From nobody Sun Jun 14 02:10:20 2026 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 773F73D171F; Fri, 12 Jun 2026 16:20:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281253; cv=none; b=t8W0SCEiW2ebC7igIhoWXVd45F+rcF8um9Gs3AcUzW6Zbq+qocDHdBDJkghWl83Xo5CvkT5ITxcrszBSeAnjVcJHcp4SphTNSSAodD90CR5SFsyO7cDXx3vwrbtxXVSCaMoeR9Oq/0V6HB0NWJUoApinX3yCMaUgnY7Ny6NcfDM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281253; c=relaxed/simple; bh=D3riEiQCFl1ODn9tbvXDDWHsiwUs95xAILXdhqFmYVI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=HLzdWfjUIb8fSgXtsIDvgi49MnMdL+EWVzXm4tk9e4KdWncZUo2XqF4NP4EVxiMNigMsV8n44eiqV13gwfRhTwg7zXqgDJYIqlZjB7UJLKZGEVRdrG8TH6SSHRLAgf7VVuuL34c+db0l6Kihx+Xkqa+085Hq+D/SsiYjevZlLfE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=Kks4Atna; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="Kks4Atna" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=zIYT/HNuvNJd7wtW3If1BoiCZk6EJ/pRukABWxJMOZ0=; b=Kks4AtnaYNx5nZiKCxP06Gd/Da Qf+VvfXREYGa3t5XvOfINjONUHMCCj9e2AE2gV5le9ZHaUyg1b9WY6XdCxGMO2iGdknHEo5SoPYZC jhPJKC4XE0xxTwrGKstcKNvDNeJzVS4TsL4dlY7Al09sb6k1aIXwnjFbLFZdp8KFQwzcW2RAv2Yvy QZovYPDtSm/XbnzJlaKTtWxUk5LyvBFubqs+99yIVAuj+WB6hT/QVkr+PHKMnXRtJnkpcsf0I7W9C 8TL8E3nW4CStXph3Ly9jbvtIep6a5eSaYr+B522k8ocAYNUEc5Z7QLDNF9zXK0hd6xpbHUfJzVLQB ok+wvfrw==; Received: from [189.78.222.70] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wY4ca-00GgP4-2B; Fri, 12 Jun 2026 18:20:40 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Fri, 12 Jun 2026 13:20:14 -0300 Subject: [PATCH v3 1/7] sched: Update get_task_comm() comment Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260612-tonyk-long_name-v3-1-7989b66e8a99@igalia.com> References: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> In-Reply-To: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> To: Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, David Laight , Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.15.2 Since commit 3a3f61ce5e0b ("exec: Make sure task->comm is always NUL-terminated"), __set_task_comm() no longer uses strscpy_pad(). Update the stale comment accordingly. Signed-off-by: Andr=C3=A9 Almeida --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 368c7b4d7cb5..60d004a49a27 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2005,7 +2005,7 @@ extern void __set_task_comm(struct task_struct *tsk, = const char *from, bool exec * User space can randomly change their names anyway, so locking for rea= ders * doesn't make sense. For writers, locking is probably necessary, as a = race * condition could lead to long-term mixed results. - * The strscpy_pad() in __set_task_comm() can ensure that the task comm = is + * The logic inside __set_task_comm() ensures that the task comm is * always NUL-terminated and zero-padded. Therefore the race condition b= etween * reader and writer is not an issue. * --=20 2.54.0 From nobody Sun Jun 14 02:10:20 2026 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D1D8929D270; Fri, 12 Jun 2026 16:20:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281254; cv=none; b=FDZZEIj7mmpfkCEC/RJErCzu4RVZGga+Tu83gvjk2hm77xmbl0kWiPNSML6HaCftJJSaTIzJcu4/TicQvWjxiQp8ltYSLjlehFuzbywCil1J1/iPgqV2XMdDN+YomodJOvpvn1pAu7JhivW/N3DgkJWN6P+xOYy8H2zNzDqRNDU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281254; c=relaxed/simple; bh=BLowunkctsS5bYFxV+v7JDzNMJflM5RaLp9DfQCFTsU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=LUmzbQ+BTM+CXi69n3J3HePPD3/7nd4NqNVuUp9qsHhvEmdC05enqKftfxu5sWJRJQJSplTTiJ473+VpifwPlKe45h6eKlxK+T46/zlASJ1oosqMq7bnW/Jo03IEn/rWOGhnanzTC9zFSj8ZZZeV2VBiNyHQ0WyTRNZSNbG4L8g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=MXHGqo6r; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="MXHGqo6r" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=aheWjUAZS1tzsTu1B8IiNBFC5FmKdXTGcNGgaZL7FLI=; b=MXHGqo6rMGhNmTklH1tywl7eq0 KrKaK0ntryTj8HIe0WhzR3PeCQ/4ihBh3vOngQWyGMEK0owSSw2Lf0N0ITth+MR0MuqV+RUDeN4t8 ciaRehkWAnHvMR/6Vs/TaU57vufdBDbTRllj1oEPB21eSHD6gTdWNn+wiV6jjBSt5U2/VSHtMqYPO EQdEA8MgVzHTIgHIbA5QbLfsy/PBV8kGF4i+bwcculkFQC66GGbzKsT0FTdJWTxAwy8xUp/i9URK0 CT/jCHtPgMQgBrBucAidZriv7/T6caOQmHb/eS9B5FG9oXJp0AaJBBH5M9LRU1LSCG9mk2WAkXaM+ eoRaOd3g==; Received: from [189.78.222.70] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wY4cf-00GgP4-Cx; Fri, 12 Jun 2026 18:20:45 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Fri, 12 Jun 2026 13:20:15 -0300 Subject: [PATCH v3 2/7] treewide: Get rid of get_task_comm() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260612-tonyk-long_name-v3-2-7989b66e8a99@igalia.com> References: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> In-Reply-To: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> To: Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, David Laight , Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.15.2 Since commit 4cc0473d7754 ("get rid of __get_task_comm()"), get_task_comm() does just a redundant check for the buffer size and call strscpy_pad(). Replace get_task_comm() calls with strscpy_pad(), that will do the right thing if the buffers sizes doesn't match: zero-pad if it's bigger, and truncate if it's smaller. Link: https://lore.kernel.org/lkml/CAHk-=3Dwi5c=3D_-FBGo_88CowJd_F-Gi6Ud9d= =3DTALm65ReN7YjrMw@mail.gmail.com/ Signed-off-by: Andr=C3=A9 Almeida --- Changes from v1: - Fix for security/ipe/audit.c and net/netfilter/nf_tables_api.c --- drivers/connector/cn_proc.c | 2 +- drivers/dma-buf/sw_sync.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 4 ++-- drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 2 +- drivers/gpu/drm/lima/lima_ctx.c | 2 +- drivers/gpu/drm/panfrost/panfrost_gem.c | 2 +- drivers/gpu/drm/panthor/panthor_gem.c | 2 +- drivers/gpu/drm/panthor/panthor_sched.c | 2 +- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 2 +- drivers/hwtracing/stm/core.c | 2 +- drivers/tty/tty_audit.c | 2 +- fs/binfmt_elf.c | 2 +- fs/binfmt_elf_fdpic.c | 2 +- fs/proc/array.c | 2 +- include/linux/sched.h | 19 ------------------- kernel/audit.c | 6 ++++-- kernel/auditsc.c | 6 ++++-- kernel/printk/printk.c | 2 +- kernel/sys.c | 2 +- net/bluetooth/hci_sock.c | 2 +- net/netfilter/nf_tables_api.c | 4 +++- security/integrity/integrity_audit.c | 3 ++- security/ipe/audit.c | 3 ++- security/landlock/domain.c | 2 +- security/lsm_audit.c | 7 ++++--- 29 files changed, 42 insertions(+), 52 deletions(-) diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c index 0056ab81fbc3..c78243ed3c2a 100644 --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -278,7 +278,7 @@ void proc_comm_connector(struct task_struct *task) ev->what =3D PROC_EVENT_COMM; ev->event_data.comm.process_pid =3D task->pid; ev->event_data.comm.process_tgid =3D task->tgid; - get_task_comm(ev->event_data.comm.comm, task); + strscpy_pad(ev->event_data.comm.comm, task->comm); =20 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack =3D 0; /* not used */ diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c index 8df20b0218a9..d501657ad801 100644 --- a/drivers/dma-buf/sw_sync.c +++ b/drivers/dma-buf/sw_sync.c @@ -312,7 +312,7 @@ static int sw_sync_debugfs_open(struct inode *inode, st= ruct file *file) struct sync_timeline *obj; char task_comm[TASK_COMM_LEN]; =20 - get_task_comm(task_comm, current); + strscpy_pad(task_comm, current->comm); =20 obj =3D sync_timeline_create(task_comm); if (!obj) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c b/drivers/gpu= /drm/amd/amdgpu/amdgpu_amdkfd_fence.c index 6a364357522b..13c8857e4ffb 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c @@ -74,7 +74,7 @@ struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u6= 4 context, /* This reference gets released in amdkfd_fence_release */ mmgrab(mm); fence->mm =3D mm; - get_task_comm(fence->timeline_name, current); + strscpy_pad(fence->timeline_name, current->comm); spin_lock_init(&fence->lock); fence->svm_bo =3D svm_bo; fence->context_id =3D context_id; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c b/drivers/g= pu/drm/amd/amdgpu/amdgpu_eviction_fence.c index 4c5e38dea4c2..faf0f36d8328 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c @@ -129,7 +129,7 @@ int amdgpu_evf_mgr_rearm(struct amdgpu_eviction_fence_m= gr *evf_mgr, return -ENOMEM; =20 ev_fence->evf_mgr =3D evf_mgr; - get_task_comm(ev_fence->timeline_name, current); + strscpy_pad(ev_fence->timeline_name, current->comm); spin_lock_init(&ev_fence->lock); dma_fence_init64(&ev_fence->base, &amdgpu_eviction_fence_ops, &ev_fence->lock, evf_mgr->ev_fence_ctx, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/= amdgpu/amdgpu_ras.c index 6c644cfe6695..c45630457155 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c @@ -4419,7 +4419,7 @@ int amdgpu_ras_init(struct amdgpu_device *adev) } =20 con->init_task_pid =3D task_pid_nr(current); - get_task_comm(con->init_task_comm, current); + strscpy_pad(con->init_task_comm, current->comm); =20 mutex_init(&con->critical_region_lock); INIT_LIST_HEAD(&con->critical_region_head); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c b/drivers/gpu/= drm/amd/amdgpu/amdgpu_userq_fence.c index e2d5f04296e1..8fdc38d8d64d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c @@ -85,7 +85,7 @@ int amdgpu_userq_fence_driver_alloc(struct amdgpu_device = *adev, =20 fence_drv->adev =3D adev; fence_drv->context =3D dma_fence_context_alloc(1); - get_task_comm(fence_drv->timeline_name, current); + strscpy_pad(fence_drv->timeline_name, current->comm); =20 *fence_drv_req =3D fence_drv; =20 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/a= mdgpu/amdgpu_vm.c index 9ba9de16a27a..de80d0ace905 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c @@ -2571,10 +2571,10 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm) return; =20 vm->task_info->task.pid =3D current->pid; - get_task_comm(vm->task_info->task.comm, current); + strscpy_pad(vm->task_info->task.comm, current->comm); =20 vm->task_info->tgid =3D current->tgid; - get_task_comm(vm->task_info->process_name, current->group_leader); + strscpy_pad(vm->task_info->process_name, current->group_leader->comm); } =20 /** diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm= /amd/amdgpu/amdgpu_vram_mgr.c index 2a241a5b12c4..f8ce59d8587a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c @@ -563,7 +563,7 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_mana= ger *man, } =20 vres->task.pid =3D task_pid_nr(current); - get_task_comm(vres->task.comm, current); + strscpy_pad(vres->task.comm, current->comm); list_add_tail(&vres->vres_node, &mgr->allocated_vres_list); =20 if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS && adjust_dcc_size) { diff --git a/drivers/gpu/drm/lima/lima_ctx.c b/drivers/gpu/drm/lima/lima_ct= x.c index 68ede7a725e2..e8c5c3601bf1 100644 --- a/drivers/gpu/drm/lima/lima_ctx.c +++ b/drivers/gpu/drm/lima/lima_ctx.c @@ -29,7 +29,7 @@ int lima_ctx_create(struct lima_device *dev, struct lima_= ctx_mgr *mgr, u32 *id) goto err_out0; =20 ctx->pid =3D task_pid_nr(current); - get_task_comm(ctx->pname, current); + strscpy_pad(ctx->pname, current->comm); =20 return 0; =20 diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panf= rost/panfrost_gem.c index 3a7fce428898..11936c4d3573 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gem.c +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c @@ -36,7 +36,7 @@ static void panfrost_gem_debugfs_bo_add(struct panfrost_d= evice *pfdev, struct panfrost_gem_object *bo) { bo->debugfs.creator.tgid =3D current->tgid; - get_task_comm(bo->debugfs.creator.process_name, current->group_leader); + strscpy_pad(bo->debugfs.creator.process_name, current->group_leader->comm= ); =20 mutex_lock(&pfdev->debugfs.gems_lock); list_add_tail(&bo->debugfs.node, &pfdev->debugfs.gems_list); diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/pantho= r/panthor_gem.c index cd49859da89b..b44fd715c17e 100644 --- a/drivers/gpu/drm/panthor/panthor_gem.c +++ b/drivers/gpu/drm/panthor/panthor_gem.c @@ -46,7 +46,7 @@ static void panthor_gem_debugfs_bo_add(struct panthor_gem= _object *bo) struct panthor_device, base); =20 bo->debugfs.creator.tgid =3D current->tgid; - get_task_comm(bo->debugfs.creator.process_name, current->group_leader); + strscpy_pad(bo->debugfs.creator.process_name, current->group_leader->comm= ); =20 mutex_lock(&ptdev->gems.lock); list_add_tail(&bo->debugfs.node, &ptdev->gems.node); diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/pant= hor/panthor_sched.c index 2fe04d0f0e3a..8ee9de96acf6 100644 --- a/drivers/gpu/drm/panthor/panthor_sched.c +++ b/drivers/gpu/drm/panthor/panthor_sched.c @@ -3603,7 +3603,7 @@ static void group_init_task_info(struct panthor_group= *group) struct task_struct *task =3D current->group_leader; =20 group->task_info.pid =3D task->pid; - get_task_comm(group->task_info.comm, task); + strscpy_pad(group->task_info.comm, task->comm); } =20 static void add_group_kbo_sizes(struct panthor_device *ptdev, diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virti= o/virtgpu_ioctl.c index c33c057365f8..d2bf221e8f01 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -50,7 +50,7 @@ static void virtio_gpu_create_context_locked(struct virti= o_gpu_device *vgdev, } else { char dbgname[TASK_COMM_LEN]; =20 - get_task_comm(dbgname, current); + strscpy_pad(dbgname, current->comm); virtio_gpu_cmd_context_create(vgdev, vfpriv->ctx_id, vfpriv->context_init, strlen(dbgname), dbgname); diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index