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chromium / chromiumos / third_party / kernel / refs/heads/merge/chromeos-5.10-arcvm_2022-01-21_2
commitbdc732d112f3e2c4160fe03c62c32308529ab0f6[log] [tgz]
authorSteven Rostedt (VMware) <rostedt@goodmis.org>Tue Dec 07 22:17:29 2021
committerRoger Liao <rogerliao@google.com>Thu Jan 20 15:54:50 2022
treea34d90ab9caf96c387afcfa97a4caa1899a0c5dd
parent8455746a4564f56f12d250657536a287066b2f28 [diff]
UPSTREAM: tracefs: Set all files to the same group ownership as the mount option

commit 48b27b6b5191e2e1f2798cd80877b6e4ef47c351 upstream.

As people have been asking to allow non-root processes to have access to
the tracefs directory, it was considered best to only allow groups to have
access to the directory, where it is easier to just set the tracefs file
system to a specific group (as other would be too dangerous), and that way
the admins could pick which processes would have access to tracefs.

Unfortunately, this broke tooling on Android that expected the other bit
to be set. For some special cases, for non-root tools to trace the system,
tracefs would be mounted and change the permissions of the top level
directory which gave access to all running tasks permission to the
tracing directory. Even though this would be dangerous to do in a
production environment, for testing environments this can be useful.

Now with the new changes to not allow other (which is still the proper
thing to do), it breaks the testing tooling. Now more code needs to be
loaded on the system to change ownership of the tracing directory.

The real solution is to have tracefs honor the gid=xxx option when
mounting. That is,

(tracing group tracing has value 1003)

 mount -t tracefs -o gid=1003 tracefs /sys/kernel/tracing

should have it that all files in the tracing directory should be of the
given group.

Copy the logic from d_walk() from dcache.c and simplify it for the mount
case of tracefs if gid is set. All the files in tracefs will be walked and
their group will be set to the value passed in.

Link: https://lkml.kernel.org/r/20211207171729.2a54e1b3@gandalf.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Kalesh Singh <kaleshsingh@google.com>
Reported-by: Yabin Cui <yabinc@google.com>
Fixes: 49d67e445742 ("tracefs: Have tracefs directories not set OTH permission bits by default")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 5f1f94c26b0d0abb9931d7b0864719078585b28a)

Bug: 214061655
Signed-off-by: Roger Liao <rogerliao@google.com>
Change-Id: Ib82bc6fec33f9fd2f926d76db752d43ec8db8dd1
1 file changed
tree: a34d90ab9caf96c387afcfa97a4caa1899a0c5dd
  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.config.aarch64
  31. build.config.allmodconfig
  32. build.config.allmodconfig.aarch64
  33. build.config.allmodconfig.arm
  34. build.config.allmodconfig.x86_64
  35. build.config.amlogic
  36. build.config.arm
  37. build.config.common
  38. build.config.db845c
  39. build.config.gki
  40. build.config.gki-debug.aarch64
  41. build.config.gki-debug.x86_64
  42. build.config.gki.aarch64
  43. build.config.gki.aarch64.fips140
  44. build.config.gki.aarch64.fips140_eval_testing
  45. build.config.gki.x86_64
  46. build.config.gki_kasan
  47. build.config.gki_kasan.aarch64
  48. build.config.gki_kasan.x86_64
  49. build.config.gki_kprobes
  50. build.config.gki_kprobes.aarch64
  51. build.config.gki_kprobes.x86_64
  52. build.config.hikey960
  53. build.config.khwasan
  54. build.config.rockchip
  55. build.config.x86_64
  56. COPYING
  57. CREDITS
  58. Kbuild
  59. Kconfig
  60. MAINTAINERS
  61. Makefile
  62. OWNERS
  63. README
  64. 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 kernel-team@android.com. If you want to proceed, post a patch that conforms to the patch requirements below.

Common Kernel patch requirements

  • All patches must conform to the Linux kernel coding standards and pass script/checkpatch.pl
  • Patches shall not break gki_defconfig or allmodconfig builds for arm, arm64, x86, x86_64 architectures (see https://source.android.com/setup/build/building-kernels)
  • If the patch is not merged from an upstream branch, the subject must be tagged with the type of patch: UPSTREAM:, BACKPORT:, FROMGIT:, FROMLIST:, or ANDROID:.
  • All patches must have a Change-Id: tag (see https://gerrit-review.googlesource.com/Documentation/user-changeid.html)
  • If an Android bug has been assigned, there must be a Bug: tag.
  • All patches must have a Signed-off-by: tag by the author and the submitter

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 <fred.jones@foo.org>
  • 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 <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • 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 <fred.jones@foo.org>

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

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 <fred.jones@foo.org>
  • 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 <fred.jones@foo.org>

        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 <joe.smith@foo.org>
  • 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 <fred.jones@foo.org>

        Bug: 135791357
        Link: https://lore.kernel.org/lkml/20190619171517.GA17557@someone.com/
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>

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 <joe.smith@foo.org>
  • 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)