iwlwifi: mvm: refactor debugfs copy_from_user()

Abstract the copy_from_user() pattern into the macros defining
debugfs files, reducing the code and making adding new files
safer by avoiding having deal with copy_from_user() directly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

2 files changed, 43 insertions, 69 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/debugfs.c b/drivers/net/wireless/iwlwifi/mvm/debugfs.c
index 6850a2d94bcb..931723a03a43 100644
--- a/drivers/net/wireless/iwlwifi/mvm/debugfs.c
+++ b/drivers/net/wireless/iwlwifi/mvm/debugfs.c
@@ -66,22 +66,15 @@
 #include "iwl-prph.h"
 #include "debugfs.h"
 
-static ssize_t iwl_dbgfs_tx_flush_write(struct file *file,
-                                        const char __user *user_buf,
+static ssize_t iwl_dbgfs_tx_flush_write(struct iwl_mvm *mvm, char *buf,
                                         size_t count, loff_t *ppos)
 {
-        struct iwl_mvm *mvm = file->private_data;
-        char buf[16] = {};
-        size_t buf_size = min(count, sizeof(buf) - 1);
         int ret;
         u32 scd_q_msk;
 
         if (!mvm->ucode_loaded || mvm->cur_ucode != IWL_UCODE_REGULAR)
                 return -EIO;
 
-        if (copy_from_user(buf, user_buf, buf_size))
-                return -EFAULT;
-
         if (sscanf(buf, "%x", &scd_q_msk) != 1)
                 return -EINVAL;
 
@@ -94,22 +87,15 @@ static ssize_t iwl_dbgfs_tx_flush_write(struct file *file,
         return ret;
 }
 
-static ssize_t iwl_dbgfs_sta_drain_write(struct file *file,
-                                         const char __user *user_buf,
+static ssize_t iwl_dbgfs_sta_drain_write(struct iwl_mvm *mvm, char *buf,
                                          size_t count, loff_t *ppos)
 {
-        struct iwl_mvm *mvm = file->private_data;
         struct ieee80211_sta *sta;
-        char buf[8] = {};
-        size_t buf_size = min(count, sizeof(buf) - 1);
         int sta_id, drain, ret;
 
         if (!mvm->ucode_loaded || mvm->cur_ucode != IWL_UCODE_REGULAR)
                 return -EIO;
 
-        if (copy_from_user(buf, user_buf, buf_size))
-                return -EFAULT;
-
         if (sscanf(buf, "%d %d", &sta_id, &drain) != 2)
                 return -EINVAL;
         if (sta_id < 0 || sta_id >= IWL_MVM_STATION_COUNT)
@@ -187,18 +173,11 @@ static ssize_t iwl_dbgfs_sram_read(struct file *file, char __user *user_buf,
         return ret;
 }
 
-static ssize_t iwl_dbgfs_sram_write(struct file *file,
-                                    const char __user *user_buf, size_t count,
-                                    loff_t *ppos)
+static ssize_t iwl_dbgfs_sram_write(struct iwl_mvm *mvm, char *buf,
+                                    size_t count, loff_t *ppos)
 {
-        struct iwl_mvm *mvm = file->private_data;
-        char buf[64] = {};
-        size_t buf_size = min(count, sizeof(buf) -  1);
         u32 offset, len;
 
-        if (copy_from_user(buf, user_buf, buf_size))
-                return -EFAULT;
-
         if (sscanf(buf, "%x,%x", &offset, &len) == 2) {
                 if ((offset & 0x3) || (len & 0x3))
                         return -EINVAL;
@@ -258,22 +237,14 @@ static ssize_t iwl_dbgfs_disable_power_off_read(struct file *file,
         return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
 }
 
-static ssize_t iwl_dbgfs_disable_power_off_write(struct file *file,
-                                                 const char __user *user_buf,
+static ssize_t iwl_dbgfs_disable_power_off_write(struct iwl_mvm *mvm, char *buf,
                                                  size_t count, loff_t *ppos)
 {
-        struct iwl_mvm *mvm = file->private_data;
-        char buf[64] = {};
-        size_t buf_size = min(count, sizeof(buf) - 1);
-        int ret;
-        int val;
+        int ret, val;
 
         if (!mvm->ucode_loaded)
                 return -EIO;
 