f48c6a8a0654..c7715439964e 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -634,7 +634,7 @@ static ssize_t stm_char_write(struct file *file, const = char __user *buf, char comm[sizeof(current->comm)]; char *ids[] =3D { comm, "default", NULL }; =20 - get_task_comm(comm, current); + strscpy_pad(comm, current->comm); =20 err =3D stm_assign_first_policy(stmf->stm, &stmf->output, ids, 1); /* diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c index d014af6ab060..d514a81d0a5c 100644 --- a/drivers/tty/tty_audit.c +++ b/drivers/tty/tty_audit.c @@ -77,7 +77,7 @@ static void tty_audit_log(const char *description, dev_t = dev, audit_log_format(ab, "%s pid=3D%u uid=3D%u auid=3D%u ses=3D%u major=3D%d = minor=3D%d comm=3D", description, pid, uid, loginuid, sessionid, MAJOR(dev), MINOR(dev)); - get_task_comm(name, current); + strscpy_pad(name, current->comm); audit_log_untrustedstring(ab, name); audit_log_format(ab, " data=3D"); audit_log_n_hex(ab, data, size); diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 16a56b6b3f6c..d25922460b63 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1557,7 +1557,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, s= truct task_struct *p, SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); rcu_read_unlock(); - get_task_comm(psinfo->pr_fname, p); + strscpy_pad(psinfo->pr_fname, p->comm); =20 return 0; } diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 7e3108489c83..c4d4e59ff34d 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1371,7 +1371,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, s= truct task_struct *p, SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); rcu_read_unlock(); - get_task_comm(psinfo->pr_fname, p); + strscpy_pad(psinfo->pr_fname, p->comm); =20 return 0; } diff --git a/fs/proc/array.c b/fs/proc/array.c index 90fb0c6b5f99..c8c3fbd9bfa9 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -110,7 +110,7 @@ void proc_task_name(struct seq_file *m, struct task_str= uct *p, bool escape) else if (p->flags & PF_KTHREAD) get_kthread_comm(tcomm, sizeof(tcomm), p); else - get_task_comm(tcomm, p); + strscpy_pad(tcomm, p->comm); =20 if (escape) seq_escape_str(m, tcomm, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); diff --git a/include/linux/sched.h b/include/linux/sched.h index 60d004a49a27..b6de742b1155 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2000,25 +2000,6 @@ extern void __set_task_comm(struct task_struct *tsk,= const char *from, bool exec __set_task_comm(tsk, from, false); \ }) =20 -/* - * - Why not use task_lock()? - * User space can randomly change their names anyway, so locking for rea= ders - * doesn't make sense. For writers, locking is probably necessary, as a = race - * condition could lead to long-term mixed results. - * The logic inside __set_task_comm() ensures that the task comm is - * always NUL-terminated and zero-padded. Therefore the race condition b= etween - * reader and writer is not an issue. - * - * - BUILD_BUG_ON() can help prevent the buf from being truncated. - * Since the callers don't perform any return value checks, this safegua= rd is - * necessary. - */ -#define get_task_comm(buf, tsk) ({ \ - BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN); \ - strscpy_pad(buf, (tsk)->comm); \ - buf; \ -}) - static __always_inline void scheduler_ipi(void) { /* diff --git a/kernel/audit.c b/kernel/audit.c index e1d489bc2dff..6fc867adbf3d 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1662,7 +1662,8 @@ static void audit_log_multicast(int group, const char= *op, int err) audit_put_tty(tty); audit_log_task_context(ab); /* subj=3D */ audit_log_format(ab, " comm=3D"); - audit_log_untrustedstring(ab, get_task_comm(comm, current)); + strscpy_pad(comm, current->comm); + audit_log_untrustedstring(ab, comm); audit_log_d_path_exe(ab, current->mm); /* exe=3D */ audit_log_format(ab, " nl-mcgrp=3D%d op=3D%s res=3D%d", group, op, !err); audit_log_end(ab); @@ -2465,7 +2466,8 @@ void audit_log_task_info(struct audit_buffer *ab) audit_get_sessionid(current)); audit_put_tty(tty); audit_log_format(ab, " comm=3D"); - audit_log_untrustedstring(ab, get_task_comm(comm, current)); + strscpy_pad(comm, current->comm); + audit_log_untrustedstring(ab, comm); audit_log_d_path_exe(ab, current->mm); audit_log_task_context(ab); } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index ab54fccba215..8e4f70105a13 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2877,7 +2877,8 @@ void __audit_log_nfcfg(const char *name, u8 af, unsig= ned int nentries, audit_log_format(ab, " pid=3D%u", task_tgid_nr(current)); audit_log_task_context(ab); /* subj=3D */ audit_log_format(ab, " comm=3D"); - audit_log_untrustedstring(ab, get_task_comm(comm, current)); + strscpy_pad(comm, current->comm); + audit_log_untrustedstring(ab, comm); audit_log_end(ab); } EXPORT_SYMBOL_GPL(__audit_log_nfcfg); @@ -2900,7 +2901,8 @@ static void audit_log_task(struct audit_buffer *ab) sessionid); audit_log_task_context(ab); audit_log_format(ab, " pid=3D%d comm=3D", task_tgid_nr(current)); - audit_log_untrustedstring(ab, get_task_comm(comm, current)); + strscpy_pad(comm, current->comm); + audit_log_untrustedstring(ab, comm); audit_log_d_path_exe(ab, current->mm); } =20 diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 0323149548f6..1f04e753ca02 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2247,7 +2247,7 @@ static u16 printk_sprint(char *text, u16 size, int fa= cility, static void printk_store_execution_ctx(struct printk_info *info) { info->caller_id2 =3D printk_caller_id2(); - get_task_comm(info->comm, current); + strscpy_pad(info->comm, current->comm); } =20 static void pmsg_load_execution_ctx(struct printk_message *pmsg, diff --git a/kernel/sys.c b/kernel/sys.c index 62e842055cc9..1d5152d2395e 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2609,7 +2609,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, ar= g2, unsigned long, arg3, proc_comm_connector(me); break; case PR_GET_NAME: - get_task_comm(comm, me); + strscpy_pad(comm, me->comm); if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) return -EFAULT; break; diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index 0290dea081f6..38e16ba2de38 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -106,7 +106,7 @@ static bool hci_sock_gen_cookie(struct sock *sk) id =3D 0xffffffff; =20 hci_pi(sk)->cookie =3D id; - get_task_comm(hci_pi(sk)->comm, current); + strscpy_pad(hci_pi(sk)->comm, current->comm); return true; } =20 diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 87387adbca65..cd00d4da1316 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -9709,9 +9709,11 @@ static int nf_tables_fill_gen_info(struct sk_buff *s= kb, struct net *net, if (!nlh) goto nla_put_failure; =20 + strscpy_pad(buf, current->comm); + if (nla_put_be32(skb, NFTA_GEN_ID, htonl(nft_base_seq(net))) || nla_put_be32(skb, NFTA_GEN_PROC_PID, htonl(task_pid_nr(current))) || - nla_put_string(skb, NFTA_GEN_PROC_NAME, get_task_comm(buf, current))) + nla_put_string(skb, NFTA_GEN_PROC_NAME, buf)) goto nla_put_failure; =20 nlmsg_end(skb, nlh); diff --git a/security/integrity/integrity_audit.c b/security/integrity/inte= grity_audit.c index d8d9e5ff1cd2..98060060929d 100644 --- a/security/integrity/integrity_audit.c +++ b/security/integrity/integrity_audit.c @@ -54,7 +54,8 @@ void integrity_audit_message(int audit_msgno, struct inod= e *inode, audit_get_sessionid(current)); audit_log_task_context(ab); audit_log_format(ab, " op=3D%s cause=3D%s comm=3D", op, cause); - audit_log_untrustedstring(ab, get_task_comm(name, current)); + strscpy_pad(name, current->comm); + audit_log_untrustedstring(ab, name); if (fname) { audit_log_format(ab, " name=3D"); audit_log_untrustedstring(ab, fname); diff --git a/security/ipe/audit.c b/security/ipe/audit.c index 93fb59fbddd6..90a6acfb7cdf 100644 --- a/security/ipe/audit.c +++ b/security/ipe/audit.c @@ -145,7 +145,8 @@ void ipe_audit_match(const struct ipe_eval_ctx *const c= tx, audit_log_format(ab, "ipe_op=3D%s ipe_hook=3D%s enforcing=3D%d pid=3D%d c= omm=3D", op, audit_hook_names[ctx->hook], READ_ONCE(enforce), task_tgid_nr(current)); - audit_log_untrustedstring(ab, get_task_comm(comm, current)); + strscpy_pad(comm, current->comm); + audit_log_untrustedstring(ab, comm); =20 if (ctx->file) { audit_log_d_path(ab, " path=3D", &ctx->file->f_path); diff --git a/security/landlock/domain.c b/security/landlock/domain.c index 06b6bd845060..a35a27f523e6 100644 --- a/security/landlock/domain.c +++ b/security/landlock/domain.c @@ -101,7 +101,7 @@ static struct landlock_details *get_current_details(voi= d) memcpy(details->exe_path, path_str, path_size); details->pid =3D get_pid(task_tgid(current)); details->uid =3D from_kuid(&init_user_ns, current_uid()); - get_task_comm(details->comm, current); + strscpy_pad(details->comm, current->comm); return details; } =20 diff --git a/security/lsm_audit.c b/security/lsm_audit.c index 737f5a263a8f..a587ffecd985 100644 --- a/security/lsm_audit.c +++ b/security/lsm_audit.c @@ -276,8 +276,8 @@ void audit_log_lsm_data(struct audit_buffer *ab, if (pid) { char tskcomm[sizeof(tsk->comm)]; audit_log_format(ab, " opid=3D%d ocomm=3D", pid); - audit_log_untrustedstring(ab, - get_task_comm(tskcomm, tsk)); + strscpy_pad(tskcomm, tsk->comm); + audit_log_untrustedstring(ab, tskcomm); } } break; @@ -417,7 +417,8 @@ static void dump_common_audit_data(struct audit_buffer = *ab, char comm[sizeof(current->comm)]; =20 audit_log_format(ab, " pid=3D%d comm=3D", task_tgid_nr(current)); - audit_log_untrustedstring(ab, get_task_comm(comm, current)); + strscpy_pad(comm, current->comm); + audit_log_untrustedstring(ab, comm); audit_log_lsm_data(ab, a); } =20 --=20 2.54.0 From nobody Sun Jun 14 02:10:20 2026 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3507A3D75CE; Fri, 12 Jun 2026 16:20:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281259; cv=none; b=tXYYcEL4Fuu1gH5zJdw1Bh5WH9w06weqPRB7SGo6mwggNRRCfIXQNvz/v96VCRkbKNg0NJXPdbmshbbZigOUnpSfagbUSKOtZVfeoVqQefhL62XKOeSB0KXVM4ZF01WAv1YF/7ob74aevCtQUlxA9d0J6BWKx5Dcg/U/zNp4ZfI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281259; c=relaxed/simple; bh=wSj4tt9C748g+EW4i7byTduV7DmkoVpCbj0Gaq6BgEU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=H8ASwCwv6UatWLHISOq9zioKQjHyGht5v1qWZb93qKQz0uNBk2vZpFLC3M7/NGrvCPENnczvGOrDxSi+kNpm01AfBYyO8ghX9sUU0mu8JUVq9DW5tSjMluWUytYyr7d7cfZ+hfem1mrsvvsqsRmT3St7GvCBmAyjisCcKRjHWIY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=qq8NYvRO; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="qq8NYvRO" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=+tud+PRK04GneOoQ8FSSWs0Xo0QqAjl9WMBoushYkQE=; b=qq8NYvROO7AcA6z7MsoF9bk28T SzaYz2ga/qaCqD+ZYC4ivsgGOeL/o+pcY4Ik46Ux4KUGs1GjkRlTMk6guZGMtH1kQWqcAh/zP5WdM egmxvOF9/CXAaPcIn8SdMqRKfMMlLoGoiPp02YW43Yu79SXGuLc8iq8cNGh0IiRhOHVZtZoJYqoKz EPW2GT5Qvgb/pSaI6WqBUh4L3jzkXbkYwifNXY0lM5vra4IvGlKz/dizZJ+t2xJfQY2Kdhsx2jUvQ clJiXrvLZqqJ+gik1ctKhLP5tblFd7eXbgALMPE3YQ+rM89bFfFzcYXzTxAb1Pi2zYnlLm+fmoiw5 ZvMnA7BQ==; Received: from [189.78.222.70] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wY4ck-00GgP4-VZ; Fri, 12 Jun 2026 18:20:51 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Fri, 12 Jun 2026 13:20:16 -0300 Subject: [PATCH v3 3/7] treewide: Replace memcpy(..., current->comm) with copy_task_comm() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260612-tonyk-long_name-v3-3-7989b66e8a99@igalia.com> References: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> In-Reply-To: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> To: Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, David Laight , Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.15.2 In order to increase the size of current->comm[] and to avoid breaking any existing code, replace memcpy() with copy_task_comm(). This new function makes sure that the copy is NUL terminated. This is crucial given that the source buffer might be larger than the destination buffer and could truncate the NUL character out of it. Signed-off-by: Andr=C3=A9 Almeida --- Changes from v3: - Bring back custom function. Changes from v2: - New patch, dropped strtostr() from last version --- include/linux/coredump.h | 2 +- include/linux/sched.h | 17 +++++++++++++++++ include/linux/tracepoint.h | 4 ++-- include/trace/events/block.h | 10 +++++----- include/trace/events/coredump.h | 2 +- include/trace/events/f2fs.h | 4 ++-- include/trace/events/oom.h | 2 +- include/trace/events/osnoise.h | 2 +- include/trace/events/sched.h | 10 +++++----- include/trace/events/signal.h | 2 +- include/trace/events/task.h | 7 ++++--- kernel/printk/nbcon.c | 2 +- kernel/printk/printk.c | 2 +- 13 files changed, 42 insertions(+), 24 deletions(-) diff --git a/include/linux/coredump.h b/include/linux/coredump.h index 68861da4cf7c..461254cd9ccc 100644 --- a/include/linux/coredump.h +++ b/include/linux/coredump.h @@ -54,7 +54,7 @@ extern void vfs_coredump(const kernel_siginfo_t *siginfo); do { \ char comm[TASK_COMM_LEN]; \ /* This will always be NUL terminated. */ \ - memcpy(comm, current->comm, sizeof(comm)); \ + copy_task_comm(comm, current, sizeof(comm)); \ printk_ratelimited(Level "coredump: %d(%*pE): " Format "\n", \ task_tgid_vnr(current), (int)strlen(comm), comm, ##__VA_ARGS__); \ } while (0) \ diff --git