* [PATCH v7 0/4] Add support for long task name
@ 2025-08-11 6:46 Bhupesh
2025-08-11 6:46 ` [PATCH v7 1/4] exec: Remove obsolete comments Bhupesh
` (3 more replies)
0 siblings, 4 replies; 16+ messages in thread
From: Bhupesh @ 2025-08-11 6:46 UTC (permalink / raw)
To: akpm
Cc: bhupesh, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
Changes since v6:
================
- v6 can be seen here: https://lore.kernel.org/all/20250724123612.206110-1-bhupesh@igalia.com/
- As suggested by Linus, we got rid of 'get_task_comm()' entirely and replaced it with
'strscpy_pad()' implementation.
- Also changed the current memcpy() use-cases which use 'current->comm' to copy the task name over
to local copies, to call a wrappper like "get_task_array()".
- Collected 'Reviewed-by' from Kees for [PATCH 1/4].
Changes since v5:
================
- v5 can be seen here: https://lore.kernel.org/lkml/20250716123916.511889-1-bhupesh@igalia.com/
- As suggested by Linus, replaced 'tsk->comm' with 'tsk->comm_str' locally, and verified basic
thread names and then changed 'tsk->comm_str' back to 'tsk->comm'. So essentially now 'tsk->comm'
is TASK_COMM_EXT_LEN i.e. 64-bytes long.
Changes since v4:
================
- v4 can be seen here: https://lore.kernel.org/lkml/20250521062337.53262-1-bhupesh@igalia.com/
- As suggested by Kees, replaced tsk->comm with tsk->comm_str, inside 'task_struct'
where TASK_COMM_EXT_LEN is 64-bytes.
Changes since v3:
================
- v3 can be seen here: https://lore.kernel.org/lkml/20250507110444.963779-1-bhupesh@igalia.com/
- As suggested by Petr and Steven, used 'comm_ext' name instead of
'real_comm'. Correspondingly the macro name is changed to 'TASK_COMM_EXT_LEN'
for the 64-byte extended comm.
- Rebased this patchset on linux-next/master, which contain the following patch from
Steven now:
155fd6c3e2f0 ("tracing/sched: Use __string() instead of fixed lengths for task->comm")
- Accordingly, v4 drops the changes done for 'trace/sched' events in v3,
but retains the 'safe' memcpy' changes for other kernel trace users.
Changes since v2:
================
- v2 can be seen here: https://lore.kernel.org/lkml/20250331121820.455916-1-bhupesh@igalia.com/
- As suggested by Yafang and Kees, picked Linus' suggested approach for
this version (see: <https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@mail.gmail.com/>).
- Dropped kthreads patch from this version. It would be sent out
separately, if we have a consensus on this approach.
Changes since v1:
================
- v1 can be seen here: https://lore.kernel.org/lkml/20250314052715.610377-1-bhupesh@igalia.com/
- As suggested by Kees, added [PATCH 3/3] to have a consistent
'full_name' entry inside 'task_struct' which both tasks and
kthreads can use.
- Fixed the commit message to indicate that the existing ABI
'/proc/$pid/task/$tid/comm' remains untouched and a parallel
'/proc/$pid/task/$tid/full_name' ABI for new (interested) users.
While working with user-space debugging tools which work especially
on linux gaming platforms, I found that the task name is truncated due
to the limitation of TASK_COMM_LEN.
Now, during debug tracing, seeing truncated names is not very useful,
especially on gaming platforms where the number of tasks running can
be very high.
This patchset does not touch 'TASK_COMM_LEN' at all, i.e.
'TASK_COMM_LEN' and the 16-byte design remains untouched.
Via this patchset, Linus suggested 'tsk->comm' is made 64-byte long
and equal to TASK_COMM_EXT_LEN.
To avoid any surprises / bug,s I replaced 'tsk->comm' with
'tsk->comm_str' locally inside 'task_struct' and checked compilation
of code and basic working of thread names:
struct task_struct {
..............
char comm_str[TASK_COMM_EXT_LEN];
..............
};
where TASK_COMM_EXT_LEN is 64-bytes.
Once done, I changed the name back to 'tsk->comm'.
To ensure that the existing ABI and userspace continues to work
as intended, we ensure that:
- Existing users of 'get_task_comm'/ 'set_task_comm' will get 'tsk->comm'
truncated to a maximum of 'TASK_COMM_LEN' (16-bytes) to maintain ABI,
- New / Modified users of 'get_task_comm'/ 'set_task_comm' will get
'tsk->comm' supported up to a maximum of 'TASK_COMM_EXT_LEN' (64-bytes).
Note, that the existing users have not been modified to migrate to
'TASK_COMM_EXT_LEN', in case they have hard-coded expectations of
dealing with only a 'TASK_COMM_LEN' long 'tsk->comm_str'.
After this change, gdb is able to show full name of the task, using a
simple app which generates threads with long names [see 1]:
# gdb ./threadnames -ex "run info thread" -ex "detach" -ex "quit" > log
# cat log
NameThatIsTooLongForComm[4662]
[1]. https://github.com/lostgoat/tasknames
Bhupesh (4):
exec: Remove obsolete comments
include: Set tsk->comm length to 64 bytes
treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
treewide: Switch memcpy() users of 'task->comm' to a more safer
implementation
drivers/connector/cn_proc.c | 2 +-
drivers/dma-buf/sw_sync.c | 2 +-
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c | 2 +-
.../drm/amd/amdgpu/amdgpu_eviction_fence.c | 2 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 2 +-
.../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/virtio/virtgpu_ioctl.c | 2 +-
drivers/hwtracing/stm/core.c | 2 +-
drivers/tty/tty_audit.c | 2 +-
fs/bcachefs/thread_with_file.c | 2 +-
fs/binfmt_elf.c | 2 +-
fs/binfmt_elf_fdpic.c | 2 +-
fs/ocfs2/cluster/netdebug.c | 1 -
fs/proc/array.c | 2 +-
include/linux/coredump.h | 2 +-
include/linux/sched.h | 50 ++++++++++++-------
include/linux/tracepoint.h | 4 +-
include/trace/events/block.h | 10 ++--
include/trace/events/oom.h | 2 +-
include/trace/events/osnoise.h | 2 +-
include/trace/events/sched.h | 13 +++--
include/trace/events/signal.h | 2 +-
include/trace/events/task.h | 4 +-
kernel/audit.c | 6 ++-
kernel/auditsc.c | 6 ++-
kernel/sys.c | 2 +-
mm/kmemleak.c | 6 ---
net/bluetooth/hci_sock.c | 2 +-
net/netfilter/nf_tables_api.c | 2 +-
security/integrity/integrity_audit.c | 3 +-
security/ipe/audit.c | 2 +-
security/landlock/domain.c | 2 +-
security/lsm_audit.c | 7 +--
tools/bpf/bpftool/pids.c | 6 +--
.../bpf/test_kmods/bpf_testmod-events.h | 2 +-
40 files changed, 91 insertions(+), 83 deletions(-)
--
2.38.1
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v7 1/4] exec: Remove obsolete comments
2025-08-11 6:46 [PATCH v7 0/4] Add support for long task name Bhupesh
@ 2025-08-11 6:46 ` Bhupesh
2025-08-11 6:46 ` [PATCH v7 2/4] include: Set tsk->comm length to 64 bytes Bhupesh
` (2 subsequent siblings)
3 siblings, 0 replies; 16+ messages in thread
From: Bhupesh @ 2025-08-11 6:46 UTC (permalink / raw)
To: akpm
Cc: bhupesh, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
Patch 3a3f61ce5e0b ("exec: Make sure task->comm is always NUL-terminated"),
replaced 'strscpy_pad()' with 'memcpy()' implementations inside
'__set_task_comm()'.
However a few left-over comments are still there, which mention
the usage of 'strscpy_pad()' inside '__set_task_comm()'.
Remove those obsolete comments.
While at it, also remove an obsolete comment regarding 'task_lock()'
usage while handing 'task->comm'.
Signed-off-by: Bhupesh <bhupesh@igalia.com>
Reviewed-by: Kees Cook <kees@kernel.org>
---
include/linux/sched.h | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2b272382673d..35f1ef06eb6c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1159,10 +1159,8 @@ struct task_struct {
*
* - normally initialized begin_new_exec()
* - set it with set_task_comm()
- * - strscpy_pad() to ensure it is always NUL-terminated and
+ * - logic inside set_task_comm() will ensure it is always NUL-terminated and
* zero-padded
- * - task_lock() to ensure the operation is atomic and the name is
- * fully updated.
*/
char comm[TASK_COMM_LEN];
@@ -1972,7 +1970,7 @@ 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 readers
* 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() should ensure that the task comm is
* always NUL-terminated and zero-padded. Therefore the race condition between
* reader and writer is not an issue.
*
--
2.38.1
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH v7 2/4] include: Set tsk->comm length to 64 bytes
2025-08-11 6:46 [PATCH v7 0/4] Add support for long task name Bhupesh
2025-08-11 6:46 ` [PATCH v7 1/4] exec: Remove obsolete comments Bhupesh
@ 2025-08-11 6:46 ` Bhupesh
2025-08-11 15:10 ` Andy Shevchenko
2025-08-11 6:46 ` [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()' Bhupesh
2025-08-11 6:46 ` [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Bhupesh
3 siblings, 1 reply; 16+ messages in thread
From: Bhupesh @ 2025-08-11 6:46 UTC (permalink / raw)
To: akpm
Cc: bhupesh, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
Historically due to the 16-byte length of TASK_COMM_LEN, the
users of 'tsk->comm' are restricted to use a fixed-size target
buffer also of TASK_COMM_LEN for 'memcpy()' like use-cases.
To fix the same, we now use a 64-byte TASK_COMM_EXT_LEN and
set the comm element inside 'task_struct' to the same length:
struct task_struct {
.....
char comm[TASK_COMM_EXT_LEN];
.....
};
where TASK_COMM_EXT_LEN is 64-bytes.
Note, that the existing users have not been modified to migrate to
'TASK_COMM_EXT_LEN', in case they have hard-coded expectations of
dealing with only a 'TASK_COMM_LEN' long 'tsk->comm'.
Signed-off-by: Bhupesh <bhupesh@igalia.com>
---
include/linux/sched.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 35f1ef06eb6c..87e9dfaf61ac 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -318,6 +318,7 @@ struct user_event_mm;
*/
enum {
TASK_COMM_LEN = 16,
+ TASK_COMM_EXT_LEN = 64,
};
extern void sched_tick(void);
@@ -1162,7 +1163,7 @@ struct task_struct {
* - logic inside set_task_comm() will ensure it is always NUL-terminated and
* zero-padded
*/
- char comm[TASK_COMM_LEN];
+ char comm[TASK_COMM_EXT_LEN];
struct nameidata *nameidata;
@@ -1961,7 +1962,7 @@ extern void kick_process(struct task_struct *tsk);
extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
#define set_task_comm(tsk, from) ({ \
- BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \
+ BUILD_BUG_ON(sizeof(from) < TASK_COMM_LEN); \
__set_task_comm(tsk, from, false); \
})
--
2.38.1
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
2025-08-11 6:46 [PATCH v7 0/4] Add support for long task name Bhupesh
2025-08-11 6:46 ` [PATCH v7 1/4] exec: Remove obsolete comments Bhupesh
2025-08-11 6:46 ` [PATCH v7 2/4] include: Set tsk->comm length to 64 bytes Bhupesh
@ 2025-08-11 6:46 ` Bhupesh
2025-08-11 11:25 ` kernel test robot
` (2 more replies)
2025-08-11 6:46 ` [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Bhupesh
3 siblings, 3 replies; 16+ messages in thread
From: Bhupesh @ 2025-08-11 6:46 UTC (permalink / raw)
To: akpm
Cc: bhupesh, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
As Linus mentioned in [1], we should get rid of 'get_task_comm()'
entirely and replace it with 'strscpy_pad()' implementation.
