[{"id":12368,"web_url":"https://patchwork.libcamera.org/comment/12368/","msgid":"<20200908075827.GY6047@pendragon.ideasonboard.com>","date":"2020-09-08T07:58:27","subject":"Re: [libcamera-devel] [PATCH] android: Protect against null\n\tcallbacks","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"On Tue, Sep 08, 2020 at 10:54:24AM +0300, Laurent Pinchart wrote:\n> According to the Android camera HAL C interface documentation, the\n> camera service is supposed to set callbacks after initializing the HAL\n> and calling get_number_of_cameras(), before any other calls to the\n> module. We rely on this behaviour and use callbacks unconditionally,\n> which would lead to a crash if the camera service behaved incorrectly.\n> \n> While the camera service isn't supposed to behave incorrectly,\n> gracefully handling the error when opening cameras isn't costly, and\n> provides better diagnostic than a crash.\n> \n> While at it, removed an unneeded [[maybe_unused]] attribute.\n\nI forgot to add\n\nReported-by: Coverity CID=298638\n\n> Signed-off-by: Laurent Pinchart \n> ---\n> src/android/camera3_hal.cpp | 2 +-\n> src/android/camera_hal_manager.cpp | 7 ++++++-\n> 2 files changed, 7 insertions(+), 2 deletions(-)\n> \n> diff --git a/src/android/camera3_hal.cpp b/src/android/camera3_hal.cpp\n> index 67a497b8c829..d6e04af21470 100644\n> --- a/src/android/camera3_hal.cpp\n> +++ b/src/android/camera3_hal.cpp\n> @@ -32,7 +32,7 @@ static int hal_get_camera_info(int id, struct camera_info *info)\n> \treturn cameraManager.getCameraInfo(id, info);\n> }\n> \n> -static int hal_set_callbacks([[maybe_unused]] const camera_module_callbacks_t *callbacks)\n> +static int hal_set_callbacks(const camera_module_callbacks_t *callbacks)\n> {\n> \tcameraManager.setCallbacks(callbacks);\n> \n> diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp\n> index a1805ebccf24..05b474010b1d 100644\n> --- a/src/android/camera_hal_manager.cpp\n> +++ b/src/android/camera_hal_manager.cpp\n> @@ -29,7 +29,7 @@ LOG_DECLARE_CATEGORY(HAL);\n> */\n> \n> CameraHalManager::CameraHalManager()\n> -\t: cameraManager_(nullptr), numInternalCameras_(0),\n> +\t: cameraManager_(nullptr), callbacks_(nullptr), numInternalCameras_(0),\n> \t nextExternalCameraId_(firstExternalCameraId_)\n> {\n> }\n> @@ -70,6 +70,11 @@ CameraDevice *CameraHalManager::open(unsigned int id,\n> {\n> \tMutexLocker locker(mutex_);\n> \n> +\tif (!callbacks_) {\n> +\t\tLOG(HAL, Error) << \"Can't open camera before callbacks are set\";\n> +\t\treturn nullptr;\n> +\t}\n> +\n> \tCameraDevice *camera = cameraDeviceFromHalId(id);\n> \tif (!camera) {\n> \t\tLOG(HAL, Error) << \"Invalid camera id '\" << id << \"'\";","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 4D505BDB1C\n\tfor ;\n\tTue, 8 Sep 2020 07:58:54 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id B799762BF9;\n\tTue, 8 Sep 2020 09:58:53 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 76C6062931\n\tfor ;\n\tTue, 8 Sep 2020 09:58:52 +0200 (CEST)","from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi\n\t[62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 060551243\n\tfor ;\n\tTue, 8 Sep 2020 09:58:51 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"j5F8YUYk\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1599551932;\n\tbh=Nx9CvD08I20pQf/N7oV43HrFBUJ8DcHessoIXSOiUR4=;\n\th=Date:From:To:Subject:References:In-Reply-To:From;\n\tb=j5F8YUYk8ws4rDBgdvUc1nnUZ8OuS7p7j7w49L5HSbr++FGwVTGAxg72AQMm6yoTT\n\tX0zLfWae5yduV/Nh7bTbHwtL/OOhVeG9q3dfCKkbyVrkl1W5PxXp3M9BFotm+lsnp3\n\tEcq3WZVTZbtrajr5IL9Lle6amsfBbwvWKcTbCvJ0=","Date":"Tue, 8 Sep 2020 10:58:27 +0300","From":"Laurent Pinchart ","To":"libcamera-devel@lists.libcamera.org","Message-ID":"<20200908075827.GY6047@pendragon.ideasonboard.com>","References":"<20200908075424.14101-1-laurent.pinchart@ideasonboard.com>","MIME-Version":"1.0","Content-Disposition":"inline","In-Reply-To":"<20200908075424.14101-1-laurent.pinchart@ideasonboard.com>","Subject":"Re: [libcamera-devel] [PATCH] android: Protect against null\n\tcallbacks","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":12369,"web_url":"https://patchwork.libcamera.org/comment/12369/","msgid":"<20200908093140.GA2984648@oden.dyn.berto.se>","date":"2020-09-08T09:31:40","subject":"Re: [libcamera-devel] [PATCH] android: Protect against null\n\tcallbacks","submitter":{"id":5,"url":"https://patchwork.libcamera.org/api/people/5/","name":"Niklas Söderlund","email":"niklas.soderlund@ragnatech.se"},"content":"Hi Laurent,\n\nThanks for your patch.\n\nOn 2020-09-08 10:54:24 +0300, Laurent Pinchart wrote:\n> According to the Android camera HAL C interface documentation, the\n> camera service is supposed to set callbacks after initializing the HAL\n> and calling get_number_of_cameras(), before any other calls to the\n> module. We rely on this behaviour and use callbacks unconditionally,\n> which would lead to a crash if the camera service behaved incorrectly.\n> \n> While the camera service isn't supposed to behave incorrectly,\n> gracefully handling the error when opening cameras isn't costly, and\n> provides better diagnostic than a crash.\n> \n> While at it, removed an unneeded [[maybe_unused]] attribute.\n> \n> Signed-off-by: Laurent Pinchart \n\nReviewed-by: Niklas Söderlund \n\n> ---\n> src/android/camera3_hal.cpp | 2 +-\n> src/android/camera_hal_manager.cpp | 7 ++++++-\n> 2 files changed, 7 insertions(+), 2 deletions(-)\n> \n> diff --git a/src/android/camera3_hal.cpp b/src/android/camera3_hal.cpp\n> index 67a497b8c829..d6e04af21470 100644\n> --- a/src/android/camera3_hal.cpp\n> +++ b/src/android/camera3_hal.cpp\n> @@ -32,7 +32,7 @@ static int hal_get_camera_info(int id, struct camera_info *info)\n> \treturn cameraManager.getCameraInfo(id, info);\n> }\n> \n> -static int hal_set_callbacks([[maybe_unused]] const camera_module_callbacks_t *callbacks)\n> +static int hal_set_callbacks(const camera_module_callbacks_t *callbacks)\n> {\n> \tcameraManager.setCallbacks(callbacks);\n> \n> diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp\n> index a1805ebccf24..05b474010b1d 100644\n> --- a/src/android/camera_hal_manager.cpp\n> +++ b/src/android/camera_hal_manager.cpp\n> @@ -29,7 +29,7 @@ LOG_DECLARE_CATEGORY(HAL);\n> */\n> \n> CameraHalManager::CameraHalManager()\n> -\t: cameraManager_(nullptr), numInternalCameras_(0),\n> +\t: cameraManager_(nullptr), callbacks_(nullptr), numInternalCameras_(0),\n> \t nextExternalCameraId_(firstExternalCameraId_)\n> {\n> }\n> @@ -70,6 +70,11 @@ CameraDevice *CameraHalManager::open(unsigned int id,\n> {\n> \tMutexLocker locker(mutex_);\n> \n> +\tif (!callbacks_) {\n> +\t\tLOG(HAL, Error) << \"Can't open camera before callbacks are set\";\n> +\t\treturn nullptr;\n> +\t}\n> +\n> \tCameraDevice *camera = cameraDeviceFromHalId(id);\n> \tif (!camera) {\n> \t\tLOG(HAL, Error) << \"Invalid camera id '\" << id << \"'\";\n> -- \n> Regards,\n> \n> Laurent Pinchart\n> \n> _______________________________________________\n> libcamera-devel mailing list\n> libcamera-devel@lists.libcamera.org\n> https://lists.libcamera.org/listinfo/libcamera-devel","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 9348DBDB1D\n\tfor ;\n\tTue, 8 Sep 2020 09:31:44 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 1CEF762BAA;\n\tTue, 8 Sep 2020 11:31:44 +0200 (CEST)","from mail-lj1-x243.google.com (mail-lj1-x243.google.com\n\t[IPv6:2a00:1450:4864:20::243])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 8AD1E60534\n\tfor ;\n\tTue, 8 Sep 2020 11:31:42 +0200 (CEST)","by mail-lj1-x243.google.com with SMTP id c2so19089918ljj.12\n\tfor ;\n\tTue, 08 Sep 2020 02:31:42 -0700 (PDT)","from localhost (h-209-203.A463.priv.bahnhof.se. 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We rely on this behaviour and use callbacks unconditionally,\n> which would lead to a crash if the camera service behaved incorrectly.\n>\n> While the camera service isn't supposed to behave incorrectly,\n> gracefully handling the error when opening cameras isn't costly, and\n> provides better diagnostic than a crash.\n>\n> While at it, removed an unneeded [[maybe_unused]] attribute.\n>\n> Signed-off-by: Laurent Pinchart \nFirst of all,\n\nReviewed-by: Umang Jain \n> ---\n> src/android/camera3_hal.cpp | 2 +-\n> src/android/camera_hal_manager.cpp | 7 ++++++-\n> 2 files changed, 7 insertions(+), 2 deletions(-)\n>\n> diff --git a/src/android/camera3_hal.cpp b/src/android/camera3_hal.cpp\n> index 67a497b8c829..d6e04af21470 100644\n> --- a/src/android/camera3_hal.cpp\n> +++ b/src/android/camera3_hal.cpp\n> @@ -32,7 +32,7 @@ static int hal_get_camera_info(int id, struct camera_info *info)\n> \treturn cameraManager.getCameraInfo(id, info);\n> }\n> \n> -static int hal_set_callbacks([[maybe_unused]] const camera_module_callbacks_t *callbacks)\n> +static int hal_set_callbacks(const camera_module_callbacks_t *callbacks)\n> {\n> \tcameraManager.setCallbacks(callbacks);\n> \n> diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp\n> index a1805ebccf24..05b474010b1d 100644\n> --- a/src/android/camera_hal_manager.cpp\n> +++ b/src/android/camera_hal_manager.cpp\n> @@ -29,7 +29,7 @@ LOG_DECLARE_CATEGORY(HAL);\n> */\n> \n> CameraHalManager::CameraHalManager()\n> -\t: cameraManager_(nullptr), numInternalCameras_(0),\n> +\t: cameraManager_(nullptr), callbacks_(nullptr), numInternalCameras_(0),\n> \t nextExternalCameraId_(firstExternalCameraId_)\n> {\n> }\n> @@ -70,6 +70,11 @@ CameraDevice *CameraHalManager::open(unsigned int id,\n> {\n> \tMutexLocker locker(mutex_);\n> \n> +\tif (!callbacks_) {\n> +\t\tLOG(HAL, Error) << \"Can't open camera before callbacks are set\";\n> +\t\treturn nullptr;\n> +\t}\n> +\nAt any point in time, were you able to trigger a crash to which, as a \nresult, is this patch came into existence? Just curious.