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android / kernel / common / ec6fe823507b2f6ef4a58f3a9bee9a5ec086c32c
commitec6fe823507b2f6ef4a58f3a9bee9a5ec086c32c[log] [tgz]
authorArd Biesheuvel <[email protected]>Mon Dec 05 11:31:25 2022 +0100
committerLee Jones <[email protected]>Mon Jan 30 16:32:02 2023 +0000
treed9ae911b67292aa62b94b75b63103ddc527091a3
parent003dacfcee549e931ca9b44673c72db3490a2efc [diff]
UPSTREAM: arm64: efi: Execute runtime services from a dedicated stack

commit ff7a167961d1b97e0e205f245f806e564d3505e7 upstream.

With the introduction of PRMT in the ACPI subsystem, the EFI rts
workqueue is no longer the only caller of efi_call_virt_pointer() in the
kernel. This means the EFI runtime services lock is no longer sufficient
to manage concurrent calls into firmware, but also that firmware calls
may occur that are not marshalled via the workqueue mechanism, but
originate directly from the caller context.

For added robustness, and to ensure that the runtime services have 8 KiB
of stack space available as per the EFI spec, introduce a spinlock
protected EFI runtime stack of 8 KiB, where the spinlock also ensures
serialization between the EFI rts workqueue (which itself serializes EFI
runtime calls) and other callers of efi_call_virt_pointer().

While at it, use the stack pivot to avoid reloading the shadow call
stack pointer from the ordinary stack, as doing so could produce a
gadget to defeat it.

Bug: 260821414
Signed-off-by: Ard Biesheuvel <[email protected]>
Cc: Lee Jones <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: Ie961576ae93cafc315cb37fb84cca0a6402eda59
3 files changed
tree: d9ae911b67292aa62b94b75b63103ddc527091a3
  1. android/
  2. arch/
  3. block/
  4. certs/
  5. crypto/
  6. Documentation/
  7. drivers/
  8. fs/
  9. include/
  10. init/
  11. ipc/
  12. kernel/
  13. lib/
  14. LICENSES/
  15. mm/
  16. net/
  17. samples/
  18. scripts/
  19. security/
  20. sound/
  21. tools/
  22. usr/
  23. virt/
  24. .clang-format
  25. .cocciconfig
  26. .get_maintainer.ignore
  27. .gitattributes
  28. .gitignore
  29. .mailmap
  30. BUILD.bazel
  31. build.config.aarch64
  32. build.config.allmodconfig
  33. build.config.allmodconfig.aarch64
  34. build.config.allmodconfig.arm
  35. build.config.allmodconfig.x86_64
  36. build.config.amlogic
  37. build.config.arm
  38. build.config.common
  39. build.config.constants
  40. build.config.db845c
  41. build.config.gce.x86_64
  42. build.config.gki
  43. build.config.gki-debug.aarch64
  44. build.config.gki-debug.x86_64
  45. build.config.gki.aarch64
  46. build.config.gki.aarch64.fips140
  47. build.config.gki.x86_64
  48. build.config.gki_kasan
  49. build.config.gki_kasan.aarch64
  50. build.config.gki_kasan.x86_64
  51. build.config.gki_kprobes
  52. build.config.gki_kprobes.aarch64
  53. build.config.gki_kprobes.x86_64
  54. build.config.khwasan
  55. build.config.rockpi4
  56. build.config.x86_64
  57. COPYING
  58. CREDITS
  59. Kbuild
  60. Kconfig
  61. Kconfig.ext
  62. MAINTAINERS
  63. Makefile
  64. OWNERS
  65. README
  66. README.md
README.md

How do I submit patches to Android Common Kernels

  1. BEST: Make all of your changes to upstream Linux. If appropriate, backport to the stable releases. These patches will be merged automatically in the corresponding common kernels. If the patch is already in upstream Linux, post a backport of the patch that conforms to the patch requirements below.

    • Do not send patches upstream that contain only symbol exports. To be considered for upstream Linux, additions of EXPORT_SYMBOL_GPL() require an in-tree modular driver that uses the symbol -- so include the new driver or changes to an existing driver in the same patchset as the export.
    • When sending patches upstream, the commit message must contain a clear case for why the patch is needed and beneficial to the community. Enabling out-of-tree drivers or functionality is not not a persuasive case.

  2. LESS GOOD: Develop your patches out-of-tree (from an upstream Linux point-of-view). Unless these are fixing an Android-specific bug, these are very unlikely to be accepted unless they have been coordinated with [email protected]. If you want to proceed, post a patch that conforms to the patch requirements below.

Common Kernel patch requirements

Additional requirements are listed below based on patch type

Requirements for backports from mainline Linux: UPSTREAM:, BACKPORT:

  • If the patch is a cherry-pick from Linux mainline with no changes at all
    • tag the patch subject with UPSTREAM:.
    • add upstream commit information with a (cherry picked from commit ...) line
    • Example:
      • if the upstream commit message is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <[email protected]>
  • then Joe Smith would upload the patch for the common kernel as
        UPSTREAM: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <[email protected]>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        Signed-off-by: Joe Smith <[email protected]>
  • If the patch requires any changes from the upstream version, tag the patch with BACKPORT: instead of UPSTREAM:.
    • use the same tags as UPSTREAM:
    • add comments about the changes under the (cherry picked from commit ...) line
    • Example:
        BACKPORT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <[email protected]>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        [joe: Resolved minor conflict in drivers/foo/bar.c ]
        Signed-off-by: Joe Smith <[email protected]>

Requirements for other backports: FROMGIT:, FROMLIST:,

  • If the patch has been merged into an upstream maintainer tree, but has not yet been merged into Linux mainline
    • tag the patch subject with FROMGIT:
    • add info on where the patch came from as (cherry picked from commit <sha1> <repo> <branch>). This must be a stable maintainer branch (not rebased, so don't use linux-next for example).
    • if changes were required, use BACKPORT: FROMGIT:
    • Example:
      • if the commit message in the maintainer tree is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <[email protected]>
  • then Joe Smith would upload the patch for the common kernel as
        FROMGIT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <[email protected]>

        Bug: 135791357
        (cherry picked from commit 878a2fd9de10b03d11d2f622250285c7e63deace
         https://git.kernel.org/pub/scm/linux/kernel/git/foo/bar.git test-branch)
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <[email protected]>
  • If the patch has been submitted to LKML, but not accepted into any maintainer tree
    • tag the patch subject with FROMLIST:
    • add a Link: tag with a link to the submittal on lore.kernel.org
    • add a Bug: tag with the Android bug (required for patches not accepted into a maintainer tree)
    • if changes were required, use BACKPORT: FROMLIST:
    • Example:
        FROMLIST: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <[email protected]>

        Bug: 135791357
        Link: https://lore.kernel.org/lkml/[email protected]/
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <[email protected]>

Requirements for Android-specific patches: ANDROID:

  • If the patch is fixing a bug to Android-specific code
    • tag the patch subject with ANDROID:
    • add a Fixes: tag that cites the patch with the bug
    • Example:
        ANDROID: fix android-specific bug in foobar.c

        This is the detailed description of the important fix

        Fixes: 1234abcd2468 ("foobar: add cool feature")
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <[email protected]>
  • If the patch is a new feature
    • tag the patch subject with ANDROID:
    • add a Bug: tag with the Android bug (required for android-specific features)