This bug happens only when the UDC needs to sleep during usb_ep_dequeue,
as is the case for (at least) dwc3.

[  382.200896] BUG: scheduling while atomic: screen/1808/0x00000100
[  382.207124] 4 locks held by screen/1808:
[  382.211266]  #0:  (rcu_callback){....}, at: [<c10b4ff0>] rcu_process_callbacks+0x260/0x440
[  382.219949]  #1:  (rcu_read_lock_sched){....}, at: [<c1358ba0>] percpu_ref_switch_to_atomic_rcu+0xb0/0x130
[  382.230034]  #2:  (&(&ctx->ctx_lock)->rlock){....}, at: [<c11f0c73>] free_ioctx_users+0x23/0xd0
[  382.230096]  #3:  (&(&ffs->eps_lock)->rlock){....}, at: [<f81e7710>] ffs_aio_cancel+0x20/0x60 [usb_f_fs]
[  382.230160] Modules linked in: usb_f_fs libcomposite configfs bnep btsdio bluetooth ecdh_generic brcmfmac brcmutil intel_powerclamp coretemp dwc3 kvm_intel ulpi udc_core kvm irqbypass crc32_pclmul crc32c_intel pcbc dwc3_pci aesni_intel aes_i586 crypto_simd cryptd ehci_pci ehci_hcd gpio_keys usbcore basincove_gpadc industrialio usb_common
[  382.230407] CPU: 1 PID: 1808 Comm: screen Not tainted 4.14.0-edison+ #117
[  382.230416] Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48
[  382.230425] Call Trace:
[  382.230438]  <SOFTIRQ>
[  382.230466]  dump_stack+0x47/0x62
[  382.230498]  __schedule_bug+0x61/0x80
[  382.230522]  __schedule+0x43/0x7a0
[  382.230587]  schedule+0x5f/0x70
[  382.230625]  dwc3_gadget_ep_dequeue+0x14c/0x270 [dwc3]
[  382.230669]  ? do_wait_intr_irq+0x70/0x70
[  382.230724]  usb_ep_dequeue+0x19/0x90 [udc_core]
[  382.230770]  ffs_aio_cancel+0x37/0x60 [usb_f_fs]
[  382.230798]  kiocb_cancel+0x31/0x40
[  382.230822]  free_ioctx_users+0x4d/0xd0
[  382.230858]  percpu_ref_switch_to_atomic_rcu+0x10a/0x130
[  382.230881]  ? percpu_ref_exit+0x40/0x40
[  382.230904]  rcu_process_callbacks+0x2b3/0x440
[  382.230965]  __do_softirq+0xf8/0x26b
[  382.231011]  ? __softirqentry_text_start+0x8/0x8
[  382.231033]  do_softirq_own_stack+0x22/0x30
[  382.231042]  </SOFTIRQ>
[  382.231071]  irq_exit+0x45/0xc0
[  382.231089]  smp_apic_timer_interrupt+0x13c/0x150
[  382.231118]  apic_timer_interrupt+0x35/0x3c
[  382.231132] EIP: __copy_user_ll+0xe2/0xf0
[  382.231142] EFLAGS: 00210293 CPU: 1
[  382.231154] EAX: bfd4508c EBX: 00000004 ECX: 00000003 EDX: f3d8fe50
[  382.231165] ESI: f3d8fe51 EDI: bfd4508d EBP: f3d8fe14 ESP: f3d8fe08
[  382.231176]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[  382.231265]  core_sys_select+0x25f/0x320
[  382.231346]  ? __wake_up_common_lock+0x62/0x80
[  382.231399]  ? tty_ldisc_deref+0x13/0x20
[  382.231438]  ? ldsem_up_read+0x1b/0x40
[  382.231459]  ? tty_ldisc_deref+0x13/0x20
[  382.231479]  ? tty_write+0x29f/0x2e0
[  382.231514]  ? n_tty_ioctl+0xe0/0xe0
[  382.231541]  ? tty_write_unlock+0x30/0x30
[  382.231566]  ? __vfs_write+0x22/0x110
[  382.231604]  ? security_file_permission+0x2f/0xd0
[  382.231635]  ? rw_verify_area+0xac/0x120
[  382.231677]  ? vfs_write+0x103/0x180
[  382.231711]  SyS_select+0x87/0xc0
[  382.231739]  ? SyS_write+0x42/0x90
[  382.231781]  do_fast_syscall_32+0xd6/0x1a0
[  382.231836]  entry_SYSENTER_32+0x47/0x71
[  382.231848] EIP: 0xb7f75b05
[  382.231857] EFLAGS: 00000246 CPU: 1
[  382.231868] EAX: ffffffda EBX: 00000400 ECX: bfd4508c EDX: bfd4510c
[  382.231878] ESI: 00000000 EDI: 00000000 EBP: 00000000 ESP: bfd45020
[  382.231889]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
[  382.232281] softirq: huh, entered softirq 9 RCU c10b4d90 with preempt_count 00000100, exited with 00000000?
Tested-by: NSam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

struct timespec is not y2038 safe. Transition vfs to use
y2038 safe struct timespec64 instead.

The change was made with the help of the following cocinelle
script. This catches about 80% of the changes.
All the header file and logic changes are included in the
first 5 rules. The rest are trivial substitutions.
I avoid changing any of the function signatures or any other
filesystem specific data structures to keep the patch simple
for review.

