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  1. 22 Jun, 2018 2 commits
  3. 21 Jun, 2018 3 commits
    • Jeenu Viswambharan's avatar
      SDEI: Make dispatches synchronous · cdb6ac94
      Jeenu Viswambharan authored 
      

SDEI event dispatches currently only sets up the Non-secure context
before returning to the caller. The actual dispatch only happens upon
exiting EL3 next time.

However, for various error handling scenarios, it's beneficial to have
the dispatch happen synchronously. I.e. when receiving SDEI interrupt,
or for a successful sdei_dispatch_event() call, the event handler is
executed; and upon the event completion, dispatcher execution resumes
after the point of dispatch. The jump primitives introduced in the
earlier patch facilitates this feature.

With this patch:

  - SDEI interrupts and calls to sdei_dispatch_event prepares the NS
    context for event dispatch, then sets a jump point, and immediately
    exits EL3. This results in the client handler executing in
    Non-secure.

  - When the SDEI client completes the dispatched event, the SDEI
    dispatcher does a longjmp to the jump pointer created earlier. For
    the caller of the sdei_dispatch_event() in particular, this would
    appear as if call returned successfully.

The dynamic workaround for CVE_2018_3639 is slightly shifted around as
part of related minor refactoring. It doesn't affect the workaround
functionality.

Documentation updated.

NOTE: This breaks the semantics of the explicit dispatch API, and any
exiting usages should be carefully reviewed.

Change-Id: Ib9c876d27ea2af7fb22de49832e55a0da83da3f9
Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      cdb6ac94
    • Jeenu Viswambharan's avatar
      SDEI: Determine client EL from NS context's SCR_EL3 · 2ccfcb2e
      Jeenu Viswambharan authored 
      

Currently, the dispatcher reads from SCR_EL3 register directly to
determine the EL of SDEI client. This is with the assumption that
SCR_EL3 is not modified throughout. However, with RAS work flows, it's
possible that SCR_EL3 register contains values corresponding to Secure
world, and therefore EL determination can go wrong. To mitigate this,
always read the register from the saved Non-secure context.

Change-Id: Ic85e4021deb18eb58757f676f9a001174998543a
Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      2ccfcb2e
    • Jeenu Viswambharan's avatar
      SDEI: Allow platforms to define explicit events · af2c9ecd
      Jeenu Viswambharan authored 
      

The current macros only allow to define dynamic and statically-bound
SDEI events. However, there ought be a mechanism to define SDEI events
that are explicitly dispatched; i.e., events that are dispatched as a
result of a previous secure interrupt or other exception

This patch introduces SDEI_EXPLICIT_EVENT() macro to define an explicit
event. They must be placed under private mappings. Only the priority
flags are allowed to be additionally specified.

Documentation updated.

Change-Id: I2e12f5571381195d6234c9dfbd5904608ad41db3
Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      af2c9ecd
  5. 08 Jun, 2018 1 commit
  7. 26 Mar, 2018 1 commit
  9. 27 Feb, 2018 1 commit
    • Jeenu Viswambharan's avatar
      SDEI: Pop dispatch context only after error checking · 8e3032f9
      Jeenu Viswambharan authored 
      

Currently, when the client attempts to do SDEI_EVENT_COMPLETE or
SDEI_EVENT_COMPLETE_AND_RESUME, the dispatcher pops off the outstanding
dispatch context for sanity check. There are however other checks
following this, which could potentially return failure. If that happens,
by popping the context, the dispatcher has inadvertently discarded a
valid context.

This patch fixes this bug by inspecting (not actually popping) the
outstanding context. The context is popped only after all error checks
are completed.

Change-Id: Ie199f6442f871a8177a8247a0c646543bad76d21
Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      8e3032f9
  11. 14 Feb, 2018 1 commit
    • Antonio Nino Diaz's avatar
      Remove URLs from comments · fb1198b1
      Antonio Nino Diaz authored 
      

This fixes all defects according to MISRA Rule 3.1: "The character
sequences /* and // shall not be used within a comment". This affects
all URLs in comments, so they have been removed:

- The link in `sdei_state.c` can also be found in the documentation file
  `docs/sdei.rst`.

- The bug that the file `io_fip.c` talks about doesn't affect the
  currently supported version of GCC, so it doesn't make sense to keep
  the comment. Note that the version of GCC officially supported is the
  one that comes with Linaro Release 17.10, which is GCC 6.2.

- The link in `tzc400.c` was broken, and it didn't correctly direct to
  the Technical Reference Manual it should. The link has been replaced
  by the title of the document, which is more convenient when looking
  for the document.

Change-Id: I89f60c25f635fd4c008a5d3a14028f814c147bbe
Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
      fb1198b1
  13. 06 Dec, 2017 1 commit
  15. 20 Nov, 2017 2 commits
  17. 13 Nov, 2017 3 commits