linux.git/drivers/usb/gadget/function/f_fs.c, branch v5.12

USB: gadget: f_fs: remove likely/unlikely

2020-12-10T15:14:34+00:00

They are used way too often in this file, in some ways that are actually
wrong.  Almost all of these are already known by the compiler and CPU so
just remove them all as none of these should be on any "hot paths" where
it actually matters.

Cc: Felipe Balbi 
Reported-by: Peter Chen 
Reviewed-by: Peter Chen 
Link: https://lore.kernel.org/r/20201127140559.381351-6-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_fs: Re-use SS descriptors for SuperSpeedPlus

2020-12-10T15:12:25+00:00

In many cases a function that supports SuperSpeed can very well
operate in SuperSpeedPlus, if a gadget controller supports it,
as the endpoint descriptors (and companion descriptors) are
generally identical and can be re-used. This is true for two
commonly used functions: Android's ADB and MTP. So we can simply
assign the usb_function's ssp_descriptors array to point to its
ss_descriptors, if available. Similarly, we need to allow an
epfile's ioctl for FUNCTIONFS_ENDPOINT_DESC to correctly
return the corresponding SuperSpeed endpoint descriptor in case
the connected speed is SuperSpeedPlus as well.

The only exception is if a function wants to implement an
Isochronous endpoint capable of transferring more than 48KB per
service interval when operating at greater than USB 3.1 Gen1
speed, in which case it would require an additional SuperSpeedPlus
Isochronous Endpoint Companion descriptor to be returned as part
of the Configuration Descriptor. Support for that would need
to be separately added to the userspace-facing FunctionFS API
which may not be a trivial task--likely a new descriptor format
(v3?) may need to be devised to allow for separate SS and SSP
descriptors to be supplied.

Signed-off-by: Jack Pham 
Cc: stable 
Link: https://lore.kernel.org/r/20201027230731.9073-1-jackp@codeaurora.org
Signed-off-by: Greg Kroah-Hartman

Merge 5.10-rc7 into usb-next

2020-12-07T09:20:51+00:00

We want the USB fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_fs: Use local copy of descriptors for userspace copy

2020-12-04T15:09:10+00:00

The function may be unbound causing the ffs_ep and its descriptors
to be freed while userspace is in the middle of an ioctl requesting
the same descriptors. Avoid dangling pointer reference by first
making a local copy of desctiptors before releasing the spinlock.

Fixes: c559a3534109 ("usb: gadget: f_fs: add ioctl returning ep descriptor")
Reviewed-by: Peter Chen 
Signed-off-by: Vamsi Krishna Samavedam 
Signed-off-by: Jack Pham 
Cc: stable 
Link: https://lore.kernel.org/r/20201130203453.28154-1-jackp@codeaurora.org
Signed-off-by: Greg Kroah-Hartman

usb: Fix fall-through warnings for Clang

2020-11-23T16:46:01+00:00

In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple break/return/fallthrough
statements instead of letting the code fall through to the next
case.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva 
Link: https://lore.kernel.org/r/a76da7ca5b4f41c13d27b298accb8222d0b04e61.1605896060.git.gustavoars@kernel.org
Signed-off-by: Greg Kroah-Hartman

usb: gadget: Use fallthrough pseudo-keyword

2020-07-10T06:55:18+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva 
Link: https://lore.kernel.org/r/20200707171500.GA13620@embeddedor
Signed-off-by: Greg Kroah-Hartman

usb: gadget: function: f_fs: Demote function header which is clearly not kerneldoc

2020-07-09T15:19:57+00:00

No attempt has been made to document the demoted function here.