The script can be a little shorter by combining different cases.
But, this version was sufficient for my usecase.

virtual patch

@ depends on patch @
identifier now;
@@
- struct timespec
+ struct timespec64
  current_time ( ... )
  {
- struct timespec now = current_kernel_time();
+ struct timespec64 now = current_kernel_time64();
  ...
- return timespec_trunc(
+ return timespec64_trunc(
  ... );
  }

@ depends on patch @
identifier xtime;
@@
 struct \( iattr \| inode \| kstat \) {
 ...
-       struct timespec xtime;
+       struct timespec64 xtime;
 ...
 }

@ depends on patch @
identifier t;
@@
 struct inode_operations {
 ...
int (*update_time) (...,
-       struct timespec t,
+       struct timespec64 t,
...);
 ...
 }

@ depends on patch @
identifier t;
identifier fn_update_time =~ "update_time$";
@@
 fn_update_time (...,
- struct timespec *t,
+ struct timespec64 *t,
 ...) { ... }

@ depends on patch @
identifier t;
@@
lease_get_mtime( ... ,
- struct timespec *t
+ struct timespec64 *t
  ) { ... }

@te depends on patch forall@
identifier ts;
local idexpression struct inode *inode_node;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn_update_time =~ "update_time$";
identifier fn;
expression e, E3;
local idexpression struct inode *node1;
local idexpression struct inode *node2;
local idexpression struct iattr *attr1;
local idexpression struct iattr *attr2;
local idexpression struct iattr attr;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
@@
(
(
- struct timespec ts;
+ struct timespec64 ts;
|
- struct timespec ts = current_time(inode_node);
+ struct timespec64 ts = current_time(inode_node);
)

<+... when != ts
(
- timespec_equal(&inode_node->i_xtime, &ts)
+ timespec64_equal(&inode_node->i_xtime, &ts)
|
- timespec_equal(&ts, &inode_node->i_xtime)
+ timespec64_equal(&ts, &inode_node->i_xtime)
|
- timespec_compare(&inode_node->i_xtime, &ts)
+ timespec64_compare(&inode_node->i_xtime, &ts)
|
- timespec_compare(&ts, &inode_node->i_xtime)
+ timespec64_compare(&ts, &inode_node->i_xtime)
|
ts = current_time(e)
|
fn_update_time(..., &ts,...)
|
inode_node->i_xtime = ts
|
node1->i_xtime = ts
|
ts = inode_node->i_xtime
|
<+... attr1->ia_xtime ...+> = ts
|
ts = attr1->ia_xtime
|
ts.tv_sec
|
ts.tv_nsec
|
btrfs_set_stack_timespec_sec(..., ts.tv_sec)
|
btrfs_set_stack_timespec_nsec(..., ts.tv_nsec)
|
- ts = timespec64_to_timespec(
+ ts =
...
-)
|
- ts = ktime_to_timespec(
+ ts = ktime_to_timespec64(
...)
|
- ts = E3
+ ts = timespec_to_timespec64(E3)
|
- ktime_get_real_ts(&ts)
+ ktime_get_real_ts64(&ts)
|
fn(...,
- ts
+ timespec64_to_timespec(ts)
,...)
)
...+>
(
<... when != ts
- return ts;
+ return timespec64_to_timespec(ts);
...>
)
|
- timespec_equal(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_equal(&node1->i_xtime2, &node2->i_xtime2)
|
- timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2)
+ timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2)
|
- timespec_compare(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_compare(&node1->i_xtime1, &node2->i_xtime2)
|
node1->i_xtime1 =
- timespec_trunc(attr1->ia_xtime1,
+ timespec64_trunc(attr1->ia_xtime1,
...)
|
- attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2,
+ attr1->ia_xtime1 =  timespec64_trunc(attr2->ia_xtime2,
...)
|
- ktime_get_real_ts(&attr1->ia_xtime1)
+ ktime_get_real_ts64(&attr1->ia_xtime1)
|
- ktime_get_real_ts(&attr.ia_xtime1)
+ ktime_get_real_ts64(&attr.ia_xtime1)
)

@ depends on patch @
struct inode *node;
struct iattr *attr;
identifier fn;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
expression e;
@@
(
- fn(node->i_xtime);
+ fn(timespec64_to_timespec(node->i_xtime));
|
 fn(...,
- node->i_xtime);
+ timespec64_to_timespec(node->i_xtime));
|
- e = fn(attr->ia_xtime);
+ e = fn(timespec64_to_timespec(attr->ia_xtime));
)

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
fn (...,
- &attr->ia_xtime,
+ &ts,
...);
)
...+>
}

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
struct kstat *stat;
identifier ia_xtime =~ "^ia_[acm]time$";
identifier i_xtime =~ "^i_[acm]time$";
identifier xtime =~ "^[acm]time$";
identifier fn, ret;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(stat->xtime);
ret = fn (...,
- &stat->xtime);
+ &ts);
)
...+>
}

@ depends on patch @
struct inode *node;
struct inode *node2;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier i_xtime3 =~ "^i_[acm]time$";
struct iattr *attrp;
struct iattr *attrp2;
struct iattr attr ;
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
struct kstat *stat;
struct kstat stat1;
struct timespec64 ts;
identifier xtime =~ "^[acmb]time$";
expression e;
@@
(
( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1  ;
|
 node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 stat->xtime = node2->i_xtime1;
|
 stat1.xtime = node2->i_xtime1;
|
( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1  ;
|
( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2;
|
- e = node->i_xtime1;
+ e = timespec64_to_timespec( node->i_xtime1 );
|
- e = attrp->ia_xtime1;
+ e = timespec64_to_timespec( attrp->ia_xtime1 );
|
node->i_xtime1 = current_time(...);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
 node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
- node->i_xtime1 = e;
+ node->i_xtime1 = timespec_to_timespec64(e);
)
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Cc: <anton@tuxera.com>
Cc: <balbi@kernel.org>
Cc: <bfields@fieldses.org>
Cc: <darrick.wong@oracle.com>
Cc: <dhowells@redhat.com>
Cc: <dsterba@suse.com>
Cc: <dwmw2@infradead.org>
Cc: <hch@lst.de>
Cc: <hirofumi@mail.parknet.co.jp>
Cc: <hubcap@omnibond.com>
Cc: <jack@suse.com>
Cc: <jaegeuk@kernel.org>
Cc: <jaharkes@cs.cmu.edu>
Cc: <jslaby@suse.com>
Cc: <keescook@chromium.org>
Cc: <mark@fasheh.com>
Cc: <miklos@szeredi.hu>
Cc: <nico@linaro.org>
Cc: <reiserfs-devel@vger.kernel.org>
Cc: <richard@nod.at>
Cc: <sage@redhat.com>
Cc: <sfrench@samba.org>
Cc: <swhiteho@redhat.com>
Cc: <tj@kernel.org>
Cc: <trond.myklebust@primarydata.com>
Cc: <tytso@mit.edu>
Cc: <viro@zeniv.linux.org.uk>

This allows 32 bit owners of ffs endpoints to
make ioctls into a 64 bit kernel.

