kernel_optimize_test/drivers/soc/qcom/rpmh.c
Stephen Boyd baef1c90aa soc: qcom: rpmh: Avoid accessing freed memory from batch API
Using the batch API from the interconnect driver sometimes leads to a
KASAN error due to an access to freed memory. This is easier to trigger
with threadirqs on the kernel commandline.

 BUG: KASAN: use-after-free in rpmh_tx_done+0x114/0x12c
 Read of size 1 at addr fffffff51414ad84 by task irq/110-apps_rs/57

 CPU: 0 PID: 57 Comm: irq/110-apps_rs Tainted: G        W         4.19.10 #72
 Call trace:
  dump_backtrace+0x0/0x2f8
  show_stack+0x20/0x2c
  __dump_stack+0x20/0x28
  dump_stack+0xcc/0x10c
  print_address_description+0x74/0x240
  kasan_report+0x250/0x26c
  __asan_report_load1_noabort+0x20/0x2c
  rpmh_tx_done+0x114/0x12c
  tcs_tx_done+0x450/0x768
  irq_forced_thread_fn+0x58/0x9c
  irq_thread+0x120/0x1dc
  kthread+0x248/0x260
  ret_from_fork+0x10/0x18

 Allocated by task 385:
  kasan_kmalloc+0xac/0x148
  __kmalloc+0x170/0x1e4
  rpmh_write_batch+0x174/0x540
  qcom_icc_set+0x8dc/0x9ac
  icc_set+0x288/0x2e8
  a6xx_gmu_stop+0x320/0x3c0
  a6xx_pm_suspend+0x108/0x124
  adreno_suspend+0x50/0x60
  pm_generic_runtime_suspend+0x60/0x78
  __rpm_callback+0x214/0x32c
  rpm_callback+0x54/0x184
  rpm_suspend+0x3f8/0xa90
  pm_runtime_work+0xb4/0x178
  process_one_work+0x544/0xbc0
  worker_thread+0x514/0x7d0
  kthread+0x248/0x260
  ret_from_fork+0x10/0x18

 Freed by task 385:
  __kasan_slab_free+0x12c/0x1e0
  kasan_slab_free+0x10/0x1c
  kfree+0x134/0x588
  rpmh_write_batch+0x49c/0x540
  qcom_icc_set+0x8dc/0x9ac
  icc_set+0x288/0x2e8
  a6xx_gmu_stop+0x320/0x3c0
  a6xx_pm_suspend+0x108/0x124
  adreno_suspend+0x50/0x60
 cr50_spi spi5.0: SPI transfer timed out
  pm_generic_runtime_suspend+0x60/0x78
  __rpm_callback+0x214/0x32c
  rpm_callback+0x54/0x184
  rpm_suspend+0x3f8/0xa90
  pm_runtime_work+0xb4/0x178
  process_one_work+0x544/0xbc0
  worker_thread+0x514/0x7d0
  kthread+0x248/0x260
  ret_from_fork+0x10/0x18

 The buggy address belongs to the object at fffffff51414ac80
  which belongs to the cache kmalloc-512 of size 512
 The buggy address is located 260 bytes inside of
  512-byte region [fffffff51414ac80, fffffff51414ae80)
 The buggy address belongs to the page:
 page:ffffffbfd4505200 count:1 mapcount:0 mapping:fffffff51e00c680 index:0x0 compound_mapcount: 0
 flags: 0x4000000000008100(slab|head)
 raw: 4000000000008100 ffffffbfd4529008 ffffffbfd44f9208 fffffff51e00c680
 raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  fffffff51414ac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  fffffff51414ad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 >fffffff51414ad80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                    ^
  fffffff51414ae00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  fffffff51414ae80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

The batch API sets the same completion for each rpmh message that's sent
and then loops through all the messages and waits for that single
completion declared on the stack to be completed before returning from
the function and freeing the message structures. Unfortunately, some
messages may still be in process and 'stuck' in the TCS. At some later
point, the tcs_tx_done() interrupt will run and try to process messages
that have already been freed at the end of rpmh_write_batch(). This will
in turn access the 'needs_free' member of the rpmh_request structure and
cause KASAN to complain. Furthermore, if there's a message that's
completed in rpmh_tx_done() and freed immediately after the complete()
call is made we'll be racing with potentially freed memory when
accessing the 'needs_free' member:

	CPU0                         CPU1
	----                         ----
	rpmh_tx_done()
	 complete(&compl)
	                             wait_for_completion(&compl)
	                             kfree(rpm_msg)
	 if (rpm_msg->needs_free)
	 <KASAN warning splat>

Let's fix this by allocating a chunk of completions for each message and
waiting for all of them to be completed before returning from the batch
API. Alternatively, we could wait for the last message in the batch, but
that may be a more complicated change because it looks like
tcs_tx_done() just iterates through the indices of the queue and
completes each message instead of tracking the last inserted message and
completing that first.

