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bes2600: drop BES2600_WRITE_DPD_TO_FILE kernel_*() file paths

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bes_chardev.c carried three functions gated behind the
BES2600_WRITE_DPD_TO_FILE Kconfig/make-flag (default off):

  - bes2600_chrdev_write_dpd_data_to_file()
      filp_open(O_CREAT | O_TRUNC | O_RDWR) + kernel_write()
      writing a raw DPD calibration blob back to
      BES2600_DPD_PATH (default /data/cfg/bes2600_dpd.bin, an
      Android-AOSP path).

  - bes2600_chrdev_read_and_check_dpd_data()
      filp_open(O_RDONLY) + kernel_read() reading the DPD blob
      from either BES2600_DPD_GOLDEN_PATH (/data/cfg/…) or
      BES2600_DEFAULT_DPD_PATH (/lib/firmware/bes2600_dpd.bin),
      followed by a CRC/version sanity check.

  - bes2600_chrdev_dpd_is_vaild() (sic), the CRC/version helper
    used only by the read path.

Plus the bes_cdev.no_dpd field, its module_param, and two
intrusion sites in bes2600_chrdev_get_dpd_data() and
bes2600_chrdev_update_dpd_data() that invoke the above.

The Makefile defaults BES2600_WRITE_DPD_TO_FILE=n, so in a stock
build all of this is dead code. It is still a standing upstream
blocker for exactly the same reasons as the factory-txt write
path removed in the preceding patch:

  - filp_open() + kernel_read()/kernel_write() bypass the
    firmware-class abstraction and LSM-governed access control
    that apply to /lib/firmware/.
  - The write target /data/cfg/ is an Android AOSP convention
    that does not exist on a Linux distribution and cannot be
    created by the kernel anyway.
  - A runtime DPD re-calibration is intended to reduce TX EVM
    after temperature or aging drift; persisting the result via
    kernel_write() is fundamentally a userspace concern (debugfs
    dump + userspace tool is the expected route).

Remove the entire #ifdef BES2600_WRITE_DPD_TO_FILE block from
bes_chardev.c (including the inner #ifdef inside
bes2600_chrdev_read_and_check_dpd_data() guarding a
DPD_BIN_FILE_SIZE size check that only applied to the read-back-
its-own-write case), the no_dpd field and module_param, and the
two invocation sites. Drop the Kconfig/make-flag and the three
associated PATH macros from the Makefile. Net: -155 lines, no
remaining filp_open/kernel_read/kernel_write anywhere in
bes_chardev.c.

The in-memory DPD state path is unchanged: bes2600_chrdev_get_dpd_
buffer() still allocates a kmalloc'd buffer used by the firmware-
download path, bes2600_chrdev_update_dpd_data() still validates
the buffer's CRC and transitions bes2600_cdev.wait_state on
success, and bes2600_chrdev_free_dpd_data() still releases the
buffer on unload. Only the file-I/O side-channel is removed.

Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
This commit is contained in:
Markus Fritsche
2026-04-23 20:04:11 +02:00
parent 0c1f98df59
commit 0768e11da6
2 changed files with 0 additions and 155 deletions
Download Patch File Download Diff File Expand all files Collapse all files
bes2600/Makefile
-12
View File
@@ -28,7 +28,6 @@ CONFIG_BES2600_WIFI_BOOT_ON ?= y
CONFIG_BES2600_BT_BOOT_ON ?= n
BES2600_GPIO_WAKEUP_AP ?= n
BES2600_WRITE_DPD_TO_FILE ?= n
BES2600_TX_MORE_RETRY ?= n
# bes evb
@@ -93,12 +92,6 @@ ccflags-y += -DBES_UNIFIED_PM
ccflags-y += -DBES_SDIO_OPTIMIZED_LEN
ccflags-y += -DBES2600_HOST_TIMESTAMP_DEBUG
ifeq ($(BES2600_WRITE_DPD_TO_FILE),y)
BES2600_DPD_PATH ?= /data/cfg/bes2600_dpd.bin
BES2600_DEFAULT_DPD_PATH ?= /lib/firmware/bes2600_dpd.bin
BES2600_DPD_GOLDEN_PATH ?= /data/cfg/bes2600_dpd_golden.bin
endif
ifeq ($(BES2600_DUMP_FW_DPD_LOG),y)
BES2600_DPD_LOG_PATH ?= /data/applog/bes2600_dpd_log.log
endif
@@ -135,9 +128,6 @@ ccflags-y += $(call boolen_flag,BSS_LOSS_CHECK,y)
ccflags-y += $(call string_flag,BES2600_LOAD_FW_TOOL_PATH)
ccflags-y += $(call string_flag,BES2600_LOAD_FW_TOOL_DEVICE)
ccflags-y += $(call string_flag,BES2600_DRV_VERSION)
ccflags-y += $(call string_flag,BES2600_DPD_PATH)
ccflags-y += $(call string_flag,BES2600_DEFAULT_DPD_PATH)
ccflags-y += $(call string_flag,BES2600_DPD_GOLDEN_PATH)
ccflags-y += $(call boolen_flag,BES2600_INDEPENDENT_EVB,y)
ccflags-y += $(call boolen_flag,BES2600_INTEGRATED_MODULE_V1,y)
@@ -159,8 +149,6 @@ ccflags-y += $(call boolen_flag,FACTORY_SAVE_MULTI_PATH,y)
ccflags-y += $(call boolen_flag,FACTORY_CRC_CHECK,y)
ccflags-y += $(call boolen_flag,BES2600_GPIO_WAKEUP_AP,y)
ccflags-y += $(call boolen_flag,BES2600_WRITE_DPD_TO_FILE,y)
ccflags-y += $(call boolen_flag,BES2600_DUMP_FW_DPD_LOG,y)
ccflags-y += $(call string_flag,BES2600_DPD_LOG_PATH)
bes2600/bes_chardev.c
-143
View File
@@ -63,9 +63,6 @@ struct bes_cdev {
struct delayed_work probe_timeout_work;
enum bus_probe_state bus_probe;
struct work_struct wifi_force_close_work;
#ifdef BES2600_WRITE_DPD_TO_FILE
int no_dpd;
#endif
enum pend_read_op read_flag;
enum wakeup_event wakeup_by_event; /* used to filter unwanted event wakeup reason report */
u16 wakeup_state; /* for userspace check wakeup reason */
@@ -85,9 +82,6 @@ struct bes2600_op_map {
static struct bes_cdev bes2600_cdev;
module_param_named(fw_type, bes2600_cdev.fw_type, int, 0644);
#ifdef BES2600_WRITE_DPD_TO_FILE
module_param_named(no_dpd, bes2600_cdev.no_dpd, int, 0644);
#endif
extern int bes2600_register_net_dev(struct sbus_priv *bus_priv);
extern int bes2600_unregister_net_dev(struct sbus_priv *bus_priv);
@@ -269,137 +263,8 @@ static int bes2600_chrdev_check_system_close_internal(void)
#ifdef BES2600_WRITE_DPD_TO_FILE
static int bes2600_chrdev_write_dpd_data_to_file(const char *path, void *buffer, int size)
{
int ret = 0;
struct file *fp;
if (buffer == NULL || size == 0)
return 0;
fp = filp_open(path, O_TRUNC | O_CREAT | O_RDWR, S_IRUSR);
if (IS_ERR(fp)) {
bes_err("BES2600 : can't open %s\n",path);