'strscpy_pad()' will already make sure comm is NUL-terminated, so
we won't need the explicit final byte termination done in
'get_task_comm()'.
The relevant 'get_task_comm()' users were identified using the
following search pattern:
$ git grep 'get_task_comm*'
[1]. https://lore.kernel.org/all/CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com/
Signed-off-by: Bhupesh <bhupesh@igalia.com>
---
drivers/connector/cn_proc.c | 2 +-
drivers/dma-buf/sw_sync.c | 2 +-
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c | 2 +-
.../drm/amd/amdgpu/amdgpu_eviction_fence.c | 2 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 2 +-
.../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/virtio/virtgpu_ioctl.c | 2 +-
drivers/hwtracing/stm/core.c | 2 +-
drivers/tty/tty_audit.c | 2 +-
fs/bcachefs/thread_with_file.c | 2 +-
fs/binfmt_elf.c | 2 +-
fs/binfmt_elf_fdpic.c | 2 +-
fs/ocfs2/cluster/netdebug.c | 1 -
fs/proc/array.c | 2 +-
include/linux/sched.h | 19 -------------------
kernel/audit.c | 6 ++++--
kernel/auditsc.c | 6 ++++--
kernel/sys.c | 2 +-
mm/kmemleak.c | 6 ------
net/bluetooth/hci_sock.c | 2 +-
net/netfilter/nf_tables_api.c | 2 +-
security/integrity/integrity_audit.c | 3 ++-
security/ipe/audit.c | 2 +-
security/landlock/domain.c | 2 +-
security/lsm_audit.c | 7 ++++---
30 files changed, 38 insertions(+), 58 deletions(-)
diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
index 44b19e696176..3c1b07198e10 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 = PROC_EVENT_COMM;
ev->event_data.comm.process_pid = task->pid;
ev->event_data.comm.process_tgid = task->tgid;
- get_task_comm(ev->event_data.comm.comm, task);
+ strscpy_pad(ev->event_data.comm.comm, task->comm);
memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
msg->ack = 0; /* not used */
diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
index 3c20f1d31cf5..1f2ddf00799b 100644
--- a/drivers/dma-buf/sw_sync.c
+++ b/drivers/dma-buf/sw_sync.c
@@ -311,7 +311,7 @@ static int sw_sync_debugfs_open(struct inode *inode, struct file *file)
struct sync_timeline *obj;
char task_comm[TASK_COMM_LEN];
- get_task_comm(task_comm, current);
+ strscpy_pad(task_comm, current->comm);
obj = 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 1ef758ac5076..ea2b99fde425 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
@@ -73,7 +73,7 @@ struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u64 context,
/* This reference gets released in amdkfd_fence_release */
mmgrab(mm);
fence->mm = mm;
- get_task_comm(fence->timeline_name, current);
+ strscpy_pad(fence->timeline_name, current->comm);
spin_lock_init(&fence->lock);
fence->svm_bo = svm_bo;
dma_fence_init(&fence->base, &amdkfd_fence_ops, &fence->lock,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
index 23d7d0b0d625..3e2ad72cafc4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
@@ -166,7 +166,7 @@ amdgpu_eviction_fence_create(struct amdgpu_eviction_fence_mgr *evf_mgr)
return NULL;
ev_fence->evf_mgr = 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 25bade9a5e95..8a4a4c03bbcd 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
@@ -4169,7 +4169,7 @@ int amdgpu_ras_init(struct amdgpu_device *adev)
}
con->init_task_pid = task_pid_nr(current);
- get_task_comm(con->init_task_comm, current);
+ strscpy_pad(con->init_task_comm, current->comm);
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 c2a983ff23c9..73aa37f65e0b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
@@ -92,7 +92,7 @@ int amdgpu_userq_fence_driver_alloc(struct amdgpu_device *adev,
fence_drv->adev = adev;
fence_drv->context = dma_fence_context_alloc(1);
- get_task_comm(fence_drv->timeline_name, current);
+ strscpy_pad(fence_drv->timeline_name, current->comm);
xa_lock_irqsave(&adev->userq_xa, flags);
r = xa_err(__xa_store(&adev->userq_xa, userq->doorbell_index,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 39b4250ede0f..83b5d5f5775c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2516,13 +2516,13 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
return;
vm->task_info->task.pid = current->pid;
- get_task_comm(vm->task_info->task.comm, current);
+ strscpy_pad(vm->task_info->task.comm, current->comm);
if (current->group_leader->mm != current->mm)
return;
vm->task_info->tgid = current->group_leader->pid;
- get_task_comm(vm->task_info->process_name, current->group_leader);
+ strscpy_pad(vm->task_info->process_name, current->group_leader->comm);
}
/**
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 77ce9cf28051..7e2f0d28b7ef 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -598,7 +598,7 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
}
vres->task.pid = 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);
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_ctx.c
index 0e668fc1e0f9..7536288ec93b 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;
ctx->pid = task_pid_nr(current);
- get_task_comm(ctx->pname, current);
+ strscpy_pad(ctx->pname, current->comm);
return 0;
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
index bb73f2a68a12..b6575fc43ee4 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -17,7 +17,7 @@ static void panfrost_gem_debugfs_bo_add(struct panfrost_device *pfdev,
struct panfrost_gem_object *bo)
{
bo->debugfs.creator.tgid = current->group_leader->pid;
- get_task_comm(bo->debugfs.creator.process_name, current->group_leader);
+ strscpy_pad(bo->debugfs.creator.process_name, current->group_leader->comm);
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/panthor/panthor_gem.c
index a123bc740ba1..ba2b80c760c9 100644
--- a/drivers/gpu/drm/panthor/panthor_gem.c
+++ b/drivers/gpu/drm/panthor/panthor_gem.c
@@ -27,7 +27,7 @@ static void panthor_gem_debugfs_bo_add(struct panthor_gem_object *bo)
struct panthor_device, base);
bo->debugfs.creator.tgid = current->group_leader->pid;
- get_task_comm(bo->debugfs.creator.process_name, current->group_leader);
+ strscpy_pad(bo->debugfs.creator.process_name, current->group_leader->comm);
mutex_lock(&ptdev->gems.lock);
list_add_tail(&bo->debugfs.node, &ptdev->gems.node);
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/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 virtio_gpu_device *vgdev,
} else {
char dbgname[TASK_COMM_LEN];
- 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 cdba4e875b28..f07784c8751c 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[] = { comm, "default", NULL };
- get_task_comm(comm, current);
+ strscpy_pad(comm, current->comm);
err = 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 75542333c54a..2724341edda0 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=%u uid=%u auid=%u ses=%u major=%d minor=%d comm=",
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=");
audit_log_n_hex(ab, data, size);
diff --git a/fs/bcachefs/thread_with_file.c b/fs/bcachefs/thread_with_file.c
index c2eae0ab7765..eda1b6b5e3b7 100644
--- a/fs/bcachefs/thread_with_file.c
+++ b/fs/bcachefs/thread_with_file.c
@@ -35,7 +35,7 @@ int bch2_run_thread_with_file(struct thread_with_file *thr,
fd_flags |= O_WRONLY;
char name[TASK_COMM_LEN];
- get_task_comm(name, current);
+ strscpy_pad(name, current->comm);
thr->ret = 0;
thr->task = kthread_create(fn, thr, "%s", name);
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 264fba0d44bd..6ea946656403 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1540,7 +1540,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct 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);
return 0;
}
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 48fd2de3bca0..605d09d3c36f 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1365,7 +1365,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct 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);
return 0;
}
diff --git a/fs/ocfs2/cluster/netdebug.c b/fs/ocfs2/cluster/netdebug.c
index bc27301eab6d..ab94ab55111e 100644
--- a/fs/ocfs2/cluster/netdebug.c
+++ b/fs/ocfs2/cluster/netdebug.c
@@ -122,7 +122,6 @@ static int nst_seq_show(struct seq_file *seq, void *v)
send = ktime_to_us(ktime_sub(now, nst->st_send_time));
status = ktime_to_us(ktime_sub(now, nst->st_status_time));
- /* get_task_comm isn't exported. oh well. */
seq_printf(seq, "%p:\n"
" pid: %lu\n"
" tgid: %lu\n"
diff --git a/fs/proc/array.c b/fs/proc/array.c
index d6a0369caa93..c65a4c2994c2 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -109,7 +109,7 @@ void proc_task_name(struct seq_file *m, struct task_struct *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);
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 87e9dfaf61ac..97ea2ac2a97a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1966,25 +1966,6 @@ extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec
__set_task_comm(tsk, from, false); \
})
-/*
- * - Why not use task_lock()?
- * User space can randomly change their names anyway, so locking for readers
- * 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() should ensure that the task comm is
- * always NUL-terminated and zero-padded. Therefore the race condition between
- * 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 safeguard 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 61b5744d0bb6..64623f186fc6 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1621,7 +1621,8 @@ static void audit_log_multicast(int group, const char *op, int err)
audit_put_tty(tty);
audit_log_task_context(ab); /* subj= */
audit_log_format(ab, " comm=");
- 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= */
audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
audit_log_end(ab);
@@ -2270,7 +2271,8 @@ void audit_log_task_info(struct audit_buffer *ab)
audit_get_sessionid(current));
audit_put_tty(tty);
audit_log_format(ab, " comm=");
- 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 eb98cd6fe91f..67a132114329 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2930,7 +2930,8 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
audit_log_format(ab, " pid=%u", task_tgid_nr(current));
audit_log_task_context(ab); /* subj= */
audit_log_format(ab, " comm=");
- 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);
@@ -2953,7 +2954,8 @@ static void audit_log_task(struct audit_buffer *ab)
sessionid);
audit_log_task_context(ab);
audit_log_format(ab, " pid=%d comm=", 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);
}
diff --git a/kernel/sys.c b/kernel/sys.c
index 0d5d27cb9cbe..cb5cce753e71 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2535,7 +2535,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, 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/mm/kmemleak.c b/mm/kmemleak.c
index 84265983f239..42e67c03cb7d 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -682,12 +682,6 @@ static struct kmemleak_object *__alloc_object(gfp_t gfp)
strscpy(object->comm, "softirq");
} else {
object->pid = current->pid;
- /*
- * There is a small chance of a race with set_task_comm(),
- * however using get_task_comm() here may cause locking
- * dependency issues with current->alloc_lock. In the worst
- * case, the command line is not correct.
