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>
John Sperbeck