Fixes: c8790cb6da ("drivers: qcom: rpmh: add support for batch RPMH request")
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: "Raju P.L.S.S.S.N" <rplsssn@codeaurora.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Evan Green <evgreen@chromium.org>
Cc: stable@vger.kernel.org
Reviewed-by: Lina Iyer <ilina@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
2019-02-01 16:08:45 -06:00

521 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
*/
#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <soc/qcom/rpmh.h>
#include "rpmh-internal.h"
#define RPMH_TIMEOUT_MS msecs_to_jiffies(10000)
#define DEFINE_RPMH_MSG_ONSTACK(dev, s, q, name) \
struct rpmh_request name = { \
.msg = { \
.state = s, \
.cmds = name.cmd, \
.num_cmds = 0, \
.wait_for_compl = true, \
}, \
.cmd = { { 0 } }, \
.completion = q, \
.dev = dev, \
.needs_free = false, \
}
#define ctrlr_to_drv(ctrlr) container_of(ctrlr, struct rsc_drv, client)
/**
* struct cache_req: the request object for caching
*
* @addr: the address of the resource
* @sleep_val: the sleep vote
* @wake_val: the wake vote
* @list: linked list obj
*/
struct cache_req {
u32 addr;
u32 sleep_val;
u32 wake_val;
struct list_head list;
};
/**
* struct batch_cache_req - An entry in our batch catch
*
* @list: linked list obj
* @count: number of messages
* @rpm_msgs: the messages
*/
struct batch_cache_req {
struct list_head list;
int count;
struct rpmh_request rpm_msgs[];
};
static struct rpmh_ctrlr *get_rpmh_ctrlr(const struct device *dev)
{
struct rsc_drv *drv = dev_get_drvdata(dev->parent);
return &drv->client;
}
void rpmh_tx_done(const struct tcs_request *msg, int r)
{
struct rpmh_request *rpm_msg = container_of(msg, struct rpmh_request,
msg);
struct completion *compl = rpm_msg->completion;
bool free = rpm_msg->needs_free;
rpm_msg->err = r;
if (r)
dev_err(rpm_msg->dev, "RPMH TX fail in msg addr=%#x, err=%d\n",
rpm_msg->msg.cmds[0].addr, r);
if (!compl)
goto exit;
/* Signal the blocking thread we are done */
complete(compl);
exit:
if (free)
kfree(rpm_msg);
}
static struct cache_req *__find_req(struct rpmh_ctrlr *ctrlr, u32 addr)
{
struct cache_req *p, *req = NULL;
list_for_each_entry(p, &ctrlr->cache, list) {
if (p->addr == addr) {
req = p;
break;
}
}
return req;
}
static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr,
enum rpmh_state state,
struct tcs_cmd *cmd)
{
struct cache_req *req;
unsigned long flags;
spin_lock_irqsave(&ctrlr->cache_lock, flags);
req = __find_req(ctrlr, cmd->addr);
if (req)
goto existing;
req = kzalloc(sizeof(*req), GFP_ATOMIC);
if (!req) {
req = ERR_PTR(-ENOMEM);
goto unlock;
}
req->addr = cmd->addr;
req->sleep_val = req->wake_val = UINT_MAX;
INIT_LIST_HEAD(&req->list);
list_add_tail(&req->list, &ctrlr->cache);
existing:
switch (state) {
case RPMH_ACTIVE_ONLY_STATE:
if (req->sleep_val != UINT_MAX)
req->wake_val = cmd->data;
break;
case RPMH_WAKE_ONLY_STATE:
req->wake_val = cmd->data;
break;
case RPMH_SLEEP_STATE:
req->sleep_val = cmd->data;
break;
default:
break;
}
ctrlr->dirty = true;
unlock:
spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
return req;
}
/**
* __rpmh_write: Cache and send the RPMH request
*
* @dev: The device making the request
* @state: Active/Sleep request type
* @rpm_msg: The data that needs to be sent (cmds).
*
* Cache the RPMH request and send if the state is ACTIVE_ONLY.
* SLEEP/WAKE_ONLY requests are not sent to the controller at
* this time. Use rpmh_flush() to send them to the controller.
*/
static int __rpmh_write(const struct device *dev, enum rpmh_state state,
struct rpmh_request *rpm_msg)
{
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
int ret = -EINVAL;
struct cache_req *req;
int i;
rpm_msg->msg.state = state;
/* Cache the request in our store and link the payload */
for (i = 0; i < rpm_msg->msg.num_cmds; i++) {
req = cache_rpm_request(ctrlr, state, &rpm_msg->msg.cmds[i]);