All of the current epfile ioctls can be handled
with the same struct definitions as regular
ioctl.
Acked-by: NMichał Nazarewicz <mina86@mina86.com>
Signed-off-by: NJerry Zhang <zhangjerry@google.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Some UDC drivers (like the DWC3) expect that the response to a setup()
request is queued from within the setup function itself so that it is
available as soon as setup() has completed.

Upon receiving a setup request the function fs driver creates an event that
is made available to userspace. And only once userspace has acknowledged
that event the response to the setup request is queued.

So it violates the requirement of those UDC drivers and random failures can
be observed. This is basically a race condition and if userspace is able to
read the event and queue the response fast enough all is good. But if it is
not, for example because other processes are currently scheduled to run,
the USB host that sent the setup request will observe an error.

To avoid this the gadget framework provides the USB_GADGET_DELAYED_STATUS
return code. If a setup() callback returns this value the UDC driver is
aware that response is not yet available and can uses the appropriate
methods to handle this case.

Since in the case of function fs the response will never be available when
the setup() function returns make sure that this status code is used.

This fixed random occasional failures that were previously observed on a
DWC3 based system under high system load.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

When using a AIO read() operation on the function FS gadget driver a URB is
submitted asynchronously and on URB completion the received data is copied
to the userspace buffer associated with the read operation.

This is done from a kernel worker thread invoking copy_to_user() (through
copy_to_iter()). And while the user space process memory is made available
to the kernel thread using use_mm(), some architecture require in addition
to this that the operation runs with USER_DS set. Otherwise the userspace
memory access will fail.

For example on ARM64 with Privileged Access Never (PAN) and User Access
Override (UAO) enabled the following crash occurs.

	Internal error: Accessing user space memory with fs=KERNEL_DS: 9600004f [#1] SMP
	Modules linked in:
	CPU: 2 PID: 1636 Comm: kworker/2:1 Not tainted 4.9.0-04081-g8ab2dfb-dirty #487
	Hardware name: ZynqMP ZCU102 Rev1.0 (DT)
	Workqueue: events ffs_user_copy_worker
	task: ffffffc87afc8080 task.stack: ffffffc87a00c000
	PC is at __arch_copy_to_user+0x190/0x220
	LR is at copy_to_iter+0x78/0x3c8
	[...]
	[<ffffff800847b790>] __arch_copy_to_user+0x190/0x220
	[<ffffff80086f25d8>] ffs_user_copy_worker+0x70/0x130
	[<ffffff80080b8c64>] process_one_work+0x1dc/0x460
	[<ffffff80080b8f38>] worker_thread+0x50/0x4b0
	[<ffffff80080bf5a0>] kthread+0xd8/0xf0
	[<ffffff8008083680>] ret_from_fork+0x10/0x50

Address this by placing a set_fs(USER_DS) before of the copy operation
and revert it again once the copy operation has finished.

This patch is analogous to commit d7ffde35 ("vhost: use USER_DS in
vhost_worker thread") which addresses the same underlying issue.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

When I debug a kernel crash issue in funcitonfs, found ffs_data.ref
overflowed, While functionfs is unmounting, ffs_data is put twice.

Commit 43938613 ("drivers, usb: convert ffs_data.ref from atomic_t to
refcount_t") can avoid refcount overflow, but that is risk some situations.
So no need put ffs data in ffs_fs_kill_sb, already put in ffs_data_closed.

The issue can be reproduced in Mediatek mt6763 SoC, ffs for ADB device.
KASAN enabled configuration reports use-after-free errro.

BUG: KASAN: use-after-free in refcount_dec_and_test+0x14/0xe0 at addr ffffffc0579386a0
Read of size 4 by task umount/4650
====================================================
BUG kmalloc-512 (Tainted: P        W  O   ): kasan: bad access detected
-----------------------------------------------------------------------------

