RE: [PATCH] scsi: megaraid: Convert timers to use timer_setup()

Sumit Saxena
2017-10-31T18:48:02Z

-----Original Message-----
From: Kees Cook [mailto:keescook@chromium.org]
Sent: Wednesday, October 25, 2017 3:37 PM
To: Martin K. Petersen
Cc: Kashyap Desai; Sumit Saxena; Shivasharan S; James E.J. Bottomley;
megaraidlinux.pdl@broadcom.com; linux-scsi@vger.kernel.org;
linux-kernel@vger.kernel.org
Subject: [PATCH] scsi: megaraid: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer
to all timer callbacks, switch to using the new timer_setup() and
from_timer() to pass the timer pointer explicitly. Also consolidates the
timer setup functions arguments, which are all identical, and corrects
on-stack timer usage.

Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: megaraidlinux.pdl@broadcom.com
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/scsi/megaraid/megaraid_ioctl.h | 6 +++++
drivers/scsi/megaraid/megaraid_mbox.c | 26 ++++++++++-----------
drivers/scsi/megaraid/megaraid_mm.c | 27 +++++++++++-----------
drivers/scsi/megaraid/megaraid_sas_base.c | 35
+++++++++++------------------
drivers/scsi/megaraid/megaraid_sas_fusion.c | 15 +++----------
5 files changed, 47 insertions(+), 62 deletions(-)

diff --git a/drivers/scsi/megaraid/megaraid_ioctl.h
b/drivers/scsi/megaraid/megaraid_ioctl.h
index 05f6e4ec3453..eedcbde46459 100644
--- a/drivers/scsi/megaraid/megaraid_ioctl.h
+++ b/drivers/scsi/megaraid/megaraid_ioctl.h
@@ -19,6 +19,7 @@

#include <linux/types.h>
#include <linux/semaphore.h>
+#include <linux/timer.h>

#include "mbox_defs.h"

@@ -153,6 +154,11 @@ typedef struct uioc {

} __attribute__ ((aligned(1024),packed)) uioc_t;

+/* For on-stack uioc timers. */
+struct uioc_timeout {
+ struct timer_list timer;
+ uioc_t *uioc;
+};

/**
* struct mraid_hba_info - information about the controller diff --git
a/drivers/scsi/megaraid/megaraid_mbox.c
b/drivers/scsi/megaraid/megaraid_mbox.c
index ec3c43854978..530358cdcb39 100644
--- a/drivers/scsi/megaraid/megaraid_mbox.c
+++ b/drivers/scsi/megaraid/megaraid_mbox.c
@@ -3904,19 +3904,19 @@ megaraid_sysfs_get_ldmap_done(uioc_t *uioc)
wake_up(&raid_dev->sysfs_wait_q);
}

-
/**
* megaraid_sysfs_get_ldmap_timeout - timeout handling for get ldmap
- * @data : timed out packet
+ * @t : timed out timer
*
* Timeout routine to recover and return to application, in case the
adapter
* has stopped responding. A timeout of 60 seconds for this command seems
like
* a good value.
*/
static void
-megaraid_sysfs_get_ldmap_timeout(unsigned long data)
+megaraid_sysfs_get_ldmap_timeout(struct timer_list *t)
{
- uioc_t *uioc = (uioc_t *)data;
+ struct uioc_timeout *timeout = from_timer(timeout, t, timer);
+ uioc_t *uioc = timeout->uioc;
adapter_t *adapter = (adapter_t *)uioc->buf_vaddr;
mraid_device_t *raid_dev = ADAP2RAIDDEV(adapter);

@@ -3951,8 +3951,7 @@ megaraid_sysfs_get_ldmap(adapter_t *adapter)
mbox64_t *mbox64;
mbox_t *mbox;
char *raw_mbox;
- struct timer_list sysfs_timer;
- struct timer_list *timerp;
+ struct uioc_timeout timeout;
caddr_t ldmap;
int rval = 0;

@@ -3988,14 +3987,12 @@ megaraid_sysfs_get_ldmap(adapter_t *adapter)
/*
* Setup a timer to recover from a non-responding controller
*/
- timerp = &sysfs_timer;
- init_timer(timerp);
-
- timerp->function = megaraid_sysfs_get_ldmap_timeout;
- timerp->data = (unsigned long)uioc;
- timerp->expires = jiffies + 60 * HZ;
+ timeout.uioc = uioc;
+ timer_setup_on_stack(&timeout.timer,
+ megaraid_sysfs_get_ldmap_timeout, 0);

Kees,
Does calling "timer_setup_on_stack" instead of "timer_setup" intentional ?
If yes, please help me understand the reason.
Otherwise changes look good to me.

