* [PATCH 2/2] scsi: ufs: Protect PM ops and err_handler from user access through sysfs
2020-12-31 4:25 [PATCH v1 0/2] Synchronize user layer access with system PM ops and error handling Can Guo
2020-12-31 4:25 ` [PATCH 1/2] scsi: ufs: Fix a possible NULL pointer issue Can Guo
@ 2020-12-31 4:25 ` Can Guo
1 sibling, 0 replies; 3+ messages in thread
From: Can Guo @ 2020-12-31 4:25 UTC (permalink / raw)
To: asutoshd, nguyenb, hongwus, ziqichen, rnayak, linux-scsi,
kernel-team, saravanak, salyzyn, cang
Cc: Alim Akhtar, Avri Altman, James E.J. Bottomley,
Martin K. Petersen, Stanley Chu, Bean Huo, Nitin Rawat,
Adrian Hunter, Bart Van Assche, Satya Tangirala, open list
User layer may access sysfs nodes when system PM ops or error handling
is running, which can cause various problems. Rename eh_sem to host_sem
and use it to protect PM ops and error handling from user layer intervene.
Signed-off-by: Can Guo <cang@codeaurora.org>
diff --git a/drivers/scsi/ufs/ufs-sysfs.c b/drivers/scsi/ufs/ufs-sysfs.c
index 08e72b7..1828b34 100644
--- a/drivers/scsi/ufs/ufs-sysfs.c
+++ b/drivers/scsi/ufs/ufs-sysfs.c
@@ -154,18 +154,29 @@ static ssize_t auto_hibern8_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
u32 ahit;
+ int ret;
struct ufs_hba *hba = dev_get_drvdata(dev);
if (!ufshcd_is_auto_hibern8_supported(hba))
return -EOPNOTSUPP;
+ down(&hba->host_sem);
+ if (hba->shutting_down) {
+ ret = -EBUSY;
+ goto out;
+ }
+
pm_runtime_get_sync(hba->dev);
ufshcd_hold(hba, false);
ahit = ufshcd_readl(hba, REG_AUTO_HIBERNATE_IDLE_TIMER);
ufshcd_release(hba);
pm_runtime_put_sync(hba->dev);
- return scnprintf(buf, PAGE_SIZE, "%d\n", ufshcd_ahit_to_us(ahit));
+ ret = scnprintf(buf, PAGE_SIZE, "%d\n", ufshcd_ahit_to_us(ahit));
+
+out:
+ up(&hba->host_sem);
+ return ret;
}
static ssize_t auto_hibern8_store(struct device *dev,
@@ -174,6 +185,7 @@ static ssize_t auto_hibern8_store(struct device *dev,
{
struct ufs_hba *hba = dev_get_drvdata(dev);
unsigned int timer;
+ int ret = 0;
if (!ufshcd_is_auto_hibern8_supported(hba))
return -EOPNOTSUPP;
@@ -184,9 +196,17 @@ static ssize_t auto_hibern8_store(struct device *dev,
if (timer > UFSHCI_AHIBERN8_MAX)
return -EINVAL;
+ down(&hba->host_sem);
+ if (hba->shutting_down) {
+ ret = -EBUSY;
+ goto out;
+ }
+
ufshcd_auto_hibern8_update(hba, ufshcd_us_to_ahit(timer));
- return count;
+out:
+ up(&hba->host_sem);
+ return ret ? ret : count;
}
static DEVICE_ATTR_RW(rpm_lvl);
@@ -225,12 +245,21 @@ static ssize_t ufs_sysfs_read_desc_param(struct ufs_hba *hba,
if (param_size > 8)
return -EINVAL;
+ down(&hba->host_sem);
+ if (hba->shutting_down) {
+ ret = -EBUSY;
+ goto out;
+ }
+
pm_runtime_get_sync(hba->dev);
ret = ufshcd_read_desc_param(hba, desc_id, desc_index,
param_offset, desc_buf, param_size);
pm_runtime_put_sync(hba->dev);
- if (ret)
- return -EINVAL;
+ if (ret) {
+ ret = -EINVAL;
+ goto out;
+ }
+
switch (param_size) {
case 1:
ret = sprintf(sysfs_buf, "0x%02X\n", *desc_buf);
@@ -249,6 +278,8 @@ static ssize_t ufs_sysfs_read_desc_param(struct ufs_hba *hba,
break;
}
+out:
+ up(&hba->host_sem);
return ret;
}
@@ -591,9 +622,16 @@ static ssize_t _name##_show(struct device *dev, \
int desc_len = QUERY_DESC_MAX_SIZE; \
u8 *desc_buf; \
\
+ down(&hba->host_sem); \
+ if (hba->shutting_down) { \
+ up(&hba->host_sem); \
+ return -EBUSY; \
+ } \
desc_buf = kzalloc(QUERY_DESC_MAX_SIZE, GFP_ATOMIC); \
- if (!desc_buf) \
- return -ENOMEM; \
+ if (!desc_buf) { \
+ up(&hba->host_sem); \
+ return -ENOMEM; \
+ } \
