cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sysfs-uevent (2324B)


      1What:           /sys/.../uevent
      2Date:           May 2017
      3KernelVersion:  4.13
      4Contact:        Linux kernel mailing list <linux-kernel@vger.kernel.org>
      5Description:
      6                Enable passing additional variables for synthetic uevents that
      7                are generated by writing /sys/.../uevent file.
      8
      9                Recognized extended format is::
     10
     11			ACTION [UUID [KEY=VALUE ...]
     12
     13                The ACTION is compulsory - it is the name of the uevent
     14                action (``add``, ``change``, ``remove``). There is no change
     15                compared to previous functionality here. The rest of the
     16                extended format is optional.
     17
     18                You need to pass UUID first before any KEY=VALUE pairs.
     19                The UUID must be in ``xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx``
     20                format where 'x' is a hex digit. The UUID is considered to be
     21                a transaction identifier so it's possible to use the same UUID
     22                value for one or more synthetic uevents in which case we
     23                logically group these uevents together for any userspace
     24                listeners. The UUID value appears in uevent as
     25                ``SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`` environment
     26                variable.
     27
     28                If UUID is not passed in, the generated synthetic uevent gains
     29                ``SYNTH_UUID=0`` environment variable automatically.
     30
     31                The KEY=VALUE pairs can contain alphanumeric characters only.
     32
     33                It's possible to define zero or more pairs - each pair is then
     34                delimited by a space character ' '. Each pair appears in
     35                synthetic uevent as ``SYNTH_ARG_KEY=VALUE``. That means the KEY
     36                name gains ``SYNTH_ARG_`` prefix to avoid possible collisions
     37                with existing variables.
     38
     39                Example of valid sequence written to the uevent file::
     40
     41                    add fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed A=1 B=abc
     42
     43                This generates synthetic uevent including these variables::
     44
     45                    ACTION=add
     46                    SYNTH_ARG_A=1
     47                    SYNTH_ARG_B=abc
     48                    SYNTH_UUID=fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed
     49
     50Users:
     51                udev, userspace tools generating synthetic uevents