\n> \tCameraDevice *camera = cameraDeviceFromHalId(id);\n> \tif (!camera) {\n> \t\tLOG(HAL, Error) << \"Invalid camera id '\" << id << \"'\";","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 4EA82BDB1C\n\tfor ;\n\tTue, 8 Sep 2020 10:30:22 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id D351B62C31;\n\tTue, 8 Sep 2020 12:30:21 +0200 (CEST)","from mail.uajain.com (static.126.159.217.95.clients.your-server.de\n\t[95.217.159.126])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id B73016056C\n\tfor ;\n\tTue, 8 Sep 2020 12:30:20 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n\tunprotected) header.d=uajain.com header.i=@uajain.com\n\theader.b=\"AL00B7TM\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=uajain.com; s=mail;\n\tt=1599561020; bh=JvWhJswuPDm8PTUBW8iF3M+BFxrqMKwks3CfzSC8ytM=;\n\th=Subject:To:References:From:In-Reply-To;\n\tb=AL00B7TMZlHPeguJbrsmZAEG8RwEjiAd9pchsb8zXl0/Ovuj2wFrweksjJ+WCceAq\n\t8IL5JvAKA0aLac/h9no0GTAtXcmNqZrbR7bzeR9cYBK1pv1kGMpdQIwCTn4rP8GPiC\n\tr4kVgUk/z2uS07AYa3ZdIf9f1wDl1Cd+s2/QHCFyfsPpoMSOK38yr7bc28ZNxkRVoS\n\tE50v903V0AdNYneFbKNwSMm3R3dgMjQzRE6XBbMxuJYa/2ZkRN7ElKR0B2jwzcx1mh\n\t4FN6nS/kjMSdBrZto88+g16n4sU+V6X12JJNsy4hEpAbt+5uu3l7ShCmLXlOPnxCvQ\n\tbQyA2YcAtmsgg==","To":"Laurent Pinchart ,\n\tlibcamera-devel@lists.libcamera.org","References":"<20200908075424.14101-1-laurent.pinchart@ideasonboard.com>","From":"Umang Jain ","Message-ID":"<874809c3-a3d5-2e9c-1933-3187c1157871@uajain.com>","Date":"Tue, 8 Sep 2020 16:00:17 +0530","Mime-Version":"1.0","In-Reply-To":"<20200908075424.14101-1-laurent.pinchart@ideasonboard.com>","Content-Language":"en-US","Subject":"Re: [libcamera-devel] [PATCH] android: Protect against null\n\tcallbacks","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Content-Transfer-Encoding":"7bit","Content-Type":"text/plain; charset=\"us-ascii\"; Format=\"flowed\"","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":12373,"web_url":"https://patchwork.libcamera.org/comment/12373/","msgid":"<20200908111634.GZ6047@pendragon.ideasonboard.com>","date":"2020-09-08T11:16:34","subject":"Re: [libcamera-devel] [PATCH] android: Protect against null\n\tcallbacks","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Umang,\n\nOn Tue, Sep 08, 2020 at 04:00:17PM +0530, Umang Jain wrote:\n> On 9/8/20 1:24 PM, Laurent Pinchart wrote:\n> > According to the Android camera HAL C interface documentation, the\n> > camera service is supposed to set callbacks after initializing the HAL\n> > and calling get_number_of_cameras(), before any other calls to the\n> > module. We rely on this behaviour and use callbacks unconditionally,\n> > which would lead to a crash if the camera service behaved incorrectly.