-        if (copy_from_user(buf, user_buf, buf_size))
-                return -EFAULT;
-
         if (!strncmp("disable_power_off_d0=", buf, 21)) {
                 if (sscanf(buf + 21, "%d", &val) != 1)
                         return -EINVAL;
@@ -568,11 +539,9 @@ static ssize_t iwl_dbgfs_fw_rx_stats_read(struct file *file,
 }
 #undef PRINT_STAT_LE32
 
-static ssize_t iwl_dbgfs_fw_restart_write(struct file *file,
-                                          const char __user *user_buf,
+static ssize_t iwl_dbgfs_fw_restart_write(struct iwl_mvm *mvm, char *buf,
                                           size_t count, loff_t *ppos)
 {
-        struct iwl_mvm *mvm = file->private_data;
         int ret;
 
         mutex_lock(&mvm->mutex);
@@ -589,12 +558,9 @@ static ssize_t iwl_dbgfs_fw_restart_write(struct file *file,
         return count;
 }
 
-static ssize_t iwl_dbgfs_fw_nmi_write(struct file *file,
-                                      const char __user *user_buf,
+static ssize_t iwl_dbgfs_fw_nmi_write(struct iwl_mvm *mvm, char *buf,
                                       size_t count, loff_t *ppos)
 {
-        struct iwl_mvm *mvm = file->private_data;
-
         iwl_write_prph(mvm->trans, DEVICE_SET_NMI_REG, 1);
 
         return count;
@@ -624,17 +590,11 @@ iwl_dbgfs_scan_ant_rxchain_read(struct file *file,
 }
 
 static ssize_t
-iwl_dbgfs_scan_ant_rxchain_write(struct file *file,
-                                 const char __user *user_buf,
+iwl_dbgfs_scan_ant_rxchain_write(struct iwl_mvm *mvm, char *buf,
                                  size_t count, loff_t *ppos)
 {
-        struct iwl_mvm *mvm = file->private_data;
-        char buf[8] = {};
-        size_t buf_size = min(count, sizeof(buf) - 1);
         u8 scan_rx_ant;
 
-        if (copy_from_user(buf, user_buf, buf_size))
-                return -EFAULT;
         if (sscanf(buf, "%hhx", &scan_rx_ant) != 1)
                 return -EINVAL;
         if (scan_rx_ant > ANT_ABC)
@@ -648,18 +608,11 @@ iwl_dbgfs_scan_ant_rxchain_write(struct file *file,
 }
 
 #ifdef CONFIG_PM_SLEEP
-static ssize_t iwl_dbgfs_d3_sram_write(struct file *file,
-                                       const char __user *user_buf,
+static ssize_t iwl_dbgfs_d3_sram_write(struct iwl_mvm *mvm, char *buf,
                                        size_t count, loff_t *ppos)
 {
-        struct iwl_mvm *mvm = file->private_data;
-        char buf[8] = {};
-        size_t buf_size = min(count, sizeof(buf) - 1);
         int store;
 
-        if (copy_from_user(buf, user_buf, buf_size))
-                return -EFAULT;
-
         if (sscanf(buf, "%d", &store) != 1)
                 return -EINVAL;
 
@@ -712,6 +665,10 @@ static ssize_t iwl_dbgfs_d3_sram_read(struct file *file, char __user *user_buf,
 }
 #endif
 
+#define MVM_DEBUGFS_WRITE_FILE_OPS(name, bufsz) \
+        _MVM_DEBUGFS_WRITE_FILE_OPS(name, bufsz, struct iwl_mvm)
+#define MVM_DEBUGFS_READ_WRITE_FILE_OPS(name, bufsz) \
+        _MVM_DEBUGFS_READ_WRITE_FILE_OPS(name, bufsz, struct iwl_mvm)
 #define MVM_DEBUGFS_ADD_FILE(name, parent, mode) do {                   \
                 if (!debugfs_create_file(#name, mode, parent, mvm,      \
                                          &iwl_dbgfs_##name##_ops))      \
@@ -719,20 +676,20 @@ static ssize_t iwl_dbgfs_d3_sram_read(struct file *file, char __user *user_buf,
         } while (0)
 
