From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH v2] drm/ioctl: Add a ioctl to label GEM objects Date: Fri, 20 Sep 2019 17:25:10 +0200 Message-ID: <20190920152510.GB10973@ulmo> References: <20190919125321.22880-1-rohan.garg@collabora.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1200741328==" Return-path: Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by gabe.freedesktop.org (Postfix) with ESMTPS id 776826E07D for ; Fri, 20 Sep 2019 15:25:14 +0000 (UTC) Received: by mail-wr1-x441.google.com with SMTP id v8so7206448wrt.2 for ; Fri, 20 Sep 2019 08:25:14 -0700 (PDT) In-Reply-To: <20190919125321.22880-1-rohan.garg@collabora.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Rohan Garg Cc: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============1200741328== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="yNb1oOkm5a9FJOVX" Content-Disposition: inline --yNb1oOkm5a9FJOVX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 19, 2019 at 02:53:21PM +0200, Rohan Garg wrote: > DRM_IOCTL_BO_SET_LABEL lets you label GEM objects, making it > easier to debug issues in userspace applications. >=20 > Changes in v2: > - Hoist the IOCTL up into the drm_driver framework >=20 > Signed-off-by: Rohan Garg > --- > drivers/gpu/drm/drm_gem.c | 64 ++++++++++++++++++++++++++++++++++ > drivers/gpu/drm/drm_internal.h | 4 +++ > drivers/gpu/drm/drm_ioctl.c | 1 + > include/drm/drm_drv.h | 18 ++++++++++ > include/drm/drm_gem.h | 7 ++++ > include/uapi/drm/drm.h | 20 +++++++++++ > 6 files changed, 114 insertions(+) >=20 > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > index 6854f5867d51..785ac561619a 100644 > --- a/drivers/gpu/drm/drm_gem.c > +++ b/drivers/gpu/drm/drm_gem.c > @@ -941,6 +941,65 @@ drm_gem_release(struct drm_device *dev, struct drm_f= ile *file_private) > idr_destroy(&file_private->object_idr); > } > =20 > +int drm_bo_set_label_ioctl(struct drm_device *dev, void *data, > + struct drm_file *file_priv) Perhaps call this drm_gem_set_label_ioctl() so that it's consistent with the other GEM related IOCTLs? > +{ > + struct drm_label_object *args =3D data; Similarly, perhaps make this struct drm_gem_set_label for consistency. > + > + if (!args->len || !args->name) > + return -EINVAL; > + > + if (dev->driver->label) > + return dev->driver->label(dev, args, file_priv); > + > + return -EOPNOTSUPP; > +} > + > +/** > + * drm_gem_label - label a given GEM object > + * @dev: drm_device for the associated GEM object > + * @data: drm_label_bo struct with a label, label length and any relevan= t flags > + * @file_private: drm file-private structure to clean up > + */ > + > +int drm_gem_set_label(struct drm_device *dev, struct drm_label_object *a= rgs, struct drm_file *file_priv) Function name doesn't match the kerneldoc. > +{ > + struct drm_gem_object *gem_obj; > + int err =3D 0; > + char *label; > + > + if (args->len > 0) > + label =3D strndup_user(u64_to_user_ptr(args->name), args->len); > + > + gem_obj =3D drm_gem_object_lookup(file_priv, args->handle); > + if (!gem_obj) { > + DRM_ERROR("Failed to look up GEM BO %d\n", args->handle); People could abuse this to spam the system logs with these error messages. Better make this DRM_DEBUG() or leave it out completely. > + err =3D -ENOENT; > + goto err; I think you're leaking the label string here. > + } > + > + if ((args->len =3D=3D 0 && args->name =3D=3D NULL) || gem_obj->label) { > + kfree(gem_obj->label); > + gem_obj->label =3D NULL; > + } > + > + gem_obj->label =3D label; > + > + drm_gem_object_put_unlocked(gem_obj); > + > + if (IS_ERR(gem_obj->label)) { > + err =3D PTR_ERR(gem_obj->label); > + goto err; > + } Why don't you check for this earlier? That seems suboptimal because now you've got some error value in gem_obj->label that you're going to have to special case at every step of the way. > + > +err: > + if (err !=3D 0) > + args->flags =3D err; Why the flags? We typically just return the error... > + > + return err; =2E.. like here. > +} Do we want to export this so that drivers can use it? > + > + > /** > * drm_gem_object_release - release GEM buffer object resources > * @obj: GEM buffer object > @@ -958,6 +1017,11 @@ drm_gem_object_release(struct drm_gem_object *obj) > =20 > dma_resv_fini(&obj->_resv); > drm_gem_free_mmap_offset(obj); > + > + if (obj->label) { > + kfree(obj->label); > + obj->label =3D NULL; > + } > } > EXPORT_SYMBOL(drm_gem_object_release); > =20 > diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_interna= l.h > index 51a2055c8f18..8259622f9ab6 100644 > --- a/drivers/gpu/drm/drm_internal.h > +++ b/drivers/gpu/drm/drm_internal.h > @@ -137,6 +137,10 @@ int drm_gem_pin(struct drm_gem_object *obj); > void drm_gem_unpin(struct drm_gem_object *obj); > void *drm_gem_vmap(struct drm_gem_object *obj); > void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr); > +int