- add_timer(timerp);
+ timeout.timer.expires = jiffies + 60 * HZ;
+ add_timer(&timeout.timer);

/*
* Send the command to the firmware
@@ -4033,7 +4030,8 @@ megaraid_sysfs_get_ldmap(adapter_t *adapter)
}

- del_timer_sync(timerp);
+ del_timer_sync(&timeout.timer);
+ destroy_timer_on_stack(&timeout.timer);

mutex_unlock(&raid_dev->sysfs_mtx);

diff --git a/drivers/scsi/megaraid/megaraid_mm.c
b/drivers/scsi/megaraid/megaraid_mm.c
index 65b6f6ace3a5..bb802b0c12b8 100644
--- a/drivers/scsi/megaraid/megaraid_mm.c
+++ b/drivers/scsi/megaraid/megaraid_mm.c
@@ -35,7 +35,7 @@ static int kioc_to_mimd(uioc_t *, mimd_t __user *);
static int handle_drvrcmd(void __user *, uint8_t, int *); static int
lld_ioctl(mraid_mmadp_t *, uioc_t *); static void ioctl_done(uioc_t *);
-static void lld_timedout(unsigned long);
+static void lld_timedout(struct timer_list *);
static void hinfo_to_cinfo(mraid_hba_info_t *, mcontroller_t *); static
mraid_mmadp_t *mraid_mm_get_adapter(mimd_t __user *, int *); static
uioc_t *mraid_mm_alloc_kioc(mraid_mmadp_t *); @@ -686,8 +686,7 @@ static
int lld_ioctl(mraid_mmadp_t *adp, uioc_t *kioc) {
int rval;
- struct timer_list timer;
- struct timer_list *tp = NULL;
+ struct uioc_timeout timeout = { };

kioc->status = -ENODATA;
rval = adp->issue_uioc(adp->drvr_data, kioc,
IOCTL_ISSUE);
@@ -698,14 +697,12 @@ lld_ioctl(mraid_mmadp_t *adp, uioc_t *kioc)
* Start the timer
*/
if (adp->timeout > 0) {
- tp = &timer;
- init_timer(tp);
+ timeout.uioc = kioc;
+ timer_setup_on_stack(&timeout.timer, lld_timedout, 0);

Same question as above.

- tp->function = lld_timedout;
- tp->data = (unsigned long)kioc;
- tp->expires = jiffies + adp->timeout * HZ;
+ timeout.timer.expires = jiffies + adp->timeout * HZ;

- add_timer(tp);
+ add_timer(&timeout.timer);
}

/*
@@ -713,8 +710,9 @@ lld_ioctl(mraid_mmadp_t *adp, uioc_t *kioc)
* call, the ioctl either completed successfully or timedout.
*/
wait_event(wait_q, (kioc->status != -ENODATA));
- if (tp) {
- del_timer_sync(tp);
+ if (timeout.timer.function) {
+ del_timer_sync(&timeout.timer);
+ destroy_timer_on_stack(&timeout.timer);
}

/*
@@ -783,12 +781,13 @@ ioctl_done(uioc_t *kioc)

/**
* lld_timedout - callback from the expired timer
- * @ptr : ioctl packet that timed out
+ * @t : timer that timed out
*/
static void
-lld_timedout(unsigned long ptr)
+lld_timedout(struct timer_list *t)
{
- uioc_t *kioc = (uioc_t *)ptr;
+ struct uioc_timeout *timeout = from_timer(timeout, t, timer);
+ uioc_t *kioc = timeout->uioc;

kioc->status = -ETIME;
kioc->timedout = 1;
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c
b/drivers/scsi/megaraid/megaraid_sas_base.c
index e518dadc8161..a36e18156e49 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -2114,22 +2114,19 @@ static void megasas_complete_cmd_dpc(unsigned long
instance_addr)
megasas_check_and_restore_queue_depth(instance);
}

