dma-buf: Fix SET_NAME ioctl uapi

danvet-intel · sumitsemwal · commit a5bff92eaac4 · 2020-04-27T16:29:41.000+05:30
The uapi is the same on 32 and 64 bit, but the number isn't. Everyone who botched this please re-read: https://www.kernel.org/doc/html/v5.4-preprc-cpu/ioctl/botching-up-ioctls.html Also, the type argument for the ioctl macros is for the type the void __user *arg pointer points at, which in this case would be the variable-sized char[] of a 0 terminated string. So this was botched in more than just the usual ways. Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Chenbo Feng <fengc@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: minchan@kernel.org Cc: surenb@google.com Cc: jenhaochen@google.com Cc: Martin Liu <liumartin@google.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Tested-by: Martin Liu <liumartin@google.com> Reviewed-by: Martin Liu <liumartin@google.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> [sumits: updated some checkpatch fixes, corrected author email] Link: https://patchwork.freedesktop.org/patch/msgid/20200407133002.3486387-1-daniel.vetter@ffwll.ch
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
@@ -388,7 +388,8 @@ static long dma_buf_ioctl(struct file *file,
 
 		return ret;
 
-	case DMA_BUF_SET_NAME:
+	case DMA_BUF_SET_NAME_A:
+	case DMA_BUF_SET_NAME_B:
 		return dma_buf_set_name(dmabuf, (const char __user *)arg);
 
 	default:
diff --git a/include/uapi/linux/dma-buf.h b/include/uapi/linux/dma-buf.h
@@ -39,6 +39,12 @@ struct dma_buf_sync {
 
 #define DMA_BUF_BASE		'b'
 #define DMA_BUF_IOCTL_SYNC	_IOW(DMA_BUF_BASE, 0, struct dma_buf_sync)
+
+/* 32/64bitness of this uapi was botched in android, there's no difference
+ * between them in actual uapi, they're just different numbers.
+ */
 #define DMA_BUF_SET_NAME	_IOW(DMA_BUF_BASE, 1, const char *)
+#define DMA_BUF_SET_NAME_A	_IOW(DMA_BUF_BASE, 1, u32)
+#define DMA_BUF_SET_NAME_B	_IOW(DMA_BUF_BASE, 1, u64)
 
 #endif
