drivers: remove get_task_comm() and print task comm directly

Since task->comm is guaranteed to be NUL-terminated, we can print it
directly without the need to copy it into a separate buffer.  This
simplifies the code and avoids unnecessary operations.

Link: https://lkml.kernel.org/r/20241219023452.69907-6-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org> (For tty)
Reviewed-by: Lyude Paul <lyude@redhat.com> (For nouveau)
Cc: Oded Gabbay <ogabbay@kernel.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tursulin@ursulin.net>
Cc: David Airlie <airlied@gmail.com>
Cc: Simona Vetter <simona@ffwll.ch>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "André Almeida" <andrealmeid@igalia.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/accel/habanalabs/common/context.c

@@ -199,7 +199,6 @@ out_err:
 
 int hl_ctx_init(struct hl_device *hdev, struct hl_ctx *ctx, bool is_kernel_ctx)
 {
-	char task_comm[TASK_COMM_LEN];
 	int rc = 0, i;
 
 	ctx->hdev = hdev;
@@ -272,7 +271,7 @@ int hl_ctx_init(struct hl_device *hdev, struct hl_ctx *ctx, bool is_kernel_ctx)
 		mutex_init(&ctx->ts_reg_lock);
 
 		dev_dbg(hdev->dev, "create user context, comm=\"%s\", asid=%u\n",
-			get_task_comm(task_comm, current), ctx->asid);
+			current->comm, ctx->asid);
 	}
 
 	return 0;

drivers/accel/habanalabs/common/habanalabs_ioctl.c

@@ -1279,13 +1279,10 @@ static long _hl_ioctl(struct hl_fpriv *hpriv, unsigned int cmd, unsigned long ar
 		retcode = -EFAULT;
 
 out_err:
-	if (retcode) {
+	if (retcode)
-		char task_comm[TASK_COMM_LEN];
-
 		dev_dbg_ratelimited(dev,
 				"error in ioctl: pid=%d, comm=\"%s\", cmd=%#010x, nr=%#04x\n",
-				task_pid_nr(current), get_task_comm(task_comm, current), cmd, nr);
+				task_pid_nr(current), current->comm, cmd, nr);
-	}
 
 	if (kdata != stack_kdata)
 		kfree(kdata);
@@ -1308,11 +1305,9 @@ long hl_ioctl_control(struct file *filep, unsigned int cmd, unsigned long arg)
 	if (nr == _IOC_NR(DRM_IOCTL_HL_INFO)) {
 		ioctl = &hl_ioctls_control[nr - HL_COMMAND_START];
 	} else {
-		char task_comm[TASK_COMM_LEN];
-
 		dev_dbg_ratelimited(hdev->dev_ctrl,
 				"invalid ioctl: pid=%d, comm=\"%s\", cmd=%#010x, nr=%#04x\n",
-				task_pid_nr(current), get_task_comm(task_comm, current), cmd, nr);
+				task_pid_nr(current), current->comm, cmd, nr);
 		return -ENOTTY;
 	}
 

drivers/gpu/drm/i915/display/intel_display_driver.c

@@ -391,7 +391,6 @@ void intel_display_driver_resume_access(struct drm_i915_private *i915)
  */
 bool intel_display_driver_check_access(struct drm_i915_private *i915)
 {
-	char comm[TASK_COMM_LEN];
 	char current_task[TASK_COMM_LEN + 16];
 	char allowed_task[TASK_COMM_LEN + 16] = "none";
 
@@ -400,12 +399,11 @@ bool intel_display_driver_check_access(struct drm_i915_private *i915)
 		return true;
 
 	snprintf(current_task, sizeof(current_task), "%s[%d]",
-		 get_task_comm(comm, current),
+		 current->comm, task_pid_vnr(current));
-		 task_pid_vnr(current));
 
 	if (i915->display.access.allowed_task)
 		snprintf(allowed_task, sizeof(allowed_task), "%s[%d]",
-			 get_task_comm(comm, i915->display.access.allowed_task),
+			 i915->display.access.allowed_task->comm,
 			 task_pid_vnr(i915->display.access.allowed_task));
 
 	drm_dbg_kms(&i915->drm,

drivers/gpu/drm/nouveau/nouveau_chan.c

@@ -279,7 +279,6 @@ nouveau_channel_ctor(struct nouveau_cli *cli, bool priv, u64 runm,
 	const u64 plength = 0x10000;
 	const u64 ioffset = plength;
 	const u64 ilength = 0x02000;
-	char name[TASK_COMM_LEN];
 	int cid, ret;
 	u64 size;
 
@@ -338,8 +337,7 @@ nouveau_channel_ctor(struct nouveau_cli *cli, bool priv, u64 runm,
 		chan->userd = &chan->user;
 	}
 
-	get_task_comm(name, current);
+	snprintf(args.name, sizeof(args.name), "%s[%d]", current->comm, task_pid_nr(current));
-	snprintf(args.name, sizeof(args.name), "%s[%d]", name, task_pid_nr(current));
 
 	ret = nvif_object_ctor(&device->object, "abi16ChanUser", 0, hosts[cid].oclass,
 			       &args, sizeof(args), &chan->user);

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -1159,7 +1159,7 @@ nouveau_drm_open(struct drm_device *dev, struct drm_file *fpriv)
 {
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nouveau_cli *cli;
-	char name[32], tmpname[TASK_COMM_LEN];
+	char name[32];
 	int ret;
 
 	/* need to bring up power immediately if opening device */
@@ -1169,10 +1169,9 @@ nouveau_drm_open(struct drm_device *dev, struct drm_file *fpriv)
 		return ret;
 	}
 
-	get_task_comm(tmpname, current);
 	rcu_read_lock();
 	snprintf(name, sizeof(name), "%s[%d]",
-		 tmpname, pid_nr(rcu_dereference(fpriv->pid)));
+		 current->comm, pid_nr(rcu_dereference(fpriv->pid)));
 	rcu_read_unlock();
 
 	if (!(cli = kzalloc(sizeof(*cli), GFP_KERNEL))) {

drivers/tty/tty_io.c

@@ -2622,14 +2622,13 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
 
 static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss)
 {
-	char comm[TASK_COMM_LEN];
 	int flags;
 
 	flags = ss->flags & ASYNC_DEPRECATED;
 
 	if (flags)
 		pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
-				__func__, get_task_comm(comm, current), flags);
+				__func__, current->comm, flags);
 
 	if (!tty->ops->set_serial)
 		return -ENOTTY;