From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6BA21CF9C77 for ; Tue, 24 Sep 2024 08:24:20 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1022F10E686; Tue, 24 Sep 2024 08:24:20 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=damsy.net header.i=@damsy.net header.b="PIxlJ6Ss"; dkim=permerror (0-bit key) header.d=damsy.net header.i=@damsy.net header.b="h0OdpMFt"; dkim-atps=neutral Received: from jeth.damsy.net (jeth.damsy.net [51.159.152.102]) by gabe.freedesktop.org (Postfix) with ESMTPS id 05EE110E68B; Tue, 24 Sep 2024 08:24:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; s=202408r; d=damsy.net; c=relaxed/relaxed; h=From:To:Subject:Date:Message-ID; t=1727166162; bh=c8mxu2J7XQbwZH/zuCa7+Bp zRE/zjDQa3rgD7ejoNl0=; b=PIxlJ6Ssz2Yaft0PNytSRnvYF1Prwvaf1Tkf9GDHME+S9xPwin uwQSj8zawLvcRwL/OPNuvAPoUHfc7lG9vXYM9/dmMbm7KGjxFVU8HcBLm8PbrNVADApsalN3VrM 36uKkzfHNDodf5THkG5lHZprLoi9TGY5M5ilVc7xAfX7SJ8AAJMhYpzG+3Ics51vUDkn9s/3hNS ot5V5S6syKHN598zGBJstpWjgfzkdfl4fuOnT5fMMWED/hbLONgdsQ5p/V+4Ekj7v7XcDBPsMGd QZVA1IpLP+m7i7pQ9wNSUCEvgpD4FNcQloN3LkqmbOtx1JBktDVIutfTa+Ld+LVUMyg==; DKIM-Signature: v=1; a=ed25519-sha256; s=202408e; d=damsy.net; c=relaxed/relaxed; h=From:To:Subject:Date:Message-ID; t=1727166162; bh=c8mxu2J7XQbwZH/zuCa7+Bp zRE/zjDQa3rgD7ejoNl0=; b=h0OdpMFtrtwbeG0KHW67R4CM/SUrSktE1UDDikOb15YoaSkb1+ 80PA3m9kLHcLfV90b3PZFU6bB1IdQCinRdCQ==; Message-ID: Date: Tue, 24 Sep 2024 10:22:41 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/6] drm: add DRM_SET_NAME ioctl To: Tvrtko Ursulin , Pierre-Eric Pelloux-Prayer , dri-devel@lists.freedesktop.org, christian.koenig@amd.com, tursulin@igalia.com, simona.vetter@ffwll.ch, robdclark@gmail.com, alexander.deucher@amd.com, amd-gfx@lists.freedesktop.org References: <20240920090920.1342694-1-pierre-eric.pelloux-prayer@amd.com> <20240920090920.1342694-2-pierre-eric.pelloux-prayer@amd.com> <7e33063e-7b5c-464a-a572-9a7817a9b9b3@igalia.com> Content-Language: en-US From: Pierre-Eric Pelloux-Prayer In-Reply-To: <7e33063e-7b5c-464a-a572-9a7817a9b9b3@igalia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" Le 23/09/2024 à 12:06, Tvrtko Ursulin a écrit : > > On 20/09/2024 10:06, Pierre-Eric Pelloux-Prayer wrote: >> Giving the opportunity to userspace to associate a free-form >> name with a drm_file struct is helpful for tracking and debugging. >> >> This is similar to the existing DMA_BUF_SET_NAME ioctl. >> >> Access to name is protected by a mutex, and the 'clients' debugfs >> file has been updated to print it. >> >> Userspace MR to use this ioctl: >>     https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/1428 >> >> The string passed by userspace is filtered a bit, to avoid messing >> output when it's going to be printed (in dmesg, fdinfo, etc): >>    * all chars failing isgraph() are replaced by '-' >>    * if a 0-length string is passed the name is cleared >> >> Signed-off-by: Pierre-Eric Pelloux-Prayer >> --- >>   drivers/gpu/drm/drm_debugfs.c | 12 ++++++--- >>   drivers/gpu/drm/drm_file.c    |  5 ++++ >>   drivers/gpu/drm/drm_ioctl.c   | 48 +++++++++++++++++++++++++++++++++++ >>   include/drm/drm_file.h        |  9 +++++++ >>   include/uapi/drm/drm.h        | 17 +++++++++++++ >>   5 files changed, 87 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c >> index 6b239a24f1df..482e71160544 100644 >> --- a/drivers/gpu/drm/drm_debugfs.c >> +++ b/drivers/gpu/drm/drm_debugfs.c >> @@ -78,12 +78,13 @@ static int drm_clients_info(struct seq_file *m, void *data) >>       kuid_t uid; >>       seq_printf(m, >> -           "%20s %5s %3s master a %5s %10s\n", >> +           "%20s %5s %3s master a %5s %10s %20s\n", > > Allow full DRM_NAME_MAX_LEN? Not sure, feels not very consequential either way. I'll switch to: seq_printf(m, "%20s %5s %3s master a %5s %10s %*s\n", "command", "tgid", "dev", "uid", "magic", DRM_CLIENT_NAME_MAX_LEN, "name"); And: seq_printf(m, "%20s %5d %3d %c %c %5d %10u %*s\n", task ? task->comm : "", pid_vnr(pid), priv->minor->index, is_current_master ? 