Merge "msm: camera: sync: protect sync obj creation from race condition" into dev/msm-4.9-camx (6e1bbe85) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/media/platform/msm/camera/cam_sync/cam_sync.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -25,22 +25,25 @@ int cam_sync_create(int32_t sync_obj, const char name)
		{
		int rc;
		long idx;
		bool bit;

		do {
		idx = find_first_zero_bit(sync_dev->bitmap, CAM_SYNC_MAX_OBJS);
		if (idx >= CAM_SYNC_MAX_OBJS)
		return -ENOMEM;
		} while (!spin_trylock_bh(&sync_dev->row_spinlocks[idx]));
		bit = test_and_set_bit(idx, sync_dev->bitmap);
		} while (bit);

		spin_lock_bh(&sync_dev->row_spinlocks[idx]);
		rc = cam_sync_init_object(sync_dev->sync_table, idx, name);
		if (rc) {
		CAM_ERR(CAM_SYNC, "Error: Unable to init row at idx = %ld",
		idx);
		clear_bit(idx, sync_dev->bitmap);
		spin_unlock_bh(&sync_dev->row_spinlocks[idx]);
		return -EINVAL;
		}

		set_bit(idx, sync_dev->bitmap);
		*sync_obj = idx;
		spin_unlock_bh(&sync_dev->row_spinlocks[idx]);

		@@ -299,6 +302,7 @@ int cam_sync_merge(int32_t sync_obj, uint32_t num_objs, int32_t merged_obj)
		{
		int rc;
		long idx = 0;
		bool bit;

		if (!sync_obj \|\| !merged_obj) {
		CAM_ERR(CAM_SYNC, "Invalid pointer(s)");
		@@ -316,9 +320,10 @@ int cam_sync_merge(int32_t sync_obj, uint32_t num_objs, int32_t merged_obj)
		idx = find_first_zero_bit(sync_dev->bitmap, CAM_SYNC_MAX_OBJS);
		if (idx >= CAM_SYNC_MAX_OBJS)
		return -ENOMEM;
		} while (!spin_trylock_bh(&sync_dev->row_spinlocks[idx]));
		bit = test_and_set_bit(idx, sync_dev->bitmap);
		} while (bit);

		set_bit(idx, sync_dev->bitmap);
		spin_lock_bh(&sync_dev->row_spinlocks[idx]);

		rc = cam_sync_init_group_object(sync_dev->sync_table,
		idx, sync_obj,
		@@ -326,6 +331,7 @@ int cam_sync_merge(int32_t sync_obj, uint32_t num_objs, int32_t merged_obj)
		if (rc < 0) {
		CAM_ERR(CAM_SYNC, "Error: Unable to init row at idx = %ld",
		idx);
		clear_bit(idx, sync_dev->bitmap);
		spin_unlock_bh(&sync_dev->row_spinlocks[idx]);
		return -EINVAL;
		}