a/include/linux/sched.h b/include/linux/sched.h index b6de742b1155..6b9408128fef 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2000,6 +2000,23 @@ extern void __set_task_comm(struct task_struct *tsk,= const char *from, bool exec __set_task_comm(tsk, from, false); \ }) =20 +/* + * Copy task name to a buffer. Final result is always a NUL-terminated str= ing. + */ +#define copy_task_comm(dst, tsk, len) \ +{ \ + const char *_src =3D (tsk)->comm; \ + size_t _dst_len =3D len + __must_be_array(dst), _src_len =3D sizeof(_src)= ; \ + char *_dst =3D dst; \ + \ + if (_dst_len <=3D _src_len) { \ + memcpy(_dst, _src, _dst_len); \ + dst[_dst_len - 1] =3D '\0'; \ + } else { \ + strscpy_pad(_dst, _src, _dst_len); \ + } \ +} + static __always_inline void scheduler_ipi(void) { /* diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 763eea4d80d8..4bdb34f628a2 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -615,10 +615,10 @@ static inline struct tracepoint *tracepoint_ptr_deref= (tracepoint_ptr_t *p) * * * * TP_fast_assign( - * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); + * copy_task_comm(__entry->next_comm, next, TASK_COMM_LEN); * __entry->prev_pid =3D prev->pid; * __entry->prev_prio =3D prev->prio; - * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); + * copy_task_comm(__entry->prev_comm, prev, TASK_COMM_LEN); * __entry->next_pid =3D next->pid; * __entry->next_prio =3D next->prio; * ), diff --git a/include/trace/events/block.h b/include/trace/events/block.h index 6aa79e2d799c..70d552b9347e 100644 --- a/include/trace/events/block.h +++ b/include/trace/events/block.h @@ -213,7 +213,7 @@ DECLARE_EVENT_CLASS(block_rq, =20 blk_fill_rwbs(__entry->rwbs, rq->cmd_flags); __get_str(cmd)[0] =3D '\0'; - memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, current, TASK_COMM_LEN); ), =20 TP_printk("%d,%d %s %u (%s) %llu + %u %s,%u,%u [%s]", @@ -351,7 +351,7 @@ DECLARE_EVENT_CLASS(block_bio, __entry->sector =3D bio->bi_iter.bi_sector; __entry->nr_sector =3D bio_sectors(bio); blk_fill_rwbs(__entry->rwbs, bio->bi_opf); - memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, current, TASK_COMM_LEN); ), =20 TP_printk("%d,%d %s %llu + %u [%s]", @@ -434,7 +434,7 @@ TRACE_EVENT(block_plug, ), =20 TP_fast_assign( - memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, current, TASK_COMM_LEN); ), =20 TP_printk("[%s]", __entry->comm) @@ -453,7 +453,7 @@ DECLARE_EVENT_CLASS(block_unplug, =20 TP_fast_assign( __entry->nr_rq =3D depth; - memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, current, TASK_COMM_LEN); ), =20 TP_printk("[%s] %d", __entry->comm, __entry->nr_rq) @@ -504,7 +504,7 @@ TRACE_EVENT(block_split, __entry->sector =3D bio->bi_iter.bi_sector; __entry->new_sector =3D new_sector; blk_fill_rwbs(__entry->rwbs, bio->bi_opf); - memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, current, TASK_COMM_LEN); ), =20 TP_printk("%d,%d %s %llu / %llu [%s]", diff --git a/include/trace/events/coredump.h b/include/trace/events/coredum= p.h index c7b9c53fc498..fdd20bc46bb0 100644 --- a/include/trace/events/coredump.h +++ b/include/trace/events/coredump.h @@ -32,7 +32,7 @@ TRACE_EVENT(coredump, =20 TP_fast_assign( __entry->sig =3D sig; - memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, current, TASK_COMM_LEN); ), =20 TP_printk("sig=3D%d comm=3D%s", diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h index b5188d2671d7..b02f6ccb6c3d 100644 --- a/include/trace/events/f2fs.h +++ b/include/trace/events/f2fs.h @@ -2505,7 +2505,7 @@ TRACE_EVENT(f2fs_lock_elapsed_time, =20 TP_fast_assign( __entry->dev =3D sbi->sb->s_dev; - memcpy(__entry->comm, p->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, p, TASK_COMM_LEN); __entry->pid =3D p->pid; __entry->prio =3D p->prio; __entry->ioprio_class =3D IOPRIO_PRIO_CLASS(ioprio); @@ -2558,7 +2558,7 @@ DECLARE_EVENT_CLASS(f2fs_priority_update, =20 TP_fast_assign( __entry->dev =3D sbi->sb->s_dev; - memcpy(__entry->comm, p->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, p, TASK_COMM_LEN); __entry->pid =3D p->pid; __entry->lock_name =3D lock_name; __entry->is_write =3D is_write; diff --git a/include/trace/events/oom.h b/include/trace/events/oom.h index 9f0a5d1482c4..8bcdc4ffc8d3 100644 --- a/include/trace/events/oom.h +++ b/include/trace/events/oom.h @@ -23,7 +23,7 @@ TRACE_EVENT(oom_score_adj_update, =20 TP_fast_assign( __entry->pid =3D task->pid; - memcpy(__entry->comm, task->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, task, TASK_COMM_LEN); __entry->oom_score_adj =3D task->signal->oom_score_adj; ), =20 diff --git a/include/trace/events/osnoise.h b/include/trace/events/osnoise.h index 3f4273623801..2cf047bb9fb7 100644 --- a/include/trace/events/osnoise.h +++ b/include/trace/events/osnoise.h @@ -116,7 +116,7 @@ TRACE_EVENT(thread_noise, ), =20 TP_fast_assign( - memcpy(__entry->comm, t->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, t, TASK_COMM_LEN); __entry->pid =3D t->pid; __entry->start =3D start; __entry->duration =3D duration; diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 535860581f15..afb24e9dac91 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -152,7 +152,7 @@ DECLARE_EVENT_CLASS(sched_wakeup_template, ), =20 TP_fast_assign( - memcpy(__entry->comm, p->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, p, TASK_COMM_LEN); __entry->pid =3D p->pid; __entry->prio =3D p->prio; /* XXX SCHED_DEADLINE */ __entry->target_cpu =3D task_cpu(p); @@ -237,11 +237,11 @@ TRACE_EVENT(sched_switch, ), =20 TP_fast_assign( - memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); + copy_task_comm(__entry->prev_comm, prev, TASK_COMM_LEN); __entry->prev_pid =3D prev->pid; __entry->prev_prio =3D prev->prio; __entry->prev_state =3D __trace_sched_switch_state(preempt, prev_state, = prev); - memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); + copy_task_comm(__entry->next_comm, next, TASK_COMM_LEN); __entry->next_pid =3D next->pid; __entry->next_prio =3D next->prio; /* XXX SCHED_DEADLINE */ @@ -346,7 +346,7 @@ TRACE_EVENT(sched_process_exit, ), =20 TP_fast_assign( - memcpy(__entry->comm, p->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, p, TASK_COMM_LEN); __entry->pid =3D p->pid; __entry->prio =3D p->prio; /* XXX SCHED_DEADLINE */ __entry->group_dead =3D group_dead; @@ -787,7 +787,7 @@ TRACE_EVENT(sched_skip_cpuset_numa, ), =20 TP_fast_assign( - memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, tsk, TASK_COMM_LEN); __entry->pid =3D task_pid_nr(tsk); __entry->tgid =3D task_tgid_nr(tsk); __entry->ngid =3D task_numa_group_id(tsk); diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h index 1db7e4b07c01..8fffe6d9bdcc 100644 --- a/include/trace/events/signal.h +++ b/include/trace/events/signal.h @@ -67,7 +67,7 @@ TRACE_EVENT(signal_generate, TP_fast_assign( __entry->sig =3D sig; TP_STORE_SIGINFO(__entry, info); - memcpy(__entry->comm, task->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, task, TASK_COMM_LEN); __entry->pid =3D task->pid; __entry->group =3D group; __entry->result =3D result; diff --git a/include/trace/events/task.h b/include/trace/events/task.h index b9a129eb54d9..62b7df4d22d0 100644 --- a/include/trace/events/task.h +++ b/include/trace/events/task.h @@ -21,7 +21,7 @@ TRACE_EVENT(task_newtask, =20 TP_fast_assign( __entry->pid =3D task->pid; - memcpy(__entry->comm, task->comm, TASK_COMM_LEN); + copy_task_comm(__entry->comm, task, TASK_COMM_LEN); __entry->clone_flags =3D clone_flags; __entry->oom_score_adj =3D task->signal->oom_score_adj; ), @@ -46,8 +46,9 @@ TRACE_EVENT(task_rename, =20 TP_fast_assign( __entry->pid =3D task->pid; - memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN); - strscpy(entry->newcomm, comm, TASK_COMM_LEN); + copy_task_comm(entry->oldcomm, task, TASK_COMM_LEN); + memcpy(entry->newcomm, comm, TASK_COMM_LEN); + entry->newcomm[TASK_COMM_LEN - 1] =3D '\0'; __entry->oom_score_adj =3D task->signal->oom_score_adj; ), =20 diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c index d7044a7a214b..6286286ac2bb 100644 --- a/kernel/printk/nbcon.c +++ b/kernel/printk/nbcon.c @@ -952,7 +952,7 @@ static void wctxt_load_execution_ctx(struct nbcon_write= _context *wctxt, { wctxt->cpu =3D pmsg->cpu; wctxt->pid =3D pmsg->pid; - memcpy(wctxt->comm, pmsg->comm, sizeof(wctxt->comm)); + copy_task_comm(wctxt->comm, pmsg, sizeof(wctxt->comm)); static_assert(sizeof(wctxt->comm) =3D=3D sizeof(pmsg->comm)); } #else diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 1f04e753ca02..58d58d024cc2 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2255,7 +2255,7 @@ static void pmsg_load_execution_ctx(struct printk_mes= sage *pmsg, { pmsg->cpu =3D printk_info_get_cpu(info); pmsg->pid =3D printk_info_get_pid(info); - memcpy(pmsg->comm, info->comm, sizeof(pmsg->comm)); + copy_task_comm(pmsg->comm, info, sizeof(pmsg->comm)); static_assert(sizeof(pmsg->comm) =3D=3D sizeof(info->comm)); } #else --=20 2.54.0 From nobody Sun Jun 14 02:10:20 2026 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5DB143AEB2B; Fri, 12 Jun 2026 16:21:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281262; cv=none; b=eDPQSeENbWKepwgAqa59DffQVBwpfiMyXW8z0kMJWF+KZSVfr1XlsfdbEAIriJ0ar0jbaNRlyZ76aMuupI7mGkMK/d7BjjZ52aC5D0T8Ch4Abs9Ldcr/4N3wcN+yrRxNocB+tt5Wepaulk7cM+6CipJEw3wixoecTLO1mysV/XQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281262; c=relaxed/simple; bh=nE7bnB+P/1MOARpZFIOLH/P2JFIQbq7M9pctlGrvCV0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=k+VYYlglI5UxruKFi6cubjlp0xJAWzz0Q6/0wLAHH1AMMNpcO78DXKDs7XHnfUn0unGmCm1zsacoEjkXnR42mLDv4V6ww9VP+mX6BuNuG+q4MzjPuKYYqocxUE2CVuhBTc402eyBJpZOH3LjLOvpHijBI6u2xuvvLCkbg3Rl1bY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=TfMOnipb; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="TfMOnipb" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=VSSjA1e2ihuYKKvGbBvJZXau5qhO8MXM5c+dt4k1Oiw=; b=TfMOnipbCra0jF35oiuYAIqHpy p3uA4YddgEQ5DegPf9CIbAKUYUM5EhCsX6+0EhUHola45xVsdavV+j/SbuzzfRYVBIczV42RpVMMl b8Ifa2UbayeeGCtqbCB0Xq1V5bvF2XMz6HP7+RssAb0diXIyluYS54UspI3bIXqKUKRz5e/fM1DBl 5MQB+pJqjbGUUYYlHcKQPPJQnMIkD5SpbK/FcA+QaD7JagxMMD3AB2V78cmKWC3WqvI+X+Wmn2j4C JmEsWq1EFIU3cw4BBERtTjd1+kNT+Ji5h0pYC4ncTizHYR041zOjXwfyn/Dg8cuRLhSVbMz/Akk/K 92cT2O9Q==; Received: from [189.78.222.70] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wY4cq-00GgP4-OX; Fri, 12 Jun 2026 18:20:56 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Fri, 12 Jun 2026 13:20:17 -0300 Subject: [PATCH v3 4/7] lib/string_kunit: Add test for copy_task_comm() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260612-tonyk-long_name-v3-4-7989b66e8a99@igalia.com> References: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> In-Reply-To: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> To: Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, David Laight , Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.15.2 Add a new test for copy_task_comm(). Check if a copy from a task_struct works, and special cases when the size of source and destination buffer mismatches. Signed-off-by: Andr=C3=A9 Almeida --- lib/tests/string_kunit.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/lib/tests/string_kunit.c b/lib/tests/string_kunit.c index 0819ace5b027..b64d7f0e54a3 100644 --- a/lib/tests/string_kunit.c +++ b/lib/tests/string_kunit.c @@ -881,6 +881,43 @@ static void string_bench_strrchr(struct kunit *test) STRING_BENCH_BUF(test, buf, len, strrchr, buf, '\0'); } =20 +#define TASK_NAME "task_name" +#define TASK_NAME_LEN 9 +#define TASK_MAX_LEN TASK_COMM_LEN +#define SMALLER_LEN TASK_NAME_LEN - 3 +#define BIGGER_LEN TASK_MAX_LEN + 3 + +static void string_copy_task_comm(struct kunit *test) +{ + char str[TASK_MAX_LEN] =3D TASK_NAME, copy[TASK_MAX_LEN], + smaller_buf[SMALLER_LEN], bigger_buf[BIGGER_LEN]; + static struct task_struct task, *tsk =3D &task; + int len1, len2, i; + + /* set and get task name */ + set_task_comm(tsk, str); + copy_task_comm(copy, tsk, TASK_COMM_LEN); + + len1 =3D strlen(str); + len2 =3D strlen(copy); + + KUNIT_ASSERT_EQ(test, len1, len2); + KUNIT_ASSERT_EQ(test, len2, TASK_NAME_LEN); + KUNIT_ASSERT_EQ(test, copy[len2], '\0'); + KUNIT_ASSERT_TRUE(test, !strcmp(str, copy)); + + /* copy to a smaller dst buffer */ + copy_task_comm(smaller_buf, tsk, sizeof(smaller_buf)); + KUNIT_ASSERT_TRUE(test, !strncmp(str, smaller_buf, SMALLER_LEN - 1)); + KUNIT_ASSERT_EQ(test, smaller_buf[SMALLER_LEN - 1], '\0'); + + /* copy to a bigger dst buffer */ + copy_task_comm(bigger_buf, tsk, sizeof(bigger_buf)); + KUNIT_ASSERT_TRUE(test, !strncmp(str, bigger_buf, TASK_NAME_LEN)); + for (i =3D TASK_NAME_LEN; i < BIGGER_LEN; i++) + KUNIT_ASSERT_EQ(test, bigger_buf[i], '\0'); +} + static struct kunit_case string_test_cases[] =3D { KUNIT_CASE(string_test_memset16), KUNIT_CASE(string_test_memset32), @@ -910,6 +947,7 @@ static struct kunit_case string_test_cases[] =3D { KUNIT_CASE(string_bench_strnlen), KUNIT_CASE(string_bench_strchr), KUNIT_CASE(string_bench_strrchr), + KUNIT_CASE(string_copy_task_comm), {} }; =20 --=20 2.54.0 From nobody Sun Jun 14 02:10:20 2026 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CB09D384CEE; Fri, 12 Jun 2026 