return -1;
}
ret = kernel_write(fp, buffer, size, &fp->f_pos);
if (ret < 0)
bes_err("write dpd to file failed\n");
filp_close(fp,NULL);
bes_devel("write dpd to %s\n", path);
return ret;
}
static bool bes2600_chrdev_dpd_is_vaild(u8 *dpd_data)
{
u32 cal_crc = 0;
u32 dpd_crc = le32_to_cpup((__le32 *)(dpd_data));
u32 dpd_ver = le32_to_cpup((__le32 *)(dpd_data + DPD_VERSION_OFFSET));
/* check version */
if (dpd_ver < DPD_CUR_VERSION)
return false;
cal_crc ^= 0xffffffffL;
cal_crc = crc32_le(cal_crc, dpd_data + 4, DPD_BIN_SIZE - 4);
cal_crc ^= 0xffffffffL;
/* check if the dpd data is valid */
if (cal_crc != dpd_crc) {
bes_err(
"bes2600 dpd data from file check failed, calc_crc:0x%08x dpd_crc: 0x%08x\n",
cal_crc, dpd_crc);
return false;
}
return true;
}
static int bes2600_chrdev_read_and_check_dpd_data(const char *file, u8 **data, u32 *len)
{
int ret = 0;
u8* read_data = NULL;
struct file *fp;
/* open file */
fp = filp_open(file, O_RDONLY, 0);//S_IRUSR
if (IS_ERR(fp)) {
bes_devel("BES2600 : can't open %s\n",file);
return -1;
}
#ifdef BES2600_WRITE_DPD_TO_FILE
if (fp->f_inode->i_size != DPD_BIN_FILE_SIZE) {
bes_err(
"bes2600 dpd data file size check failed, read_size: %lld file_size: %d\n",
fp->f_inode->i_size, DPD_BIN_FILE_SIZE);
filp_close(fp, NULL);
return -1;
}
#endif
/* allocate memory for storing reading data */
read_data = kmalloc(fp->f_inode->i_size, GFP_KERNEL);
if (read_data == NULL) {
bes_devel("%s alloc mem fail\n", __func__);
goto err1;
}
/* read data from file */
ret = kernel_read(fp, read_data, fp->f_inode->i_size, &fp->f_pos);
if (ret < DPD_BIN_SIZE) {
bes_err("%s read fail, ret=%d\n", __func__, ret);
goto err2;
}
/* check dpd version and crc */
if (!bes2600_chrdev_dpd_is_vaild(read_data))
goto err2;
/* close file */
filp_close(fp, NULL);
/* copy data to external */
*data = read_data;
*len = DPD_BIN_SIZE;;
/* output debug information */
bes_devel("read dpd data from %s\n", file);
return 0;
err2:
kfree(read_data);
err1:
filp_close(fp, NULL);
*data = NULL;
*len = 0;
return -1;
}
#endif
const u8* bes2600_chrdev_get_dpd_data(u32 *len)
{
#ifdef BES2600_WRITE_DPD_TO_FILE
if (!bes2600_cdev.dpd_calied && bes2600_cdev.no_dpd) {
/* read dpd data from file that stores factory dpd calibration data */
if ((bes2600_chrdev_read_and_check_dpd_data(BES2600_DPD_GOLDEN_PATH,
&bes2600_cdev.dpd_data, &bes2600_cdev.dpd_len) < 0) &&
(bes2600_chrdev_read_and_check_dpd_data(BES2600_DEFAULT_DPD_PATH,
&bes2600_cdev.dpd_data, &bes2600_cdev.dpd_len) < 0)) {
bes_err("%s read dpd data fail\n", __func__);
return NULL;
} else {
bes2600_cdev.dpd_calied = true;
}
}
#endif
if (!bes2600_cdev.dpd_calied)
return NULL;
if (len)
@@ -460,14 +325,6 @@ int bes2600_chrdev_update_dpd_data(void)
}
spin_unlock(&bes2600_cdev.status_lock);
#ifdef BES2600_WRITE_DPD_TO_FILE
/* write dpd data to file */
memset(bes2600_cdev.dpd_data + DPD_BIN_SIZE, 0, DPD_BIN_FILE_SIZE - DPD_BIN_SIZE);
bes2600_chrdev_write_dpd_data_to_file(BES2600_DPD_PATH,
bes2600_cdev.dpd_data, DPD_BIN_FILE_SIZE);
#endif
return 0;
}