if (IS_ERR(req))
return PTR_ERR(req);
}
rpm_msg->msg.state = state;
if (state == RPMH_ACTIVE_ONLY_STATE) {
WARN_ON(irqs_disabled());
ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msg->msg);
} else {
/* Clean up our call by spoofing tx_done */
ret = 0;
rpmh_tx_done(&rpm_msg->msg, ret);
}
return ret;
}
static int __fill_rpmh_msg(struct rpmh_request *req, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n)
{
if (!cmd || !n || n > MAX_RPMH_PAYLOAD)
return -EINVAL;
memcpy(req->cmd, cmd, n * sizeof(*cmd));
req->msg.state = state;
req->msg.cmds = req->cmd;
req->msg.num_cmds = n;
return 0;
}
/**
* rpmh_write_async: Write a set of RPMH commands
*
* @dev: The device making the request
* @state: Active/sleep set
* @cmd: The payload data
* @n: The number of elements in payload
*
* Write a set of RPMH commands, the order of commands is maintained
* and will be sent as a single shot.
*/
int rpmh_write_async(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n)
{
struct rpmh_request *rpm_msg;
int ret;
rpm_msg = kzalloc(sizeof(*rpm_msg), GFP_ATOMIC);
if (!rpm_msg)
return -ENOMEM;
rpm_msg->needs_free = true;
ret = __fill_rpmh_msg(rpm_msg, state, cmd, n);
if (ret) {
kfree(rpm_msg);
return ret;
}
return __rpmh_write(dev, state, rpm_msg);
}
EXPORT_SYMBOL(rpmh_write_async);
/**
* rpmh_write: Write a set of RPMH commands and block until response
*
* @rc: The RPMH handle got from rpmh_get_client
* @state: Active/sleep set
* @cmd: The payload data
* @n: The number of elements in @cmd
*
* May sleep. Do not call from atomic contexts.
*/
int rpmh_write(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n)
{
DECLARE_COMPLETION_ONSTACK(compl);
DEFINE_RPMH_MSG_ONSTACK(dev, state, &compl, rpm_msg);
int ret;
if (!cmd || !n || n > MAX_RPMH_PAYLOAD)
return -EINVAL;
memcpy(rpm_msg.cmd, cmd, n * sizeof(*cmd));
rpm_msg.msg.num_cmds = n;
ret = __rpmh_write(dev, state, &rpm_msg);
if (ret)
return ret;
ret = wait_for_completion_timeout(&compl, RPMH_TIMEOUT_MS);
WARN_ON(!ret);
return (ret > 0) ? 0 : -ETIMEDOUT;
}
EXPORT_SYMBOL(rpmh_write);
static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req)
{
unsigned long flags;
spin_lock_irqsave(&ctrlr->cache_lock, flags);
list_add_tail(&req->list, &ctrlr->batch_cache);
spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
}
static int flush_batch(struct rpmh_ctrlr *ctrlr)
{
struct batch_cache_req *req;
const struct rpmh_request *rpm_msg;
unsigned long flags;
int ret = 0;
int i;
/* Send Sleep/Wake requests to the controller, expect no response */
spin_lock_irqsave(&ctrlr->cache_lock, flags);
list_for_each_entry(req, &ctrlr->batch_cache, list) {
for (i = 0; i < req->count; i++) {
rpm_msg = req->rpm_msgs + i;
ret = rpmh_rsc_write_ctrl_data(ctrlr_to_drv(ctrlr),
&rpm_msg->msg);
if (ret)
break;
}
}
spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
return ret;
}
static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
{
struct batch_cache_req *req, *tmp;
unsigned long flags;
spin_lock_irqsave(&ctrlr->cache_lock, flags);
list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
kfree(req);
INIT_LIST_HEAD(&ctrlr->batch_cache);
spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
}
/**
* rpmh_write_batch: Write multiple sets of RPMH commands and wait for the
* batch to finish.
*
* @dev: the device making the request
* @state: Active/sleep set
* @cmd: The payload data
* @n: The array of count of elements in each batch, 0 terminated.
*
* Write a request to the RSC controller without caching. If the request
* state is ACTIVE, then the requests are treated as completion request
* and sent to the controller immediately. The function waits until all the
* commands are complete. If the request was to SLEEP or WAKE_ONLY, then the
* request is sent as fire-n-forget and no ack is expected.
*