16:21:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281272; cv=none; b=POq/eHuFO84on47LVa4PgwLmj9L5O4p6yHP2V2K9Je1aQT+o8oGSgYlIjMAUJbpbdFGYVdkzbKJ722IjT3y0vUVvjSFIDrPWnOrSs/HqIplRUsrorcgfJb4O5XE5SaJtl+aL34yQlM/MzW8Xs3xLKCJWFR4g5Qp1U3Uz/1MXbt0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281272; c=relaxed/simple; bh=S6/kJgcdRBdlBUY1QKlod6jYsy5ehFxr72LylAL3tHw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=aV+YwHUkOvW+atWst3dFeL9r+BenkT5m7IPyt3+YaDLy46nbcwoAMVHSqyRdJIGJGgb2hNFGKcjtYa8mlODMSEa2+s4i7QV3rpQb6vafqTMbUiRZMelYrDe0JFQvxv2sQV3zLFl2aYUxIK57UwPmh5oHRFTI73kJtPK/Oalfnvg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=b+FGMirv; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="b+FGMirv" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=2P29qc+6UPDY7W0A1wdk8G93G2x2BCG+qxADi0fmd1k=; b=b+FGMirvnScizBjA5g1/q6jNlK lU74NYQq6p4zvp57oHXMebImcwOfBpVNfBGiTCEEQPY4naav1k8rPeVGz43k1sXGo6KlV37f6Fpc6 R1CByTE7g+iIi6Ui3rpYGpKgXYm9UaUOIt8pq58mFshwXaK+mUxTV0gqBSj3Zf3sjVFAvVAOTtUeP CPQbu5//AKReZ6hA4jHBCQj90QbHonkcwHa2U41uC7AACCU0ODAggKpKzy4dxZmmtmZUziXkNqUyr SMz6anwcmdP1SW6Z9IpuB5qh+cJkTpzCVhq+NxWNhW9QnLHoI/H3bxPl1ezwFxsT1dziMhPEYHZuP sKyqfIeQ==; Received: from [189.78.222.70] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wY4cw-00GgP4-3P; Fri, 12 Jun 2026 18:21:02 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Fri, 12 Jun 2026 13:20:18 -0300 Subject: [PATCH v3 5/7] sched: Extend task command name with TASK_COMM_EXT_LEN Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260612-tonyk-long_name-v3-5-7989b66e8a99@igalia.com> References: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> In-Reply-To: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> To: Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, David Laight , Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.15.2 Command name has been restrict to only 16 bytes, which is too limiting, specially when debugging and tracing complex software with thousands of threads and the need to differentiate them. Just as it was done with kthreads in commit 6b59808bfe48 ("workqueue: Show the latest workqueue name in /proc/PID/{comm,stat,status}"), support long names for userspace threads as well. To avoid buffer overflows, cap all existing userspace APIs to TASK_COMM_LEN, and leave the full extended name for a new interface. Signed-off-by: Andr=C3=A9 Almeida --- fs/proc/array.c | 2 +- include/linux/sched.h | 3 ++- kernel/sys.c | 10 +++++----- lib/tests/string_kunit.c | 2 +- 4 files changed, 9 insertions(+), 8 deletions(-) diff --git a/fs/proc/array.c b/fs/proc/array.c index c8c3fbd9bfa9..312371eddc7f 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -110,7 +110,7 @@ void proc_task_name(struct seq_file *m, struct task_str= uct *p, bool escape) else if (p->flags & PF_KTHREAD) get_kthread_comm(tcomm, sizeof(tcomm), p); else - strscpy_pad(tcomm, p->comm); + strscpy_pad(tcomm, p->comm, TASK_COMM_LEN); =20 if (escape) seq_escape_str(m, tcomm, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\"); diff --git a/include/linux/sched.h b/include/linux/sched.h index 6b9408128fef..a5dc0f4e7975 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -323,6 +323,7 @@ struct user_event_mm; */ enum { TASK_COMM_LEN =3D 16, + TASK_COMM_EXT_LEN =3D 64, }; =20 extern void sched_tick(void); @@ -1167,7 +1168,7 @@ struct task_struct { * - set it with set_task_comm() to ensure it is always * NUL-terminated and zero-padded */ - char comm[TASK_COMM_LEN]; + char comm[TASK_COMM_EXT_LEN]; =20 struct nameidata *nameidata; =20 diff --git a/kernel/sys.c b/kernel/sys.c index 1d5152d2395e..76d77218ab19 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2535,7 +2535,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, ar= g2, unsigned long, arg3, unsigned long, arg4, unsigned long, arg5) { struct task_struct *me =3D current; - unsigned char comm[sizeof(me->comm)]; + unsigned char comm[TASK_COMM_LEN]; long error; =20 error =3D security_task_prctl(option, arg2, arg3, arg4, arg5); @@ -2601,16 +2601,16 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, = arg2, unsigned long, arg3, error =3D -EINVAL; break; case PR_SET_NAME: - comm[sizeof(me->comm) - 1] =3D 0; + comm[TASK_COMM_LEN - 1] =3D 0; if (strncpy_from_user(comm, (char __user *)arg2, - sizeof(me->comm) - 1) < 0) + TASK_COMM_LEN - 1) < 0) return -EFAULT; set_task_comm(me, comm); proc_comm_connector(me); break; case PR_GET_NAME: - strscpy_pad(comm, me->comm); - if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) + strscpy_pad(comm, me->comm, TASK_COMM_LEN); + if (copy_to_user((char __user *)arg2, comm, TASK_COMM_LEN)) return -EFAULT; break; case PR_GET_ENDIAN: diff --git a/lib/tests/string_kunit.c b/lib/tests/string_kunit.c index b64d7f0e54a3..5d26029d2d01 100644 --- a/lib/tests/string_kunit.c +++ b/lib/tests/string_kunit.c @@ -883,7 +883,7 @@ static void string_bench_strrchr(struct kunit *test) =20 #define TASK_NAME "task_name" #define TASK_NAME_LEN 9 -#define TASK_MAX_LEN TASK_COMM_LEN +#define TASK_MAX_LEN TASK_COMM_EXT_LEN #define SMALLER_LEN TASK_NAME_LEN - 3 #define BIGGER_LEN TASK_MAX_LEN + 3 =20 --=20 2.54.0 From nobody Sun Jun 14 02:10:20 2026 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E62AE29D270; Fri, 12 Jun 2026 16:21:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281272; cv=none; b=qKL1Urxrbz4fmG2gInAOMhQxiHWjiAA7X+j0knszx6vml5MqzKRtFSVvo4b75wfTF2MqlsWRhWjhiEivYWIEpqs07+Nn9hX/dWKOHWZsjUekuEOgZnUDkhx9hVRv7h9Wl6S5/L3gYlxFDEoZf/bLrFmUloudqNSVFWFmQ/auDZ0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281272; c=relaxed/simple; bh=+v7sbVYDGSUf0BVLWGMMLNg0OmezUrfSrXgMZfVI7nc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qLPsWZZAzOlhDBRxvl0wijJzDSK5QPBTVlp3qOLG560qGmU7A107jglcItp6EKqS7RIs+9INq3ILkRF2IdBcDZ3oX63jBThpTmSvvoBSHUYMbaNWreMsOcBPe9Xkk4U4Ek6heGRQ0I972+/aBy6/mRHuJ65LSAt2fQ0RmFllp9M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=lH7OBkoF; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="lH7OBkoF" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=RCddDmgd7eKFHxOU+gGkLiMWpKP/CXyHYadGUBnbgDc=; b=lH7OBkoFezBTIbiZ4lBQYtBZZG VDG6Vt4vZv0nBOXZHUh9ccIW7afgI/OCu5JfZ04fAx6WmoURNjBzHH2dTqliAp+Z6ndbbSqIVR560 2oZXxn4j3dQjOBsHryau9UGU9ULniy9GSueDDdLcIvEet1A5urdQame+fE2SGuFGATDU6QLNeo59k aV9BvLLrfCFxQSW7z8AJYxO0KLnR+zYUmah5SewUU4DCj+/WEQoFAHIu16hzXH9iJ9DuLS40Y9F6c epnyGajFpAQJLU0KR4LZTCd7+1EDOR/sbMtxcPeRPUAMkBq2OW7b/F+fafoK8+4nFMUJjxvFFqSLg Y/gWD9Jg==; Received: from [189.78.222.70] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wY4d1-00GgP4-E2; Fri, 12 Jun 2026 18:21:07 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Fri, 12 Jun 2026 13:20:19 -0300 Subject: [PATCH v3 6/7] prctl: Add support for long user thread names Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260612-tonyk-long_name-v3-6-7989b66e8a99@igalia.com> References: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> In-Reply-To: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> To: Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, David Laight , Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.15.2 Add support for getting and setting long user thread names with PR_{SET,GET}_EXT_NAME. Signed-off-by: Andr=C3=A9 Almeida --- include/linux/sched.h | 2 +- include/uapi/linux/prctl.h | 3 +++ kernel/sys.c | 15 ++++++++++++++- 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index a5dc0f4e7975..5e167023fb81 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1997,7 +1997,7 @@ extern void kick_process(struct task_struct *tsk); =20 extern void __set_task_comm(struct task_struct *tsk, const char *from, boo= l exec); #define set_task_comm(tsk, from) ({ \ - BUILD_BUG_ON(sizeof(from) !