linux/drivers/staging/android/sync.c, branch v3.16

staging: android: describe use of memory barrier on sync.c

2014-05-25T18:09:14Z

Added comments describing the purpose of using write memory barrier in the context of sync_timeline_destory. Signed-off-by: Niv Yehezkel Signed-off-by: Greg Kroah-Hartman

staging: android: fix missing a blank line after declarations

2014-05-03T23:46:30Z

This patch fixes "Missing a blank line after declarations" warnings. Signed-off-by: Seunghun Lee Signed-off-by: Greg Kroah-Hartman

staging: android: sync: Signal pt before sync_timeline object gets destroyed

2014-02-07T17:36:27Z

There is a race condition Assume we have *one* sync_fence object, with *one* sync_pt which belongs to *one* sync_timeline, given this condition, sync_timeline->kref will have two counts, one for sync_timeline (implicit) and another for sync_pt. Assume following is the situation on CPU Theead-1 : (Thread which calls sync_timeline_destroy()) -> (some function calls) -> sync_timeline_destory() -> sync_timeline_signal() (CPU is inside this function after putting reference to sync_timeline) At this time Thread-2 comes and does following Thread-2 : (fclose on fence fd) > sync_fence_release() -> because of fclose() on fence object -> sync_fence_free() -> sync_pt_free() -> kref_put(&pt->parent->kref, sync_timeline_free); -> sync_timeline_free() (CPU is inside this because this time kref will be zero after _put) Thread-2 will free sync_timeline object before Thread-1 has finished its work inside sync_timeline_signal. With this change we signals all sync_pt before putting reference to sync_timeline object. Cc: Colin Cross Cc: Android Kernel Team Signed-off-by: Prakash Kamliya [jstultz: minor commit subject tweak] Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman

staging: sync: Fix a race condition between release_obj and print_obj

2014-02-07T17:03:16Z

Before this change, a timeline would only be removed from the timeline list *after* the sync driver had its release_obj() called. However, the driver's release_obj() may free resources needed by print_obj(). Although the timeline list is locked when print_obj() is called, it is not locked when release_obj() is called. If one CPU was in print_obj() when another was in release_obj(), the print_obj() may make unsafe accesses. It is not actually necessary to hold the timeline list lock when calling release_obj() if the call is made after the timeline is unlinked from the list, since there is no possibility another thread could be in -- or enter -- print_obj() for that timeline. This change moves the release_obj() call to after the timeline is unlinked, preventing the above race from occurring. Cc: Colin Cross Cc: Android Kernel Team Signed-off-by: Alistair Strachan [jstultz: minor commit subject tweak] Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman

android/sync: use get_unused_fd_flags(O_CLOEXEC) instead of get_unused_fd()

2013-08-16T00:27:30Z

Macro get_unused_fd() is used to allocate a file descriptor with default flags. Those default flags (0) can be "unsafe": O_CLOEXEC must be used by default to not leak file descriptor across exec(). Instead of macro get_unused_fd(), functions anon_inode_getfd() or get_unused_fd_flags() should be used with flags given by userspace. If not possible, flags should be set to O_CLOEXEC to provide userspace with a default safe behavor. In a further patch, get_unused_fd() will be removed so that new code start using anon_inode_getfd() or get_unused_fd_flags() with correct flags. This patch replaces calls to get_unused_fd() with call to get_unused_fd_flags(O_CLOEXEC) following advice from Erik Gilling. Signed-off-by: Yann Droneaud Cc: Erik Gilling Cc: Colin Cross Link: http://lkml.kernel.org/r/CACSP8SjXGMk2_kX_+RgzqqQwqKernvF1Wt3K5tw991W5dfAnCA@mail.gmail.com Link: http://lkml.kernel.org/r/cover.1376327678.git.ydroneaud@opteya.com Signed-off-by: Greg Kroah-Hartman

staging: android: sync: fix up a sparse warning

2013-06-04T22:59:23Z

Fix up a sparse warning about sync_dump that was reported. Reported-by: kbuild test robot Cc: Erik Gilling Cc: John Stultz Signed-off-by: Greg Kroah-Hartman

staging: android: Replace seq_printf with seq_puts

2013-05-12T15:36:02Z

Fixes the following checkpatch warning: WARNING: Prefer seq_puts to seq_printf Signed-off-by: Hema Prathaban Signed-off-by: Greg Kroah-Hartman

staging: android: Remove unnecessary braces

2013-05-12T15:36:01Z

Fixes the following checkpatch warning: WARNING: braces {} are not necessary for single statement blocks Signed-off-by: Hema Prathaban Signed-off-by: Greg Kroah-Hartman

staging: sync: Add compat_ioctl handlers to sync drivers

2013-03-29T19:35:28Z

The sync drivers are missing compat_ioctl handlers, so this patch adds them. The same change has been submitted to AOSP: https://android-review.googlesource.com/#/c/54901/ Change-Id: If1a1ecc3952b321c8d64c6a8b050104859efc4b1 Cc: Erik Gilling Cc: Dmitry Pervushin Cc: Bernhard Rosenkränzer Cc: Android Kernel Team Signed-off-by: Dmitry Pervushin Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman

staging: sync: fix return value check in sync_fence_alloc()

2013-03-11T17:14:35Z

In case of error, the function anon_inode_getfile() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR(). Signed-off-by: Wei Yongjun Signed-off-by: Greg Kroah-Hartman