\n> >\n> > While the camera service isn't supposed to behave incorrectly,\n> > gracefully handling the error when opening cameras isn't costly, and\n> > provides better diagnostic than a crash.\n> >\n> > While at it, removed an unneeded [[maybe_unused]] attribute.\n> >\n> > Signed-off-by: Laurent Pinchart \n>\n> First of all,\n> \n> Reviewed-by: Umang Jain \n>\n> > ---\n> > src/android/camera3_hal.cpp | 2 +-\n> > src/android/camera_hal_manager.cpp | 7 ++++++-\n> > 2 files changed, 7 insertions(+), 2 deletions(-)\n> >\n> > diff --git a/src/android/camera3_hal.cpp b/src/android/camera3_hal.cpp\n> > index 67a497b8c829..d6e04af21470 100644\n> > --- a/src/android/camera3_hal.cpp\n> > +++ b/src/android/camera3_hal.cpp\n> > @@ -32,7 +32,7 @@ static int hal_get_camera_info(int id, struct camera_info *info)\n> > \treturn cameraManager.getCameraInfo(id, info);\n> > }\n> > \n> > -static int hal_set_callbacks([[maybe_unused]] const camera_module_callbacks_t *callbacks)\n> > +static int hal_set_callbacks(const camera_module_callbacks_t *callbacks)\n> > {\n> > \tcameraManager.setCallbacks(callbacks);\n> > \n> > diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp\n> > index a1805ebccf24..05b474010b1d 100644\n> > --- a/src/android/camera_hal_manager.cpp\n> > +++ b/src/android/camera_hal_manager.cpp\n> > @@ -29,7 +29,7 @@ LOG_DECLARE_CATEGORY(HAL);\n> > */\n> > \n> > CameraHalManager::CameraHalManager()\n> > -\t: cameraManager_(nullptr), numInternalCameras_(0),\n> > +\t: cameraManager_(nullptr), callbacks_(nullptr), numInternalCameras_(0),\n> > \t nextExternalCameraId_(firstExternalCameraId_)\n> > {\n> > }\n> > @@ -70,6 +70,11 @@ CameraDevice *CameraHalManager::open(unsigned int id,\n> > {\n> > \tMutexLocker locker(mutex_);\n> > \n> > +\tif (!callbacks_) {\n> > +\t\tLOG(HAL, Error) << \"Can't open camera before callbacks are set\";\n> > +\t\treturn nullptr;\n> > +\t}\n> > +\n> \n> At any point in time, were you able to trigger a crash to which, as a \n> result, is this patch came into existence? Just curious.\n\nNo, I haven't. I was looking at the coverity scans, one of the issues\npointed out was that callbacks_ was not initialized. It's a theoretical\nissue as the camera service shouldn't behave incorrectly, but I thought\nthis one may be worth handling correctly. If anyone disagrees I'm happy\nto drop the patch (although I'd then submit a smaller patch to drop the\n[[maybe_unused]]).\n\n> > \tCameraDevice *camera = cameraDeviceFromHalId(id);\n> > \tif (!camera) {\n> > \t\tLOG(HAL, Error) << \"Invalid camera id '\" << id << \"'\";","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 2A0A3BDB1D\n\tfor ;\n\tTue, 8 Sep 2020 11:17:03 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id A160862C37;\n\tTue, 8 Sep 2020 13:17:02 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 7D79162C30\n\tfor ;\n\tTue, 8 Sep 2020 13:17:00 +0200 (CEST)","from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi\n\t[62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id D5AC939;\n\tTue, 8 Sep 2020 13:16:59 