INFO: Allocated in ffs_fs_mount+0x194/0x844 age=22856 cpu=2 pid=566
    alloc_debug_processing+0x1ac/0x1e8
    ___slab_alloc.constprop.63+0x640/0x648
    __slab_alloc.isra.57.constprop.62+0x24/0x34
    kmem_cache_alloc_trace+0x1a8/0x2bc
    ffs_fs_mount+0x194/0x844
    mount_fs+0x6c/0x1d0
    vfs_kern_mount+0x50/0x1b4
    do_mount+0x258/0x1034
INFO: Freed in ffs_data_put+0x25c/0x320 age=0 cpu=3 pid=4650
    free_debug_processing+0x22c/0x434
    __slab_free+0x2d8/0x3a0
    kfree+0x254/0x264
    ffs_data_put+0x25c/0x320
    ffs_data_closed+0x124/0x15c
    ffs_fs_kill_sb+0xb8/0x110
    deactivate_locked_super+0x6c/0x98
    deactivate_super+0xb0/0xbc
INFO: Object 0xffffffc057938600 @offset=1536 fp=0x          (null)
......
Call trace:
[<ffffff900808cf5c>] dump_backtrace+0x0/0x250
[<ffffff900808d3a0>] show_stack+0x14/0x1c
[<ffffff90084a8c04>] dump_stack+0xa0/0xc8
[<ffffff900826c2b4>] print_trailer+0x158/0x260
[<ffffff900826d9d8>] object_err+0x3c/0x40
[<ffffff90082745f0>] kasan_report_error+0x2a8/0x754
[<ffffff9008274f84>] kasan_report+0x5c/0x60
[<ffffff9008273208>] __asan_load4+0x70/0x88
[<ffffff90084cd81c>] refcount_dec_and_test+0x14/0xe0
[<ffffff9008d98f9c>] ffs_data_put+0x80/0x320
[<ffffff9008d9d904>] ffs_fs_kill_sb+0xc8/0x110
[<ffffff90082852a0>] deactivate_locked_super+0x6c/0x98
[<ffffff900828537c>] deactivate_super+0xb0/0xbc
[<ffffff90082af0c0>] cleanup_mnt+0x64/0xec
[<ffffff90082af1b0>] __cleanup_mnt+0x10/0x18
[<ffffff90080d9e68>] task_work_run+0xcc/0x124
[<ffffff900808c8c0>] do_notify_resume+0x60/0x70
[<ffffff90080866e4>] work_pending+0x10/0x14

Cc: stable@vger.kernel.org
Signed-off-by: NXinyong <xinyong.fang@linux.alibaba.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

In commit 2bfa0719 ("usb: gadget: function: f_fs: pass
companion descriptor along") there is a pointer arithmetic
bug where the comp_desc is obtained as follows:

 comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
	       USB_DT_ENDPOINT_SIZE);

Since ds is a pointer to usb_endpoint_descriptor, adding
7 to it ends up going out of bounds (7 * sizeof(struct
usb_endpoint_descriptor), which is actually 7*9 bytes) past
the SS descriptor. As a result the maxburst value will be
read incorrectly, and the UDC driver will also get a garbage
comp_desc (assuming it uses it).

Since Felipe wrote, "Eventually, f_fs.c should be converted
to use config_ep_by_speed() like all other functions, though",
let's finally do it. This allows the other usb_ep fields to
be properly populated, such as maxpacket and mult. It also
eliminates the awkward speed-based descriptor lookup since
config_ep_by_speed() does that already using the ones found
in struct usb_function.

Fixes: 2bfa0719 ("usb: gadget: function: f_fs: pass companion descriptor along")
Cc: stable@vger.kernel.org
Signed-off-by: NJack Pham <jackp@codeaurora.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

During _ffs_func_bind(), the received descriptors are evaluated
to prepare for binding with the gadget in order to allocate
endpoints and optionally set up OS descriptors. However, the
high- and super-speed descriptors are only parsed based on
whether the gadget_is_dualspeed() and gadget_is_superspeed()
calls are true, respectively.

This is a problem in case a userspace program always provides
all of the {full,high,super,OS} descriptors when configuring a
function. Then, for example if a gadget device is not capable
of SuperSpeed, the call to ffs_do_descs() for the SS descriptors
is skipped, resulting in an incorrect offset calculation for
the vla_ptr when moving on to the OS descriptors that follow.
This causes ffs_do_os_descs() to fail as it is now looking at
the SS descriptors' offset within the raw_descs buffer instead.

_ffs_func_bind() should evaluate the descriptors unconditionally,
so remove the checks for gadget speed.

Fixes: f0175ab5 ("usb: gadget: f_fs: OS descriptors support")
Cc: stable@vger.kernel.org
Co-Developed-by: NMayank Rana <mrana@codeaurora.org>
Signed-off-by: NMayank Rana <mrana@codeaurora.org>
Signed-off-by: NJack Pham <jackp@codeaurora.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Upon usb composition switch there is possibility of ep0 file
release happening after gadget driver bind. In case of composition
switch from adb to a non-adb composition gadget will never gets
bound again resulting into failure of usb device enumeration. Fix
this issue by checking FFS_FL_BOUND flag and avoid extra
gadget driver unbind if it is already done as part of composition
switch.

This fixes adb reconnection error reported on Android running
v4.4 and above kernel versions. Verified on Hikey running vanilla
v4.15-rc7 + few out of tree Mali patches.

Reviewed-at: https://android-review.googlesource.com/#/c/582632/

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Greg KH <gregkh@linux-foundation.org>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Badhri <badhri@google.com>
Cc: Android Kernel Team <kernel-team@android.com>
Cc: stable@vger.kernel.org
Signed-off-by: NHemant Kumar <hemantk@codeaurora.org>
[AmitP: Cherry-picked it from android-4.14 and updated the commit log]
Signed-off-by: NAmit Pundir <amit.pundir@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Silences the following warnings:
drivers/usb/gadget/function/f_fs.c:1253:37: warning: incorrect type in argument 1 (different address spaces)
drivers/usb/gadget/function/f_fs.c:1253:37:    expected void [noderef] <asn:1>*to
drivers/usb/gadget/function/f_fs.c:1253:37:    got void *<noident>
drivers/usb/gadget/function/f_fs.c:2322:23: warning: cast to restricted __le32
drivers/usb/gadget/function/f_fs.c:2876:38: warning: cast to restricted __le32
drivers/usb/gadget/function/f_fs.c:272:12: warning: context imbalance in '__ffs_ep0_queue_wait' - unexpected unlock
drivers/usb/gadget/function/f_fs.c:450:17: warning: context imbalance in 'ffs_ep0_write' - different lock contexts for basic block
drivers/usb/gadget/function/f_fs.c:490:24: warning: context imbalance in '__ffs_ep0_read_events' - unexpected unlock
drivers/usb/gadget/function/f_fs.c:496:16: warning: context imbalance in 'ffs_ep0_read' - different lock contexts for basic block

Also, add an "unlocks spinlock" comment for consistency with existing ones.
No behaviour change is intended.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The specification says that the Reserved1 field in OS_DESC_EXT_COMPAT
must have the value "1", but when this feature was first implemented we
rejected any non-zero values.

