If the i2c bus driver ignores the I2C_M_RECV_LEN flag (as some of
them do), it is possible for an I2C_SMBUS_BLOCK_DATA read issued
on some random device to return an arbitrary value in the first
byte (and nothing else). When this happens, i2c_smbus_xfer_emulated()
will happily write past the end of the supplied data buffer, thus
causing Bad Things to happen. To prevent this, check the size
before copying the data block and return an error if it is too large.
Fixes: 209d27c3b1 ("i2c: Emulate SMBus block read over I2C")
Signed-off-by: Mans Rullgard <mans@mansr.com>
[wsa: use better errno]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Fix spelling mistake in the comments with help of `codespell`.
seperate ==> separate
Signed-off-by: Keyur Patel <iamkeyur96@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
IRQ levels are now handled within the IRQ core. Remove the forgotten
references from the documentation.
Fixes: 9b9f2b8bc2 ("i2c: i2c-smbus: Use threaded irq for smbalert")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Only few drivers use this call, so drivers and I2C core are converted at
once with this patch. By simply using i2c_new_client_device() instead of
i2c_new_device(), we easily can return an ERRPTR for this function as
well. To make out of tree users aware that something changed, the
function is renamed to i2c_new_smbus_alert_device().
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
We checked I2C calls, but not SMBus. Refactor the helper to an inline
function and use it for both, I2C and SMBus.
Fixes: 9ac6cb5fbb ("i2c: add suspended flag and accessors for i2c adapters")
Reported-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We had the request to access devices very late when interrupts are not
available anymore multiple times now. Mostly to prepare shutdown or
reboot. Allow adapters to specify a specific callback for this case.
Note that we fall back to the generic {master|smbus}_xfer callback if
this new atomic one is not present. This is intentional to preserve the
previous behaviour and avoid regressions. Because there are drivers not
using interrupts or because it might have worked "accidently" before.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Stefan Lengfeld <contact@stefanchrist.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If I2C transfers are executed in atomic contexts, trylock is used
instead of lock. This behaviour was missing for SMBUS, although a lot of
transfers are of SMBUS type, either emulated or direct. So, factor out
the locking routine into a helper and use it for I2C and SMBUS.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If an smbus transfer fails, there's no guarantee that the output
buffer was written. So, avoid trying to show the output buffer when
tracing after an error. This was 'mostly harmless', but would trip
up kasan checking if left-over cruft in byte 0 is a large length,
causing us to read from unwritten memory.
Signed-off-by: John Sperbeck <jsperbeck@google.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Removes all locking from i2c_smbus_xfer and renames it to __i2c_smbus_xfer,
then adds a new i2c_smbus_xfer function that simply grabs the lock while
calling the unlocked variant.
This is not perfectly equivalent, since i2c_smbus_xfer was callable from
atomic/irq context if you happened to end up emulating SMBus with an I2C
transfer, and that is no longer the case with this patch. It is unknown
(to me) if anything depends on that quirk, but it seems fragile enough to
simply break those cases and require them to call i2c_transfer directly
instead.
While at it, for consistency rename the 2nd to last argument (size) of
the i2c_smbus_xfer declaration to protocol and remove the surplus extern
marker.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If DMA safe memory was allocated, but the subsequent I2C transfer
fails the memory is leaked. Plug this leak.
Fixes: 8a77821e74 ("i2c: smbus: use DMA safe buffers for emulated SMBus transactions")
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
In i2c_smbus_xfer_emulated(), the function i2c_transfer() is invoked to
transfer i2c messages. The number of actual transferred messages is
returned and saved to 'status'. If 'status' is negative, that means an
error occurred during the transfer process. In that case, the value of
'status' is an error code to indicate the reason of the transfer failure.
In most cases, i2c_transfer() can transfer 'num' messages with no error.
And so 'status' == 'num'. However, due to unexpected errors, it is probable
that only partial messages are transferred by i2c_transfer(). As a result,
'status' != 'num'. This special case is not checked after the invocation of
i2c_transfer() and can potentially lead to unexpected issues in the
following execution since it is expected that 'status' == 'num'.