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"N4nEKOLQ\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1599563820;\n\tbh=sNUeEMgeLtGrjZwhk7bKn5uR94JqN0427KnWQPP67DY=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=N4nEKOLQ2fochJz8l7e5j6XbxnsGlyE2S2fwgxdxGDtS3CHveXNB4hduYEewwatbo\n\tigSx5TiNZkOxZy/5OJRgYgQIOgLUQRJV+b5hTG0GiuwggunEx/4LIIJLzIypFTTFzl\n\tkyxqlkcJVnsqXioKIDO4DlsRgiLnrG8twn/KtzCk=","Date":"Tue, 8 Sep 2020 14:16:34 +0300","From":"Laurent Pinchart ","To":"Umang Jain ","Message-ID":"<20200908111634.GZ6047@pendragon.ideasonboard.com>","References":"<20200908075424.14101-1-laurent.pinchart@ideasonboard.com>\n\t<874809c3-a3d5-2e9c-1933-3187c1157871@uajain.com>","MIME-Version":"1.0","Content-Disposition":"inline","In-Reply-To":"<874809c3-a3d5-2e9c-1933-3187c1157871@uajain.com>","Subject":"Re: [libcamera-devel] [PATCH] android: Protect against null\n\tcallbacks","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"libcamera-devel@lists.libcamera.org","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":12376,"web_url":"https://patchwork.libcamera.org/comment/12376/","msgid":"","date":"2020-09-08T12:21:14","subject":"Re: [libcamera-devel] [PATCH] android: Protect against null\n\tcallbacks","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Hi Laurent,\n\nOn 08/09/2020 12:16, Laurent Pinchart wrote:\n> Hi Umang,\n> \n> On Tue, Sep 08, 2020 at 04:00:17PM +0530, Umang Jain wrote:\n>> On 9/8/20 1:24 PM, Laurent Pinchart wrote:\n>>> According to the Android camera HAL C interface documentation, the\n>>> camera service is supposed to set callbacks after initializing the HAL\n>>> and calling get_number_of_cameras(), before any other calls to the\n>>> module. We rely on this behaviour and use callbacks unconditionally,\n>>> which would lead to a crash if the camera service behaved incorrectly.\n>>>\n>>> While the camera service isn't supposed to behave incorrectly,\n>>> gracefully handling the error when opening cameras isn't costly, and\n>>> provides better diagnostic than a crash.\n>>>\n>>> While at it, removed an unneeded [[maybe_unused]] attribute.\n>>>\n>>> Signed-off-by: Laurent Pinchart \n>>\n>> First of all,\n>>\n>> Reviewed-by: Umang Jain \n>>\n>>> ---\n>>> src/android/camera3_hal.cpp | 2 +-\n>>> src/android/camera_hal_manager.cpp | 7 ++++++-\n>>> 2 files changed, 7 insertions(+), 2 deletions(-)\n>>>\n>>> diff --git a/src/android/camera3_hal.cpp b/src/android/camera3_hal.cpp\n>>> index 67a497b8c829..d6e04af21470 100644\n>>> --- a/src/android/camera3_hal.cpp\n>>> +++ b/src/android/camera3_hal.cpp\n>>> @@ -32,7 +32,7 @@ static int hal_get_camera_info(int id, struct camera_info *info)\n>>> \treturn cameraManager.getCameraInfo(id, info);\n>>> }\n>>> \n>>> -static int hal_set_callbacks([[maybe_unused]] const camera_module_callbacks_t *callbacks)\n>>> +static int hal_set_callbacks(const camera_module_callbacks_t *callbacks)\n>>> {\n>>> \tcameraManager.setCallbacks(callbacks);\n>>> \n>>> diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp\n>>> index a1805ebccf24..05b474010b1d 100644\n>>> --- a/src/android/camera_hal_manager.cpp\n>>> +++ b/src/android/camera_hal_manager.cpp\n>>> @@ -29,7 +29,7 @@ LOG_DECLARE_CATEGORY(HAL);\n>>> */\n>>> \n>>> CameraHalManager::CameraHalManager()\n>>> -\t: cameraManager_(nullptr), numInternalCameras_(0),\n>>> +\t: cameraManager_(nullptr), callbacks_(nullptr), numInternalCameras_(0),\n>>> \t nextExternalCameraId_(firstExternalCameraId_)\n>>> {\n>>> }\n>>> @@ -70,6 +70,11 @@ CameraDevice *CameraHalManager::open(unsigned int id,\n>>> {\n>>> \tMutexLocker locker(mutex_);\n>>> \n>>> +\tif (!callbacks_) {\n>>> +\t\tLOG(HAL, Error) << \"Can't open camera before callbacks are set\";\n>>> +\t\treturn nullptr;\n>>> +\t}\n>>> +\n>>\n>> At any point in time, were you able to trigger a crash to which, as a \n>> result, is this patch came into existence? Just curious.\n> \n> No, I haven't. I was looking at the coverity scans, one of the issues\n> pointed out was that callbacks_ was not initialized. It's a theoretical\n> issue as the camera service shouldn't behave incorrectly, but I thought\n> this one may be worth handling correctly. If anyone disagrees I'm happy\n> to drop the patch (although I'd then submit a smaller patch to drop the\n> [[maybe_unused]]).\n\nI prefer being safe. This is cheap.\n\nReviewed-by: Kieran Bingham \n\n> \n>>> \tCameraDevice *camera = cameraDeviceFromHalId(id);\n>>> \tif (!camera) {\n>>> \t\tLOG(HAL, Error) << \"Invalid camera id '\" << id << \"'\";\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 089A0BDB1C\n\tfor ;\n\tTue, 8 Sep 2020 12:21:19 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 87D9162C3B;\n\tTue, 8 Sep 2020 14:21:18 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id E7D8B62C30\n\tfor ;\n\tTue, 8 Sep 2020 14:21:17 +0200 (CEST)","from [192.168.0.20]\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 8A48339;\n\tTue, 8 Sep 2020 14:21:16 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"nYwrP3K7\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1599567676;\n\tbh=FjkVKaCjN/Pbv+5lSCOrZY6VbxmUPg1ekQB2O/lGEJc=;\n\th=Reply-To:Subject:To:Cc:References:From:Date:In-Reply-To:From;\n\tb=nYwrP3K70D/F9CL0ZtGvwlW5PoqSB3+a9i8xStXog2PT36hg17Y/rwHQD+kCLKTn7\n\tOZK+VKP96Y4VzK4PtUwdUO+XBBPTNyF+0FZREt5kwjDPoi5Ye0pByhrNTjXvhAcU/W\n\t3WL1R4smiKDu9BRzx/EOg+ZRiECHeSWJnsGb2GkY=","To":"Laurent Pinchart ,\n\tUmang Jain ","References":"<20200908075424.14101-1-laurent.pinchart@ideasonboard.com>\n\t<874809c3-a3d5-2e9c-1933-3187c1157871@uajain.com>\n\t<20200908111634.GZ6047@pendragon.ideasonboard.com>","From":"Kieran Bingham ","Autocrypt":"addr=kieran.bingham@ideasonboard.com; keydata=\n\tmQINBFYE/WYBEACs1PwjMD9rgCu1hlIiUA1AXR4rv2v+BCLUq//vrX5S5bjzxKAryRf0uHat\n\tV/zwz6hiDrZuHUACDB7X8OaQcwhLaVlq6byfoBr25+hbZG7G3+5EUl9cQ7dQEdvNj6V6y/SC\n\trRanWfelwQThCHckbobWiQJfK9n7rYNcPMq9B8e9F020LFH7Kj6YmO95ewJGgLm+idg1Kb3C\n\tpotzWkXc1xmPzcQ1fvQMOfMwdS+4SNw4rY9f07Xb2K99rjMwZVDgESKIzhsDB5GY465sCsiQ\n\tcSAZRxqE49RTBq2+EQsbrQpIc8XiffAB8qexh5/QPzCmR4kJgCGeHIXBtgRj+nIkCJPZvZtf\n\tKr2EAbc6tgg6DkAEHJb+1okosV09+0+TXywYvtEop/WUOWQ+zo+Y/OBd+8Ptgt1pDRyOBzL8\n\tRXa8ZqRf0Mwg75D+dKntZeJHzPRJyrlfQokngAAs4PaFt6UfS+ypMAF37T6CeDArQC41V3ko\n\tlPn1yMsVD0p+6i3DPvA/GPIksDC4owjnzVX9kM8Zc5Cx+XoAN0w5Eqo4t6qEVbuettxx55gq\n\t8K8FieAjgjMSxngo/HST8TpFeqI5nVeq0/lqtBRQKumuIqDg+Bkr