This was adjusted to accept all non-zero values (while now rejecting
zero) in commit 53642399 ("usb: gadget: f_fs: Fix wrong check on
reserved1 of OS_DESC_EXT_COMPAT"), but that breaks any userspace
programs that worked previously by returning EINVAL when Reserved1 == 0
which was previously the only value that succeeded!

If we just set the field to "1" ourselves, both old and new userspace
programs continue to work correctly and, as a bonus, old programs are
now compliant with the specification without having to fix anything
themselves.

Fixes: 53642399 ("usb: gadget: f_fs: Fix wrong check on reserved1 of OS_DESC_EXT_COMPAT")
Cc: <stable@vger.kernel.org>
Signed-off-by: NJohn Keeping <john@metanate.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Found using DEBUG_ATOMIC_SLEEP while submitting an AIO read operation:

[  100.853642] BUG: sleeping function called from invalid context at mm/slab.h:421
[  100.861148] in_atomic(): 1, irqs_disabled(): 1, pid: 1880, name: python
[  100.867954] 2 locks held by python/1880:
[  100.867961]  #0:  (&epfile->mutex){....}, at: [<f8188627>] ffs_mutex_lock+0x27/0x30 [usb_f_fs]
[  100.868020]  #1:  (&(&ffs->eps_lock)->rlock){....}, at: [<f818ad4b>] ffs_epfile_io.isra.17+0x24b/0x590 [usb_f_fs]
[  100.868076] CPU: 1 PID: 1880 Comm: python Not tainted 4.14.0-edison+ #118
[  100.868085] Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48
[  100.868093] Call Trace:
[  100.868122]  dump_stack+0x47/0x62
[  100.868156]  ___might_sleep+0xfd/0x110
[  100.868182]  __might_sleep+0x68/0x70
[  100.868217]  kmem_cache_alloc_trace+0x4b/0x200
[  100.868248]  ? dwc3_gadget_ep_alloc_request+0x24/0xe0 [dwc3]
[  100.868302]  dwc3_gadget_ep_alloc_request+0x24/0xe0 [dwc3]
[  100.868343]  usb_ep_alloc_request+0x16/0xc0 [udc_core]
[  100.868386]  ffs_epfile_io.isra.17+0x444/0x590 [usb_f_fs]
[  100.868424]  ? _raw_spin_unlock_irqrestore+0x27/0x40
[  100.868457]  ? kiocb_set_cancel_fn+0x57/0x60
[  100.868477]  ? ffs_ep0_poll+0xc0/0xc0 [usb_f_fs]
[  100.868512]  ffs_epfile_read_iter+0xfe/0x157 [usb_f_fs]
[  100.868551]  ? security_file_permission+0x9c/0xd0
[  100.868587]  ? rw_verify_area+0xac/0x120
[  100.868633]  aio_read+0x9d/0x100
[  100.868692]  ? __fget+0xa2/0xd0
[  100.868727]  ? __might_sleep+0x68/0x70
[  100.868763]  SyS_io_submit+0x471/0x680
[  100.868878]  do_int80_syscall_32+0x4e/0xd0
[  100.868921]  entry_INT80_32+0x2a/0x2a
[  100.868932] EIP: 0xb7fbb676
[  100.868941] EFLAGS: 00000292 CPU: 1
[  100.868951] EAX: ffffffda EBX: b7aa2000 ECX: 00000002 EDX: b7af8368
[  100.868961] ESI: b7fbb660 EDI: b7aab000 EBP: bfb6c658 ESP: bfb6c638
[  100.868973]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

KASAN enabled configuration reports an error

BUG: KASAN: use-after-free in ffs_free_inst+... [usb_f_fs] at addr ...
Write of size 8 by task ...

This is observed after "ffs-test" is run and interrupted. If after that
functionfs is unmounted and g_ffs module is unloaded, that use-after-free
occurs during g_ffs module removal.

Although the report indicates ffs_free_inst() function, the actual
use-after-free condition occurs in _ffs_free_dev() function, which
is probably inlined into ffs_free_inst().

This happens due to keeping the ffs_data reference in device structure
during functionfs unmounting, while ffs_data itself is freed as no longer
needed. The fix is to clear that reference in ffs_closed() function,
which is a counterpart of ffs_ready(), where the reference is stored.

Fixes: 3262ad82 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference")
Cc: stable@vger.kernel.org
Signed-off-by: NAndrew Gabbasov <andrew_gabbasov@mentor.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Oliver Neukum <oneukum@suse.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jerry Zhang <zhangjerry@google.com>
Cc: John Keeping <john@metanate.com>
Cc: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Abdulhadi Mohamed <abdulahhadi2@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Janusz Dziedzic <januszx.dziedzic@linux.intel.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make these structures const as they are only passed to the const
argument of the functions config_{group/item}_init_type_name.
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

By submitting completed transfers to the system workqueue there is no
guarantee that completion events will be queued up in the correct order,
as in multi-processor systems there is a thread running for each
processor and the work items are not bound to a particular core.

This means that several completions are in the queue at the same time,
they may be processed in parallel and complete out of order, resulting
in data appearing corrupt when read by userspace.

Create a single-threaded workqueue for FunctionFS so that data completed
requests is passed to userspace in the order in which they complete.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NJohn Keeping <john@metanate.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Users can apply i/o in the wrong direction on an
endpoint to stall it. In case there is an error
that does not allow the endpoint to be stalled,
we want the user to know.

An operation to stall the endpoint will return
EBADMSG if successful, EAGAIN if there are still
queued requests, and other errors depending on
the underlying implementation.

