diff options
| author | Carlos Llamas <cmllamas@google.com> | 2023-05-02 20:12:18 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-13 20:30:16 +0900 |
| commit | c0fd2101781ef761b636769b2f445351f71c3626 (patch) | |
| tree | 093d23560158ab82210ba65e57f9232902ff2c6e /drivers/android/binder_alloc_selftest.c | |
| parent | b15655b12ddca7ade09807f790bafb6fab61b50a (diff) | |
Revert "android: binder: stop saving a pointer to the VMA"
This reverts commit a43cfc87caaf46710c8027a8c23b8a55f1078f19.
This patch fixed an issue reported by syzkaller in [1]. However, this
turned out to be only a band-aid in binder. The root cause, as bisected
by syzkaller, was fixed by commit 5789151e48ac ("mm/mmap: undo ->mmap()
when mas_preallocate() fails"). We no longer need the patch for binder.
Reverting such patch allows us to have a lockless access to alloc->vma
in specific cases where the mmap_lock is not required. This approach
avoids the contention that caused a performance regression.
[1] https://lore.kernel.org/all/0000000000004a0dbe05e1d749e0@google.com
[cmllamas: resolved conflicts with rework of alloc->mm and removal of
binder_alloc_set_vma() also fixed comment section]
Fixes: a43cfc87caaf ("android: binder: stop saving a pointer to the VMA")
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20230502201220.1756319-2-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/android/binder_alloc_selftest.c')
| -rw-r--r-- | drivers/android/binder_alloc_selftest.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/android/binder_alloc_selftest.c b/drivers/android/binder_alloc_selftest.c index 43a881073a42..c2b323bc3b3a 100644 --- a/drivers/android/binder_alloc_selftest.c +++ b/drivers/android/binder_alloc_selftest.c @@ -287,7 +287,7 @@ void binder_selftest_alloc(struct binder_alloc *alloc) if (!binder_selftest_run) return; mutex_lock(&binder_selftest_lock); - if (!binder_selftest_run || !alloc->vma_addr) + if (!binder_selftest_run || !alloc->vma) goto done; pr_info("STARTED\n"); binder_selftest_alloc_offset(alloc, end_offset, 0); |