+static void megasas_sriov_heartbeat_handler(struct timer_list *t);
+
/**
- * megasas_start_timer - Initializes a timer object
+ * megasas_start_timer - Initializes sriov heartbeat timer object
* @instance: Adapter soft state
- * @timer: timer object to be initialized
- * @fn: timer function
- * @interval: time interval between timer function call
*
*/
-void megasas_start_timer(struct megasas_instance *instance,
- struct timer_list *timer,
- void *fn, unsigned long interval)
-{
- init_timer(timer);
- timer->expires = jiffies + interval;
- timer->data = (unsigned long)instance;
- timer->function = fn;
+void megasas_start_timer(struct megasas_instance *instance) {
+ struct timer_list *timer = &instance->sriov_heartbeat_timer;
+
+ timer_setup(timer, megasas_sriov_heartbeat_handler, 0);
+ timer->expires = jiffies + MEGASAS_SRIOV_HEARTBEAT_INTERVAL_VF;
add_timer(timer);
}

@@ -2515,10 +2512,10 @@ int megasas_sriov_start_heartbeat(struct
megasas_instance *instance, }

/* Handler for SR-IOV heartbeat */
-void megasas_sriov_heartbeat_handler(unsigned long instance_addr)
+static void megasas_sriov_heartbeat_handler(struct timer_list *t)
{
struct megasas_instance *instance =
- (struct megasas_instance *)instance_addr;
+ from_timer(instance, t, sriov_heartbeat_timer);

if (instance->hb_host_mem->HB.fwCounter !=
instance->hb_host_mem->HB.driverCounter) { @@ -5493,10 +5490,7
@@ static int megasas_init_fw(struct megasas_instance *instance)
/* Launch SR-IOV heartbeat timer */
if (instance->requestorId) {
if (!megasas_sriov_start_heartbeat(instance, 1))
- megasas_start_timer(instance,
-
&instance->sriov_heartbeat_timer,
-
megasas_sriov_heartbeat_handler,
-
MEGASAS_SRIOV_HEARTBEAT_INTERVAL_VF);
+ megasas_start_timer(instance);
else
instance->skip_heartbeat_timer_del = 1;
}
@@ -6507,10 +6501,7 @@ megasas_resume(struct pci_dev *pdev)
/* Re-launch SR-IOV heartbeat timer */
if (instance->requestorId) {
if (!megasas_sriov_start_heartbeat(instance, 0))
- megasas_start_timer(instance,
-
&instance->sriov_heartbeat_timer,
-
megasas_sriov_heartbeat_handler,
-
MEGASAS_SRIOV_HEARTBEAT_INTERVAL_VF);
+ megasas_start_timer(instance);
else {
instance->skip_heartbeat_timer_del = 1;
goto fail_init_mfi;
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c
b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index 11bd2e698b84..3c399e7b3fe1 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -85,12 +85,9 @@ int megasas_transition_to_ready(struct megasas_instance
*instance, int ocr); void megaraid_sas_kill_hba(struct megasas_instance
*instance);

extern u32 megasas_dbg_lvl;
-void megasas_sriov_heartbeat_handler(unsigned long instance_addr); int
megasas_sriov_start_heartbeat(struct megasas_instance *instance,
int initial);
-void megasas_start_timer(struct megasas_instance *instance,
- struct timer_list *timer,
- void *fn, unsigned long interval);
+void megasas_start_timer(struct megasas_instance *instance);
extern struct megasas_mgmt_info megasas_mgmt_info; extern unsigned int
resetwaittime; extern unsigned int dual_qdepth_disable; @@ -4369,10
+4366,7 @@ int megasas_reset_fusion(struct Scsi_Host *shost, int reason)
/* Restart SR-IOV heartbeat */
if (instance->requestorId) {
if
(!megasas_sriov_start_heartbeat(instance, 0))
- megasas_start_timer(instance,
-
&instance->sriov_heartbeat_timer,
-
megasas_sriov_heartbeat_handler,
-
MEGASAS_SRIOV_HEARTBEAT_INTERVAL_VF);
+ megasas_start_timer(instance);
else
instance->skip_heartbeat_timer_del
= 1;
}
@@ -4404,10 +4398,7 @@ int megasas_reset_fusion(struct Scsi_Host *shost,
int reason)
} else {
/* For VF: Restart HB timer if we didn't OCR */
if (instance->requestorId) {
- megasas_start_timer(instance,
-
&instance->sriov_heartbeat_timer,
-
megasas_sriov_heartbeat_handler,
-
MEGASAS_SRIOV_HEARTBEAT_INTERVAL_VF);
+ megasas_start_timer(instance);
}
clear_bit(MEGASAS_FUSION_IN_RESET,
&instance->reset_flags);
instance->instancet->enable_intr(instance);
--
2.7.4

--
Kees Cook
Pixel Security