Also remove the conditional since it is always true.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NJerry Zhang <zhangjerry@google.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

There were individual waitqueues for each epfile but eps_enable
would iterate through all of them, resulting in essentially the
same wakeup time.

The waitqueue represents the function being enabled, so a central
waitqueue in ffs_data makes more sense and is less redundant.

Also use wake_up_interruptible to reflect use of
wait_event_interruptible.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NJerry Zhang <zhangjerry@google.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This allows users to make an ioctl call as the first action on a
connection. Ex, some functions might want to get endpoint size
before making any i/os.

Previously, calling ioctls before read/write would depending on the
timing of endpoints being enabled.

ESHUTDOWN is now a possible return value and ENODEV is not, so change
docs accordingly.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NJerry Zhang <zhangjerry@google.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Companion descriptor is only used for SuperSpeed endpoints,
if the endpoints are HighSpeed or FullSpeed, the Companion
descriptor will not allocated, so we can only access it if
gadget is SuperSpeed.

I can reproduce this issue on Rockchip platform rk3368 SoC
which supports USB 2.0, and use functionfs for ADB. Kernel
build with CONFIG_KASAN=y and CONFIG_SLUB_DEBUG=y report
the following BUG:

==================================================================
BUG: KASAN: slab-out-of-bounds in ffs_func_set_alt+0x224/0x3a0 at addr ffffffc0601f6509
Read of size 1 by task swapper/0/0
============================================================================
BUG kmalloc-256 (Not tainted): kasan: bad access detected
----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: Allocated in ffs_func_bind+0x52c/0x99c age=1275 cpu=0 pid=1
alloc_debug_processing+0x128/0x17c
___slab_alloc.constprop.58+0x50c/0x610
__slab_alloc.isra.55.constprop.57+0x24/0x34
__kmalloc+0xe0/0x250
ffs_func_bind+0x52c/0x99c
usb_add_function+0xd8/0x1d4
configfs_composite_bind+0x48c/0x570
udc_bind_to_driver+0x6c/0x170
usb_udc_attach_driver+0xa4/0xd0
gadget_dev_desc_UDC_store+0xcc/0x118
configfs_write_file+0x1a0/0x1f8
__vfs_write+0x64/0x174
vfs_write+0xe4/0x200
SyS_write+0x68/0xc8
el0_svc_naked+0x24/0x28
INFO: Freed in inode_doinit_with_dentry+0x3f0/0x7c4 age=1275 cpu=7 pid=247
...
Call trace:
[<ffffff900808aab4>] dump_backtrace+0x0/0x230
[<ffffff900808acf8>] show_stack+0x14/0x1c
[<ffffff90084ad420>] dump_stack+0xa0/0xc8
[<ffffff90082157cc>] print_trailer+0x188/0x198
[<ffffff9008215948>] object_err+0x3c/0x4c
[<ffffff900821b5ac>] kasan_report+0x324/0x4dc
[<ffffff900821aa38>] __asan_load1+0x24/0x50
[<ffffff90089eb750>] ffs_func_set_alt+0x224/0x3a0
[<ffffff90089d3760>] composite_setup+0xdcc/0x1ac8
[<ffffff90089d7394>] android_setup+0x124/0x1a0
[<ffffff90089acd18>] _setup+0x54/0x74
[<ffffff90089b6b98>] handle_ep0+0x3288/0x4390
[<ffffff90089b9b44>] dwc_otg_pcd_handle_out_ep_intr+0x14dc/0x2ae4
[<ffffff90089be85c>] dwc_otg_pcd_handle_intr+0x1ec/0x298
[<ffffff90089ad680>] dwc_otg_pcd_irq+0x10/0x20
[<ffffff9008116328>] handle_irq_event_percpu+0x124/0x3ac
[<ffffff9008116610>] handle_irq_event+0x60/0xa0
[<ffffff900811af30>] handle_fasteoi_irq+0x10c/0x1d4
[<ffffff9008115568>] generic_handle_irq+0x30/0x40
[<ffffff90081159b4>] __handle_domain_irq+0xac/0xdc
[<ffffff9008080e9c>] gic_handle_irq+0x64/0xa4
...
Memory state around the buggy address:
  ffffffc0601f6400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffffffc0601f6480: 00 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc
 >ffffffc0601f6500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                       ^
  ffffffc0601f6580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffffffc0601f6600: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
==================================================================
Signed-off-by: NWilliam Wu <william.wu@rock-chips.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Currently ffs_dev::name can be either allocated by the client of
the ffs_dev structure or by the f_fs.c core itself.  The former
is used by g_ffs while the latter happens with configfs.

Historically, g_ffs did not need to allocate separate buffer for
the name so what is now f_fs.c core never cared about freeing
that space.  With configfs the name needs to be copied since the
memory is not guaranteed to be availeble after ffs_set_inst_name
finishes.

The complication is therefore here to avoid allocations in the
g_ffs case but it complicates the code inproportinally to
benefits it provides.  In particular, g_ffs is considered
‘legacy’ so optimising for its sake is unlikely to be worth the
effort.

With that observation in mind, simplify the code by unifying the
code paths in g_ffs and configfs paths.  Furthermore, instead of
allocating a new buffer for the name, simply embed it in the
ffs_dev structure.  This further makes the memory management
less convoluted and error-prone.

The configfs interface for functionfs imposed a limit of 40
characters for the name so this results in a 41-byte buffer
added to the structure.  (For short names this may lead to
wasted memory but the actual amount is not immediately obvious
and depends on pointer size and which slab buckets the structure
and name would fall into).
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit ac670a3a650b899fc020b81f63e810d06015b865.