'y' : 'n', priv->authenticated ? 'y' : 'n', from_kuid_munged(seq_user_ns(m), uid), priv->magic, DRM_CLIENT_NAME_MAX_LEN, priv->client_name ? priv->client_name : ""); > >>              "command", >>              "tgid", >>              "dev", >>              "uid", >> -           "magic"); >> +           "magic", >> +           "name"); >>       /* dev->filelist is sorted youngest first, but we want to present >>        * oldest first (i.e. kernel, servers, clients), so walk backwardss. >> @@ -94,19 +95,22 @@ static int drm_clients_info(struct seq_file *m, void *data) >>           struct task_struct *task; >>           struct pid *pid; >> +        mutex_lock(&priv->name_lock); >>           rcu_read_lock(); /* Locks priv->pid and pid_task()->comm! */ >>           pid = rcu_dereference(priv->pid); >>           task = pid_task(pid, PIDTYPE_TGID); >>           uid = task ? __task_cred(task)->euid : GLOBAL_ROOT_UID; >> -        seq_printf(m, "%20s %5d %3d   %c    %c %5d %10u\n", >> +        seq_printf(m, "%20s %5d %3d   %c    %c %5d %10u %20s\n", >>                  task ? task->comm : "", >>                  pid_vnr(pid), >>                  priv->minor->index, >>                  is_current_master ? 'y' : 'n', >>                  priv->authenticated ? 'y' : 'n', >>                  from_kuid_munged(seq_user_ns(m), uid), >> -               priv->magic); >> +               priv->magic, >> +               priv->name ?: ""); >>           rcu_read_unlock(); >> +        mutex_unlock(&priv->name_lock); >>       } >>       mutex_unlock(&dev->filelist_mutex); >>       return 0; >> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c >> index 01fde94fe2a9..e9dd0e90a1f9 100644 >> --- a/drivers/gpu/drm/drm_file.c >> +++ b/drivers/gpu/drm/drm_file.c >> @@ -158,6 +158,7 @@ struct drm_file *drm_file_alloc(struct drm_minor *minor) >>       spin_lock_init(&file->master_lookup_lock); >>       mutex_init(&file->event_read_lock); >> +    mutex_init(&file->name_lock); >>       if (drm_core_check_feature(dev, DRIVER_GEM)) >>           drm_gem_open(dev, file); >> @@ -259,6 +260,10 @@ void drm_file_free(struct drm_file *file) >>       WARN_ON(!list_empty(&file->event_list)); >>       put_pid(rcu_access_pointer(file->pid)); >> + >> +    mutex_destroy(&file->name_lock); >> +    kfree(file->name); >> + >>       kfree(file); >>   } >> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c >> index 51f39912866f..46dadbd1bb35 100644 >> --- a/drivers/gpu/drm/drm_ioctl.c >> +++ b/drivers/gpu/drm/drm_ioctl.c >> @@ -540,6 +540,52 @@ int drm_version(struct drm_device *dev, void *data, >>       return err; >>   } >> +static int drm_set_name(struct drm_device *dev, void *data, >> +            struct drm_file *file_priv) >> +{ >> +    struct drm_set_name *name = data; >> +    void __user *user_ptr; >> +    char *new_name; >> +    size_t i, len; >> + >> +    if (name->name_len > DRM_NAME_MAX_LEN) >> +        return -EINVAL; >> + >> +    user_ptr = u64_to_user_ptr(name->name); >> + >> +    new_name = memdup_user_nul(user_ptr, name->name_len); >> +    if (IS_ERR(new_name)) >> +        return PTR_ERR(new_name); >> + >> +    len = strlen(new_name); >> + >> +    if (len != name->name_len) { >> +        kfree(new_name); >> +        return -EINVAL; >> +    } >> + >> +    /* >> +     * Filter out control char / spaces / new lines etc in the name >> +     * since it's going to be used in dmesg or fdinfo's output. >> +     */ >> +    for (i = 0; i < len; i++) { >> +        if (!isgraph(new_name[i])) >> +            