- */
strscpy(object->comm, current->comm);
}
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index fc866759910d..759a508024be 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 = 0xffffffff;
hci_pi(sk)->cookie = id;
- get_task_comm(hci_pi(sk)->comm, current);
+ strscpy_pad(hci_pi(sk)->comm, current->comm);
return true;
}
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 13d0ed9d1895..e3a73ca4e9c3 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9658,7 +9658,7 @@ static int nf_tables_fill_gen_info(struct sk_buff *skb, struct net *net,
if (nla_put_be32(skb, NFTA_GEN_ID, htonl(nft_net->base_seq)) ||
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, strscpy_pad(buf, current->comm)))
goto nla_put_failure;
nlmsg_end(skb, nlh);
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index 0ec5e4c22cb2..28c203f0cdb7 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 inode *inode,
audit_get_sessionid(current));
audit_log_task_context(ab);
audit_log_format(ab, " op=%s cause=%s comm=", 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=");
audit_log_untrustedstring(ab, fname);
diff --git a/security/ipe/audit.c b/security/ipe/audit.c
index de5fed62592e..b4318988c65d 100644
--- a/security/ipe/audit.c
+++ b/security/ipe/audit.c
@@ -144,7 +144,7 @@ void ipe_audit_match(const struct ipe_eval_ctx *const ctx,
audit_log_format(ab, "ipe_op=%s ipe_hook=%s enforcing=%d pid=%d comm=",
op, audit_hook_names[ctx->hook], READ_ONCE(enforce),
task_tgid_nr(current));
- audit_log_untrustedstring(ab, get_task_comm(comm, current));
+ audit_log_untrustedstring(ab, strscpy_pad(comm, current->comm));
if (ctx->file) {
audit_log_d_path(ab, " path=", &ctx->file->f_path);
diff --git a/security/landlock/domain.c b/security/landlock/domain.c
index a647b68e8d06..77b678f0f469 100644
--- a/security/landlock/domain.c
+++ b/security/landlock/domain.c
@@ -102,7 +102,7 @@ static struct landlock_details *get_current_details(void)
memcpy(details->exe_path, path_str, path_size);
details->pid = get_pid(task_tgid(current));
details->uid = from_kuid(&init_user_ns, current_uid());
- get_task_comm(details->comm, current);
+ strscpy_pad(details->comm, current->comm);
return details;
}
diff --git a/security/lsm_audit.c b/security/lsm_audit.c
index 7d623b00495c..b4d3b8a69cfe 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=%d ocomm=", 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)];
audit_log_format(ab, " pid=%d comm=", 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);
}
--
2.38.1
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation
2025-08-11 6:46 [PATCH v7 0/4] Add support for long task name Bhupesh
` (2 preceding siblings ...)
2025-08-11 6:46 ` [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()' Bhupesh
@ 2025-08-11 6:46 ` Bhupesh
2025-08-11 15:08 ` Andy Shevchenko
2025-08-11 16:37 ` kernel test robot
3 siblings, 2 replies; 16+ messages in thread
From: Bhupesh @ 2025-08-11 6:46 UTC (permalink / raw)
To: akpm
Cc: bhupesh, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
As Linus mentioned in [1], currently we have several memcpy() use-cases
which use 'current->comm' to copy the task name over to local copies.
For an example:
...
char comm[TASK_COMM_LEN];
memcpy(comm, current->comm, TASK_COMM_LEN);
...
These should be rather calling a wrappper like "get_task_array()",
which is implemented as:
static __always_inline void
__cstr_array_copy(char *dst,
const char *src, __kernel_size_t size)
{
memcpy(dst, src, size);
dst[size] = 0;
}
#define get_task_array(dst,src) \
__cstr_array_copy(dst, src, __must_be_array(dst))
The relevant 'memcpy()' users were identified using the following search
pattern:
$ git grep 'memcpy.*->comm\>'
[1]. https://lore.kernel.org/all/CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com/
Signed-off-by: Bhupesh <bhupesh@igalia.com>
---
include/linux/coredump.h | 2 +-
include/linux/sched.h | 32 +++++++++++++++++++
include/linux/tracepoint.h | 4 +--
include/trace/events/block.h | 10 +++---
include/trace/events/oom.h | 2 +-
include/trace/events/osnoise.h | 2 +-
include/trace/events/sched.h | 13 ++++----
include/trace/events/signal.h | 2 +-
include/trace/events/task.h | 4 +--
tools/bpf/bpftool/pids.c | 6 ++--
.../bpf/test_kmods/bpf_testmod-events.h | 2 +-
11 files changed, 54 insertions(+), 25 deletions(-)
diff --git a/include/linux/coredump.h b/include/linux/coredump.h
index 68861da4cf7c..bcee0afc5eaf 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)); \
+ get_task_array(comm, current->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 97ea2ac2a97a..6602ec132297 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1960,12 +1960,44 @@ extern void wake_up_new_task(struct task_struct *tsk);
extern void kick_process(struct task_struct *tsk);
+/*
+ * - Why not use task_lock()?
+ * User space can randomly change their names anyway, so locking for readers
+ * 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() should ensure that the task comm is
+ * always NUL-terminated and zero-padded. Therefore the race condition between
+ * reader and writer is not an issue.
+ */
+
extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
#define set_task_comm(tsk, from) ({ \
BUILD_BUG_ON(sizeof(from) < TASK_COMM_LEN); \
__set_task_comm(tsk, from, false); \
})
+/*
+ * 'get_task_array' can be 'data-racy' in the destination and
+ * should not be used for cases where a 'stable NUL at the end'
+ * is needed. Its better to use strscpy and friends for such
+ * use-cases.
+ *
+ * It is suited mainly for a 'just copy comm to a constant-sized
+ * array' case - especially in performance sensitive use-cases,
+ * like tracing.
+ */
+
+static __always_inline void
+ __cstr_array_copy(char *dst, const char *src,
+ __kernel_size_t size)
+{
+ memcpy(dst, src, size);
+ dst[size] = 0;
+}
+
+#define get_task_array(dst, src) \
+ __cstr_array_copy(dst, src, __must_be_array(dst))
+
static __always_inline void scheduler_ipi(void)
{
/*
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 826ce3f8e1f8..40e04cb660ce 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -570,10 +570,10 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
* *
*
* TP_fast_assign(
- * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
+ * get_task_array(__entry->next_comm, next->comm);
* __entry->prev_pid = prev->pid;
* __entry->prev_prio = prev->prio;
- * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
+ * get_task_array(__entry->prev_comm, prev->comm);
* __entry->next_pid = next->pid;
* __entry->next_prio = next->prio;
* ),
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 6aa79e2d799c..de1fe35333fc 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -213,7 +213,7 @@ DECLARE_EVENT_CLASS(block_rq,
blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
__get_str(cmd)[0] = '\0';
- memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, current->comm);
),
TP_printk("%d,%d %s %u (%s) %llu + %u %s,%u,%u [%s]",
@@ -351,7 +351,7 @@ DECLARE_EVENT_CLASS(block_bio,
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio_sectors(bio);
blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
- memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, current->comm);
),
TP_printk("%d,%d %s %llu + %u [%s]",
@@ -434,7 +434,7 @@ TRACE_EVENT(block_plug,
),
TP_fast_assign(
- memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, current->comm);
),
TP_printk("[%s]", __entry->comm)
@@ -453,7 +453,7 @@ DECLARE_EVENT_CLASS(block_unplug,
TP_fast_assign(
__entry->nr_rq = depth;
- memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, current->comm);
),
TP_printk("[%s] %d", __entry->comm, __entry->nr_rq)
@@ -504,7 +504,7 @@ TRACE_EVENT(block_split,
__entry->sector = bio->bi_iter.bi_sector;
__entry->new_sector = new_sector;
blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
- memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, current->comm);
),
TP_printk("%d,%d %s %llu / %llu [%s]",
diff --git a/include/trace/events/oom.h b/include/trace/events/oom.h
index 9f0a5d1482c4..31e5b7295188 100644
--- a/include/trace/events/oom.h
+++ b/include/trace/events/oom.h
@@ -23,7 +23,7 @@ TRACE_EVENT(oom_score_adj_update,
TP_fast_assign(
__entry->pid = task->pid;
- memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, task->comm);
__entry->oom_score_adj = task->signal->oom_score_adj;
),
diff --git a/include/trace/events/osnoise.h b/include/trace/events/osnoise.h
index 3f4273623801..f67f8b5eca75 100644
--- a/include/trace/events/osnoise.h
+++ b/include/trace/events/osnoise.h
@@ -116,7 +116,7 @@ TRACE_EVENT(thread_noise,
),
TP_fast_assign(
- memcpy(__entry->comm, t->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, t->comm);
__entry->pid = t->pid;
__entry->start = start;
__entry->duration = duration;
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 7b2645b50e78..66fe808f2654 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -152,7 +152,7 @@ DECLARE_EVENT_CLASS(sched_wakeup_template,
),
TP_fast_assign(
- memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, p->comm);
__entry->pid = p->pid;
__entry->prio = p->prio; /* XXX SCHED_DEADLINE */
__entry->target_cpu = task_cpu(p);
@@ -237,11 +237,11 @@ TRACE_EVENT(sched_switch,
),
TP_fast_assign(
- memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
+ get_task_array(__entry->prev_comm, prev->comm);
__entry->prev_pid = prev->pid;
__entry->prev_prio = prev->prio;
__entry->prev_state = __trace_sched_switch_state(preempt, prev_state, prev);
- memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
+ get_task_array(__entry->next_comm, next->comm);
__entry->next_pid = next->pid;
__entry->next_prio = next->prio;
/* XXX SCHED_DEADLINE */
@@ -346,7 +346,7 @@ TRACE_EVENT(sched_process_exit,
),
TP_fast_assign(
- memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, p->comm);
__entry->pid = p->pid;
__entry->prio = p->prio; /* XXX SCHED_DEADLINE */
__entry->group_dead = group_dead;
@@ -787,14 +787,13 @@ TRACE_EVENT(sched_skip_cpuset_numa,
),
TP_fast_assign(
- memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, tsk->comm);
__entry->pid = task_pid_nr(tsk);
__entry->tgid = task_tgid_nr(tsk);
__entry->ngid = task_numa_group_id(tsk);
BUILD_BUG_ON(sizeof(nodemask_t) != \
BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long));
- memcpy(__entry->mem_allowed, mem_allowed_ptr->bits,
- sizeof(__entry->mem_allowed));
+ get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
),
TP_printk("comm=%s pid=%d tgid=%d ngid=%d mem_nodes_allowed=%*pbl",
diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h
index 1db7e4b07c01..0681dc5ab1de 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 = sig;
TP_STORE_SIGINFO(__entry, info);
- memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, task->comm);
__entry->pid = task->pid;
__entry->group = group;
__entry->result = result;
diff --git a/include/trace/events/task.h b/include/trace/events/task.h
index af535b053033..9553946943a6 100644
--- a/include/trace/events/task.h
+++ b/include/trace/events/task.h
@@ -21,7 +21,7 @@ TRACE_EVENT(task_newtask,
TP_fast_assign(
__entry->pid = task->pid;
- memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, task->comm);
__entry->clone_flags = clone_flags;
__entry->oom_score_adj = task->signal->oom_score_adj;
),
@@ -44,7 +44,7 @@ TRACE_EVENT(task_rename,
),
TP_fast_assign(
- memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN);
+ get_task_array(entry->oldcomm, task->comm);
strscpy(entry->newcomm, comm, TASK_COMM_LEN);
__entry->oom_score_adj = task->signal->oom_score_adj;
),
diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c
index 23f488cf1740..a5d339cb8ca3 100644
--- a/tools/bpf/bpftool/pids.c
+++ b/tools/bpf/bpftool/pids.c
@@ -53,8 +53,7 @@ static void add_ref(struct hashmap *map, struct pid_iter_entry *e)
refs->refs = tmp;
ref = &refs->refs[refs->ref_cnt];
ref->pid = e->pid;
- memcpy(ref->comm, e->comm, sizeof(ref->comm));
- ref->comm[sizeof(ref->comm) - 1] = '\0';
+ get_task_array(ref->comm, e->comm);
refs->ref_cnt++;
return;
@@ -77,8 +76,7 @@ static void add_ref(struct hashmap *map, struct pid_iter_entry *e)
}
ref = &refs->refs[0];
ref->pid = e->pid;
- memcpy(ref->comm, e->comm, sizeof(ref->comm));
- ref->comm[sizeof(ref->comm) - 1] = '\0';
+ get_task_array(ref->comm, e->comm);
refs->ref_cnt = 1;
refs->has_bpf_cookie = e->has_bpf_cookie;
refs->bpf_cookie = e->bpf_cookie;
diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h b/tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h
index aeef86b3da74..81880748550f 100644
--- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h
+++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h
@@ -20,7 +20,7 @@ TRACE_EVENT(bpf_testmod_test_read,
),
TP_fast_assign(
__entry->pid = task->pid;
- memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
+ get_task_array(__entry->comm, task->comm);
__entry->off = ctx->off;
__entry->len = ctx->len;
),
--
2.38.1
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
2025-08-11 6:46 ` [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()' Bhupesh
@ 2025-08-11 11:25 ` kernel test robot
2025-08-11 14:49 ` Bhupesh Sharma
2025-08-11 15:05 ` Andy Shevchenko
2025-08-12 3:47 ` kernel test robot
2 siblings, 1 reply; 16+ messages in thread
From: kernel test robot @ 2025-08-11 11:25 UTC (permalink / raw)
To: Bhupesh, akpm
Cc: oe-kbuild-all, bhupesh, kernel-dev, linux-kernel, bpf,
linux-perf-users, linux-fsdevel, linux-mm, oliver.sang, lkp,
laoar.shao, pmladek, rostedt, mathieu.desnoyers, arnaldo.melo,
alexei.starovoitov, andrii.nakryiko, mirq-linux, peterz, willy,
david, viro, keescook, ebiederm, brauner, jack, mingo, juri.lelli,
bsegall, mgorman
Hi Bhupesh,
kernel test robot noticed the following build errors:
[auto build test ERROR on next-20250808]
[cannot apply to trace/for-next tip/sched/core brauner-vfs/vfs.all linus/master v6.17-rc1 v6.16 v6.16-rc7 v6.17-rc1]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Bhupesh/exec-Remove-obsolete-comments/20250811-144920
base: next-20250808
patch link: https://lore.kernel.org/r/20250811064609.918593-4-bhupesh%40igalia.com
patch subject: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
config: sh-randconfig-002-20250811 (https://download.01.org/0day-ci/archive/20250811/202508111835.JFL8DgKY-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250811/202508111835.JFL8DgKY-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508111835.JFL8DgKY-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from include/linux/bitmap.h:13,
from include/linux/cpumask.h:12,
from include/linux/smp.h:13,
from include/linux/lockdep.h:14,
from include/linux/spinlock.h:63,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:7,
from include/linux/umh.h:4,
from include/linux/kmod.h:9,
from include/linux/module.h:18,
from net/netfilter/nf_tables_api.c:8:
net/netfilter/nf_tables_api.c: In function 'nf_tables_fill_gen_info':
>> include/linux/string.h:116:50: error: passing argument 3 of 'nla_put_string' makes pointer from integer without a cast [-Wint-conversion]
116 | #define sized_strscpy_pad(dest, src, count) ({ \
| ~^~~~~~~~~~~~~~~~~~~~~~~~
| |
| ssize_t {aka int}
117 | char *__dst = (dest); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
118 | const char *__src = (src); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
119 | const size_t __count = (count); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
120 | ssize_t __wrote; \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
121 | \
| ~
122 | __wrote = sized_strscpy(__dst, __src, __count); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
123 | if (__wrote >= 0 && __wrote < __count) \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
124 | memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
125 | __wrote; \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
126 | })
| ~~
include/linux/string.h:86:9: note: in expansion of macro 'sized_strscpy_pad'
86 | sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
| ^~~~~~~~~~~~~~~~~
include/linux/args.h:25:24: note: in expansion of macro '__strscpy_pad0'
25 | #define __CONCAT(a, b) a ## b
| ^
include/linux/args.h:26:27: note: in expansion of macro '__CONCAT'
26 | #define CONCATENATE(a, b) __CONCAT(a, b)
| ^~~~~~~~
include/linux/string.h:149:9: note: in expansion of macro 'CONCATENATE'
149 | CONCATENATE(__strscpy_pad, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
| ^~~~~~~~~~~
net/netfilter/nf_tables_api.c:9661:53: note: in expansion of macro 'strscpy_pad'
9661 | nla_put_string(skb, NFTA_GEN_PROC_NAME, strscpy_pad(buf, current->comm)))
| ^~~~~~~~~~~
In file included from include/linux/netfilter/nfnetlink.h:7,
from net/netfilter/nf_tables_api.c:17:
include/net/netlink.h:1655:46: note: expected 'const char *' but argument is of type 'ssize_t' {aka 'int'}
1655 | const char *str)
| ~~~~~~~~~~~~^~~
vim +/nla_put_string +116 include/linux/string.h
e6584c3964f2ff Kees Cook 2023-09-20 74
e6584c3964f2ff Kees Cook 2023-09-20 75 /*
e6584c3964f2ff Kees Cook 2023-09-20 76 * The 2 argument style can only be used when dst is an array with a
e6584c3964f2ff Kees Cook 2023-09-20 77 * known size.
e6584c3964f2ff Kees Cook 2023-09-20 78 */
e6584c3964f2ff Kees Cook 2023-09-20 79 #define __strscpy0(dst, src, ...) \
559048d156ff33 Kees Cook 2024-08-05 80 sized_strscpy(dst, src, sizeof(dst) + __must_be_array(dst) + \
559048d156ff33 Kees Cook 2024-08-05 81 __must_be_cstr(dst) + __must_be_cstr(src))
559048d156ff33 Kees Cook 2024-08-05 82 #define __strscpy1(dst, src, size) \
559048d156ff33 Kees Cook 2024-08-05 83 sized_strscpy(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src))
e6584c3964f2ff Kees Cook 2023-09-20 84
8366d124ec937c Kees Cook 2024-02-02 85 #define __strscpy_pad0(dst, src, ...) \
559048d156ff33 Kees Cook 2024-08-05 86 sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
559048d156ff33 Kees Cook 2024-08-05 87 __must_be_cstr(dst) + __must_be_cstr(src))
559048d156ff33 Kees Cook 2024-08-05 88 #define __strscpy_pad1(dst, src, size) \
559048d156ff33 Kees Cook 2024-08-05 89 sized_strscpy_pad(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src))
458a3bf82df4fe Tobin C. Harding 2019-04-05 90
e6584c3964f2ff Kees Cook 2023-09-20 91 /**
e6584c3964f2ff Kees Cook 2023-09-20 92 * strscpy - Copy a C-string into a sized buffer
e6584c3964f2ff Kees Cook 2023-09-20 93 * @dst: Where to copy the string to
e6584c3964f2ff Kees Cook 2023-09-20 94 * @src: Where to copy the string from
e6584c3964f2ff Kees Cook 2023-09-20 95 * @...: Size of destination buffer (optional)
e6584c3964f2ff Kees Cook 2023-09-20 96 *
e6584c3964f2ff Kees Cook 2023-09-20 97 * Copy the source string @src, or as much of it as fits, into the
e6584c3964f2ff Kees Cook 2023-09-20 98 * destination @dst buffer. The behavior is undefined if the string
e6584c3964f2ff Kees Cook 2023-09-20 99 * buffers overlap. The destination @dst buffer is always NUL terminated,
e6584c3964f2ff Kees Cook 2023-09-20 100 * unless it's zero-sized.
e6584c3964f2ff Kees Cook 2023-09-20 101 *
e6584c3964f2ff Kees Cook 2023-09-20 102 * The size argument @... is only required when @dst is not an array, or
e6584c3964f2ff Kees Cook 2023-09-20 103 * when the copy needs to be smaller than sizeof(@dst).
e6584c3964f2ff Kees Cook 2023-09-20 104 *
e6584c3964f2ff Kees Cook 2023-09-20 105 * Preferred to strncpy() since it always returns a valid string, and
e6584c3964f2ff Kees Cook 2023-09-20 106 * doesn't unnecessarily force the tail of the destination buffer to be
e6584c3964f2ff Kees Cook 2023-09-20 107 * zero padded. If padding is desired please use strscpy_pad().
e6584c3964f2ff Kees Cook 2023-09-20 108 *
e6584c3964f2ff Kees Cook 2023-09-20 109 * Returns the number of characters copied in @dst (not including the
e6584c3964f2ff Kees Cook 2023-09-20 110 * trailing %NUL) or -E2BIG if @size is 0 or the copy from @src was
e6584c3964f2ff Kees Cook 2023-09-20 111 * truncated.
e6584c3964f2ff Kees Cook 2023-09-20 112 */
e6584c3964f2ff Kees Cook 2023-09-20 113 #define strscpy(dst, src, ...) \
e6584c3964f2ff Kees Cook 2023-09-20 114 CONCATENATE(__strscpy, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
458a3bf82df4fe Tobin C. Harding 2019-04-05 115
8366d124ec937c Kees Cook 2024-02-02 @116 #define sized_strscpy_pad(dest, src, count) ({ \
8366d124ec937c Kees Cook 2024-02-02 117 char *__dst = (dest); \
8366d124ec937c Kees Cook 2024-02-02 118 const char *__src = (src); \
8366d124ec937c Kees Cook 2024-02-02 119 const size_t __count = (count); \
8366d124ec937c Kees Cook 2024-02-02 120 ssize_t __wrote; \
8366d124ec937c Kees Cook 2024-02-02 121 \
8366d124ec937c Kees Cook 2024-02-02 122 __wrote = sized_strscpy(__dst, __src, __count); \
8366d124ec937c Kees Cook 2024-02-02 123 if (__wrote >= 0 && __wrote < __count) \
8366d124ec937c Kees Cook 2024-02-02 124 memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \
8366d124ec937c Kees Cook 2024-02-02 125 __wrote; \
8366d124ec937c Kees Cook 2024-02-02 126 })
8366d124ec937c Kees Cook 2024-02-02 127
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
2025-08-11 11:25 ` kernel test robot
@ 2025-08-11 14:49 ` Bhupesh Sharma
2025-08-11 14:58 ` Andy Shevchenko
0 siblings, 1 reply; 16+ messages in thread
From: Bhupesh Sharma @ 2025-08-11 14:49 UTC (permalink / raw)
To: kernel test robot, Bhupesh, akpm
Cc: oe-kbuild-all, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman
Hi,
On 8/11/25 4:55 PM, kernel test robot wrote:
> Hi Bhupesh,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on next-20250808]
> [cannot apply to trace/for-next tip/sched/core brauner-vfs/vfs.all linus/master v6.17-rc1 v6.16 v6.16-rc7 v6.17-rc1]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Bhupesh/exec-Remove-obsolete-comments/20250811-144920
> base: next-20250808
> patch link: https://lore.kernel.org/r/20250811064609.918593-4-bhupesh%40igalia.com
> patch subject: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
> config: sh-randconfig-002-20250811 (https://download.01.org/0day-ci/archive/20250811/202508111835.JFL8DgKY-lkp@intel.com/config)
> compiler: sh4-linux-gcc (GCC) 15.1.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250811/202508111835.JFL8DgKY-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202508111835.JFL8DgKY-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> In file included from include/linux/bitmap.h:13,
> from include/linux/cpumask.h:12,
> from include/linux/smp.h:13,
> from include/linux/lockdep.h:14,
> from include/linux/spinlock.h:63,
> from include/linux/mmzone.h:8,
> from include/linux/gfp.h:7,
> from include/linux/umh.h:4,
> from include/linux/kmod.h:9,
> from include/linux/module.h:18,
> from net/netfilter/nf_tables_api.c:8:
> net/netfilter/nf_tables_api.c: In function 'nf_tables_fill_gen_info':
>>> include/linux/string.h:116:50: error: passing argument 3 of 'nla_put_string' makes pointer from integer without a cast [-Wint-conversion]
> 116 | #define sized_strscpy_pad(dest, src, count) ({ \
> | ~^~~~~~~~~~~~~~~~~~~~~~~~
> | |
> | ssize_t {aka int}
> 117 | char *__dst = (dest); \
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 118 | const char *__src = (src); \
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 119 | const size_t __count = (count); \
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 120 | ssize_t __wrote; \
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 121 | \
> | ~
> 122 | __wrote = sized_strscpy(__dst, __src, __count); \
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 123 | if (__wrote >= 0 && __wrote < __count) \
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 124 | memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 125 | __wrote; \
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 126 | })
> | ~~
> include/linux/string.h:86:9: note: in expansion of macro 'sized_strscpy_pad'
> 86 | sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
> | ^~~~~~~~~~~~~~~~~
> include/linux/args.h:25:24: note: in expansion of macro '__strscpy_pad0'
> 25 | #define __CONCAT(a, b) a ## b
> | ^
> include/linux/args.h:26:27: note: in expansion of macro '__CONCAT'
> 26 | #define CONCATENATE(a, b) __CONCAT(a, b)
> | ^~~~~~~~
> include/linux/string.h:149:9: note: in expansion of macro 'CONCATENATE'
> 149 | CONCATENATE(__strscpy_pad, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
> | ^~~~~~~~~~~
> net/netfilter/nf_tables_api.c:9661:53: note: in expansion of macro 'strscpy_pad'
> 9661 | nla_put_string(skb, NFTA_GEN_PROC_NAME, strscpy_pad(buf, current->comm)))
> | ^~~~~~~~~~~
> In file included from include/linux/netfilter/nfnetlink.h:7,
> from net/netfilter/nf_tables_api.c:17:
> include/net/netlink.h:1655:46: note: expected 'const char *' but argument is of type 'ssize_t' {aka 'int'}
> 1655 | const char *str)
> | ~~~~~~~~~~~~^~~
>
>
> vim +/nla_put_string +116 include/linux/string.h
>
> e6584c3964f2ff Kees Cook 2023-09-20 74
> e6584c3964f2ff Kees Cook 2023-09-20 75 /*
> e6584c3964f2ff Kees Cook 2023-09-20 76 * The 2 argument style can only be used when dst is an array with a
> e6584c3964f2ff Kees Cook 2023-09-20 77 * known size.