pm_runtime_get_sync(hba->dev); \
ret = ufshcd_query_descriptor_retry(hba, \
UPIU_QUERY_OPCODE_READ_DESC, QUERY_DESC_IDN_DEVICE, \
@@ -613,6 +651,7 @@ static ssize_t _name##_show(struct device *dev, \
out: \
pm_runtime_put_sync(hba->dev); \
kfree(desc_buf); \
+ up(&hba->host_sem); \
return ret; \
} \
static DEVICE_ATTR_RO(_name)
@@ -651,15 +690,26 @@ static ssize_t _name##_show(struct device *dev, \
u8 index = 0; \
int ret; \
struct ufs_hba *hba = dev_get_drvdata(dev); \
+ \
+ down(&hba->host_sem); \
+ if (hba->shutting_down) { \
+ up(&hba->host_sem); \
+ return -EBUSY; \
+ } \
if (ufshcd_is_wb_flags(QUERY_FLAG_IDN##_uname)) \
index = ufshcd_wb_get_query_index(hba); \
pm_runtime_get_sync(hba->dev); \
ret = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG, \
QUERY_FLAG_IDN##_uname, index, &flag); \
pm_runtime_put_sync(hba->dev); \
- if (ret) \
- return -EINVAL; \
- return sprintf(buf, "%s\n", flag ? "true" : "false"); \
+ if (ret) { \
+ ret = -EINVAL; \
+ goto out; \
+ } \
+ ret = sprintf(buf, "%s\n", flag ? "true" : "false"); \
+out: \
+ up(&hba->host_sem); \
+ return ret; \
} \
static DEVICE_ATTR_RO(_name)
@@ -709,15 +759,26 @@ static ssize_t _name##_show(struct device *dev, \
u32 value; \
int ret; \
u8 index = 0; \
+ \
+ down(&hba->host_sem); \
+ if (hba->shutting_down) { \
+ up(&hba->host_sem); \
+ return -EBUSY; \
+ } \
if (ufshcd_is_wb_attrs(QUERY_ATTR_IDN##_uname)) \
index = ufshcd_wb_get_query_index(hba); \
pm_runtime_get_sync(hba->dev); \
ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR, \
QUERY_ATTR_IDN##_uname, index, 0, &value); \
pm_runtime_put_sync(hba->dev); \
- if (ret) \
- return -EINVAL; \
- return sprintf(buf, "0x%08X\n", value); \
+ if (ret) { \
+ ret = -EINVAL; \
+ goto out; \
+ } \
+ ret = sprintf(buf, "0x%08X\n", value); \
+out: \
+ up(&hba->host_sem); \
+ return ret; \
} \
static DEVICE_ATTR_RO(_name)
@@ -850,13 +911,26 @@ static ssize_t dyn_cap_needed_attribute_show(struct device *dev,
u8 lun = ufshcd_scsi_to_upiu_lun(sdev->lun);
int ret;
+ down(&hba->host_sem);
+ if (hba->shutting_down) {
+ ret = -EBUSY;
+ goto out;
+ }
+
pm_runtime_get_sync(hba->dev);
ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
QUERY_ATTR_IDN_DYN_CAP_NEEDED, lun, 0, &value);
pm_runtime_put_sync(hba->dev);
- if (ret)
- return -EINVAL;
- return sprintf(buf, "0x%08X\n", value);
+ if (ret) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = sprintf(buf, "0x%08X\n", value);
+
+out:
+ up(&hba->host_sem);
+ return ret;
}
static DEVICE_ATTR_RO(dyn_cap_needed_attribute);
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 34e2541..b035bd0 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1522,11 +1522,17 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
{
struct ufs_hba *hba = dev_get_drvdata(dev);
u32 value;
- int err;
+ int err = 0;
if (kstrtou32(buf, 0, &value))
return -EINVAL;
+ down(&hba->host_sem);
+ if (hba->shutting_down) {
+ err = -EBUSY;
+ goto out;
+ }
+
value = !!value;
if (value == hba->clk_scaling.is_allowed)
goto out;
@@ -1552,7 +1558,8 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
ufshcd_release(hba);
pm_runtime_put_sync(hba->dev);
out:
- return count;
+ up(&hba->host_sem);
+ return err ? err : count;
}
static void ufshcd_clkscaling_init_sysfs(struct ufs_hba *hba)
@@ -5720,9 +5727,10 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)
{
- return (!hba->is_powered || hba->ufshcd_state == UFSHCD_STATE_ERROR ||
+ return (!hba->is_powered || hba->shutting_down ||
+ hba->ufshcd_state == UFSHCD_STATE_ERROR ||
