mailbox: mailbox-test: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: Fix an error check in mbox_test_probe()

mbox_test_request_channel() function returns NULL or
error value embedded in the pointer (PTR_ERR).
Evaluate the return value using IS_ERR_OR_NULL.

Signed-off-by: Minjie Du <duminjie@vivo.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: Use devm_platform_get_and_ioremap_resource()

Convert platform_get_resource(), devm_ioremap_resource() to a single
call to devm_platform_get_and_ioremap_resource(), as this is exactly
what this function does.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: fix a locking issue in mbox_test_message_write()

There was a bug where this code forgot to unlock the tdev->mutex if the
kzalloc() failed. Fix this issue, by moving the allocation outside the
lock.

Fixes: 2d1e952a2b8e ("mailbox: mailbox-test: Fix potential double-free in mbox_test_message_write()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: Fix potential double-free in mbox_test_message_write()

If a user can make copy_from_user() fail, there is a potential for
UAF/DF due to a lack of locking around the allocation, use and freeing
of the data buffers.

This issue is not theoretical. I managed to author a POC for it:

BUG: KASAN: double-free in kfree+0x5c/0xac
Free of addr ffff29280be5de00 by task poc/356
CPU: 1 PID: 356 Comm: poc Not tainted 6.1.0-00001-g961aa6552c04-dirty #20
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace.part.0+0xe0/0xf0
show_stack+0x18/0x40
dump_stack_lvl+0x64/0x80
print_report+0x188/0x48c
kasan_report_invalid_free+0xa0/0xc0
____kasan_slab_free+0x174/0x1b0
__kasan_slab_free+0x18/0x24
__kmem_cache_free+0x130/0x2e0
kfree+0x5c/0xac
mbox_test_message_write+0x208/0x29c
full_proxy_write+0x90/0xf0
vfs_write+0x154/0x440
ksys_write+0xcc/0x180
__arm64_sys_write+0x44/0x60
invoke_syscall+0x60/0x190
el0_svc_common.constprop.0+0x7c/0x160
do_el0_svc+0x40/0xf0
el0_svc+0x2c/0x6c
el0t_64_sync_handler+0xf4/0x120
el0t_64_sync+0x18c/0x190

Allocated by task 356:
kasan_save_stack+0x3c/0x70
kasan_set_track+0x2c/0x40
kasan_save_alloc_info+0x24/0x34
__kasan_kmalloc+0xb8/0xc0
kmalloc_trace+0x58/0x70
mbox_test_message_write+0x6c/0x29c
full_proxy_write+0x90/0xf0
vfs_write+0x154/0x440
ksys_write+0xcc/0x180
__arm64_sys_write+0x44/0x60
invoke_syscall+0x60/0x190
el0_svc_common.constprop.0+0x7c/0x160
do_el0_svc+0x40/0xf0
el0_svc+0x2c/0x6c
el0t_64_sync_handler+0xf4/0x120
el0t_64_sync+0x18c/0x190

Freed by task 357:
kasan_save_stack+0x3c/0x70
kasan_set_track+0x2c/0x40
kasan_save_free_info+0x38/0x5c
____kasan_slab_free+0x13c/0x1b0
__kasan_slab_free+0x18/0x24
__kmem_cache_free+0x130/0x2e0
kfree+0x5c/0xac
mbox_test_message_write+0x208/0x29c
full_proxy_write+0x90/0xf0
vfs_write+0x154/0x440
ksys_write+0xcc/0x180
__arm64_sys_write+0x44/0x60
invoke_syscall+0x60/0x190
el0_svc_common.constprop.0+0x7c/0x160
do_el0_svc+0x40/0xf0
el0_svc+0x2c/0x6c
el0t_64_sync_handler+0xf4/0x120
el0t_64_sync+0x18c/0x190

Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: Explicitly include header for spinlock support

Presently the support appears to be implied.

Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mailbox: mailbox-test: fix null pointer if no mmio

Fix null pointer issue if resource_size is called with no ioresource.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: fix debugfs in multi-instances

Create one debug entry directory per instance to support the multi
instantiation.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

vfs: do bulk POLL* -> EPOLL* replacement

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: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

the rest of drivers/*: annotate ->poll() instances

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

mailbox: mailbox-test: don't rely on rx_buffer content to signal data ready

Currently we rely on the first byte of the Rx buffer to check if there's
any data available to be read. If the first byte of the received buffer
is zero (i.e. null character), then we fail to signal that data is
available even when it's available.