> e6584c3964f2ff Kees Cook 2023-09-20 78 */
> e6584c3964f2ff Kees Cook 2023-09-20 79 #define __strscpy0(dst, src, ...) \
> 559048d156ff33 Kees Cook 2024-08-05 80 sized_strscpy(dst, src, sizeof(dst) + __must_be_array(dst) + \
> 559048d156ff33 Kees Cook 2024-08-05 81 __must_be_cstr(dst) + __must_be_cstr(src))
> 559048d156ff33 Kees Cook 2024-08-05 82 #define __strscpy1(dst, src, size) \
> 559048d156ff33 Kees Cook 2024-08-05 83 sized_strscpy(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src))
> e6584c3964f2ff Kees Cook 2023-09-20 84
> 8366d124ec937c Kees Cook 2024-02-02 85 #define __strscpy_pad0(dst, src, ...) \
> 559048d156ff33 Kees Cook 2024-08-05 86 sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
> 559048d156ff33 Kees Cook 2024-08-05 87 __must_be_cstr(dst) + __must_be_cstr(src))
> 559048d156ff33 Kees Cook 2024-08-05 88 #define __strscpy_pad1(dst, src, size) \
> 559048d156ff33 Kees Cook 2024-08-05 89 sized_strscpy_pad(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src))
> 458a3bf82df4fe Tobin C. Harding 2019-04-05 90
> e6584c3964f2ff Kees Cook 2023-09-20 91 /**
> e6584c3964f2ff Kees Cook 2023-09-20 92 * strscpy - Copy a C-string into a sized buffer
> e6584c3964f2ff Kees Cook 2023-09-20 93 * @dst: Where to copy the string to
> e6584c3964f2ff Kees Cook 2023-09-20 94 * @src: Where to copy the string from
> e6584c3964f2ff Kees Cook 2023-09-20 95 * @...: Size of destination buffer (optional)
> e6584c3964f2ff Kees Cook 2023-09-20 96 *
> e6584c3964f2ff Kees Cook 2023-09-20 97 * Copy the source string @src, or as much of it as fits, into the
> e6584c3964f2ff Kees Cook 2023-09-20 98 * destination @dst buffer. The behavior is undefined if the string
> e6584c3964f2ff Kees Cook 2023-09-20 99 * buffers overlap. The destination @dst buffer is always NUL terminated,
> e6584c3964f2ff Kees Cook 2023-09-20 100 * unless it's zero-sized.
> e6584c3964f2ff Kees Cook 2023-09-20 101 *
> e6584c3964f2ff Kees Cook 2023-09-20 102 * The size argument @... is only required when @dst is not an array, or
> e6584c3964f2ff Kees Cook 2023-09-20 103 * when the copy needs to be smaller than sizeof(@dst).
> e6584c3964f2ff Kees Cook 2023-09-20 104 *
> e6584c3964f2ff Kees Cook 2023-09-20 105 * Preferred to strncpy() since it always returns a valid string, and
> e6584c3964f2ff Kees Cook 2023-09-20 106 * doesn't unnecessarily force the tail of the destination buffer to be
> e6584c3964f2ff Kees Cook 2023-09-20 107 * zero padded. If padding is desired please use strscpy_pad().
> e6584c3964f2ff Kees Cook 2023-09-20 108 *
> e6584c3964f2ff Kees Cook 2023-09-20 109 * Returns the number of characters copied in @dst (not including the
> e6584c3964f2ff Kees Cook 2023-09-20 110 * trailing %NUL) or -E2BIG if @size is 0 or the copy from @src was
> e6584c3964f2ff Kees Cook 2023-09-20 111 * truncated.
> e6584c3964f2ff Kees Cook 2023-09-20 112 */
> e6584c3964f2ff Kees Cook 2023-09-20 113 #define strscpy(dst, src, ...) \
> e6584c3964f2ff Kees Cook 2023-09-20 114 CONCATENATE(__strscpy, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
> 458a3bf82df4fe Tobin C. Harding 2019-04-05 115
> 8366d124ec937c Kees Cook 2024-02-02 @116 #define sized_strscpy_pad(dest, src, count) ({ \
> 8366d124ec937c Kees Cook 2024-02-02 117 char *__dst = (dest); \
> 8366d124ec937c Kees Cook 2024-02-02 118 const char *__src = (src); \
> 8366d124ec937c Kees Cook 2024-02-02 119 const size_t __count = (count); \
> 8366d124ec937c Kees Cook 2024-02-02 120 ssize_t __wrote; \
> 8366d124ec937c Kees Cook 2024-02-02 121 \
> 8366d124ec937c Kees Cook 2024-02-02 122 __wrote = sized_strscpy(__dst, __src, __count); \
> 8366d124ec937c Kees Cook 2024-02-02 123 if (__wrote >= 0 && __wrote < __count) \
> 8366d124ec937c Kees Cook 2024-02-02 124 memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \
> 8366d124ec937c Kees Cook 2024-02-02 125 __wrote; \
> 8366d124ec937c Kees Cook 2024-02-02 126 })
> 8366d124ec937c Kees Cook 2024-02-02 127
>
As mentioned in the accompanying cover letter, this patchset is based on
'linux-next/master' (the exact sha-id used for rebase is:
b1549501188cc9eba732c25b033df7a53ccc341f ).
Thanks,
Bhupesh
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
2025-08-11 14:49 ` Bhupesh Sharma
@ 2025-08-11 14:58 ` Andy Shevchenko
2025-08-13 10:26 ` Bhupesh Sharma
0 siblings, 1 reply; 16+ messages in thread
From: Andy Shevchenko @ 2025-08-11 14:58 UTC (permalink / raw)
To: Bhupesh Sharma
Cc: kernel test robot, Bhupesh, akpm, oe-kbuild-all, kernel-dev,
linux-kernel, bpf, linux-perf-users, linux-fsdevel, linux-mm,
oliver.sang, laoar.shao, pmladek, rostedt, mathieu.desnoyers,
arnaldo.melo, alexei.starovoitov, andrii.nakryiko, mirq-linux,
peterz, willy, david, viro, keescook, ebiederm, brauner, jack,
mingo, juri.lelli, bsegall, mgorman
On Mon, Aug 11, 2025 at 08:19:08PM +0530, Bhupesh Sharma wrote:
> On 8/11/25 4:55 PM, kernel test robot wrote:
> As mentioned in the accompanying cover letter, this patchset is based on
> 'linux-next/master' (the exact sha-id used for rebase is:
> b1549501188cc9eba732c25b033df7a53ccc341f ).
Instead of getting false positive reports and this rather unneeded reply from
you, use --base parameter when formatting patch series. It will help all,
including CIs and bots.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
2025-08-11 6:46 ` [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()' Bhupesh
2025-08-11 11:25 ` kernel test robot
@ 2025-08-11 15:05 ` Andy Shevchenko
2025-08-13 10:27 ` Bhupesh Sharma
2025-08-12 3:47 ` kernel test robot
2 siblings, 1 reply; 16+ messages in thread
From: Andy Shevchenko @ 2025-08-11 15:05 UTC (permalink / raw)
To: Bhupesh
Cc: akpm, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
On Mon, Aug 11, 2025 at 12:16:08PM +0530, Bhupesh wrote:
> As Linus mentioned in [1], we should get rid of 'get_task_comm()'
> entirely and replace it with 'strscpy_pad()' implementation.
>
> 'strscpy_pad()' will already make sure comm is NUL-terminated, so
> we won't need the explicit final byte termination done in
> 'get_task_comm()'.
>
> The relevant 'get_task_comm()' users were identified using the
> following search pattern:
> $ git grep 'get_task_comm*'
> [1]. https://lore.kernel.org/all/CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com/
>
> Signed-off-by: Bhupesh <bhupesh@igalia.com>
Make that a Link tag?
Link: https://lore.kernel.org/all/CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com/ #1
Signed-off-by: Bhupesh <bhupesh@igalia.com>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation
2025-08-11 6:46 ` [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Bhupesh
@ 2025-08-11 15:08 ` Andy Shevchenko
2025-08-11 16:37 ` kernel test robot
1 sibling, 0 replies; 16+ messages in thread
From: Andy Shevchenko @ 2025-08-11 15:08 UTC (permalink / raw)
To: Bhupesh
Cc: akpm, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
On Mon, Aug 11, 2025 at 12:16:09PM +0530, Bhupesh wrote:
> As Linus mentioned in [1], currently we have several memcpy() use-cases
> which use 'current->comm' to copy the task name over to local copies.
> For an example:
>
> ...
> char comm[TASK_COMM_LEN];
> memcpy(comm, current->comm, TASK_COMM_LEN);
> ...
>
> These should be rather calling a wrappper like "get_task_array()",
> which is implemented as:
>
> static __always_inline void
> __cstr_array_copy(char *dst,
> const char *src, __kernel_size_t size)
> {
> memcpy(dst, src, size);
> dst[size] = 0;
> }
>
> #define get_task_array(dst,src) \
> __cstr_array_copy(dst, src, __must_be_array(dst))
>
> The relevant 'memcpy()' users were identified using the following search
> pattern:
> $ git grep 'memcpy.*->comm\>'
> [1]. https://lore.kernel.org/all/CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com/
>
> Signed-off-by: Bhupesh <bhupesh@igalia.com>
Same suggestion, make it a Link tag.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 2/4] include: Set tsk->comm length to 64 bytes
2025-08-11 6:46 ` [PATCH v7 2/4] include: Set tsk->comm length to 64 bytes Bhupesh
@ 2025-08-11 15:10 ` Andy Shevchenko
2025-08-13 10:29 ` Bhupesh Sharma
0 siblings, 1 reply; 16+ messages in thread
From: Andy Shevchenko @ 2025-08-11 15:10 UTC (permalink / raw)
To: Bhupesh
Cc: akpm, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
On Mon, Aug 11, 2025 at 12:16:07PM +0530, Bhupesh wrote:
> Historically due to the 16-byte length of TASK_COMM_LEN, the
> users of 'tsk->comm' are restricted to use a fixed-size target
> buffer also of TASK_COMM_LEN for 'memcpy()' like use-cases.