=3D TASK_COMM_LEN); \ + BUILD_BUG_ON(sizeof(from) < TASK_COMM_LEN); \ __set_task_comm(tsk, from, false); \ }) =20 diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index b6ec6f693719..a07f8edadd65 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -56,6 +56,9 @@ #define PR_SET_NAME 15 /* Set process name */ #define PR_GET_NAME 16 /* Get process name */ =20 +#define PR_SET_EXT_NAME 17 /* Set extended process name */ +#define PR_GET_EXT_NAME 18 /* Get extended process name */ + /* Get/set process endian */ #define PR_GET_ENDIAN 19 #define PR_SET_ENDIAN 20 diff --git a/kernel/sys.c b/kernel/sys.c index 76d77218ab19..1b70d53da998 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2535,7 +2535,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, ar= g2, unsigned long, arg3, unsigned long, arg4, unsigned long, arg5) { struct task_struct *me =3D current; - unsigned char comm[TASK_COMM_LEN]; + unsigned char comm[TASK_COMM_EXT_LEN]; long error; =20 error =3D security_task_prctl(option, arg2, arg3, arg4, arg5); @@ -2613,6 +2613,19 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, a= rg2, unsigned long, arg3, if (copy_to_user((char __user *)arg2, comm, TASK_COMM_LEN)) return -EFAULT; break; + case PR_SET_EXT_NAME: + comm[TASK_COMM_EXT_LEN - 1] =3D 0; + if (strncpy_from_user(comm, (char __user *)arg2, + TASK_COMM_EXT_LEN - 1) < 0) + return -EFAULT; + set_task_comm(me, comm); + proc_comm_connector(me); + break; + case PR_GET_EXT_NAME: + strscpy_pad(comm, me->comm, TASK_COMM_EXT_LEN); + if (copy_to_user((char __user *)arg2, comm, TASK_COMM_EXT_LEN)) + return -EFAULT; + break; case PR_GET_ENDIAN: error =3D GET_ENDIAN(me, arg2); break; --=20 2.54.0 From nobody Sun Jun 14 02:10:20 2026 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F3F52F1FD0; Fri, 12 Jun 2026 16:21:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281279; cv=none; b=tZQf/O2EsDBu7Lou/FMJSUDYhAqzYqn91G/7EWn2gFSD89kXPYvCs9/hvMZ8EgOoS4s4Xm0Xe6mIakeSRwa0s/KDs4pEhPF/GVLEs9SQL5ku+pJ6ELqxZsQMwGtZj1QiXFPMorOvBvuOiq0ADA2fsUVefww9LMTpH2I3OJrq8uQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781281279; c=relaxed/simple; bh=DQGECCu54qCFjAJEEwdPLsPC8heYQxz75RhXI6ITvYw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=g8EvyD+b3Eo0REJRNucFkYHmgq7fjjpKxbDKTwl5jVA6Qjr2mE8JKK1puZuOHyW3qto1qYSj6v8ZYju2JvoYNulN/9TxD0venBDhknUNWoS9Q92a0aHppfttxN0qrLfba9UmZ69zkh8WpD2fEJmMPKILgy9EKg0qsKpsH9t6MjQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=nxgcXRoK; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="nxgcXRoK" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:In-Reply-To:References:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=EOUkvSr2Gn8JmW0nio1LgmkdjEeAiY0SGNTncIeyo40=; b=nxgcXRoKu7qdZklZlsuvOJA97/ vcAYycAQ9Kv5wgl5ZvuXa5vUEdh1TjK913+ngRL4O5K7pha3ONAivVIksQN96WElQHilWBKq+vCdv K3syL2vPfWrnVAd7LQeZiTxo2H1X1W0u0Md6dr8khOuNootnwrf+SlFbjn80mfvqCS5LQTWO00VdS TB+KR6pJSa3oM8WjogsUh77JrsbalxJQNAllBAF6/fNGbxEI1JWF1/nF/prqCXcgvspbwhRMXeWcJ /R4aIBFNgajVvQVS5aj1omhnClCSfC61i29LyBlEP9EFDn8hZvHEjEgR543H7kM9FtHJrFhSTOHPx sPBG5Aqw==; Received: from [189.78.222.70] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wY4d6-00GgP4-Ow; Fri, 12 Jun 2026 18:21:12 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Fri, 12 Jun 2026 13:20:20 -0300 Subject: [PATCH v3 7/7] selftests: prctl: Add test for long thread names Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260612-tonyk-long_name-v3-7-7989b66e8a99@igalia.com> References: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> In-Reply-To: <20260612-tonyk-long_name-v3-0-7989b66e8a99@igalia.com> To: Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, David Laight , Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.15.2 Add tests for the new interface to set and get long thread names. The kernel should accept the LONG_NAME and returning it accordingly. For the old PR_GET_NAME interface, the kernel should truncate the name up to 16 chars. /proc//comm should return the same string ad PR_GET_NAME. Signed-off-by: Andr=C3=A9 Almeida --- tools/testing/selftests/prctl/set-process-name.c | 36 ++++++++++++++++++++= ++++ 1 file changed, 36 insertions(+) diff --git a/tools/testing/selftests/prctl/set-process-name.c b/tools/testi= ng/selftests/prctl/set-process-name.c index 3f7b146d36df..0f20f7deac67 100644 --- a/tools/testing/selftests/prctl/set-process-name.c +++ b/tools/testing/selftests/prctl/set-process-name.c @@ -9,9 +9,17 @@ =20 #include "kselftest_harness.h" =20 +#ifndef PR_SET_EXT_NAME +# define PR_SET_EXT_NAME 17 +# define PR_GET_EXT_NAME 18 +#endif + #define CHANGE_NAME "changename" +#define LONG_NAME "change_to_very_long_extended_name" +#define LONG_NAME_CAP "change_to_very_" #define EMPTY_NAME "" #define TASK_COMM_LEN 16 +#define TASK_COMM_EXT_LEN 64 #define MAX_PATH_LEN 50 =20 int set_name(char *name) @@ -25,6 +33,16 @@ int set_name(char *name) return res; } =20 +int set_ext_name(char *name) +{ + int res; + + res =3D prctl(PR_SET_EXT_NAME, name, NULL, NULL, NULL); + + if (res < 0) + return -errno; +} + int check_is_name_correct(char *check_name) { char name[TASK_COMM_LEN]; @@ -38,6 +56,19 @@ int check_is_name_correct(char *check_name) return !strcmp(name, check_name); } =20 +int check_is_ext_name_correct(char *check_name) +{ + char name[TASK_COMM_EXT_LEN]; + int res; + + res =3D prctl(PR_GET_EXT_NAME, name, NULL, NULL, NULL); + + if (res < 0) + return -errno; + + return !strcmp(name, check_name); +} + int check_null_pointer(char *check_name) { char *name =3D NULL; @@ -82,6 +113,11 @@ TEST(rename_process) { EXPECT_GE(set_name(CHANGE_NAME), 0); EXPECT_TRUE(check_is_name_correct(CHANGE_NAME)); =20 + EXPECT_GE(set_ext_name(LONG_NAME), 0); + EXPECT_TRUE(check_is_ext_name_correct(LONG_NAME)); + EXPECT_TRUE(check_is_name_correct(LONG_NAME_CAP)); + EXPECT_TRUE(check_name()); + EXPECT_GE(set_name(EMPTY_NAME), 0); EXPECT_TRUE(check_is_name_correct(EMPTY_NAME)); =20 --=20 2.54.0