Fixes the following W=1 kernel build warning(s):

 drivers/usb/gadget/function/f_fs.c:2361: warning: Function parameter or member 'type' not described in '__ffs_data_do_os_desc'
 drivers/usb/gadget/function/f_fs.c:2361: warning: Function parameter or member 'h' not described in '__ffs_data_do_os_desc'
 drivers/usb/gadget/function/f_fs.c:2361: warning: Function parameter or member 'data' not described in '__ffs_data_do_os_desc'
 drivers/usb/gadget/function/f_fs.c:2361: warning: Function parameter or member 'len' not described in '__ffs_data_do_os_desc'
 drivers/usb/gadget/function/f_fs.c:2361: warning: Function parameter or member 'priv' not described in '__ffs_data_do_os_desc'

Cc: Felipe Balbi 
Cc: David Howells 
Cc: Michal Nazarewicz 
Signed-off-by: Lee Jones 
Link: https://lore.kernel.org/r/20200706133341.476881-12-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman

kernel: set USER_DS in kthread_use_mm

2020-06-11T02:14:18+00:00

Some architectures like arm64 and s390 require USER_DS to be set for
kernel threads to access user address space, which is the whole purpose of
kthread_use_mm, but other like x86 don't.  That has lead to a huge mess
where some callers are fixed up once they are tested on said
architectures, while others linger around and yet other like io_uring try
to do "clever" optimizations for what usually is just a trivial asignment
to a member in the thread_struct for most architectures.

Make kthread_use_mm set USER_DS, and kthread_unuse_mm restore to the
previous value instead.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Tested-by: Jens Axboe 
Reviewed-by: Jens Axboe 
Acked-by: Michael S. Tsirkin 
Cc: Alex Deucher 
Cc: Al Viro 
Cc: Felipe Balbi 
Cc: Felix Kuehling 
Cc: Jason Wang 
Cc: Zhenyu Wang 
Cc: Zhi Wang 
Cc: Greg Kroah-Hartman 
Link: http://lkml.kernel.org/r/20200404094101.672954-7-hch@lst.de
Signed-off-by: Linus Torvalds

kernel: better document the use_mm/unuse_mm API contract

2020-06-11T02:14:18+00:00

Switch the function documentation to kerneldoc comments, and add
WARN_ON_ONCE asserts that the calling thread is a kernel thread and does
not have ->mm set (or has ->mm set in the case of unuse_mm).

Also give the functions a kthread_ prefix to better document the use case.

[hch@lst.de: fix a comment typo, cover the newly merged use_mm/unuse_mm caller in vfio]
  Link: http://lkml.kernel.org/r/20200416053158.586887-3-hch@lst.de
[sfr@canb.auug.org.au: powerpc/vas: fix up for {un}use_mm() rename]
  Link: http://lkml.kernel.org/r/20200422163935.5aa93ba5@canb.auug.org.au

Signed-off-by: Christoph Hellwig 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Tested-by: Jens Axboe 
Reviewed-by: Jens Axboe 
Acked-by: Felix Kuehling 
Acked-by: Greg Kroah-Hartman  [usb]
Acked-by: Haren Myneni 
Cc: Alex Deucher 
Cc: Al Viro 
Cc: Felipe Balbi 
Cc: Jason Wang 
Cc: "Michael S. Tsirkin" 
Cc: Zhenyu Wang 
Cc: Zhi Wang 
Link: http://lkml.kernel.org/r/20200404094101.672954-6-hch@lst.de
Signed-off-by: Linus Torvalds

kernel: move use_mm/unuse_mm to kthread.c

2020-06-11T02:14:18+00:00

Patch series "improve use_mm / unuse_mm", v2.

This series improves the use_mm / unuse_mm interface by better documenting
the assumptions, and my taking the set_fs manipulations spread over the
callers into the core API.

This patch (of 3):

Use the proper API instead.

Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de

These helpers are only for use with kernel threads, and I will tie them
more into the kthread infrastructure going forward.  Also move the
prototypes to kthread.h - mmu_context.h was a little weird to start with
as it otherwise contains very low-level MM bits.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Tested-by: Jens Axboe 
Reviewed-by: Jens Axboe 
Acked-by: Felix Kuehling 
Cc: Alex Deucher 
Cc: Al Viro 
Cc: Felipe Balbi 
Cc: Jason Wang 
Cc: "Michael S. Tsirkin" 
Cc: Zhenyu Wang 
Cc: Zhi Wang 
Cc: Greg Kroah-Hartman 
Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200416053158.586887-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200404094101.672954-5-hch@lst.de
Signed-off-by: Linus Torvalds