>
> To fix the same, we now use a 64-byte TASK_COMM_EXT_LEN and
> set the comm element inside 'task_struct' to the same length:
> struct task_struct {
> .....
> char comm[TASK_COMM_EXT_LEN];
> .....
> };
>
> where TASK_COMM_EXT_LEN is 64-bytes.
>
> Note, that the existing users have not been modified to migrate to
> 'TASK_COMM_EXT_LEN', in case they have hard-coded expectations of
> dealing with only a 'TASK_COMM_LEN' long 'tsk->comm'.
...
> - BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \
> + BUILD_BUG_ON(sizeof(from) < TASK_COMM_LEN); \
Wondering if we may convert this to static_assert().
(rather in a separate patch)
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation
2025-08-11 6:46 ` [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Bhupesh
2025-08-11 15:08 ` Andy Shevchenko
@ 2025-08-11 16:37 ` kernel test robot
1 sibling, 0 replies; 16+ messages in thread
From: kernel test robot @ 2025-08-11 16:37 UTC (permalink / raw)
To: Bhupesh, akpm
Cc: oe-kbuild-all, bhupesh, kernel-dev, linux-kernel, bpf,
linux-perf-users, linux-fsdevel, linux-mm, oliver.sang, lkp,
laoar.shao, pmladek, rostedt, mathieu.desnoyers, arnaldo.melo,
alexei.starovoitov, andrii.nakryiko, mirq-linux, peterz, willy,
david, viro, keescook, ebiederm, brauner, jack, mingo, juri.lelli,
bsegall, mgorman
Hi Bhupesh,
kernel test robot noticed the following build errors:
[auto build test ERROR on next-20250808]
[cannot apply to trace/for-next tip/sched/core brauner-vfs/vfs.all linus/master v6.17-rc1 v6.16 v6.16-rc7 v6.17-rc1]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Bhupesh/exec-Remove-obsolete-comments/20250811-144920
base: next-20250808
patch link: https://lore.kernel.org/r/20250811064609.918593-5-bhupesh%40igalia.com
patch subject: [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation
config: x86_64-buildonly-randconfig-001-20250811 (https://download.01.org/0day-ci/archive/20250812/202508120011.j4Pmr6Rf-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250812/202508120011.j4Pmr6Rf-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508120011.j4Pmr6Rf-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from include/trace/define_trace.h:132,
from include/trace/events/sched.h:901,
from kernel/sched/core.c:85:
include/trace/events/sched.h: In function 'do_trace_event_raw_event_sched_skip_cpuset_numa':
>> include/trace/events/sched.h:796:39: error: passing argument 1 of '__cstr_array_copy' from incompatible pointer type [-Werror=incompatible-pointer-types]
796 | get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
include/trace/trace_events.h:427:11: note: in definition of macro '__DECLARE_EVENT_CLASS'
427 | { assign; } \
| ^~~~~~
include/trace/trace_events.h:435:23: note: in expansion of macro 'PARAMS'
435 | PARAMS(assign), PARAMS(print)) \
| ^~~~~~
include/trace/trace_events.h:40:9: note: in expansion of macro 'DECLARE_EVENT_CLASS'
40 | DECLARE_EVENT_CLASS(name, \
| ^~~~~~~~~~~~~~~~~~~
include/trace/trace_events.h:44:30: note: in expansion of macro 'PARAMS'
44 | PARAMS(assign), \
| ^~~~~~
include/trace/events/sched.h:775:1: note: in expansion of macro 'TRACE_EVENT'
775 | TRACE_EVENT(sched_skip_cpuset_numa,
| ^~~~~~~~~~~
include/trace/events/sched.h:789:9: note: in expansion of macro 'TP_fast_assign'
789 | TP_fast_assign(
| ^~~~~~~~~~~~~~
include/trace/events/sched.h:796:17: note: in expansion of macro 'get_task_array'
796 | get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
| ^~~~~~~~~~~~~~
In file included from include/linux/percpu.h:12,
from arch/x86/include/asm/msr.h:16,
from arch/x86/include/asm/tsc.h:11,
from arch/x86/include/asm/timex.h:6,
from include/linux/timex.h:67,
from include/linux/time32.h:13,
from include/linux/time.h:60,
from include/linux/stat.h:19,
from include/linux/fs.h:11,
from include/linux/highmem.h:5,
from kernel/sched/core.c:10:
include/linux/sched.h:1991:33: note: expected 'char *' but argument is of type 'long unsigned int *'
1991 | __cstr_array_copy(char *dst, const char *src,
| ~~~~~~^~~
include/trace/events/sched.h:796:69: error: passing argument 2 of '__cstr_array_copy' from incompatible pointer type [-Werror=incompatible-pointer-types]
796 | get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
| ~~~~~~~~~~~~~~~^~~~~~
| |
| long unsigned int *
include/trace/trace_events.h:427:11: note: in definition of macro '__DECLARE_EVENT_CLASS'
427 | { assign; } \
| ^~~~~~
include/trace/trace_events.h:435:23: note: in expansion of macro 'PARAMS'
435 | PARAMS(assign), PARAMS(print)) \
| ^~~~~~
include/trace/trace_events.h:40:9: note: in expansion of macro 'DECLARE_EVENT_CLASS'
40 | DECLARE_EVENT_CLASS(name, \
| ^~~~~~~~~~~~~~~~~~~
include/trace/trace_events.h:44:30: note: in expansion of macro 'PARAMS'
44 | PARAMS(assign), \
| ^~~~~~
include/trace/events/sched.h:775:1: note: in expansion of macro 'TRACE_EVENT'
775 | TRACE_EVENT(sched_skip_cpuset_numa,
| ^~~~~~~~~~~
include/trace/events/sched.h:789:9: note: in expansion of macro 'TP_fast_assign'
789 | TP_fast_assign(
| ^~~~~~~~~~~~~~
include/trace/events/sched.h:796:17: note: in expansion of macro 'get_task_array'
796 | get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
| ^~~~~~~~~~~~~~
include/linux/sched.h:1991:50: note: expected 'const char *' but argument is of type 'long unsigned int *'
1991 | __cstr_array_copy(char *dst, const char *src,
| ~~~~~~~~~~~~^~~
In file included from include/trace/define_trace.h:133:
include/trace/events/sched.h: In function 'do_perf_trace_sched_skip_cpuset_numa':
>> include/trace/events/sched.h:796:39: error: passing argument 1 of '__cstr_array_copy' from incompatible pointer type [-Werror=incompatible-pointer-types]
796 | get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
include/trace/perf.h:51:11: note: in definition of macro '__DECLARE_EVENT_CLASS'
51 | { assign; } \
| ^~~~~~
include/trace/perf.h:67:23: note: in expansion of macro 'PARAMS'
67 | PARAMS(assign), PARAMS(print)) \
| ^~~~~~
include/trace/trace_events.h:40:9: note: in expansion of macro 'DECLARE_EVENT_CLASS'
40 | DECLARE_EVENT_CLASS(name, \
| ^~~~~~~~~~~~~~~~~~~
include/trace/trace_events.h:44:30: note: in expansion of macro 'PARAMS'
44 | PARAMS(assign), \
| ^~~~~~
include/trace/events/sched.h:775:1: note: in expansion of macro 'TRACE_EVENT'
775 | TRACE_EVENT(sched_skip_cpuset_numa,
| ^~~~~~~~~~~
include/trace/events/sched.h:789:9: note: in expansion of macro 'TP_fast_assign'
789 | TP_fast_assign(
| ^~~~~~~~~~~~~~
include/trace/events/sched.h:796:17: note: in expansion of macro 'get_task_array'
796 | get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
| ^~~~~~~~~~~~~~
include/linux/sched.h:1991:33: note: expected 'char *' but argument is of type 'long unsigned int *'
1991 | __cstr_array_copy(char *dst, const char *src,
| ~~~~~~^~~
include/trace/events/sched.h:796:69: error: passing argument 2 of '__cstr_array_copy' from incompatible pointer type [-Werror=incompatible-pointer-types]
796 | get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
| ~~~~~~~~~~~~~~~^~~~~~
| |
| long unsigned int *
include/trace/perf.h:51:11: note: in definition of macro '__DECLARE_EVENT_CLASS'
51 | { assign; } \
| ^~~~~~
include/trace/perf.h:67:23: note: in expansion of macro 'PARAMS'
67 | PARAMS(assign), PARAMS(print)) \
| ^~~~~~
include/trace/trace_events.h:40:9: note: in expansion of macro 'DECLARE_EVENT_CLASS'
40 | DECLARE_EVENT_CLASS(name, \
| ^~~~~~~~~~~~~~~~~~~
include/trace/trace_events.h:44:30: note: in expansion of macro 'PARAMS'
44 | PARAMS(assign), \
| ^~~~~~
include/trace/events/sched.h:775:1: note: in expansion of macro 'TRACE_EVENT'
775 | TRACE_EVENT(sched_skip_cpuset_numa,
| ^~~~~~~~~~~
include/trace/events/sched.h:789:9: note: in expansion of macro 'TP_fast_assign'
789 | TP_fast_assign(
| ^~~~~~~~~~~~~~
include/trace/events/sched.h:796:17: note: in expansion of macro 'get_task_array'
796 | get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
| ^~~~~~~~~~~~~~
include/linux/sched.h:1991:50: note: expected 'const char *' but argument is of type 'long unsigned int *'
1991 | __cstr_array_copy(char *dst, const char *src,
| ~~~~~~~~~~~~^~~
cc1: some warnings being treated as errors
vim +/__cstr_array_copy +796 include/trace/events/sched.h
776
777 TP_PROTO(struct task_struct *tsk, nodemask_t *mem_allowed_ptr),
778
779 TP_ARGS(tsk, mem_allowed_ptr),
780
781 TP_STRUCT__entry(
782 __array( char, comm, TASK_COMM_LEN )
783 __field( pid_t, pid )
784 __field( pid_t, tgid )
785 __field( pid_t, ngid )
786 __array( unsigned long, mem_allowed, BITS_TO_LONGS(MAX_NUMNODES))
787 ),
788
789 TP_fast_assign(
790 get_task_array(__entry->comm, tsk->comm);
791 __entry->pid = task_pid_nr(tsk);
792 __entry->tgid = task_tgid_nr(tsk);
793 __entry->ngid = task_numa_group_id(tsk);
794 BUILD_BUG_ON(sizeof(nodemask_t) != \
795 BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long));
> 796 get_task_array(__entry->mem_allowed, mem_allowed_ptr->bits);
797 ),
798
799 TP_printk("comm=%s pid=%d tgid=%d ngid=%d mem_nodes_allowed=%*pbl",
800 __entry->comm,
801 __entry->pid,
802 __entry->tgid,
803 __entry->ngid,
804 MAX_NUMNODES, __entry->mem_allowed)
805 );
806 #endif /* CONFIG_NUMA_BALANCING */
807
808 /*
809 * Tracepoint for waking a polling cpu without an IPI.
