diff options
| author | Mitchel Humpherys <mitchelh@codeaurora.org> | 2014-05-23 13:01:22 -0700 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2016-12-11 11:52:45 +0100 |
| commit | 1286bf76de7611dc6b3f0ac38228d3c2e513b201 (patch) | |
| tree | 66cae3255002df8284caefc603e9dc3933a11cc8 | |
| parent | 98b4be487822c30d2e769c274178211530bc2804 (diff) | |
staging: ion: WARN when the handle kmap_cnt is going to wrap around
There are certain client bugs (double unmap, for example) that can cause
the handle->kmap_cnt (an unsigned int) to wrap around from zero. This
causes problems when the handle is destroyed because we have:
while (handle->kmap_cnt)
ion_handle_kmap_put(handle);
which takes a long time to complete when kmap_cnt starts at ~0 and can
result in a watchdog timeout.
WARN and bail when kmap_cnt is about to wrap around from zero.
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/android/ion/ion.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 21d8a0b6a..26b0ac892 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -749,6 +749,10 @@ static void ion_handle_kmap_put(struct ion_handle *handle) { struct ion_buffer *buffer = handle->buffer; + if (!handle->kmap_cnt) { + WARN(1, "%s: Double unmap detected! bailing...\n", __func__); + return; + } handle->kmap_cnt--; if (!handle->kmap_cnt) ion_buffer_kmap_put(buffer); |