This introduce bug we already fixed in
commit 53642399 ("usb: gadget: f_fs: Fix wrong check on reserved1 wof OS_DESC_EXT_COMPAT")

Next FFS (adb) SS enumeration fail with Windows OS.
Signed-off-by: NJanusz Dziedzic <januszx.dziedzic@linux.intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If we're dealing with SuperSpeed endpoints, we need
to make sure to pass along the companion descriptor
and initialize fields needed by the Gadget
API. Eventually, f_fs.c should be converted to use
config_ep_by_speed() like all other functions,
though.

Cc: <stable@vger.kernel.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

OS descriptor head, when flagged as provided, is accessed without
checking if it fits in provided buffer. Verify length before access.
Also, there are other places where buffer length it checked
after accessing offsets which are potentially past the end. Check
buffer length before as well to fail cleanly.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It is allowed by the USB specification to enabled same-address, opposite-
direction endpoints simultaneously, which means 30 non-zero endpoints
are allowed. So double eps_addrmap length to 30.
The original code only accepted 14 descriptors out of a likely intended 15
(as there are 15 endpoint addresses, ignoring direction), because the first
eps_addrmap entry is unused (it is a placeholder for endpoint zero). So
increase eps_addrmap length by one to 31.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Endpoint descriptors come in 2 sizes, struct usb_endpoint_descriptor being
the largest. Use bLength to stop on endpoint descriptor boundary, and not
2 bytes too far.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

When zero endpoints are declared for a function, there is no endpoint
to disable, enable or free, so replace do...while loops with while loops.
Change pre-decrement to post-decrement to iterate the same number of times
when there are endpoints to process.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

When system try to close /dev/usb-ffs/adb/ep0 on one core, at the same
time another core try to attach new UDC, which will cause deadlock as
below scenario. Thus we should release ffs lock before issuing
unregister_gadget_item().

[   52.642225] c1 ======================================================
[   52.642228] c1 [ INFO: possible circular locking dependency detected ]
[   52.642236] c1 4.4.6+ #1 Tainted: G        W  O
[   52.642241] c1 -------------------------------------------------------
[   52.642245] c1 usb ffs open/2808 is trying to acquire lock:
[   52.642270] c0  (udc_lock){+.+.+.}, at: [<ffffffc00065aeec>]
		usb_gadget_unregister_driver+0x3c/0xc8
[   52.642272] c1  but task is already holding lock:
[   52.642283] c0  (ffs_lock){+.+.+.}, at: [<ffffffc00066b244>]
		ffs_data_clear+0x30/0x140
[   52.642285] c1 which lock already depends on the new lock.
[   52.642287] c1
               the existing dependency chain (in reverse order) is:
[   52.642295] c0
	       -> #1 (ffs_lock){+.+.+.}:
[   52.642307] c0        [<ffffffc00012340c>] __lock_acquire+0x20f0/0x2238
[   52.642314] c0        [<ffffffc000123b54>] lock_acquire+0xe4/0x298
[   52.642322] c0        [<ffffffc000aaf6e8>] mutex_lock_nested+0x7c/0x3cc
[   52.642328] c0        [<ffffffc00066f7bc>] ffs_func_bind+0x504/0x6e8
[   52.642334] c0        [<ffffffc000654004>] usb_add_function+0x84/0x184
[   52.642340] c0        [<ffffffc000658ca4>] configfs_composite_bind+0x264/0x39c
[   52.642346] c0        [<ffffffc00065b348>] udc_bind_to_driver+0x58/0x11c
[   52.642352] c0        [<ffffffc00065b49c>] usb_udc_attach_driver+0x90/0xc8
[   52.642358] c0        [<ffffffc0006598e0>] gadget_dev_desc_UDC_store+0xd4/0x128
[   52.642369] c0        [<ffffffc0002c14e8>] configfs_write_file+0xd0/0x13c
[   52.642376] c0        [<ffffffc00023c054>] vfs_write+0xb8/0x214
[   52.642381] c0        [<ffffffc00023cad4>] SyS_write+0x54/0xb0
[   52.642388] c0        [<ffffffc000085ff0>] el0_svc_naked+0x24/0x28
[   52.642395] c0
              -> #0 (udc_lock){+.+.+.}:
[   52.642401] c0        [<ffffffc00011e3d0>] print_circular_bug+0x84/0x2e4
[   52.642407] c0        [<ffffffc000123454>] __lock_acquire+0x2138/0x2238
[   52.642412] c0        [<ffffffc000123b54>] lock_acquire+0xe4/0x298
[   52.642420] c0        [<ffffffc000aaf6e8>] mutex_lock_nested+0x7c/0x3cc
[   52.642427] c0        [<ffffffc00065aeec>] usb_gadget_unregister_driver+0x3c/0xc8
[   52.642432] c0        [<ffffffc00065995c>] unregister_gadget_item+0x28/0x44
[   52.642439] c0        [<ffffffc00066b34c>] ffs_data_clear+0x138/0x140
[   52.642444] c0        [<ffffffc00066b374>] ffs_data_reset+0x20/0x6c
[   52.642450] c0        [<ffffffc00066efd0>] ffs_data_closed+0xac/0x12c
[   52.642454] c0        [<ffffffc00066f070>] ffs_ep0_release+0x20/0x2c
[   52.642460] c0        [<ffffffc00023dbe4>] __fput+0xb0/0x1f4
[   52.642466] c0        [<ffffffc00023dd9c>] ____fput+0x20/0x2c
[   52.642473] c0        [<ffffffc0000ee944>] task_work_run+0xb4/0xe8
[   52.642482] c0        [<ffffffc0000cd45c>] do_exit+0x360/0xb9c
[   52.642487] c0        [<ffffffc0000cf228>] do_group_exit+0x4c/0xb0
[   52.642494] c0        [<ffffffc0000dd3c8>] get_signal+0x380/0x89c
[   52.642501] c0        [<ffffffc00008a8f0>] do_signal+0x154/0x518
[   52.642507] c0        [<ffffffc00008af00>] do_notify_resume+0x70/0x78
[   52.642512] c0        [<ffffffc000085ee8>] work_pending+0x1c/0x20
[   52.642514] c1
              other info that might help us debug this:
[   52.642517] c1  Possible unsafe locking scenario:
[   52.642518] c1        CPU0                    CPU1
[   52.642520] c1        ----                    ----
[   52.642525] c0   lock(ffs_lock);
[   52.642529] c0                                lock(udc_lock);
[   52.642533] c0                                lock(ffs_lock);
[   52.642537] c0   lock(udc_lock);
[   52.642539] c1
                      *** DEADLOCK ***
[   52.642543] c1 1 lock held by usb ffs open/2808:
[   52.642555] c0  #0:  (ffs_lock){+.+.+.}, at: [<ffffffc00066b244>]
		ffs_data_clear+0x30/0x140
[   52.642557] c1 stack backtrace:
[   52.642563] c1 CPU: 1 PID: 2808 Comm: usb ffs open Tainted: G
[   52.642565] c1 Hardware name: Spreadtrum SP9860g Board (DT)
[   52.642568] c1 Call trace:
[   52.642573] c1 [<ffffffc00008b430>] dump_backtrace+0x0/0x170
[   52.642577] c1 [<ffffffc00008b5c0>] show_stack+0x20/0x28
[   52.642583] c1 [<ffffffc000422694>] dump_stack+0xa8/0xe0
[   52.642587] c1 [<ffffffc00011e548>] print_circular_bug+0x1fc/0x2e4
[   52.642591] c1 [<ffffffc000123454>] __lock_acquire+0x2138/0x2238
[   52.642595] c1 [<ffffffc000123b54>] lock_acquire+0xe4/0x298
[   52.642599] c1 [<ffffffc000aaf6e8>] mutex_lock_nested+0x7c/0x3cc
[   52.642604] c1 [<ffffffc00065aeec>] usb_gadget_unregister_driver+0x3c/0xc8
[   52.642608] c1 [<ffffffc00065995c>] unregister_gadget_item+0x28/0x44
[   52.642613] c1 [<ffffffc00066b34c>] ffs_data_clear+0x138/0x140
[   52.642618] c1 [<ffffffc00066b374>] ffs_data_reset+0x20/0x6c
[   52.642621] c1 [<ffffffc00066efd0>] ffs_data_closed+0xac/0x12c
[   52.642625] c1 [<ffffffc00066f070>] ffs_ep0_release+0x20/0x2c
[   52.642629] c1 [<ffffffc00023dbe4>] __fput+0xb0/0x1f4
[   52.642633] c1 [<ffffffc00023dd9c>] ____fput+0x20/0x2c
[   52.642636] c1 [<ffffffc0000ee944>] task_work_run+0xb4/0xe8
[   52.642640] c1 [<ffffffc0000cd45c>] do_exit+0x360/0xb9c
[   52.642644] c1 [<ffffffc0000cf228>] do_group_exit+0x4c/0xb0
[   52.642647] c1 [<ffffffc0000dd3c8>] get_signal+0x380/0x89c
[   52.642651] c1 [<ffffffc00008a8f0>] do_signal+0x154/0x518
[   52.642656] c1 [<ffffffc00008af00>] do_notify_resume+0x70/0x78
[   52.642659] c1 [<ffffffc000085ee8>] work_pending+0x1c/0x20
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Reserved1 is documented as expected to be set to 0, but this test fails
when it it set to 0. Reverse the condition.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

