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* ptp: fix Spectre v1 vulnerabilityGustavo A. R. Silva2018-12-161-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit efa61c8cf2950ab5c0e66cff3cabe2a2b24e81ba upstream. pin_index can be indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/ptp/ptp_chardev.c:253 ptp_ioctl() warn: potential spectre issue 'ops->pin_config' [r] (local cap) Fix this by sanitizing pin_index before using it to index ops->pin_config, and before passing it as an argument to function ptp_set_pinfunc(), in which it is used to index info->pin_config. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ptp: introduce programmable pins.Richard Cochran2014-03-211-1/+127
| | | | | | | | | | This patch adds a pair of new ioctls to the PTP Hardware Clock device interface. Using the ioctls, user space programs can query each pin to find out its current function and also reprogram a different function if desired. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ptp: reduce stack usage when measuring the system time offsetRichard Cochran2012-11-261-7/+14
| | | | | | | | This patch removes the large buffer from the stack of the system offset ioctl and replaces it with a kmalloced buffer. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ptp: reduce stack usage when reading external time stampsRichard Cochran2012-11-261-5/+17
| | | | | | | | This patch removes the large buffer from the stack of the read file operation and replaces it with a kmalloced buffer. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ptp: add an ioctl to compare PHC time with system timeRichard Cochran2012-11-011-0/+32
| | | | | | | | | | | | | This patch adds an ioctl for PTP Hardware Clock (PHC) devices that allows user space to measure the time offset between the PHC and the system clock. Rather than hard coding any kind of estimation algorithm into the kernel, this patch takes the more flexible approach of just delivering an array of raw clock readings. In that way, the user space clock servo may be adapted to new and different hardware clocks. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ptp: Fix some locking bugs in ptp_read()Dan Carpenter2011-06-011-4/+4
| | | | | | | | | In ptp_read there is an unlock missing on an error path, and a double unlock on another error path. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Richard Cochran <richard.cochran@omicron.at> Signed-off-by: John Stultz <john.stultz@linaro.org>
* ptp: Return -EFAULT on copy_to_user() errorsDan Carpenter2011-06-011-1/+2
| | | | | | | | | copy_to_user() returns the number of bytes remaining, but we want a negative error code in ptp_ioctl. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Richard Cochran <richard.cochran@omicron.at> Signed-off-by: John Stultz <john.stultz@linaro.org>
* ptp: Added a brand new class driver for ptp clocks.Richard Cochran2011-05-231-0/+159
This patch adds an infrastructure for hardware clocks that implement IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a registration method to particular hardware clock drivers. Each clock is presented as a standard POSIX clock. The ancillary clock features are exposed in two different ways, via the sysfs and by a character device. Signed-off-by: Richard Cochran <richard.cochran@omicron.at> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: John Stultz <john.stultz@linaro.org>