This patch checks the return value of i2c_transfer() and returns an error
code -EIO if the number of actual transferred messages 'status' is not
equal to 'num'.
Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
"I2C has the following changes for you:
- new flag to mark DMA safe buffers in i2c_msg. Also, some
infrastructure around it. And docs.
- huge refactoring of the at24 driver led by the new maintainer
Bartosz
- update I2C bus recovery to send STOP after recovery
- conversion from gpio to gpiod for I2C bus recovery
- adding a fault-injector to the i2c-gpio driver
- lots of small driver improvements, and bigger ones to
i2c-sh_mobile"
* 'i2c/for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (99 commits)
i2c: mv64xxx: Add myself as maintainer for this driver
i2c: mv64xxx: Fix clock resource by adding an optional bus clock
i2c: mv64xxx: Remove useless test before clk_disable_unprepare
i2c: mxs: use true and false for boolean values
i2c: meson: update doc description to fix build warnings
i2c: meson: add configurable divider factors
dt-bindings: i2c: update documentation for the Meson-AXG
i2c: imx-lpi2c: add runtime pm support
i2c: rcar: fix some trivial typos in comments
i2c: davinci: fix the cpufreq transition
i2c: rk3x: add proper kerneldoc header
i2c: rk3x: account for const type of of_device_id.data
i2c: acorn: remove outdated path from file header
i2c: acorn: add MODULE_LICENSE tag
i2c: rcar: implement bus recovery
i2c: send STOP after successful bus recovery
i2c: ensure SDA is released in recovery if SDA is controllable
i2c: add 'set_sda' to bus_recovery_info
i2c: add identifier in declarations for i2c_bus_recovery
i2c: make kerneldoc about bus recovery more precise
...
On a I2C_SMBUS_I2C_BLOCK_DATA read request, if data->block[0] is
greater than I2C_SMBUS_BLOCK_MAX + 1, the underlying I2C driver writes
data out of the msgbuf1 array boundary.
It is possible from a user application to run into that issue by
calling the I2C_SMBUS ioctl with data.block[0] greater than
I2C_SMBUS_BLOCK_MAX + 1.
This patch makes the code compliant with
Documentation/i2c/dev-interface by raising an error when the requested
size is larger than 32 bytes.
Call Trace:
[<ffffffff8139f695>] dump_stack+0x67/0x92
[<ffffffff811802a4>] panic+0xc5/0x1eb
[<ffffffff810ecb5f>] ? vprintk_default+0x1f/0x30
[<ffffffff817456d3>] ? i2cdev_ioctl_smbus+0x303/0x320
[<ffffffff8109a68b>] __stack_chk_fail+0x1b/0x20
[<ffffffff817456d3>] i2cdev_ioctl_smbus+0x303/0x320
[<ffffffff81745aed>] i2cdev_ioctl+0x4d/0x1e0
[<ffffffff811f761a>] do_vfs_ioctl+0x2ba/0x490
[<ffffffff81336e43>] ? security_file_ioctl+0x43/0x60
[<ffffffff811f7869>] SyS_ioctl+0x79/0x90
[<ffffffff81a22e97>] entry_SYSCALL_64_fastpath+0x12/0x6a
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
For all block commands, try to allocate a DMA safe buffer and mark it
accordingly. Only use the stack, if the buffers cannot be allocated.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit adds of_i2c_setup_smbus_alert which allows the smbalert
driver to be attached to an i2c adapter via the device tree.
Signed-off-by: Phil Reid <preid@electromag.com.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In preparation to adding of_i2c_setup_smbus_alert() move
i2c_setup_smbus_alert() to core module. of_i2c_setup_smbus_alert()
will call i2c_setup_smbus_alert() and this avoid module dependecy issues.
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Break out the exported SMBus functions and the emulation layer into a
separate file. This also involved splitting up the tracing header into
an I2C and an SMBus part.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