810 */
811 TRACE_EVENT(sched_wake_idle_without_ipi,
812
813 TP_PROTO(int cpu),
814
815 TP_ARGS(cpu),
816
817 TP_STRUCT__entry(
818 __field( int, cpu )
819 ),
820
821 TP_fast_assign(
822 __entry->cpu = cpu;
823 ),
824
825 TP_printk("cpu=%d", __entry->cpu)
826 );
827
828 /*
829 * Following tracepoints are not exported in tracefs and provide hooking
830 * mechanisms only for testing and debugging purposes.
831 */
832 DECLARE_TRACE(pelt_cfs,
833 TP_PROTO(struct cfs_rq *cfs_rq),
834 TP_ARGS(cfs_rq));
835
836 DECLARE_TRACE(pelt_rt,
837 TP_PROTO(struct rq *rq),
838 TP_ARGS(rq));
839
840 DECLARE_TRACE(pelt_dl,
841 TP_PROTO(struct rq *rq),
842 TP_ARGS(rq));
843
844 DECLARE_TRACE(pelt_hw,
845 TP_PROTO(struct rq *rq),
846 TP_ARGS(rq));
847
848 DECLARE_TRACE(pelt_irq,
849 TP_PROTO(struct rq *rq),
850 TP_ARGS(rq));
851
852 DECLARE_TRACE(pelt_se,
853 TP_PROTO(struct sched_entity *se),
854 TP_ARGS(se));
855
856 DECLARE_TRACE(sched_cpu_capacity,
857 TP_PROTO(struct rq *rq),
858 TP_ARGS(rq));
859
860 DECLARE_TRACE(sched_overutilized,
861 TP_PROTO(struct root_domain *rd, bool overutilized),
862 TP_ARGS(rd, overutilized));
863
864 DECLARE_TRACE(sched_util_est_cfs,
865 TP_PROTO(struct cfs_rq *cfs_rq),
866 TP_ARGS(cfs_rq));
867
868 DECLARE_TRACE(sched_util_est_se,
869 TP_PROTO(struct sched_entity *se),
870 TP_ARGS(se));
871
872 DECLARE_TRACE(sched_update_nr_running,
873 TP_PROTO(struct rq *rq, int change),
874 TP_ARGS(rq, change));
875
876 DECLARE_TRACE(sched_compute_energy,
877 TP_PROTO(struct task_struct *p, int dst_cpu, unsigned long energy,
878 unsigned long max_util, unsigned long busy_time),
879 TP_ARGS(p, dst_cpu, energy, max_util, busy_time));
880
881 DECLARE_TRACE(sched_entry,
882 TP_PROTO(bool preempt),
883 TP_ARGS(preempt));
884
885 DECLARE_TRACE(sched_exit,
886 TP_PROTO(bool is_switch),
887 TP_ARGS(is_switch));
888
889 DECLARE_TRACE_CONDITION(sched_set_state,
890 TP_PROTO(struct task_struct *tsk, int state),
891 TP_ARGS(tsk, state),
892 TP_CONDITION(!!(tsk->__state) != !!state));
893
894 DECLARE_TRACE(sched_set_need_resched,
895 TP_PROTO(struct task_struct *tsk, int cpu, int tif),
896 TP_ARGS(tsk, cpu, tif));
897
898 #endif /* _TRACE_SCHED_H */
899
900 /* This part must be outside protection */
> 901 #include <trace/define_trace.h>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
2025-08-11 6:46 ` [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()' Bhupesh
2025-08-11 11:25 ` kernel test robot
2025-08-11 15:05 ` Andy Shevchenko
@ 2025-08-12 3:47 ` kernel test robot
2 siblings, 0 replies; 16+ messages in thread
From: kernel test robot @ 2025-08-12 3:47 UTC (permalink / raw)
To: Bhupesh, akpm
Cc: oe-kbuild-all, bhupesh, kernel-dev, linux-kernel, bpf,
linux-perf-users, linux-fsdevel, linux-mm, oliver.sang, lkp,
laoar.shao, pmladek, rostedt, mathieu.desnoyers, arnaldo.melo,
alexei.starovoitov, andrii.nakryiko, mirq-linux, peterz, willy,
david, viro, keescook, ebiederm, brauner, jack, mingo, juri.lelli,
bsegall, mgorman
Hi Bhupesh,
kernel test robot noticed the following build warnings:
[auto build test WARNING on next-20250808]
[cannot apply to trace/for-next tip/sched/core brauner-vfs/vfs.all linus/master v6.17-rc1 v6.16 v6.16-rc7 v6.17-rc1]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Bhupesh/exec-Remove-obsolete-comments/20250811-144920
base: next-20250808
patch link: https://lore.kernel.org/r/20250811064609.918593-4-bhupesh%40igalia.com
patch subject: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
config: arc-randconfig-002-20250812 (https://download.01.org/0day-ci/archive/20250812/202508121145.d07aFegg-lkp@intel.com/config)
compiler: arc-linux-gcc (GCC) 12.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250812/202508121145.d07aFegg-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508121145.d07aFegg-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from include/linux/build_bug.h:5,
from include/linux/container_of.h:5,
from include/linux/list.h:5,
from include/linux/module.h:12,
from net/netfilter/nf_tables_api.c:8:
net/netfilter/nf_tables_api.c: In function 'nf_tables_fill_gen_info':
>> include/linux/string.h:116:50: warning: passing argument 3 of 'nla_put_string' makes pointer from integer without a cast [-Wint-conversion]
116 | #define sized_strscpy_pad(dest, src, count) ({ \
| ~^~~~~~~~~~~~~~~~~~~~~~~~
| |
| ssize_t {aka int}
117 | char *__dst = (dest); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
118 | const char *__src = (src); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
119 | const size_t __count = (count); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
120 | ssize_t __wrote; \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
121 | \
| ~
122 | __wrote = sized_strscpy(__dst, __src, __count); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
123 | if (__wrote >= 0 && __wrote < __count) \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
124 | memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
125 | __wrote; \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
126 | })
| ~~
include/linux/compiler.h:57:52: note: in definition of macro '__trace_if_var'
57 | #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
| ^~~~
net/netfilter/nf_tables_api.c:9659:9: note: in expansion of macro 'if'
9659 | if (nla_put_be32(skb, NFTA_GEN_ID, htonl(nft_net->base_seq)) ||
| ^~
include/linux/string.h:86:9: note: in expansion of macro 'sized_strscpy_pad'
86 | sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
| ^~~~~~~~~~~~~~~~~
include/linux/args.h:25:24: note: in expansion of macro '__strscpy_pad0'
25 | #define __CONCAT(a, b) a ## b
| ^
include/linux/args.h:26:27: note: in expansion of macro '__CONCAT'
26 | #define CONCATENATE(a, b) __CONCAT(a, b)
| ^~~~~~~~
include/linux/string.h:149:9: note: in expansion of macro 'CONCATENATE'
149 | CONCATENATE(__strscpy_pad, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
| ^~~~~~~~~~~
net/netfilter/nf_tables_api.c:9661:53: note: in expansion of macro 'strscpy_pad'
9661 | nla_put_string(skb, NFTA_GEN_PROC_NAME, strscpy_pad(buf, current->comm)))
| ^~~~~~~~~~~
In file included from include/linux/netfilter/nfnetlink.h:7,
from net/netfilter/nf_tables_api.c:17:
include/net/netlink.h:1655:46: note: expected 'const char *' but argument is of type 'ssize_t' {aka 'int'}
1655 | const char *str)
| ~~~~~~~~~~~~^~~
>> include/linux/string.h:116:50: warning: passing argument 3 of 'nla_put_string' makes pointer from integer without a cast [-Wint-conversion]
116 | #define sized_strscpy_pad(dest, src, count) ({ \
| ~^~~~~~~~~~~~~~~~~~~~~~~~
| |
| ssize_t {aka int}
117 | char *__dst = (dest); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
118 | const char *__src = (src); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
119 | const size_t __count = (count); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
120 | ssize_t __wrote; \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
121 | \
| ~
122 | __wrote = sized_strscpy(__dst, __src, __count); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
123 | if (__wrote >= 0 && __wrote < __count) \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
124 | memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
125 | __wrote; \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
126 | })
| ~~
include/linux/compiler.h:57:61: note: in definition of macro '__trace_if_var'
57 | #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
| ^~~~
net/netfilter/nf_tables_api.c:9659:9: note: in expansion of macro 'if'
9659 | if (nla_put_be32(skb, NFTA_GEN_ID, htonl(nft_net->base_seq)) ||
| ^~
include/linux/string.h:86:9: note: in expansion of macro 'sized_strscpy_pad'
86 | sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
| ^~~~~~~~~~~~~~~~~
include/linux/args.h:25:24: note: in expansion of macro '__strscpy_pad0'
25 | #define __CONCAT(a, b) a ## b
| ^
include/linux/args.h:26:27: note: in expansion of macro '__CONCAT'
26 | #define CONCATENATE(a, b) __CONCAT(a, b)
| ^~~~~~~~
include/linux/string.h:149:9: note: in expansion of macro 'CONCATENATE'
149 | CONCATENATE(__strscpy_pad, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
| ^~~~~~~~~~~
net/netfilter/nf_tables_api.c:9661:53: note: in expansion of macro 'strscpy_pad'
9661 | nla_put_string(skb, NFTA_GEN_PROC_NAME, strscpy_pad(buf, current->comm)))
| ^~~~~~~~~~~
include/net/netlink.h:1655:46: note: expected 'const char *' but argument is of type 'ssize_t' {aka 'int'}
1655 | const char *str)
| ~~~~~~~~~~~~^~~
>> include/linux/string.h:116:50: warning: passing argument 3 of 'nla_put_string' makes pointer from integer without a cast [-Wint-conversion]
116 | #define sized_strscpy_pad(dest, src, count) ({ \
| ~^~~~~~~~~~~~~~~~~~~~~~~~
| |
| ssize_t {aka int}
117 | char *__dst = (dest); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
118 | const char *__src = (src); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
119 | const size_t __count = (count); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
120 | ssize_t __wrote; \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
121 | \
| ~
122 | __wrote = sized_strscpy(__dst, __src, __count); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
123 | if (__wrote >= 0 && __wrote < __count) \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
124 | memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
125 | __wrote; \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
126 | })
| ~~
include/linux/compiler.h:68:10: note: in definition of macro '__trace_if_value'
68 | (cond) ? \
| ^~~~
include/linux/compiler.h:55:28: note: in expansion of macro '__trace_if_var'
55 | #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
| ^~~~~~~~~~~~~~
net/netfilter/nf_tables_api.c:9659:9: note: in expansion of macro 'if'
9659 | if (nla_put_be32(skb, NFTA_GEN_ID, htonl(nft_net->base_seq)) ||
| ^~
include/linux/string.h:86:9: note: in expansion of macro 'sized_strscpy_pad'
86 | sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
| ^~~~~~~~~~~~~~~~~
include/linux/args.h:25:24: note: in expansion of macro '__strscpy_pad0'
25 | #define __CONCAT(a, b) a ## b
| ^
include/linux/args.h:26:27: note: in expansion of macro '__CONCAT'
26 | #define CONCATENATE(a, b) __CONCAT(a, b)
| ^~~~~~~~
include/linux/string.h:149:9: note: in expansion of macro 'CONCATENATE'
149 | CONCATENATE(__strscpy_pad, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
| ^~~~~~~~~~~
net/netfilter/nf_tables_api.c:9661:53: note: in expansion of macro 'strscpy_pad'
9661 | nla_put_string(skb, NFTA_GEN_PROC_NAME, strscpy_pad(buf, current->comm)))
| ^~~~~~~~~~~
include/net/netlink.h:1655:46: note: expected 'const char *' but argument is of type 'ssize_t' {aka 'int'}
1655 | const char *str)
| ~~~~~~~~~~~~^~~
vim +/nla_put_string +116 include/linux/string.h
e6584c3964f2ff Kees Cook 2023-09-20 74
e6584c3964f2ff Kees Cook 2023-09-20 75 /*
e6584c3964f2ff Kees Cook 2023-09-20 76 * The 2 argument style can only be used when dst is an array with a
e6584c3964f2ff Kees Cook 2023-09-20 77 * known size.