4L1V/PSB6XgQcOdhtd36\n\tOe9X9dXB8YSNt7VjOcO7BTmFn/Z8r92mSAfHXpb07YJWJosQOQARAQABtDBLaWVyYW4gQmlu\n\tZ2hhbSA8a2llcmFuLmJpbmdoYW1AaWRlYXNvbmJvYXJkLmNvbT6JAlcEEwEKAEECGwMFCwkI\n\tBwIGFQgJCgsCBBYCAwECHgECF4ACGQEWIQSQLdeYP70o/eNy1HqhHkZyEKRh/QUCXWTtygUJ\n\tCyJXZAAKCRChHkZyEKRh/f8dEACTDsbLN2nioNZMwyLuQRUAFcXNolDX48xcUXsWS2QjxaPm\n\tVsJx8Uy8aYkS85mdPBh0C83OovQR/OVbr8AxhGvYqBs3nQvbWuTl/+4od7DfK2VZOoKBAu5S\n\tQK2FYuUcikDqYcFWJ8DQnubxfE8dvzojHEkXw0sA4igINHDDFX3HJGZtLio+WpEFQtCbfTAG\n\tYZslasz1YZRbwEdSsmO3/kqy5eMnczlm8a21A3fKUo3g8oAZEFM+f4DUNzqIltg31OAB/kZS\n\tenKZQ/SWC8PmLg/ZXBrReYakxXtkP6w3FwMlzOlhGxqhIRNiAJfXJBaRhuUWzPOpEDE9q5YJ\n\tBmqQL2WJm1VSNNVxbXJHpaWMH1sA2R00vmvRrPXGwyIO0IPYeUYQa3gsy6k+En/aMQJd27dp\n\taScf9am9PFICPY5T4ppneeJLif2lyLojo0mcHOV+uyrds9XkLpp14GfTkeKPdPMrLLTsHRfH\n\tfA4I4OBpRrEPiGIZB/0im98MkGY/Mu6qxeZmYLCcgD6qz4idOvfgVOrNh+aA8HzIVR+RMW8H\n\tQGBN9f0E3kfwxuhl3omo6V7lDw8XOdmuWZNC9zPq1UfryVHANYbLGz9KJ4Aw6M+OgBC2JpkD\n\thXMdHUkC+d20dwXrwHTlrJi1YNp6rBc+xald3wsUPOZ5z8moTHUX/uPA/qhGsbkCDQRWBP1m\n\tARAAzijkb+Sau4hAncr1JjOY+KyFEdUNxRy+hqTJdJfaYihxyaj0Ee0P0zEi35CbE6lgU0Uz\n\ttih9fiUbSV3wfsWqg1Ut3/5rTKu7kLFp15kF7eqvV4uezXRD3Qu4yjv/rMmEJbbD4cTvGCYI\n\td6MDC417f7vK3hCbCVIZSp3GXxyC1LU+UQr3fFcOyCwmP9vDUR9JV0BSqHHxRDdpUXE26Dk6\n\tmhf0V1YkspE5St814ETXpEus2urZE5yJIUROlWPIL+hm3NEWfAP06vsQUyLvr/GtbOT79vXl\n\tEn1aulcYyu20dRRxhkQ6iILaURcxIAVJJKPi8dsoMnS8pB0QW12AHWuirPF0g6DiuUfPmrA5\n\tPKe56IGlpkjc8cO51lIxHkWTpCMWigRdPDexKX+Sb+W9QWK/0JjIc4t3KBaiG8O4yRX8ml2R\n\t+rxfAVKM6V769P/hWoRGdgUMgYHFpHGSgEt80OKK5HeUPy2cngDUXzwrqiM5Sz6Od0qw5pCk\n\tNlXqI0W/who0iSVM+8+RmyY0OEkxEcci7rRLsGnM15B5PjLJjh1f2ULYkv8s4SnDwMZ/kE04\n\t/UqCMK/KnX8pwXEMCjz0h6qWNpGwJ0/tYIgQJZh6bqkvBrDogAvuhf60Sogw+mH8b+PBlx1L\n\toeTK396wc+4c3BfiC6pNtUS5GpsPMMjYMk7kVvEAEQEAAYkCPAQYAQoAJgIbDBYhBJAt15g/\n\tvSj943LUeqEeRnIQpGH9BQJdizzIBQkLSKZiAAoJEKEeRnIQpGH9eYgQAJpjaWNgqNOnMTmD\n\tMJggbwjIotypzIXfhHNCeTkG7+qCDlSaBPclcPGYrTwCt0YWPU2TgGgJrVhYT20ierN8LUvj\n\t6qOPTd+Uk7NFzL65qkh80ZKNBFddx1AabQpSVQKbdcLb8OFs85kuSvFdgqZwgxA1vl4TFhNz\n\tPZ79NAmXLackAx3sOVFhk4WQaKRshCB7cSl+RIng5S/ThOBlwNlcKG7j7W2MC06BlTbdEkUp\n\tECzuuRBv8wX4OQl+hbWbB/VKIx5HKlLu1eypen/5lNVzSqMMIYkkZcjV2SWQyUGxSwq0O/sx\n\tS0A8/atCHUXOboUsn54qdxrVDaK+6jIAuo8JiRWctP16KjzUM7MO0/+4zllM8EY57rXrj48j\n\tsbEYX0YQnzaj+jO6kJtoZsIaYR7rMMq9aUAjyiaEZpmP1qF/2sYenDx0Fg2BSlLvLvXM0vU8\n\tpQk3kgDu7kb/7PRYrZvBsr21EIQoIjXbZxDz/o7z95frkP71EaICttZ6k9q5oxxA5WC6sTXc\n\tMW8zs8avFNuA9VpXt0YupJd2ijtZy2mpZNG02fFVXhIn4G807G7+9mhuC4XG5rKlBBUXTvPU\n\tAfYnB4JBDLmLzBFavQfvonSfbitgXwCG3vS+9HEwAjU30Bar1PEOmIbiAoMzuKeRm2LVpmq4\n\tWZw01QYHU/GUV/zHJSFk","Organization":"Ideas on Board","Message-ID":"","Date":"Tue, 8 Sep 2020 13:21:14 +0100","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101\n\tThunderbird/68.10.0","MIME-Version":"1.0","In-Reply-To":"<20200908111634.GZ6047@pendragon.ideasonboard.com>","Content-Language":"en-GB","Subject":"Re: [libcamera-devel] [PATCH] android: Protect against null\n\tcallbacks","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Reply-To":"kieran.bingham@ideasonboard.com","Cc":"libcamera-devel@lists.libcamera.org","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]