From c830c90995fc0877348e2ed9cdeccf9b739138d2 Mon Sep 17 00:00:00 2001

From: Anatol Pomozov <anatol.pomozov@gmail.com>

Date: Mon, 10 Oct 2022 10:47:57 -0700

Subject: [PATCH] Update usage of usbdevfs_urb to match new kernel UAPI

Linux kernel API has been changed by commit 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members")

where zero-length array iso_frame_desc in struct usbdevfs_urb was replaced with a proper flexible-array member.

Current USB API usage causes a compilation error at Linux 6.0:

In file included from /home/mae/.cache/kiss/proc/121205/build/android-tools/vendor/adb/client/usb_linux.cpp:28:

/usr/include/linux/usbdevice_fs.h:134:41: error: flexible array member Б─≤usbdevfs_urb::iso_frame_descБ─≥ not at end of Б─≤struct usb_handleБ─≥

  134 |         struct usbdevfs_iso_packet_desc iso_frame_desc[];

      |                                         ^~~~~~~~~~~~~~

/home/mae/.cache/kiss/proc/121205/build/android-tools/vendor/adb/client/usb_linux.cpp:76:18: note: next member Б─≤usbdevfs_urb usb_handle::urb_outБ─≥ declared here

   76 |     usbdevfs_urb urb_out;

      |                  ^~~~~~~

/home/mae/.cache/kiss/proc/121205/build/android-tools/vendor/adb/client/usb_linux.cpp:61:8: note: in the definition of Б─≤struct usb_handleБ─≥

   61 | struct usb_handle {

      |        ^~~~~~~~~~

Fix it by using pointers to a struct with flexible-array members.

Current fix works both with the old and the new API.

See https://github.com/nmeum/android-tools/issues/74 for more context.

Tested: built on Linux against kernel 5.19 and 6.0; 'adb shell' over USB

cable

Acked-by: Gustavo A. R. Silva gustavoars@kernel.org

Change-Id: I7f0f7b35d9a3ab980d3520b541b60c7857a6b101

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>

---

diff --git a/client/usb_linux.cpp b/client/usb_linux.cpp

index 7f92626..235a21b 100644

--- a/client/usb_linux.cpp

+++ b/client/usb_linux.cpp

@@ -71,8 +71,8 @@

     unsigned zero_mask;

     unsigned writeable = 1;

-    usbdevfs_urb urb_in;

-    usbdevfs_urb urb_out;

+    usbdevfs_urb *urb_in;

+    usbdevfs_urb *urb_out;

     bool urb_in_busy = false;

     bool urb_out_busy = false;

@@ -303,7 +303,7 @@

     std::unique_lock<std::mutex> lock(h->mutex);

     D("++ usb_bulk_write ++");

-    usbdevfs_urb* urb = &h->urb_out;

+    usbdevfs_urb* urb = h->urb_out;

     memset(urb, 0, sizeof(*urb));

     urb->type = USBDEVFS_URB_TYPE_BULK;

     urb->endpoint = h->ep_out;

@@ -342,7 +342,7 @@

     std::unique_lock<std::mutex> lock(h->mutex);

     D("++ usb_bulk_read ++");

-    usbdevfs_urb* urb = &h->urb_in;

+    usbdevfs_urb* urb = h->urb_in;

     memset(urb, 0, sizeof(*urb));

     urb->type = USBDEVFS_URB_TYPE_BULK;

     urb->endpoint = h->ep_in;

@@ -387,7 +387,7 @@

         }

         D("[ urb @%p status = %d, actual = %d ]", out, out->status, out->actual_length);

-        if (out == &h->urb_in) {

+        if (out == h->urb_in) {

             D("[ reap urb - IN complete ]");

             h->urb_in_busy = false;

             if (urb->status != 0) {

@@ -396,7 +396,7 @@

             }

             return urb->actual_length;

         }

-        if (out == &h->urb_out) {

+        if (out == h->urb_out) {

             D("[ reap urb - OUT compelete ]");

             h->urb_out_busy = false;

             h->cv.notify_all();

@@ -500,10 +500,10 @@

             ** but this ensures that a reader blocked on REAPURB

             ** will get unblocked

             */

-            ioctl(h->fd, USBDEVFS_DISCARDURB, &h->urb_in);

-            ioctl(h->fd, USBDEVFS_DISCARDURB, &h->urb_out);

-            h->urb_in.status = -ENODEV;

-            h->urb_out.status = -ENODEV;

+            ioctl(h->fd, USBDEVFS_DISCARDURB, h->urb_in);

+            ioctl(h->fd, USBDEVFS_DISCARDURB, h->urb_out);

+            h->urb_in->status = -ENODEV;

+            h->urb_out->status = -ENODEV;

             h->urb_in_busy = false;

             h->urb_out_busy = false;

             h->cv.notify_all();

@@ -519,6 +519,8 @@

     D("-- usb close %p (fd = %d) --", h, h->fd);

+    delete h->urb_in;

+    delete h->urb_out;

     delete h;

     return 0;

@@ -572,6 +574,8 @@

     usb->ep_out = ep_out;

     usb->zero_mask = zero_mask;

     usb->max_packet_size = max_packet_size;

+    usb->urb_in = new usbdevfs_urb;

+    usb->urb_out = new usbdevfs_urb;

     // Initialize mark so we don't get garbage collected after the device scan.

     usb->mark = true;