[Buildroot] [PATCH] package/openocd: Fix segfault when using ST-Link driver

[Arnout Vandecappelle]

On 04/05/2022 18:42, Yannick Brosseau wrote:
> Recent changes in libusb have exposed a bug in OpenOCD which now crash when trying
> to use the ST-Link driver.
> 
> Upstream has a fix as commit cff0e417da58adef1ceef9a63a99412c2cc87ff3. This add the commit
> as a stand alone patch.
> 
> Should be removed when OpenOCD is updated to a newer release than 0.11

Add a Signed-off-by line for yourself.  This is a short way for you to
assert that you are entitled to contribute the patch under buildroot's
GPL license.  See  http://elinux.org/Developer_Certificate_Of_Origin
for more details.

> ---
>   ...GV-with-libusb-v1.0.24-33-g32a2206-1.patch | 88 +++++++++++++++++++
>   1 file changed, 88 insertions(+)
>   create mode 100644 package/openocd/0003-stlink-fix-SIGSEGV-with-libusb-v1.0.24-33-g32a2206-1.patch
> 
> diff --git a/package/openocd/0003-stlink-fix-SIGSEGV-with-libusb-v1.0.24-33-g32a2206-1.patch b/package/openocd/0003-stlink-fix-SIGSEGV-with-libusb-v1.0.24-33-g32a2206-1.patch
> new file mode 100644
> index 0000000000..5de3c91fbe
> --- /dev/null
> +++ b/package/openocd/0003-stlink-fix-SIGSEGV-with-libusb-v1.0.24-33-g32a2206-1.patch
> @@ -0,0 +1,88 @@
> +From cff0e417da58adef1ceef9a63a99412c2cc87ff3 Mon Sep 17 00:00:00 2001
> +From: Antonio Borneo <borneo.antonio at gmail.com>
> +Date: Wed, 23 Jun 2021 16:52:16 +0200
> +Subject: [PATCH] stlink: fix SIGSEGV with libusb v1.0.24-33-g32a2206 (11618)
> +MIME-Version: 1.0
> +Content-Type: text/plain; charset=UTF-8
> +Content-Transfer-Encoding: 8bit
> +
> +The stlink driver incorrectly uses a NULL pointer for libusb's
> +struct libusb_context.
> +The correct value to be used is local in libusb_helper.c.
> +
> +Move in the helper file, in a wrapper function, the only call that
> +requires the above value, and let stlink driver to use this
> +wrapper.
> +
> +This issue has not triggered any visible problem until a code
> +refactoring [1] in libusb has made OpenOCD crashing on Windows and
> +on MacOS.

  I guess not only Windows and MacOS but also Linux, otherwise you wouldn't have 
sent this, right?

> +
> +Change-Id: Id1818c8af7cf0d4d17dfa1d22aad079da01ef740
> +Signed-off-by: Antonio Borneo <borneo.antonio at gmail.com>
> +Fixes: https://sourceforge.net/p/openocd/tickets/308/
> +Fixes: https://github.com/libusb/libusb/issues/928/
> +Fixes: 42d8fa899c6a ("stlink_usb: Submit multiple USB URBs at once to improve performance")
> +Link: [1] https://github.com/libusb/libusb/commit/32a22069428c
> +Reported-by: Andrzej Sierżęga <asier70 at gmail.com>
> +Co-developed-by: Andrzej Sierżęga <asier70 at gmail.com>
> +Co-developed-by: Xiaofan Chen <xiaofanc at gmail.com>
> +Reviewed-on: http://openocd.zylin.com/6331
> +Tested-by: jenkins
> +Reviewed-by: Marc Schink <dev at zapb.de>
> +Reviewed-by: Xiaofan <xiaofanc at gmail.com>
> +Reviewed-by: Andrzej Sierżęga <asier70 at gmail.com>
> +Reviewed-by: Oleksij Rempel <linux at rempel-privat.de>
> +Reviewed-by: Andreas Fritiofson <andreas.fritiofson at gmail.com>

  Here, you need to add your Signed-off-by as well. This is needed because the 
package license may be different from Buildroot's, and the patch takes the 
package's license.

  Regards,
  Arnout

> +---
> + src/jtag/drivers/libusb_helper.c | 5 +++++
> + src/jtag/drivers/libusb_helper.h | 1 +
> + src/jtag/drivers/stlink_usb.c    | 7 +------
> + 3 files changed, 7 insertions(+), 6 deletions(-)
> +
> +diff --git a/src/jtag/drivers/libusb_helper.c b/src/jtag/drivers/libusb_helper.c
> +index f0122d534..18fe4bad4 100644
> +--- a/src/jtag/drivers/libusb_helper.c
> ++++ b/src/jtag/drivers/libusb_helper.c
> +@@ -363,3 +363,8 @@ int jtag_libusb_get_pid(struct libusb_device *dev, uint16_t *pid)
> +
> + 	return ERROR_FAIL;
> + }
> ++
> ++int jtag_libusb_handle_events_completed(int *completed)
> ++{
> ++	return libusb_handle_events_completed(jtag_libusb_context, completed);
> ++}
> +diff --git a/src/jtag/drivers/libusb_helper.h b/src/jtag/drivers/libusb_helper.h
> +index fa7d06e28..3e77865d6 100644
> +--- a/src/jtag/drivers/libusb_helper.h
> ++++ b/src/jtag/drivers/libusb_helper.h
> +@@ -60,5 +60,6 @@ int jtag_libusb_choose_interface(struct libusb_device_handle *devh,
> + 		unsigned int *usb_write_ep,
> + 		int bclass, int subclass, int protocol, int trans_type);
> + int jtag_libusb_get_pid(struct libusb_device *dev, uint16_t *pid);
> ++int jtag_libusb_handle_events_completed(int *completed);
> +
> + #endif /* OPENOCD_JTAG_DRIVERS_LIBUSB_HELPER_H */
> +diff --git a/src/jtag/drivers/stlink_usb.c b/src/jtag/drivers/stlink_usb.c
> +index c68bbb3ca..7b1932b9f 100644
> +--- a/src/jtag/drivers/stlink_usb.c
> ++++ b/src/jtag/drivers/stlink_usb.c
> +@@ -497,13 +497,8 @@ static void sync_transfer_wait_for_completion(struct libusb_transfer *transfer)
> + {
> + 	int r, *completed = transfer->user_data;
> +
> +-	/* Assuming a single libusb context exists.  There no existing interface into this
> +-	 * module to pass a libusb context.
> +-	 */
> +-	struct libusb_context *ctx = NULL;
> +-
> + 	while (!*completed) {
> +-		r = libusb_handle_events_completed(ctx, completed);
> ++		r = jtag_libusb_handle_events_completed(completed);
> + 		if (r < 0) {
> + 			if (r == LIBUSB_ERROR_INTERRUPTED)
> + 				continue;
> +--
> +2.35.1
> +