e6584c3964f2ff Kees Cook 2023-09-20 78 */
e6584c3964f2ff Kees Cook 2023-09-20 79 #define __strscpy0(dst, src, ...) \
559048d156ff33 Kees Cook 2024-08-05 80 sized_strscpy(dst, src, sizeof(dst) + __must_be_array(dst) + \
559048d156ff33 Kees Cook 2024-08-05 81 __must_be_cstr(dst) + __must_be_cstr(src))
559048d156ff33 Kees Cook 2024-08-05 82 #define __strscpy1(dst, src, size) \
559048d156ff33 Kees Cook 2024-08-05 83 sized_strscpy(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src))
e6584c3964f2ff Kees Cook 2023-09-20 84
8366d124ec937c Kees Cook 2024-02-02 85 #define __strscpy_pad0(dst, src, ...) \
559048d156ff33 Kees Cook 2024-08-05 86 sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
559048d156ff33 Kees Cook 2024-08-05 87 __must_be_cstr(dst) + __must_be_cstr(src))
559048d156ff33 Kees Cook 2024-08-05 88 #define __strscpy_pad1(dst, src, size) \
559048d156ff33 Kees Cook 2024-08-05 89 sized_strscpy_pad(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src))
458a3bf82df4fe Tobin C. Harding 2019-04-05 90
e6584c3964f2ff Kees Cook 2023-09-20 91 /**
e6584c3964f2ff Kees Cook 2023-09-20 92 * strscpy - Copy a C-string into a sized buffer
e6584c3964f2ff Kees Cook 2023-09-20 93 * @dst: Where to copy the string to
e6584c3964f2ff Kees Cook 2023-09-20 94 * @src: Where to copy the string from
e6584c3964f2ff Kees Cook 2023-09-20 95 * @...: Size of destination buffer (optional)
e6584c3964f2ff Kees Cook 2023-09-20 96 *
e6584c3964f2ff Kees Cook 2023-09-20 97 * Copy the source string @src, or as much of it as fits, into the
e6584c3964f2ff Kees Cook 2023-09-20 98 * destination @dst buffer. The behavior is undefined if the string
e6584c3964f2ff Kees Cook 2023-09-20 99 * buffers overlap. The destination @dst buffer is always NUL terminated,
e6584c3964f2ff Kees Cook 2023-09-20 100 * unless it's zero-sized.
e6584c3964f2ff Kees Cook 2023-09-20 101 *
e6584c3964f2ff Kees Cook 2023-09-20 102 * The size argument @... is only required when @dst is not an array, or
e6584c3964f2ff Kees Cook 2023-09-20 103 * when the copy needs to be smaller than sizeof(@dst).
e6584c3964f2ff Kees Cook 2023-09-20 104 *
e6584c3964f2ff Kees Cook 2023-09-20 105 * Preferred to strncpy() since it always returns a valid string, and
e6584c3964f2ff Kees Cook 2023-09-20 106 * doesn't unnecessarily force the tail of the destination buffer to be
e6584c3964f2ff Kees Cook 2023-09-20 107 * zero padded. If padding is desired please use strscpy_pad().
e6584c3964f2ff Kees Cook 2023-09-20 108 *
e6584c3964f2ff Kees Cook 2023-09-20 109 * Returns the number of characters copied in @dst (not including the
e6584c3964f2ff Kees Cook 2023-09-20 110 * trailing %NUL) or -E2BIG if @size is 0 or the copy from @src was
e6584c3964f2ff Kees Cook 2023-09-20 111 * truncated.
e6584c3964f2ff Kees Cook 2023-09-20 112 */
e6584c3964f2ff Kees Cook 2023-09-20 113 #define strscpy(dst, src, ...) \
e6584c3964f2ff Kees Cook 2023-09-20 114 CONCATENATE(__strscpy, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
458a3bf82df4fe Tobin C. Harding 2019-04-05 115
8366d124ec937c Kees Cook 2024-02-02 @116 #define sized_strscpy_pad(dest, src, count) ({ \
8366d124ec937c Kees Cook 2024-02-02 117 char *__dst = (dest); \
8366d124ec937c Kees Cook 2024-02-02 118 const char *__src = (src); \
8366d124ec937c Kees Cook 2024-02-02 119 const size_t __count = (count); \
8366d124ec937c Kees Cook 2024-02-02 120 ssize_t __wrote; \
8366d124ec937c Kees Cook 2024-02-02 121 \
8366d124ec937c Kees Cook 2024-02-02 122 __wrote = sized_strscpy(__dst, __src, __count); \
8366d124ec937c Kees Cook 2024-02-02 123 if (__wrote >= 0 && __wrote < __count) \
8366d124ec937c Kees Cook 2024-02-02 124 memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \
8366d124ec937c Kees Cook 2024-02-02 125 __wrote; \
8366d124ec937c Kees Cook 2024-02-02 126 })
8366d124ec937c Kees Cook 2024-02-02 127
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
2025-08-11 14:58 ` Andy Shevchenko
@ 2025-08-13 10:26 ` Bhupesh Sharma
0 siblings, 0 replies; 16+ messages in thread
From: Bhupesh Sharma @ 2025-08-13 10:26 UTC (permalink / raw)
To: Andy Shevchenko
Cc: kernel test robot, Bhupesh, akpm, oe-kbuild-all, kernel-dev,
linux-kernel, bpf, linux-perf-users, linux-fsdevel, linux-mm,
oliver.sang, laoar.shao, pmladek, rostedt, mathieu.desnoyers,
arnaldo.melo, alexei.starovoitov, andrii.nakryiko, mirq-linux,
peterz, willy, david, viro, keescook, ebiederm, brauner, jack,
mingo, juri.lelli, bsegall, mgorman
On 8/11/25 8:28 PM, Andy Shevchenko wrote:
> On Mon, Aug 11, 2025 at 08:19:08PM +0530, Bhupesh Sharma wrote:
>> On 8/11/25 4:55 PM, kernel test robot wrote:
>> As mentioned in the accompanying cover letter, this patchset is based on
>> 'linux-next/master' (the exact sha-id used for rebase is:
>> b1549501188cc9eba732c25b033df7a53ccc341f ).
> Instead of getting false positive reports and this rather unneeded reply from
> you, use --base parameter when formatting patch series. It will help all,
> including CIs and bots.
>
Sure, will include it in next version. Waiting for further reviews on
this v7.
Thanks.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()'
2025-08-11 15:05 ` Andy Shevchenko
@ 2025-08-13 10:27 ` Bhupesh Sharma
0 siblings, 0 replies; 16+ messages in thread
From: Bhupesh Sharma @ 2025-08-13 10:27 UTC (permalink / raw)
To: Andy Shevchenko, Bhupesh
Cc: akpm, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
On 8/11/25 8:35 PM, Andy Shevchenko wrote:
> On Mon, Aug 11, 2025 at 12:16:08PM +0530, Bhupesh wrote:
>> As Linus mentioned in [1], we should get rid of 'get_task_comm()'
>> entirely and replace it with 'strscpy_pad()' implementation.
>>
>> 'strscpy_pad()' will already make sure comm is NUL-terminated, so
>> we won't need the explicit final byte termination done in
>> 'get_task_comm()'.
>>
>> The relevant 'get_task_comm()' users were identified using the
>> following search pattern:
>> $ git grep 'get_task_comm*'
>> [1]. https://lore.kernel.org/all/CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com/
>>
>> Signed-off-by: Bhupesh <bhupesh@igalia.com>
> Make that a Link tag?
>
> Link: https://lore.kernel.org/all/CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com/ #1
> Signed-off-by: Bhupesh <bhupesh@igalia.com>
>
Sure, will include it in next version. Waiting for further reviews on
this v7.
Thanks.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v7 2/4] include: Set tsk->comm length to 64 bytes
2025-08-11 15:10 ` Andy Shevchenko
@ 2025-08-13 10:29 ` Bhupesh Sharma
0 siblings, 0 replies; 16+ messages in thread
From: Bhupesh Sharma @ 2025-08-13 10:29 UTC (permalink / raw)
To: Andy Shevchenko, Bhupesh
Cc: akpm, kernel-dev, linux-kernel, bpf, linux-perf-users,
linux-fsdevel, linux-mm, oliver.sang, lkp, laoar.shao, pmladek,
rostedt, mathieu.desnoyers, arnaldo.melo, alexei.starovoitov,
andrii.nakryiko, mirq-linux, peterz, willy, david, viro, keescook,
ebiederm, brauner, jack, mingo, juri.lelli, bsegall, mgorman,
vschneid, linux-trace-kernel, kees, torvalds
On 8/11/25 8:40 PM, Andy Shevchenko wrote:
> On Mon, Aug 11, 2025 at 12:16:07PM +0530, Bhupesh wrote:
>> Historically due to the 16-byte length of TASK_COMM_LEN, the
>> users of 'tsk->comm' are restricted to use a fixed-size target
>> buffer also of TASK_COMM_LEN for 'memcpy()' like use-cases.
>>
>> To fix the same, we now use a 64-byte TASK_COMM_EXT_LEN and
>> set the comm element inside 'task_struct' to the same length:
>> struct task_struct {
>> .....
>> char comm[TASK_COMM_EXT_LEN];
>> .....
>> };
>>
>> where TASK_COMM_EXT_LEN is 64-bytes.
>>
>> Note, that the existing users have not been modified to migrate to
>> 'TASK_COMM_EXT_LEN', in case they have hard-coded expectations of
>> dealing with only a 'TASK_COMM_LEN' long 'tsk->comm'.
> ...
>
>> - BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \
>> + BUILD_BUG_ON(sizeof(from) < TASK_COMM_LEN); \
> Wondering if we may convert this to static_assert().
> (rather in a separate patch)
That's a fair suggestion. If others don't have an objection to the
suggested change, I can club it in v8 along with any other requested
changes.
Thanks.
^ permalink raw reply [flat|nested] 16+ messages in thread
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2025-08-11 6:46 [PATCH v7 0/4] Add support for long task name Bhupesh
2025-08-11 6:46 ` [PATCH v7 1/4] exec: Remove obsolete comments Bhupesh
2025-08-11 6:46 ` [PATCH v7 2/4] include: Set tsk->comm length to 64 bytes Bhupesh
2025-08-11 15:10 ` Andy Shevchenko
2025-08-13 10:29 ` Bhupesh Sharma
2025-08-11 6:46 ` [PATCH v7 3/4] treewide: Replace 'get_task_comm()' with 'strscpy_pad()' Bhupesh
2025-08-11 11:25 ` kernel test robot
2025-08-11 14:49 ` Bhupesh Sharma
2025-08-11 14:58 ` Andy Shevchenko
2025-08-13 10:26 ` Bhupesh Sharma
2025-08-11 15:05 ` Andy Shevchenko
2025-08-13 10:27 ` Bhupesh Sharma
2025-08-12 3:47 ` kernel test robot
2025-08-11 6:46 ` [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Bhupesh
2025-08-11 15:08 ` Andy Shevchenko
2025-08-11 16:37 ` kernel test robot
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