Instead introduce a boolean variable to track the data availability and
update it in the channel receive callback as ready and clear it when the
data is read.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

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: Linus 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: Ingo Molnar <mingo@kernel.org>

mailbox: mailbox-test: allow reserved areas in SRAM

When CONFIG_SRAM is enable and the SRAM region is found, the entire SRAM
region resource is requested and marked as occupied by SRAM driver even
if certain parts of regions is marked reserved.

It's quite possible that a small region of the SRAM is reserved for all
the mailbox communication and hence it may fail to request the region
as it's already marked busy region.

This patch tries to just do a ioremap of this mailbox memory region if
it finds it busy.

Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: add support for fasync/poll

Currently the read operation on the message debug file returns error if
there's no data ready to be read. It expects the userspace to retry if
it fails. Since the mailbox response could be asynchronous, it would be
good to add support to block the read until the data is available.

We can also implement poll file operations so that the userspace can
wait to become ready to perform any I/O.

This patch implements the poll and fasync file operation callback for
the test mailbox device.

Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: Fix module autoload

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/mailbox/mailbox-test.ko | grep alias
$

After this patch:

$ modinfo drivers/mailbox/mailbox-test.ko | grep alias
alias: of:N*T*Cmailbox-testC*
alias: of:N*T*Cmailbox-test

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: set tdev->signal to NULL after freeing

tdev->signal is not set NULL after it's freed. This will cause random
exceptions when the stale pointer is accessed after tdev->signal is
freed. Also, since tdev->signal allocation is skipped the next time
it's written, this leads to continuous fault finally leading to the
total death of the system.

Fixes: d1c2f87c9a8f ("mailbox: mailbox-test: Prevent memory leak")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: Prevent memory leak

If we set the Signal twice or more, without using it as part of a message,
memory will be re-allocated and the pointer over-written. Prevent this
potential leak by only allocating memory when there isn't any already.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: Use more consistent format for calling copy_from_user()

While we're at it, ensure copy-to location is NULL'ed in the error path.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: add support for separate tx/rx buffer with single channel

This patch adds support for different MMIO region for Tx and Rx paths.
If only one region is specified, it's assumed to be shared between Rx
and Tx, thereby retaining backward compatibility.

Also in order to support single channel dealing with both Tx and Rx with
dedicated MMIO regions, Tx channel itself is assigned to Rx if MMIO
regions are different and Rx is not specified.

Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: use print_hex_dump_bytes to allow dynamic printk

Reduce the logging from info to debug. Also use print_hex_dump_bytes
instead as it has support for dynamic printk providing options to
conditionally enable/disable these logs.

Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: fix the compatible string

Underscores are usually forbidden in the compatible strings. So lets
remove it before the first users of this is seen.

Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: rename driver as generic test driver

This mailbox-test driver was designed to be generic, so let's remove ST
tag on it and make it generic.

Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: mailbox-test: avoid reading iomem twice

Don't pass mmio region as source to print_hex_dump() and then
again to memcpy_fromio(). Do it once and give print_hex_dump()
the buffer we just read the data in.

Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: Off by one in mbox_test_message_read()

We need to leave space for the NUL char.

Fixes: 8ea4484d0c2b ('mailbox: Add generic mechanism for testing Mailbox Controllers')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

mailbox: mailbox-test: Correctly repair Sparse warnings

Kbuild test robot reported some Sparse warnings to the tune of:

sparse: incorrect type in argument 6 (different address spaces)
expected void const *buf
got void [noderef] <asn:2>*mmio

This was due to passing variables tagged with the Sparse cookie
'__iomem' through into memcpy() and print_hex_dump() without
adequate protection or casting. These issues were fixed in a
previous patch suppressing the warnings, but the issue is indeed
still present.

This patch fixes the warnings in the correct way, i.e. by using
the purposely authored memcpy_{from,to}io() derivatives in the
memcpy() case and casting the memory address to (void *) and
forcing Sparse to ignore to ignore it in the print_hex_dump()
case [NB: This is also what the memcpy() derivatives do].

Reported-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: Fix a couple of trivial static checker issues

This patch deals with a few spelling, white space and type
warnings reported by Intel's Kbuild Test Robot.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: Add generic mechanism for testing Mailbox Controllers

This particular Client implementation uses shared memory in order
to pass messages between Mailbox users; however, it can be easily
hacked to support any type of Controller.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>