(!(hba->saved_err || hba->saved_uic_err || hba->force_reset ||
- ufshcd_is_link_broken(hba))));
+ ufshcd_is_link_broken(hba))));
}
#ifdef CONFIG_PM
@@ -5792,13 +5800,13 @@ static void ufshcd_err_handler(struct work_struct *work)
hba = container_of(work, struct ufs_hba, eh_work);
- down(&hba->eh_sem);
+ down(&hba->host_sem);
spin_lock_irqsave(hba->host->host_lock, flags);
if (ufshcd_err_handling_should_stop(hba)) {
if (hba->ufshcd_state != UFSHCD_STATE_ERROR)
hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
spin_unlock_irqrestore(hba->host->host_lock, flags);
- up(&hba->eh_sem);
+ up(&hba->host_sem);
return;
}
ufshcd_set_eh_in_progress(hba);
@@ -5967,7 +5975,7 @@ static void ufshcd_err_handler(struct work_struct *work)
spin_unlock_irqrestore(hba->host->host_lock, flags);
ufshcd_scsi_unblock_requests(hba);
ufshcd_err_handling_unprepare(hba);
- up(&hba->eh_sem);
+ up(&hba->host_sem);
}
/**
@@ -7869,10 +7877,10 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
struct ufs_hba *hba = (struct ufs_hba *)data;
int ret;
- down(&hba->eh_sem);
+ down(&hba->host_sem);
/* Initialize hba, detect and initialize UFS device */
ret = ufshcd_probe_hba(hba, true);
- up(&hba->eh_sem);
+ up(&hba->host_sem);
if (ret)
goto out;
@@ -8899,7 +8907,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
if (!hba)
return 0;
- down(&hba->eh_sem);
+ down(&hba->host_sem);
if (!hba->is_powered)
return 0;
@@ -8931,7 +8939,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
if (!ret)
hba->is_sys_suspended = true;
else
- up(&hba->eh_sem);
+ up(&hba->host_sem);
return ret;
}
EXPORT_SYMBOL(ufshcd_system_suspend);
@@ -8965,7 +8973,7 @@ int ufshcd_system_resume(struct ufs_hba *hba)
hba->curr_dev_pwr_mode, hba->uic_link_state);
if (!ret)
hba->is_sys_suspended = false;
- up(&hba->eh_sem);
+ up(&hba->host_sem);
return ret;
}
EXPORT_SYMBOL(ufshcd_system_resume);
@@ -9057,7 +9065,10 @@ int ufshcd_shutdown(struct ufs_hba *hba)
{
int ret = 0;
- down(&hba->eh_sem);
+ down(&hba->host_sem);
+ hba->shutting_down = true;
+ up(&hba->host_sem);
+
if (!hba->is_powered)
goto out;
@@ -9075,7 +9086,6 @@ int ufshcd_shutdown(struct ufs_hba *hba)
if (ret)
dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
hba->is_powered = false;
- up(&hba->eh_sem);
/* allow force shutdown even in case of errors */
return 0;
}
@@ -9270,7 +9280,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
INIT_WORK(&hba->eh_work, ufshcd_err_handler);
INIT_WORK(&hba->eeh_work, ufshcd_exception_event_handler);
- sema_init(&hba->eh_sem, 1);
+ sema_init(&hba->host_sem, 1);
/* Initialize UIC command mutex */
mutex_init(&hba->uic_cmd_mutex);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 9bb5f0e..af33c82 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -655,6 +655,8 @@ struct ufs_hba_variant_params {
* @intr_mask: Interrupt Mask Bits
* @ee_ctrl_mask: Exception event control mask
* @is_powered: flag to check if HBA is powered
+ * @shutting_down: flag to check if shutdown has been invoked
+ * @host_sem: semaphore used to serialize concurrent contexts
* @eh_wq: Workqueue that eh_work works on
* @eh_work: Worker to handle UFS errors that require s/w attention
* @eeh_work: Worker to handle exception events
@@ -751,7 +753,8 @@ struct ufs_hba {
u32 intr_mask;
u16 ee_ctrl_mask;
bool is_powered;
- struct semaphore eh_sem;
+ bool shutting_down;
+ struct semaphore host_sem;
/* Work Queues */
struct workqueue_struct *eh_wq;
--
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