 /* Device wide debugfs entries */
-MVM_DEBUGFS_WRITE_FILE_OPS(tx_flush);
-MVM_DEBUGFS_WRITE_FILE_OPS(sta_drain);
-MVM_DEBUGFS_READ_WRITE_FILE_OPS(sram);
+MVM_DEBUGFS_WRITE_FILE_OPS(tx_flush, 16);
+MVM_DEBUGFS_WRITE_FILE_OPS(sta_drain, 8);
+MVM_DEBUGFS_READ_WRITE_FILE_OPS(sram, 64);
 MVM_DEBUGFS_READ_FILE_OPS(stations);
 MVM_DEBUGFS_READ_FILE_OPS(bt_notif);
 MVM_DEBUGFS_READ_FILE_OPS(bt_cmd);
-MVM_DEBUGFS_READ_WRITE_FILE_OPS(disable_power_off);
+MVM_DEBUGFS_READ_WRITE_FILE_OPS(disable_power_off, 64);
 MVM_DEBUGFS_READ_FILE_OPS(fw_rx_stats);
-MVM_DEBUGFS_WRITE_FILE_OPS(fw_restart);
-MVM_DEBUGFS_WRITE_FILE_OPS(fw_nmi);
-MVM_DEBUGFS_READ_WRITE_FILE_OPS(scan_ant_rxchain);
+MVM_DEBUGFS_WRITE_FILE_OPS(fw_restart, 10);
+MVM_DEBUGFS_WRITE_FILE_OPS(fw_nmi, 10);
+MVM_DEBUGFS_READ_WRITE_FILE_OPS(scan_ant_rxchain, 8);
 
 #ifdef CONFIG_PM_SLEEP
-MVM_DEBUGFS_READ_WRITE_FILE_OPS(d3_sram);
+MVM_DEBUGFS_READ_WRITE_FILE_OPS(d3_sram, 8);
 #endif
 
 int iwl_mvm_dbgfs_register(struct iwl_mvm *mvm, struct dentry *dbgfs_dir)
diff --git a/drivers/net/wireless/iwlwifi/mvm/debugfs.h b/drivers/net/wireless/iwlwifi/mvm/debugfs.h
index faa73b80b624..85f9f958bfd2 100644
--- a/drivers/net/wireless/iwlwifi/mvm/debugfs.h
+++ b/drivers/net/wireless/iwlwifi/mvm/debugfs.h
@@ -68,17 +68,34 @@ static const struct file_operations iwl_dbgfs_##name##_ops = {		\
         .llseek = generic_file_llseek,                                  \
 }
 
-#define MVM_DEBUGFS_READ_WRITE_FILE_OPS(name)                           \
+#define MVM_DEBUGFS_WRITE_WRAPPER(name, buflen, argtype)                \
+static ssize_t _iwl_dbgfs_##name##_write(struct file *file,             \
+                                         const char __user *user_buf,   \
+                                         size_t count, loff_t *ppos)    \
+{                                                                       \
+        argtype *arg = file->private_data;                              \
+        char buf[buflen] = {};                                          \
+        size_t buf_size = min(count, sizeof(buf) -  1);                 \
+                                                                        \
+        if (copy_from_user(buf, user_buf, buf_size))                    \
+                return -EFAULT;                                         \
+                                                                        \
+        return iwl_dbgfs_##name##_write(arg, buf, buf_size, ppos);      \
+}                                                                       \
+
+#define _MVM_DEBUGFS_READ_WRITE_FILE_OPS(name, buflen, argtype)         \
+MVM_DEBUGFS_WRITE_WRAPPER(name, buflen, argtype)                        \
 static const struct file_operations iwl_dbgfs_##name##_ops = {          \
-        .write = iwl_dbgfs_##name##_write,                              \
+        .write = _iwl_dbgfs_##name##_write,                             \
         .read = iwl_dbgfs_##name##_read,                                \
         .open = simple_open,                                            \
         .llseek = generic_file_llseek,                                  \
 };
 
-#define MVM_DEBUGFS_WRITE_FILE_OPS(name)                                \
+#define _MVM_DEBUGFS_WRITE_FILE_OPS(name, buflen, argtype)              \
+MVM_DEBUGFS_WRITE_WRAPPER(name, buflen, argtype)                        \
 static const struct file_operations iwl_dbgfs_##name##_ops = {          \
-        .write = iwl_dbgfs_##name##_write,                              \
+        .write = _iwl_dbgfs_##name##_write,                             \
         .open = simple_open,                                            \
         .llseek = generic_file_llseek,                                  \
 };