drm_bo_set_label_ioctl(struct drm_device *dev, void *data, > + struct drm_file *file_priv); > +int drm_gem_set_label(struct drm_device *dev, struct drm_label_object *a= rgs, > + struct drm_file *file_priv); This one seems to be unused now. > =20 > /* drm_debugfs.c drm_debugfs_crc.c */ > #if defined(CONFIG_DEBUG_FS) > diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c > index f675a3bb2c88..079d1422f9c5 100644 > --- a/drivers/gpu/drm/drm_ioctl.c > +++ b/drivers/gpu/drm/drm_ioctl.c > @@ -709,6 +709,7 @@ static const struct drm_ioctl_desc drm_ioctls[] =3D { > DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl,= DRM_MASTER), > DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_M= ASTER), > DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl,= DRM_MASTER), > + DRM_IOCTL_DEF(DRM_IOCTL_BO_SET_LABEL, drm_bo_set_label_ioctl, DRM_RENDE= R_ALLOW), > }; > =20 > #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls ) > diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h > index 8976afe48c1c..f736ba1f42a6 100644 > --- a/include/drm/drm_drv.h > +++ b/include/drm/drm_drv.h > @@ -715,6 +715,24 @@ struct drm_driver { > struct drm_device *dev, > uint32_t handle); > =20 > + > + /** > + * @label: > + * > + * This label's a buffer object. > + * > + * Called by the user via ioctl. > + * > + * The default implementation is drm_gem_label(). GEM based drivers > + * must not overwrite this. > + Spurious blank line. > + * Returns: > + * > + * Zero on success, negative errno on failure. > + */ > + int (*label)(struct drm_device *dev, struct drm_label_object *args, > + struct drm_file *file_priv); If I understand correctly, you use this so that non-GEM drivers can use this IOCTL to label their non-GEM objects. Do you think that's really useful? I mean they've already got quite a bit of special code to deal with their objects, so singling out this IOCTL seems a bit odd. Then again, I guess it doesn't really hurt since GEM-based drivers will always use the standard implementation. > + > /** > * @gem_vm_ops: Driver private ops for this object > * > diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h > index 6aaba14f5972..f801c054e972 100644 > --- a/include/drm/drm_gem.h > +++ b/include/drm/drm_gem.h > @@ -237,6 +237,13 @@ struct drm_gem_object { > */ > int name; > =20 > + /** > + * @label: > + * > + * Label for this object, should be a human readable string. > + */ > + char *label; > + > /** > * @dma_buf: > * > diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h > index 8a5b2f8f8eb9..23b507f5c571 100644 > --- a/include/uapi/drm/drm.h > +++ b/include/uapi/drm/drm.h > @@ -626,6 +626,25 @@ struct drm_gem_open { > __u64 size; > }; > =20 > +/** struct drm_label_object - ioctl argument for labelling BOs. > + * > + * This label's a BO with a userspace label > + * > + */ > +struct drm_label_object { > + /** Handle for the object being labelled. */ > + __u32 handle; > + > + /** Label and label length. > + * length includes the trailing NULL. Nit: I think you mean "trailing NUL". Also, the parameter is called len below, so the comment here should match. Thierry > + */ > + __u32 len; > + __u64 name; > + > + /** Flags */ > + int flags; > +}; > + > #define DRM_CAP_DUMB_BUFFER 0x1 > #define DRM_CAP_VBLANK_HIGH_CRTC 0x2 > #define DRM_CAP_DUMB_PREFERRED_DEPTH 0x3 > @@ -946,6 +965,7 @@ extern "C" { > #define DRM_IOCTL_SYNCOBJ_QUERY DRM_IOWR(0xCB, struct drm_syncobj_timel= ine_array) > #define DRM_IOCTL_SYNCOBJ_TRANSFER DRM_IOWR(0xCC, struct drm_syncobj_tra= nsfer) > #define DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL DRM_IOWR(0xCD, struct drm_sync= obj_timeline_array) > +#define DRM_IOCTL_BO_SET_LABEL DRM_IOWR(0xCE, struct drm_label_obje= ct) > =20 > /** > * Device specific ioctls should only be in their respective headers > --=20 > 2.17.1 >=20 > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel --yNb1oOkm5a9FJOVX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAl2E71MACgkQ3SOs138+ s6EBiQ/+OcKfLXO9g3YigRDU2BQq+5tvfEdOzOnnpYXSaHGf35+y2hSBzADNGYRW r003O4/lh6doWEwv35oMw/GvMjHHsEtBPCj3G+t1j8GVVtT5hshYnCtifkvPQDtd q5g2IgNKBJHADaW+kBgNgrAj1BjNP73jxSk7yFg9UEPQw0U8eBVxFoOiMzizVEpn BSZk6KUYj/C50UjYDCoKajf5G7Xe/uSaBOdPRzhjKTvBumlyAqhZtMf3fSM8mQ4N Xt/clJdvVmF66kIl4GbTDi6JqzYfK5Vyla95mm3x2Y7m8Ff3YCoAem3kd7vz8tLN 5SVuwgTfzDVM+x4+1CE/mPpe1AlY232G3yTLNVfxveP76g1RVJYtwc/4HE94076U JXnQHsrlrq77EeLkhyLnxu1rA8o2fBKTwDCmQphcfb5uf4pSUqffa8lIrbkrXzGo B5cFaG6OjCpOJSjfXMJjrrBZIajdjHt8Y+w7JmKdElIpdV2Blpuku7LWMeVupN4q xTdH4gTYZfbOc1Cq0RNmpJVE/TDA0w9g9AHx74ODbMB+mMrunalzLoLpmGVyPVuA 8g2jqmei1oKFWO1jVXn97+58b0VGWzkRJDmZCOaNwAAjMp1P7uGvAjZl2ZK5N9wo Zh0VvdOeSJkbsTOTisDgbnlLkR2Qpx58V4gxAmD0/reWU2tiazQ= =QJQU -----END PGP SIGNATURE----- --yNb1oOkm5a9FJOVX-- --===============1200741328== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVs --===============1200741328==--