* May sleep. Do not call from atomic contexts for ACTIVE_ONLY requests.
*/
int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 *n)
{
struct batch_cache_req *req;
struct rpmh_request *rpm_msgs;
struct completion *compls;
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
unsigned long time_left;
int count = 0;
int ret, i;
void *ptr;
if (!cmd || !n)
return -EINVAL;
while (n[count] > 0)
count++;
if (!count)
return -EINVAL;
ptr = kzalloc(sizeof(*req) +
count * (sizeof(req->rpm_msgs[0]) + sizeof(*compls)),
GFP_ATOMIC);
if (!ptr)
return -ENOMEM;
req = ptr;
compls = ptr + sizeof(*req) + count * sizeof(*rpm_msgs);
req->count = count;
rpm_msgs = req->rpm_msgs;
for (i = 0; i < count; i++) {
__fill_rpmh_msg(rpm_msgs + i, state, cmd, n[i]);
cmd += n[i];
}
if (state != RPMH_ACTIVE_ONLY_STATE) {
cache_batch(ctrlr, req);
return 0;
}
for (i = 0; i < count; i++) {
struct completion *compl = &compls[i];
init_completion(compl);
rpm_msgs[i].completion = compl;
ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msgs[i].msg);
if (ret) {
pr_err("Error(%d) sending RPMH message addr=%#x\n",
ret, rpm_msgs[i].msg.cmds[0].addr);
break;
}
}
time_left = RPMH_TIMEOUT_MS;
while (i--) {
time_left = wait_for_completion_timeout(&compls[i], time_left);
if (!time_left) {
/*
* Better hope they never finish because they'll signal
* the completion that we're going to free once
* we've returned from this function.
*/
WARN_ON(1);
ret = -ETIMEDOUT;
goto exit;
}
}
exit:
kfree(ptr);
return ret;
}
EXPORT_SYMBOL(rpmh_write_batch);
static int is_req_valid(struct cache_req *req)
{
return (req->sleep_val != UINT_MAX &&
req->wake_val != UINT_MAX &&
req->sleep_val != req->wake_val);
}
static int send_single(const struct device *dev, enum rpmh_state state,
u32 addr, u32 data)
{
DEFINE_RPMH_MSG_ONSTACK(dev, state, NULL, rpm_msg);
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
/* Wake sets are always complete and sleep sets are not */
rpm_msg.msg.wait_for_compl = (state == RPMH_WAKE_ONLY_STATE);
rpm_msg.cmd[0].addr = addr;
rpm_msg.cmd[0].data = data;
rpm_msg.msg.num_cmds = 1;
return rpmh_rsc_write_ctrl_data(ctrlr_to_drv(ctrlr), &rpm_msg.msg);
}
/**
* rpmh_flush: Flushes the buffered active and sleep sets to TCS
*
* @dev: The device making the request
*
* Return: -EBUSY if the controller is busy, probably waiting on a response
* to a RPMH request sent earlier.
*
* This function is always called from the sleep code from the last CPU
* that is powering down the entire system. Since no other RPMH API would be
* executing at this time, it is safe to run lockless.
*/
int rpmh_flush(const struct device *dev)
{
struct cache_req *p;
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
int ret;
if (!ctrlr->dirty) {
pr_debug("Skipping flush, TCS has latest data.\n");
return 0;
}
/* First flush the cached batch requests */
ret = flush_batch(ctrlr);
if (ret)
return ret;
/*
* Nobody else should be calling this function other than system PM,
* hence we can run without locks.
*/
list_for_each_entry(p, &ctrlr->cache, list) {
if (!is_req_valid(p)) {
pr_debug("%s: skipping RPMH req: a:%#x s:%#x w:%#x",
__func__, p->addr, p->sleep_val, p->wake_val);
continue;
}
ret = send_single(dev, RPMH_SLEEP_STATE, p->addr, p->sleep_val);
if (ret)
return ret;
ret = send_single(dev, RPMH_WAKE_ONLY_STATE,
p->addr, p->wake_val);
if (ret)
return ret;
}
ctrlr->dirty = false;
return 0;
}
EXPORT_SYMBOL(rpmh_flush);
/**
* rpmh_invalidate: Invalidate all sleep and active sets
* sets.
*
* @dev: The device making the request
*
* Invalidate the sleep and active values in the TCS blocks.
*/
int rpmh_invalidate(const struct device *dev)
{
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
int ret;
invalidate_batch(ctrlr);
ctrlr->dirty = true;
do {
ret = rpmh_rsc_invalidate(ctrlr_to_drv(ctrlr));
} while (ret == -EAGAIN);
return ret;
}
EXPORT_SYMBOL(rpmh_invalidate);