new_name[i] = '-'; >> +    } >> + >> +    mutex_lock(&file_priv->name_lock); >> +    kfree(file_priv->name); >> +    if (len > 0) { >> +        file_priv->name = new_name; >> +    } else { >> +        kfree(new_name); >> +        file_priv->name = NULL; >> +    } >> +    mutex_unlock(&file_priv->name_lock); >> + >> +    return 0; >> +} >> + >>   static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv) >>   { >>       /* ROOT_ONLY is only for CAP_SYS_ADMIN */ >> @@ -610,6 +656,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = { >>       DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW), >>       DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW), >> +    DRM_IOCTL_DEF(DRM_IOCTL_SET_NAME, drm_set_name, DRM_RENDER_ALLOW), >> + >>       DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0), >>       DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0), >>       DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER), >> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h >> index 8c0030c77308..df26eee8f79c 100644 >> --- a/include/drm/drm_file.h >> +++ b/include/drm/drm_file.h >> @@ -388,6 +388,15 @@ struct drm_file { >>        * Per-file buffer caches used by the PRIME buffer sharing code. >>        */ >>       struct drm_prime_file_private prime; >> + >> +    /** >> +     * @name: >> +     * >> +     * Userspace-provided name; useful for accounting and debugging. >> +     */ >> +    const char *name; >> +    /** @name_lock: Protects @name. */ >> +    struct mutex name_lock; >>   }; >>   /** >> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h >> index 16122819edfe..f5e92e4f909b 100644 >> --- a/include/uapi/drm/drm.h >> +++ b/include/uapi/drm/drm.h >> @@ -1024,6 +1024,13 @@ struct drm_crtc_queue_sequence { >>       __u64 user_data;    /* user data passed to event */ >>   }; >> +#define DRM_NAME_MAX_LEN    64 >> +struct drm_set_name { >> +    __u64 name_len; >> +    __u64 name; >> +}; >> + >> + >>   #if defined(__cplusplus) >>   } >>   #endif >> @@ -1288,6 +1295,16 @@ extern "C" { >>    */ >>   #define DRM_IOCTL_MODE_CLOSEFB        DRM_IOWR(0xD0, struct drm_mode_closefb) >> +/** >> + * DRM_IOCTL_SET_NAME - Attach a name to a drm_file >> + * >> + * This ioctl is similar to DMA_BUF_SET_NAME - it allows for easier tracking >> + * and debugging. >> + * The length of the name must <= DRM_NAME_MAX_LEN. All characters that are >> + * non-printable or whitespaces will be replaced by -. >> + */ >> +#define DRM_IOCTL_SET_NAME        DRM_IOWR(0xD1, struct drm_set_name) >> + > > A comment, nice! :) Overal looks good to me. > > Reviewed-by: Tvrtko Ursulin > > I do however wish for more opinions (before merging) on whether strings with invalid characters > should perhaps instead be rejected. I don't currently have a solid argument either way. > > Perhaps the only argument against silent transformation is if someone sets some wild string, then > greps for it somewhere, which would be a false negative without the understanding of what kind of > remapping kernel does. It is weak but it is uapi so worth discussing every crazy possibility I think. > > On the other hand it would create another annoying source of EINVAL. :shrug: No strong feelings either, but I agree that gathering more opinions before merging would be useful. > > Also, how are with with testing the DRM core features? Add something for the uapi in > IGT/tests/drm_client_name, or some such? Something like using the ioctl and then reading back the name using /sys/kernel/debug/dri/0/clients? I can do that if it's required / useful. Thanks, Pierre-Eric > > Regards, > > Tvrtko > >>   /* >>    * Device specific ioctls should only be in their respective headers >>    * The device specific ioctl range is from 0x40 to 0x9f.