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path: root/drivers/android/binder_alloc.c
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Diffstat (limited to 'drivers/android/binder_alloc.c')
-rw-r--r--drivers/android/binder_alloc.c55
1 files changed, 52 insertions, 3 deletions
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 8c98d12b7beb..910c53ba2c91 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -338,12 +338,50 @@ static inline struct vm_area_struct *binder_alloc_get_vma(
return vma;
}
+static void debug_low_async_space_locked(struct binder_alloc *alloc, int pid)
+{
+ /*
+ * Find the amount and size of buffers allocated by the current caller;
+ * The idea is that once we cross the threshold, whoever is responsible
+ * for the low async space is likely to try to send another async txn,
+ * and at some point we'll catch them in the act. This is more efficient
+ * than keeping a map per pid.
+ */
+ struct rb_node *n = alloc->free_buffers.rb_node;
+ struct binder_buffer *buffer;
+ size_t total_alloc_size = 0;
+ size_t num_buffers = 0;
+
+ for (n = rb_first(&alloc->allocated_buffers); n != NULL;
+ n = rb_next(n)) {
+ buffer = rb_entry(n, struct binder_buffer, rb_node);
+ if (buffer->pid != pid)
+ continue;
+ if (!buffer->async_transaction)
+ continue;
+ total_alloc_size += binder_alloc_buffer_size(alloc, buffer)
+ + sizeof(struct binder_buffer);
+ num_buffers++;
+ }
+
+ /*
+ * Warn if this pid has more than 50 transactions, or more than 50% of
+ * async space (which is 25% of total buffer size).
+ */
+ if (num_buffers > 50 || total_alloc_size > alloc->buffer_size / 4) {
+ binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+ "%d: pid %d spamming oneway? %zd buffers allocated for a total size of %zd\n",
+ alloc->pid, pid, num_buffers, total_alloc_size);
+ }
+}
+
static struct binder_buffer *binder_alloc_new_buf_locked(
struct binder_alloc *alloc,
size_t data_size,
size_t offsets_size,
size_t extra_buffers_size,
- int is_async)
+ int is_async,
+ int pid)
{
struct rb_node *n = alloc->free_buffers.rb_node;
struct binder_buffer *buffer;
@@ -486,11 +524,20 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
buffer->offsets_size = offsets_size;
buffer->async_transaction = is_async;
buffer->extra_buffers_size = extra_buffers_size;
+ buffer->pid = pid;
if (is_async) {
alloc->free_async_space -= size + sizeof(struct binder_buffer);
binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
"%d: binder_alloc_buf size %zd async free %zd\n",
alloc->pid, size, alloc->free_async_space);
+ if (alloc->free_async_space < alloc->buffer_size / 10) {
+ /*
+ * Start detecting spammers once we have less than 20%
+ * of async space left (which is less than 10% of total
+ * buffer size).
+ */
+ debug_low_async_space_locked(alloc, pid);
+ }
}
return buffer;
@@ -508,6 +555,7 @@ err_alloc_buf_struct_failed:
* @offsets_size: user specified buffer offset
* @extra_buffers_size: size of extra space for meta-data (eg, security context)
* @is_async: buffer for async transaction
+ * @pid: pid to attribute allocation to (used for debugging)
*
* Allocate a new buffer given the requested sizes. Returns
* the kernel version of the buffer pointer. The size allocated
@@ -520,13 +568,14 @@ struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
size_t data_size,
size_t offsets_size,
size_t extra_buffers_size,
- int is_async)
+ int is_async,
+ int pid)
{
struct binder_buffer *buffer;
mutex_lock(&alloc->mutex);
buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size,
- extra_buffers_size, is_async);
+ extra_buffers_size, is_async, pid);
mutex_unlock(&alloc->mutex);
return buffer;
}