When FUNCTIONFS_EVENTFD flag is set, __ffs_data_got_descs reads a 32bits,
little-endian value right after the fixed structure header, and passes it
to eventfd_ctx_fdget. Document this.

Also, rephrase a comment to be affirmative about the role of string
descriptor at index 0. Ref: USB 2.0 spec paragraph "9.6.7 String", and
also checked to still be current in USB 3.0 spec paragraph "9.6.9 String".
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

copy_from_iter_full(), copy_from_iter_full_nocache() and
csum_and_copy_from_iter_full() - counterparts of copy_from_iter()
et.al., advancing iterator only in case of successful full copy
and returning whether it had been successful or not.

Convert some obvious users.  *NOTE* - do not blindly assume that
something is a good candidate for those unless you are sure that
not advancing iov_iter in failure case is the right thing in
this case.  Anything that does short read/short write kind of
stuff (or is in a loop, etc.) is unlikely to be a good one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Properly check the return code of ffs_func_revmap_intf() and
ffs_func_revmap_ep() for a non-negative value.

Instead of checking the return code, the comparison was performed for the last
parameter of the function calls, because of wrong parenthesis.

This also fixes the following static checker warning:
drivers/usb/gadget/function/f_fs.c:3152 ffs_func_req_match()
warn: always true condition '(((creq->wIndex)) >= 0) => (0-u16max >= 0)'
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NFelix Hädicke <felixhaedicke@web.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

There is only one waiter for the completion, therefore there
is no need to use complete_all(). Let's make that clear by
using complete() instead of complete_all().

The usage pattern of the completion is:

waiter context                          waker context
  reinit_completion()
  usb_esp_queue()
  wait_for_completion_interruptible()

					ffs_ep0_complete()
					  complete()
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

ffs_func_eps_disable is called from atomic context so it cannot sleep
thus cannot grab a mutex.  Change the handling of epfile->read_buffer
to use non-sleeping synchronisation method.
Reported-by: NChen Yu <chenyu56@huawei.com>
Signed-off-by: NMichał Nazarewicz <mina86@mina86.com>
Fixes: 9353afbb ("buffer data from ‘oversized’ OUT requests")
Tested-by: NJohn Stultz <john.stultz@linaro.org>
Tested-by: NChen Yu <chenyu56@huawei.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>