Linville
parent 7b4e6cfbae
commit 94543a8d4f
3 changed files with 18 additions and 16 deletions

View File

@ -350,7 +350,7 @@ int iwl_queue_space(const struct iwl_queue *q);
/*****************************************************
* Error handling
******************************************************/
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);
/*****************************************************

View File

@ -555,7 +555,7 @@ static void iwl_irq_handle_error(struct iwl_trans *trans)
}
iwl_dump_csr(trans);
iwl_dump_fh(trans, NULL, false);
iwl_dump_fh(trans, NULL);
iwl_op_mode_nic_error(trans->op_mode);
}

View File

@ -1649,13 +1649,9 @@ static const char *get_fh_string(int cmd)
#undef IWL_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,
@ -1667,29 +1663,35 @@ 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) {
bufsz = ARRAY_SIZE(fh_tbl) * 48 + 40;
#ifdef CONFIG_IWLWIFI_DEBUGFS
if (buf) {
int pos = 0;
size_t 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;
}
@ -1982,11 +1984,11 @@ 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);