[PATCH v3 6/7] prctl: Add support for long user thread names
From: André Almeida <andrealmeid@igalia.com>
Date: 2026-06-12 16:21:10
Also in:
linux-mm, lkml
Subsystem:
scheduler, the rest · Maintainers:
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
Add support for getting and setting long user thread names with
PR_{SET,GET}_EXT_NAME.
Signed-off-by: André Almeida <andrealmeid@igalia.com>
---
include/linux/sched.h | 2 +-
include/uapi/linux/prctl.h | 3 +++
kernel/sys.c | 15 ++++++++++++++-
3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index a5dc0f4e7975..5e167023fb81 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h@@ -1997,7 +1997,7 @@ extern void kick_process(struct task_struct *tsk); 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); \ })
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index b6ec6f693719..a07f8edadd65 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h@@ -56,6 +56,9 @@ #define PR_SET_NAME 15 /* Set process name */ #define PR_GET_NAME 16 /* Get process name */ +#define PR_SET_EXT_NAME 17 /* Set extended process name */ +#define PR_GET_EXT_NAME 18 /* Get extended process name */ + /* Get/set process endian */ #define PR_GET_ENDIAN 19 #define PR_SET_ENDIAN 20
diff --git a/kernel/sys.c b/kernel/sys.c
index 76d77218ab19..1b70d53da998 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c@@ -2535,7 +2535,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, unsigned long, arg4, unsigned long, arg5) { struct task_struct *me = current; - unsigned char comm[TASK_COMM_LEN]; + unsigned char comm[TASK_COMM_EXT_LEN]; long error; error = security_task_prctl(option, arg2, arg3, arg4, arg5);
@@ -2613,6 +2613,19 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, if (copy_to_user((char __user *)arg2, comm, TASK_COMM_LEN)) return -EFAULT; break; + case PR_SET_EXT_NAME: + comm[TASK_COMM_EXT_LEN - 1] = 0; + if (strncpy_from_user(comm, (char __user *)arg2, + TASK_COMM_EXT_LEN - 1) < 0) + return -EFAULT; + set_task_comm(me, comm); + proc_comm_connector(me); + break; + case PR_GET_EXT_NAME: + strscpy_pad(comm, me->comm, TASK_COMM_EXT_LEN); + if (copy_to_user((char __user *)arg2, comm, TASK_COMM_EXT_LEN)) + return -EFAULT; + break; case PR_GET_ENDIAN: error = GET_ENDIAN(me, arg2); break;
--
2.54.0